REFF,P,EhTG.T COW Do Not Remove from the Library

U. S. Fish and Wildlife Service - - - Biological Report 82 (11.61) National Wetlands Kesearcn c- August 1986

TR EL-82-4 700 Cajun Dome Boulevard ~a fa~e t te , Louisiana 70506

Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (South Florida)

SPINY LOBSTER

Coastal Ecology Group Fish and Wildlife Service Waterways Experiment Station U.S. Department of the Interior U.S. Army Corps of Engineers

B i o l o g i c a l Report 82(11.61) TR EL-82-4 August 1986

Species P ro f i les : L i f e H i s t o r i e s and Environmental Requirements o f Coastal Fishes and Inve r teb ra tes (South F l o r i d a )

SPINY LOBSTER

James M. Marx and

Wi l l i am F. Herrnkind Department o f B i o l o g i c a l Science

F l o r i d a Sta te U n i v e r s i t y T a l l ahassee, FL 32306

P r o j e c t O f f i c e r John Parsons

Nat iona l Wetlands Research Center U. S. F i sh and W i l d l i f e Serv ice

1010 Gause Boulevard S l i d e l l , LA 70458

Performed f o r

Coastal Ecology Group Waterways Experiment S t a t i o n

U. S. Army Corps o f Engineers Vicksburg, MS 39180

and

Nat iona l Wetlands Research Center Research and Development

F i s h and W i l d l i f e Serv ice U. S. Department o f t h e I n t e r i o r

Washi ngton, DC 20240

This se r ies should be referenced as f o l l o w s :

U. S. F i sh and W i l d l i f e Service. 1983-19-. Species p r o f i l e s : 1 i f e h i s t o r i e s and environmental requirements o f coas ta l f i shes and inve r teb ra tes . U. S. F i sh Wi ld l . Serv. B i o l . Rep. 82(11). U.S. Army Corps o f Engineers, TR EL-82-4.

Th is p r o f i l e should be c i t e d as fo l l ows :

Marx, J.M., and W.F. Herrnkind. 1986. Species p r o f i l e s : l i f e h i s t o r i e s and environmental requirements o f coasta l f i shes and inve r teb ra tes (south F lor ida) - -sp iny l obs te r . U.S. F i sh W i l d l . Serv. B i o l . Rep. 82(11.61). U.S. Army Corps o f Engineers, TR EL-82-4. 2 1 pp.

PREFACE

Th is species p r o f i l e i s one of a s e r i e s on coasta l aquat ic organisms, p r i n c i p a l l y f i s h , o f spo r t , commercial, o r eco log i ca l importance. The p r o f i l e s are designed t o p rov ide coasta l managers, engineers, and b i o l o g i s t s w i t h a b r i e f comprehensive sketch o f t h e b i o l o g i c a l c h a r a c t e r i s t i c s and envi ronmental requirements o f t h e species and t o descr ibe how popu la t ions o f t he species may be expected t o r e a c t t o environmental changes caused by coasta l development. Each p r o f i l e has sec t ions on taxonomy, 1 i f e h i s t o r y , eco log i ca l r o l e , environmental requirements, and economic importance, i f app l icab le . A t h r e e - r i n g b inde r i s used f o r t h i s se r ies so t h a t new p r o f i l e s can be added as they are prepared. Th is p r o j e c t i s j o i n t l y planned and f inanced by the U. S. Army Corps o f Engineers and the U.S. F i s h and W i l d l i f e Service.

Suggestions o r questions regard ing t h i s r e p o r t should be d i r e c t e d t o one of the f o l l owing addresses.

I n fo rma t ion Transfer S p e c i a l i s t Nat iona l Wetlands Research Center U.S. F i sh and W i l d l i f e Serv ice NASA-Sl i d e l 1 Computer Complex 1010 Gause Boulevard S l i d e l l , LA 70458

U. S. Army Engineer Waterways Experiment S t a t i o n A t ten t i on : WESER-C Post O f f i c e Box 631 Vicksburg, MS 39180

CONVERSION TABLE

M e t r i c t o U.S . Customary

Mu1 t i p l y & To O b t a i n

m i l 1 i m e t e r s (mn) cen t imete rs ( an) meters (m) k i 1 ometers ( km)

2 square meters (m ) 10.76 square k i 1 m e t e r s ( km2) 0.3861 hec ta res (ha) 2.471

1 i t e r s ( 1 ) c u b i c ineters (m3) c u b i c meters

m i l 1 igrams (mg ) grams ( g ) k i l og rams ( k g ) m e t r i c tons ( t ) m e t r i c tons k i 1 ocal o r i es ( kca l )

inches inches f e e t m i l e s

square f e e t square i n i l es acres

gal 1 ons c u b i c f e e t acre- f e e t

ounces ounces pounds pounds s h o r t tons B r i t i s h t h e m a l u n i t s

Ce ls ius deyrees 1.8("C) + 32 Fahrenhei t degrees

U.S. Customary t o M e t r i c

inches 25.40 inches 2.54 f e e t ( f t ) 0.3048 fathoms 1.829 m i l e s ( m i ) 1.609 n a u t i c a l m i l e s ( m i ) 1.852

square f e e t ( f t 2 ) acres 2 square m i l e s (mi

ga l 1 ons ( gal ) cub ic f e e t ( f t 3 ) a c r e - f e e t

ounces (02) 28.35 pounds ( l b ) 0.4536 s h o r t t o n s ( t o n ) 0.9072 B r i t i s h thermal u n i t s ( B t u ) 0.2520

m i l 1 imete rs cen t imete rs ineters meters k i l o m e t e r s k i 1 ometers

square meters hectares square k i l o m e t e r s

1 i t e r s c u b i c meters cub ic meters

grains k i 1 og rams m e t r i c tons k i 1 ocal o r i e s

Fahrenhe i t degrees 0.5556(OF - 32) Ce ls ius degrees

CONTENTS Page

PREFACE .................................................................... iii CONVERSION TABLE ........................................................... i V ACKNOWLEDGMENTS ............................................................ v i

NONMENCLATURE/TAXONOMY/RANGE ............................................... 1 MORPHOLOGY/IDENTIFICATION A I D S ............................................. 1

............................................. REASON FOR INCLUSION I N SERIES 3 LIFE HISTORY .............................................................. 3

Spawning Habits .......................................................... 3 ................................................................... Larvae 5

Postlarvae and Ear ly Juveniles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Late Juveniles and Adul ts ................................................ 7

GROWTH CHARACTERISTICS ..................................................... 8 COMMERCIAL AND SPORT FISHERY ............................................... 10

Population Size Composition and Reproductive Po ten t ia l ................... 10 Fishery-Induced Juveni le Mortal i ty/Growth Reduction ...................... 12

ECOLOGICAL ROLE ........................................................... 12 ENVIRONMENTAL REQUIREMENTS ................................................. 13

Habi ta t .................................................................. 13 Temperature .............................................................. 14 S a l i n i t y ................................................................ 15 Hydrodynamics ............................................................ 15 Oceanic C i r cu l a t i on ...................................................... 16

LITERATURE CITED ........................................................... 17

ACKNOWLEDGMENTS

For t h e i r h e l p f u l rev iews and suggestions, we thank Gary Davis, Nat iona l Park Service, Ventura, C a l i f o r n i a , and W i l l iam Lyons, F l o r i d a Department o f Natura l Resources, St . Petersburg, F l o r i d a .

.

..... Carapace

Figure 1. Dorsal view o f an a d u l t sp iny l obs te r , Panu l i rus argus.

SPINY LOBSTER

S c i e n t i f i c name. . . . Panu l i rus argus ( L a t r e i l l e )

Preferred common name. .Spiny l obs te r , c raw f i sh (F igu re 1 )

Other common names. .Crayf ish, F l o r i d a sp iny l obs te r , Western At1 a n t i c sp iny l obs te r , Caribbean sp iny l obs te r , rock l obs te r , "bug"

Class. . . . . . . . . . . . Crustacea Order. . . . . . . . . . . . .Decapoda Fami ly . . . . . . . . . . Pal i n u r i d a e

Geographic range: The sp iny l o b s t e r i n h a b i t s t h e coasta l waters and shal low Cont inenta l She l f waters from North Caro l i na south t o B r a z i l , i n c l u d i n g Bermuda and the G u l f o f Mexico (Wi l l iams 1965) (F igu re 2) . A few specimens have been c o l l e c t e d

i n t h e G u l f o f Guinea, West A f r i c a (Marchal 1968).

MORPHOLOGY/IDENTIFICATION AIDS

General : The subcyl i n d r i c a l carapace i s studded w i t h forward- p r o j e c t i n g spines, and prominent r o s t r a 1 horns extend over s t a l ked eyes. Long, whip-1 i k e antennae are tapered a n t e r i o r l y and covered w i t h small spines. The slender, e longate wa lk ing l egs (pereopods) bear setose dac ty l s . The t a i l i s smooth except where notched along t h e l a t e r a l edges, and t h e t ransverse groove on each t a i l segment i s i n t e r r u p t e d a t t h e m id l i ne . The t a i l f an i s composed o f a c e n t r a l t e l s o n bordered by a p a i r o f biramous uropods.

ATLANTIC OCEAN

ST. PETE RSBU

PALM BEACH

OKEECHOBEE

b CAPE ROMANO

43

\ \ \ \ \ \ \ \ \

I \ \

MILES

I 0 50 100

I Offshore range llrnits II.

0 50 100

KILOMETERS Aroa of high concentration

A

Figure 2. Distribution of the spiny lobster, Panulirus argus, on the south Florida coast. . .

Color : I n young j u v e n i l e s (7 t o 20 mm carapace length ; a l l l eng ths of l o b s t e r s i n t h i s p r o f i l e are carapace lengths unless o therw ise s ta ted ) , t h e antennae and pereopods are banded w i t h d i s t i n c t wh i t e s t r i p e s ; a broad wh i te s t r i p e extends along t h e dorsa l mid1 i n e o f t he carapace and abdomen. The general body c o l o r s are shades o f brown, black, and purp le . Adu l t c o l o r v a r i e s from l i g h t gray o r t a n w i t h green and brown shades t o deeper brown w i t h r e d and b lack shades. The second and s i x t h t a i l segments have l a r g e wh i te o r y e l l o w i s h o c e l l i ; small o c e l l i are d o r s o l a t e r a l on o the r t a i l segments. The l egs are s t r i p e d l o n g i - t u d i n a l l y w i t h d u l l blue, and t h e pleopods are b r i g h t orange and b lack .

Sexual dimorphism: Females are d i s t i n g u i s h e d by t h e smal l che la on t h e d a c t y l s o f t h e f i f t h pereopods; t h e a d u l t male i s cha rac te r i zed b y an e longate second p a i r o f l egs bear ing extended, curved dac ty l s . The endopo- d i t e of female pleopods i s w e l l deve- loped, h o o k l i ke, and h e a v i l y setose. I n males, t h e r a i s e d g e n i t a l openings l i e a t t h e base o f t h e f i f t h p a i r o f legs; i n females t hey l i e a t t h e base o f t h e t h i r d p a i r o f legs. The female sternum i s s t r i a t e d and narrower a t i t s p o s t e r i o r margin than i n t h e male.

Related species : The sympatr i c P. l aev icauda has no do rsa l grooves - on t h e t a i l segments and bears smal l wh i t e spots along t h e l a t e r a l margin o f t h e t a i l ; P. g u t t a t u s has a s i ng le , un in tF r rup ted t ransverse groove on t h e second through t h e f i f t h t a i l segments and has many wh i te spots over t h e body.

REASON FOR INCLUSION I N THE SERIES

Panu l i r us argus supports major commercial f i s h e r i e s i n south F lo r i da , t h e Bahamas, Cuba, B r a z i l , and throughout t h e Caribbean. Spiny l o b s t e r s are mid- t o h i g h - l e v e l preda- t o r s and probab ly a re impor tan t i n

s t r u c t u r i n g marine ben th i c com- mun i t i es . Throughout t h e i r l i v e s , l o b s t e r s l i v e among d i v e r s e h a b i t a t s and e x h i b i t behav io ra l and p h y s i o l o g i - c a l c h a r a c t e r i s t i c s t h a t make them e x c e l l e n t t e s t organisms f o r bas ic research.

LIFE HISTORY

The l i f e h i s t o r y o f t h e sp iny l o b s t e r c o n s i s t s o f f i v e major phases, having t h e f o l l o w i n g d i s t i n c t i v e beha- v i o r s and h a b i t a t use: ( 1 ) oceanic p l a n k t o n i c phyllosome 1 arvae, ( 2 ) swimming p o s t l a r v a l p u e r u l i ( s i n g u l a r = puerulus) , (3) e a r l y ben th i c "banded" j uven i l es , (4) l a t e r j u v e n i l e s (20-65 mm carapace length, CL), and (5) adu l t s . A broad range o f marine h a b i t a t s a re used du r i ng t h e i r l i f e c y c l e (F igu re 3) .

Spawning Hab i ts

Most sp iny l o b s t e r i n F l o r i d a waters reproduce du r i ng 1 a te s p r i n g and e a r l y sumner. Crawford and De Smidt (1922) repo r ted peak spawning i n A p r i l and May; Dawson and I d y l l (1951) observed a peak i n A p r i l (29% o f f e - males sampled bore eggs); and Lyons e t a1. (1981) noted h igh l e v e l s i n May (32.8%) and June (30.3%). Davis (1975) repo r ted an A p r i l peak (55%) f o r an un f ished popu la t i on o f l a r g e l o b s t e r s a t Dry Tortugas. Year ly v a r i a t i o n s i n peak spawning t ime depend l a r g e l y on water temperature. Crawford (1921) repo r ted op t ima l spawning a t 24O C, whereas Lyons e t a l . (1981) observed t h a t spawning began a t 24O C i n deep r e e f areas (30 m). I n F l o r i d a , t he re i s no d i r e c t evidence t h a t l o b s t e r s spawn more than once a year, b u t some repeat spawning by some i n d i v i d u a l s i s suspected i n Bermuda waters (Creaser 1950; S u t c l i f f e 1952).

The sp iny l o b s t e r spawns i n o f fshore waters a long t h e deeper r e e f f r i n g e s (Kanci ruk and Herrnk ind 1976; Warner e t a l . 1977; Lyons e t a l .

F igu re 3. The s p a t i a l aspects o f t he l i f e c y c l e o f t he sp iny l o b s t e r Panu l i rus argus. The p o s t l a r v a l pueru l i move inshore, s e t t l i n g i n s u b t i d a l algae. Juven i les du r ing t h e f i r s t 2 years of benth ic l i f e remain i n lagoons and shal low seagrass beds and show both nomadic and r e s i d e n t i a l phases i n apparent accord w i t h food and she l te r . The subadul ts g radua l l y emigrate f rom the nursery and d isperse about t h e ex tens ive shal low (3-10 m depth) banks c h a r a c t e r i s t i c o f t h e i r range. A f te r breeding on t h e reefs, t he females move t o waters border ing oceanic cu r ren ts t o re lease la rvae. Adu l ts e x h i b i t seasonal cyc les o f residency, noma- dism, rep roduc t i ve migra t ion , and inshore-o f fshore m ig ra t i on (sometimes en masse). The p a t t e r n o f movement v a r i e s cons iderab ly over t h e range o f t h e spe- c i es ( f rom Her rnk i nd 1980 r e p r i n t e d w i t h permission f rom Academic Press, New York).

1981). Although a d u l t males and fe - males sometimes i n h a b i t bays, 1 agoons, es tuar ies , and shal low banks, none are known t o spawn there. Requirements o f o f f sho re spawning are h igh s h e l t e r qua1 i t y , s u i t a b l e water cond i t i ons ( s t a b l e temperature and s a l i n i t y , low surge and t u r b i d i t y ) , and adequate l a r v a l t r a n s p o r t by oceanic c u r r e n t s (Kanciruk and Herrnkind 1976).

Mat ing f o l l o w s a b r i e f cou r t sh ip i n v o l v i n g s igna l s by both male and female. Dur ing copu la t ion , t h e male holds t h e female sternum t o sternum aga ins t him and extrudes a sper- matophoric mass. The gray t a r r y sper-

matophore adheres t o t he female s t e r - num u n t i l spawning. The sperm may remain v i a b l e f o r as long as one month.

Spawning i s descr ibed i n d e t a i l by Crawford and De Smidt (1922) and Su tc l i f f e (1952). The female abdomen i s f l e x e d i n c u p l i k e fash ion beneath t h e cephalothorax, and t h e t e l s o n and uropods are spread. Eggs ( sphe r i ca l , 0.5 mm diameter) are l i b e r a t e d e x t e r - n a l l y through t h e gonopores l oca ted a t t h e base o f t h e t h i r d p a i r o f wa lk ing 1 egs. F e r t i l i z a t i o n begins as a female scratches a t t h e spermatophore packet us ing t h e che la te d a c t y l s o f

t h e f i f t h wa lk ing legs . The b r i g h t orange, y o l k - f i l l e d eggs adhere t o h o o k l i k e p leopodal setae on t h e under- s i d e o f t h e abdomen. Fecund i ty v a r i e s d i r e c t l y w i t h s i ze : females 71 t o 75 mm long c a r r y 230,000 eggs; females longer than 100 mm may c a r r y over 700,000 eggs ( Mota-Alves and Bezerra 1968). Embryonic development l a s t s about 3 weeks (Crawford 1921). The eggs t u r n brown a few days b e f o r e ha tch ing . The phyl losomes emerge f rom t h e egg membrane and d i spe rse i n t o t h e water column ass i s ted by abdominal movements o f t h e female.

The r e l a t i v e (percentage) c o n t r i - b u t i o n o f each s i z e c l a s s i n t h e popu- l a t i o n t o t h e t o t a l number o f eggs layed can be es t imated u s i n g t h e Index o f Reproduct ive P o t e n t i a1 ( IRP; Kanc i ruk and Her rnk ind 19761, which s t a t e s :

IRP = (A x B x C)/D

where A = t o t a l females w i t h i n a g iven s i z e . c l a s s / t o t a l females i n t h e popu 1 a t i on

B = % o f females bea r i ng eggs i n t h a t s i z e c l a s s

C = f e ~ u n d i ~ t y o f females i n t h a t s i z e c l a s s

D = a cons tan t ( t o t a l eggs 1 aid/100%) d e r i v e d t o s e t t h e index o f a par- t i c u l a r s i z e c l a s s a t t h e percentage c o n t r i - b u t i o n t o t h e t o t a l egg p roduc t i on .

App ly ing t h e IRP t o t h e l o b s t e r popu- l a t i o n o f t h e upper F l o r i d a Keys, Lyons e t a l . (1981) es t imated t h a t t h e 76-85 mm CL s i z e c l a s s c o n t r i b u t e d 48% o f t o t a l egg produc t ion . Females longer than 85 mm made up o n l y 20% o f a1 1 females, b u t c o n t r i b u t e d about 41% o f eggs. Smal ler s i z e c l asses ( < 76 mm CL) c o n s t i t u t e d 25% o f a l l females, b u t c o n t r i b u t e d o n l y 11% of t h e eggs. Compared t o t h e index values f o r t h e un f i shed p o p u l a t i o n a t Dry Tor tugas ( d a t a p rov ided by Davis 19751, Lyons

e t a l . (1981) es t imated t h a t egg p ro - d u c t i o n i n t h e F l o r i d a Keys was o n l y 12% o f t h a t t o be expected f rom an unf ished p o p u l a t i o n o f s i m i l a r s ize .

I n tense f i s h i n g may have caused a d e c l i n e i n t h e minimum s i z e o f spawning females i n F l o r i d a waters. The sma l l es t egg-bearing females r e p o r t e d by Crawford and De Smidt i n 1922 were 76 mm, b u t i n r e c e n t surveys egg-bearing females were as smal l as 71 mm (Warner e t a l . 1977) and 65 m (Lyons e t a l . 1981). I n c o n t r a s t , t h e sma l l es t egg bearer observed f rom an un f i shed p o p u l a t i o n a t Dry Tortugas was 78 mm (Dav is 1975). Suggested causes f o r t h i s apparent d e c l i n e i n s i z e a re gene t i c s e l e c t i o n (Warner e t a l . 1977), m o d i f i e d sexual behavior when l a r g e females a re r a r e (Lyons e t a l . 19811, and reduced growth caused by h i g h i n j u r y r a t e s (Davis and D o d r i l l 1980). The minimum l e g a l s i z e ( e s t a b l i s h e d i n 1965) may n o t ade- q u a t e l y p r o t e c t spawning stock i n F l o r i d a (see a r e l a t e d d i scuss ion i n t h e s e c t i o n on t h e Commercial and Spor t F i she ry ) .

Larvae

Eggs ha tch as t ransparen t , phyl losome ( l ea f -bod ied ) la rvae . They a re m o r p h o l o g i c a l l y w e l l equipped f o r p l a n k t o n i c l i f e , bea r i ng long, h i g h l y setose appendages ex tend ing f rom a do rsoven t ra l l y f 1 attened, b i lobed cephalothorax. Phyllosomes swim i n a h o r i z o n t a l p o s i t i o n by means o f t h e exopodal a c t i o n o f t h e biramous l egs (Provenzano 1968). They undergo a d i e 1 p a t t e r n o f v e r t i c a l d i s t r i b u t i o n , ascending t o su r face waters a t n i g h t and descending d u r i n g t h e day (Sims and I n g l e 1967). D i s t r i b u t i o n i s o the rw i se r e g u l a t e d by ocean c u r r e n t s and o t h e r f a c t o r s t h a t i n f l u e n c e water c i r c u l a t i o n p a t t e r n s ( A u s t i n 1972).

Phyllosomes develop th rough about 11 stages, i n c r e a s i n g i n s i z e from 2 nun ( t o t a l l e n g t h ) a t ha tch ing t o n e a r l y 34 m be fo re metamorphosis (Lewis 1951). Du ra t i on o f t h e p h y l l o -

some stage i s about 6 t o 12 months (Lewis 1951; Lyons e t a l . 1981).

The u n c e r t a i n t y o f the d u r a t i o n o f t h e phyllosome stage renders the quest ion o f l a r v a l o r i g i n s problema- t i c . Major f a c t o r s causing uncer- t a i n t y are v a r i a t i o n s i n growth ra tes , delays i n metamorphosis, t h e widespread abundance o f 1 arvae, and t h e i nhe ren t comp lex i t i es of oceanic c i r c u l a t i o n throughout t he western A t l a n t i c reg ion (Lewis 1951; Sims and I n g l e 1967; Aust in 1972; Richards and P o t t h o f f 1981). The l a r v a l source f o r F l o r i d a is.unknown, b u t two d i f f e r e n t o r i g i n s are proposed: (1 ) l a r v a e of Caribbean spawning stocks (Lewis 1951; Sims and I n g l e 1967) are t ranspor ted downcurrent t o F l o r i d a , and (2) l a r v a e o f l o c a l s tocks a re r e t a i n e d by i d i o - s y n c r a t i c c u r r e n t p a t t e r n s o f f t h e coast o f F l o r i d a (Menzies and Ker r igan 1979). Ne i the r proposal i s conclusive, and new research approaches a re under study, p a r t i c u l a r l y biochemical genet ics (Menzies 1981; see Lyons 1981 f o r a thorough review).

Post1 arvae and E a r l v Juven i les

The sp iny l o b s t e r l a r v a meta- morphoses i n t o a puerulus, a b r i e f (severa l weeks), nonfeeding, oceanic phase (Lyons 1980). The puerulus possesses a number o f d i s t i n c t i v e fea tu res i n c l u d i n g adaptat ions f o r rap id , e f f i c i e n t swimming (e.g., a smooth, 1 igh twe ight t ransparent body 1 acking c a l c i f i c a t i o n and spines, and a dorsovent ra l l y f l a t t e n e d carapace).

A f t e r metamorphosis o f f s h o r e (Sweat 1968; Witham e t a l . 19681, p u e r u l i swim shoreward by n igh t , antennae d i r e c t e d forward, w i t h i n a few cent imeters o f t he water sur face (Lyons 1980). Propu ls ion i s p rov ided by spec ia l i zed abdominal pleopods. Large numbers o f p u e r u l i a r r i v e a long the southeast F l o r i d a coast and southern shores o f the F l o r i d a Keys throughout t he year, p r i n c i p a l l y du r i ng t h e new and f i r s t - q u a r t e r l una r

phases (Sweat 1968; Witham e t a l . 1968; L i t t l e 1977; L i t t l e and Mi lano 1980). The season of peak r e c r u i t - ment v a r i e s cons iderab ly f rom year t o year and r e g i o n a l l y , b u t maximum num- bers g e n e r a l l y a r r i v e inshore i n spr ing ; t h e r e i s a l esse r peak i n f a l l ( Lyons 1980 1. Because F l o r i d a l o b s t e r s spawn almost e x c l u s i v e l y i n l a t e spr ing, year-round rec ru i tmen t o f l a r vae suggests t h a t a s u b s t a n t i a l number o f p u e r u l i o r i g i n a t e elsewhere.

P u e r u l i s e t t l e r a p i d l y when they encounter s u i t a b l e inshore substrate. They acqu i re reddish-brown pigmen- t a t i o n and w i t h i n days m o l t i n t o t he f i r s t j u v e n i l e stage. The d i s t i n c t i v e c o l o r p a t t e r n s o f e a r l y ben th i c juve- n i l e s are a combination o f c r y p t i c ( d i f f e r e n t shades) and d i s r u p t i v e (bands o r s t r i p e s ) f ea tu res t h a t make j u v e n i l e s i n vege ta t i on n e a r l y i n v i s - i b l e .

L i t t l e i s known about f a c t o r s t h a t s t i m u l a t e p o s t l a rva l se t t lement and s p e c i f i c h a b i t a t requirements o f e a r l y j uven i l es . Witham e t a l . (1964) caught p o s t l arvae and young j uven i l e s up t o 25 mm long among a l g a l - f o u l e d mangrove r o o t s and a l g a l clumps c o l l e c t e d f rom shal low seagrass beds. Marx ( 1983 ) observed pos t 1 arvae and j u v e n i l e s up t o 20 mm l ong i n shal low (2-3 m) macroalgal assemblages domi- nated by severa l species o f the r e d a lga Laurencia. Somewhat 1 a t e r stages (31 = 21 mm CL) i nhab i ted small ho les and c rev i ces w i t h i n a shal low, a l g a l - f o u l e d r u b b l e zone dominated by va r i ous r e d algae, p r i m a r i l y Laurencia (Andree 1981). Eldred e t a l . (1972) and Davis (1979) repo r ted s u b s t a n t i a l catches of l o b s t e r s 11 t o 30 mm l ong i n Biscayne Bay by b a i t shrimp t raw le rs . Trawl ing took p lace over sand/mud bottoms w i t h abundant seagrasses, calcareous green algae, and Laurencia.

E a r l y b e n t h i c l a r vae and juve- n i l e s apparent ly concent ra te i n macroalgae beds along rocky sho re l i nes and may be i n te rspe rsed among l a r g e

expanses o f seagrass t h a t t y p i f y known nursery areas l i k e F l o r i d a Bay (Davis and Dodri 11 1980; Lyons e t a1 . 1981) and Biscayne Bay (Davis 1979).

E a r l y benth ic l o b s t e r s tend t o l i v e a s o l i t a r y ex is tence (Andree 1981; Marx 1983). Because they have easy access t o t h e i r food supply, f o r a g i n g t ime f o r young j u v e n i l e s and exposure t o predators are minimal. Young j u v e n i l e s are h i g h l y aggressive, us ing the antennae t o lash o r p r y conspec i f i cs , suggesting t h a t d ispersed spacing pa t te rns may be mainta ined by a g o n i s t i c behavior .

La te Juven i les and Adu l ts

Most l o b s t e r s longer than 20 mm aggregate i n va r i ous s h e l t e r i n g s t r u c - t u r e s i n p ro tec ted bays, i n c l u d i n g es tua r ies w i t h h igh s a l i n i t y (Olsen e t a l . 1975; Davis 1979). She1 t e r s i nc lude l a r g e sponges, c o r a l heads, mangrove roo ts , grass-bed undercuts, s o l u t i o n holes, rocky outcroppings o r ledges, and even clumps o f sea u rch ins (Davis 1971). Most s h e l t e r s supply p a r t i a l camouflage, p h y s i c a l l y de te r predators, and prov ide re fuge f rom phys i ca l s t ress . Adu l t c o l o r a t i o n rep laces t h e c r y p t i c pa t te rn , and l a t e j u v e n i l e s begin t o e x h i b i t a c t i v e a n t i p redator defense using t h e anten- nae as f o i l s .

The ontogenet ic t r a n s i t i o n f rom 'sol i t a r y - a s o c i a l l1 t o "aggregat ive- s o c i a l " i s apparent ly no t r i g i d l y f i x e d , and probably depends i n p a r t on t h e d i s t r i b u t i o n and phys i ca l charac- t e r i s t i c s o f l o b s t e r s h e l t e r (Andree 1981; Marx 1983). Juven i les tend t o be nomadic, u s u a l l y t a k i n g s h e l t e r a f t e r f o rag ing a t n i g h t . Where juve- n i l e d e n s i t y i s high, t r a n s i e n t move- ments are especi a1 l y apparent i n areas o f i n t e r m i t t e n t she l te r , e.g., t h e shal low waters o f the F l o r i d a Keys (Herrnkind 1980).

Lobsters approaching m a t u r i t y (70-80 mm) emigrate o f f s h o r e (Witham

e t a l . 1968; Olsen e t a l . 1975; Davis 1979). These emigra t ions are u s u a l l y gradual and nomadic, b u t shor t - te rm mass movements do occur. These move- ments w ide l y d isperse t h e l o b s t e r s a long t h e ree fs t h a t p a r a l l e l t he F l o r i d a Keys (Warner e t a l . 1977; Davis 1979; Herrnkind 1980). Sex r a t i o s inshore i n d i c a t e t h a t more females than males emigrate o f f s h o r e (Olsen e t a l . 1975; Davis and D o d r i l l 1980; Lyons e t a l . 1981).

Of fshore l o b s t e r popu la t ions are composed predomi n a n t l y o f adu l t s r e s i d i n g i n d i v i d u a l l y o r communally i n c rev i ces o f rock o r co ra l . A f t e r f o rag ing a t n i g h t (up t o several hundred meters) most adu l t s r e t u r n t o t h e same o r nearby dens (Her rnk ind e t a1 . 1975). Homing apparent ly i nvo l ves o r i e n t a t i o n of t h e l o b s t e r t o hydrody- namic ( c u r r e n t and wave surge), chemi- ca l , topographic, and g r a v i t a t i o n a l (s lope) cues (Her rnk ind 1980). Adu l t l o b s t e r s are h i g h l y s e l e c t i v e o f dens, r e s i d i n g most f r e q u e n t l y i n c rev ices t h a t a l l ow f u l l wi thdrawal o f t he body, deny access by l a r g e predators, and con ta in o the r l o b s t e r s (Herrnkind e t a l . 1975). The preference f o r an occupied den i s g e n e r a l l y i n t e r p r e t e d as a s o c i a l response, i .e., being a t t r a c t e d t o conspeci f i c s . Both 1 a te j u v e n i l e s and adu l t s a re gregar ious.

The tendency f o r a d u l t l o b s t e r s t o congregate probab ly i s a r e q u i r e - ment f o r adequate defense, mating, and s h e l t e r use. Lobsters may r e s i s t p redators by b l o c k i n g 1 arge den open- ings o r by forming a cohesive group ad jacent t o l e s s fo rmidab le she1 t e r s l i k e sponges and sea whips. Males i n i t i a t e mat ing by seeking recep t i ve females o f t e n found congregated du r ing t h e day ( L i p c i u s e t a l . 1983).

Concentrat ions o f sp iny l o b s t e r s i n t h e waters o f t he F l o r i d a Keys tend t o s h i f t i n autumn and du r ing t h e sp r i ng rep roduc t i ve per iod . Some movements a re sex dependent and some- t imes cause sharp d i f f e r e n c e s i n male- female r a t i o s f rom p lace t o p lace

(Herrnkind 1980). Females move t o deeper ree fs i n t h e spr ing, presumably t o mate and shed l a rvae (Crawford and De Smidt 1922; Davis 1977; Lyons e t a1 . 1981). A t Dry Tortugas, females r e t u r n t o shal low water a f t e r r e l e a s i n g t h e i r larvae. Normal sex r a t i o s (about 1 : l ) are res to red by f a l l (Davis 1977). Both sexes emigrate o f f s h o r e i n t h e f a l l as water temperatures decl i n e and fa1 1 storms a r r i v e (Davis 1977; Kanciruk and Herrnkind 1978; Herrnkind 1982). Sometimes o f f s h o r e movements are spec- t a c u l a r mass m ig ra t i ons o f l o b s t e r s forming s i n g l e - f i l e columns o r queues (Herrnkind and Kanciruk 1978; Kanciruk and Herrnkind 1978; Herrnkind 1980).

GROWTH CHARACTERISTICS

The growth o f t h e sp iny l o b s t e r i s l a r g e l y c o r r e l a t e d w i t h t h e f r e - quency of m o l t i n g and increment growth w h i l e mo l t i ng (Aiken 1980). General ly , t h e frequency o f t h e mo l t s and increment growth d e c l i n e w i t h age, as i s borne o u t by the von B e r t a l a n f f y growth model (a decaying exponent ia l curve), which s ta tes :

where L t = carapace l eng th a t t ime t L = asymptot ic carapace l eng th e = base o f n a t u r a l logar i thms t o = t ime a t which carapace

l eng th was 0, k = t he growth c o e f f i c i e n t

( r a t e a t which L t approaches L 1.

Est imates o f t h e growth coef- f i c i e n t s ( k ) i n d i f f e r e n t waters some- t imes vary considerably. C o e f f i c i e n t s were 0.11 f o r t h e lower F l o r i d a Keys (Yang and Obert 1978), 0.21 f o r F l o r i d a and Be1 i ze combined (Munro 1974), 0.31-0.36 f o r south F l o r i d a (see G u l f o f Mexico and South A t l a n t i c F ishery Management Counci 1 s CGMSAFMCI 1982), 0.03-0.24 f o r t he Bahamas (Waugh 19811, and 0.43 f o r St . John,

U.S. V i r g i n I s l ands (Olsen and Kob l i ck 1975). V a r i a t i o n i s caused p a r t l y by d i f f e r e n c e s i n methodology used t o es t imate growth, b u t most d i f f e rences are caused by changes i n environmental cond i t ions . Local v a r i a b i l i t y i n food abundance, popu la t i on dens i ty , preda- t o r y a t tacks ( i nduc ing i n j u r i e s ) , and water temperature g r e a t l y a f f e c t s growth r a t e s o f sp iny l o b s t e r s (Newman and Po l l ock 1974; Ch i t t leborough 1976; Davis 1979; Aiken 1980; Waugh 1981).

Growth sometimes v a r i e s w i t h i n a r e 1 a t i v e l y small area; consequently, t h e r e l a t i o n s among s ize , sex, and growth are unpredictable. Furthermore, data from recaptured tagged l o b s t e r s are d i f f i c u l t t o o b t a i n f o r a l l s i z e ranges, p roh ib- i t i ng accurate ana lys i s o f mol t f re - quency and increment per mo l t and t h e use of von B e r t a l a n f f y growth models (Davis 1979; Waugh 1981). Growth data f o r F l o r i d a l o b s t e r s are u s u a l l y shown as mean s i z e increments per u n i t of t ime f o r p a r t i c u l a r s i z e groups.

The monthly growth r a t e o f sp iny l o b s t e r ( s t a r t i n g w i t h p u e r u l i 6 mm CL) reared f o r 7 months was 3.8 t o 4.2 mn/mo, g iven an average s i z e of 34 mm ( 6 mn CL a t metamorphosis p l u s 7 X 4 mn o r 28 mn) (Witham e t a l . 1968); an average growth r a t e o f 5 mm/mo f o r t h e f i r s t 9-10 months a f t e r se t t lement was est imated f rom l e n g t h (CL) frequency data (E ldred e t a l . 1972) f rom l o b s t e r s sampled i n Biscayne Bay. The p a t t e r n of 1 ength frequency, however, i s r e l i a b l e o n l y up t o lengths o f 25 mn, a f t e r which i n t e r p r e t a t i o n s o f f i e l d da ta are s e r i o u s l y b iased by the l ack o f d i s t i n c t s e t t l i n g classes. Young j u v e n i l e s conf ined i n small aquar ia w i t h a l i m i t e d d i v e r s i t y o f food grew s u b s t a n t i a l l y slower ( < 2 mn/mo) than most n a t u r a l popu la t ions (Lewis e t a l . 1952; Sweat 1968).

Growth r a t e s were est imated du r ing a 2-year tag-and-recapture study i n Biscayne Bay and F l o r i d a Bay, bo th of which are major nursery areas (Davis and D o d r i l l 1980; Davis 1981).

I n Biscayne Bay, t h e mean growth r a t e o f l o b s t e r s 40-85 mm long was 1.8 mm/mo. The phys i ca l c o n d i t i o n o f i n d i v i d u a l s s i g n i f i c a n t l y a f f e c t e d growth: un in ju red l o b s t e r s grew 2.2 mn/mo, b u t those m iss ing l egs and antennae grew o n l y 1.3 mm/mo, a 41% reduc t ion . I n F l o r i d a Bay, mean growth r a t e o f l o b s t e r s o f about t h e same s i z e was 3.3 mm/mo. I n j u r e d l o b s t e r s grew n e a r l y as f a s t . Davis and Dodr i 11 (1980) a t t r i b u t e d increased growth and t h e l ack o f damaging e f f e c t s f rom i n j u r y t o o p t i - mal growing c o n d i t i o n s and low f i s h i n g e f f o r t i n F l o r i d a Bay. I n waters near Key West, tagged l o b s t e r s 49 t o 83 mm long grew an average o f 3.1 mm/mo ( L i t t l e 1972).

The pos tse t t lement t ime r e q u i r e d f o r j u v e n i l e s t o reach minimum l e g a l s i z e i s impor tan t t o f i s h e r y manage- ment. Est imates o f pos tse t t lement times, and o f carapace l eng ths a f t e r 2 years o f ben th i c l i f e , are shown i n Table 1. The f i r s t 7 months o f each growth es t ima te a f t e r t h e beg inn ing o f t h e pueru lus stage ( 6 mn CL) are based on a mean growth r a t e o f 4.0 mm/mo; t hus t h e l o b s t e r s are 34 mm

long 7 months a f t e r s e t t l i n g (Witham e t a l . 1968). The remain ing 17 months o f each es t imate are based on growth r a t e s o f l o b s t e r s over 40 mm long i n va r i ous areas. For example, t h e es t imated carapace l eng th o f i n j u r e d F l o r i d a Bay l o b s t e r s a f t e r 2 years was 34 mm + (17 mo x 3.2 mm/mo) = 88 mm. The est imated number o f months t o reach l e g a l s i z e (76 mm) i s ob ta ined by d i v i d i n g 42 mm (76 mm - 34 mm = 42 mm, t h e growth a f t e r 7 mo) by t h e observed growth r a t e a f t e r 7 months and adding 7 months. From t h e above da ta i t was c a l c u l a t e d t h a t t h e l o b s t e r s reach l e g a l l e n g t h i n about 20 months (42 mm/3.2 mm/mo + 7 mo).

An i n t e r a c t i o n between sex and growth o f sp iny l o b s t e r s i s known (Chi t t l e b o r o u g h 1976; Aiken 1980). Lobs ters o f t h e two sexes show near equal growth i n t h e nu rse r i es o f F l o r i d a Bay and Biscayne Bay (Davis and D o d r i l l 1980). However, a d u l t female l o b s t e r s grow slower than males. Th i s growth d i f f e r e n t i a l has been repo r ted f o r t h e lower F l o r i d a Keys ( L i t t l e 19721, Bahamas (Waugh 19811, and U.S. V i r g i n I s l ands (Olsen and Kobl i c k 1975).

Table 1. Est imated t imea f o r i n j u r e d and u n i n j u r e d l o b s t e r s a t d i f f e r e n t loca- t i o n s t o reach l e g a l s i z e (76 mm carapace l e n g t h [CL]).

Locat ion Numberof Meangrowth Carapace leng th N u m b e r o f m o n t h s t o and c o n d i t i o n observa t ions (mm/month) (mm) a f t e r 2 years reach l e g a l l eng tha

F l o r i d a Bayb 644 I n j u r e d 3.2 88 Un in ju red 3.4 92

Biscayne Bayb 1688 I n j u r e d 1.3 56 Un in ju red 2.2 7 1

Key WestC Combined 44 3.1 8 7

a A f t e r pueru lus se t t lement ; add 9 months t o o b t a i n approximate age. b Based on Davis and D o d r i l l (1980). c Based on L i t t l e (1972).

9

Length-weight re1 a t i onsh ips d i f f e r s i g n i f i c a n t l y by sex. Lyons e t a l . (1981) der ived t h e f o l l o w i n g equations:

Ma1 es W = 0.00315 'CL 2.69934

Females W = 0.00361 CL 2.68379

where W = wet weight i n grams, CL = carapace l eng th i n mm.

The der ived equat ion f o r combined sexes,

W = 0,00422 CL 2.64091 9

g ives a reasonable approximation.

COMMERCIAL AND SPORT FISHERY

The F l o r i d a sp iny l o b s t e r i s a va luab le spo r t and commercial species. The sp iny l o b s t e r supports F l o r i d a ' s second most va luab le s h e l l f i s h e r y . I n 1980 t h e commercial ca tch was 6.7 m i l l i o n l b , w i t h a dockside value exceeding $14 m i l l i o n (Nat iona l Marine F i she r ies Service, S t a t i s t i c a l Report ing Service, Miami, F l o r i d a ) . Sport and commercial f i s h i n g f o r t h i s species i s concentrated i n t h e F l o r i d a Keys (Monroe County). Some sp iny l o b s t e r s a re taken by sportsmen i n most coas ta l waters o f F lo r i da .

Fishermen using top -en t r y wood- s l a t t r a p s account f o r 99% o f t h e t o t a l commercial catch; commercial d i v e r s and shrimpers, who occas iona l l y capture l o b s t e r s i n t r a w l s (GMSAFMC 1982), account f o r t h e remainder. Sport d i v e r s use sk in - o r scuba-div ing gear, gloves, and small hand-held ne ts t o ca tch l obs te rs . The s p o r t ca tch i s about 10% o f t h e commercial catch and provides a seasonal boost t o t h e t o u r i sm-dependent economy o f t h e F l o r i d a Keys (GMSAFMC 1982). Regulat ions i n 1984 p r o h i b i t e d l o b s t e r f i s h i n g f rom ,1 A p r i l through 25 J u l y and requ i red t h a t a l l l o b s t e r s must be

> 76 mm CL o r have t a i l lengths o f a t - l e a s t 140 mm. Egg-bearing females must be re tu rned t o t h e sea.

Commercial f i s h i n g has i n t e n s i f i e d g r e a t l y s ince t h e 1960's. New boats have entered t h e f i s h e r y , t h e number o f t r a p s f i shed per boat has increased, and Miami -based boats began f i s h i n g l o c a l l y a f t e r Bahamian waters were c losed t o f o r e i g n f i s h i n g i n 1975. To ta l land ings have no t r i s e n desp i te increased f i s h i n g i n t e n s i t y . The consequence has been a dramat ic d e c l i n e i n ca tch per t rap , e.g., ca tch per u n i t e f f o r t (CPUE; Table 2). Landings have remained r e l a t i v e l y s t a b l e s ince 1970, averaging 4.8 m i l l i o n lb/year. Some f i s h e r i e s b i o l o g i s t s b e l i e v e t h a t t h e s t a b l e land ings i n d i c a t e s t a b l e rec ru i tmen t and abundance o f harves tab le stocks. Lowered CPUE i s blamed on i n d u s t r i a1 overcapi t a l i z a t i o n (Aus t i n 1981; GMSAFMC 1982). Poss ib l y t h r e e t imes t h e number of t r a p s are f i s h e d as are needed t o harves t t h e a v a i l a b l e y i e l d (GMSAFMC 19821, so t o t a l mor ta l i t y est imates and e x p l o i t a t i o n r a t i o s increased f rom 1975-76 t o 1978-79 (Table 3) . I f these increases t r u l y r e f l e c t t h e e f f i c i e n c y o f e x p l o i t a t i o n ( r e s u l t i n g f rom increased e f f o r t ) , t o t a l land ings should have increased g iven a constant harves tab le stock. I n shor t , s t a b l e land ings may be a mis lead ing consequence o f increased f i s h i n g i n t e n s i t y on d e c l i n i n g stocks.

Popu la t ion S ize Composition and Reproduct ive P o t e n t i a l

Lyons e t a1 . (1981) noted a 12-mm decrease (90 mm t o 78 mm CL) i n t h e modal l e n g t h o f F l o r i d a Keys l o b s t e r s s ince 1945-49 (Dawson and I d y l l 1951). The modal carapace l e n g t h o f 78 mm i s about 30% smal le r than t h a t o f t h e un f ished popu la t i on a t Dry Tortugas (100 mm CL; Davis 1977). The d e c l i n e i n t h e s i z e o f t h e mature female has caused a marked reduc t i on i n reproduc- t i v e p o t e n t i a l (egg product ion) . Lyons e t a l . (1981) est imated the F l o r i d a Keys popu la t i on spawns o n l y

Table 2. The land ings ( m i l l i o n s o f pounds) and ex-vessel values ( m i l l i o n s o f U. S. do1 l a r s ) i n domestic waters and the landings, number o f t r aps f i shed, and ca tch pe r t r a p f o r Monroe County ( F l o r i d a Keys), 1970-79 (adapted from GMSAFMC 1982).

F l o r i d a land ings Monroe County landings

Year To ta l a To ta l Domestic To ta l Number o f Catch ( I b ) (1b) ($1 (1b) (1b) t r a p s p e r t r a p

a F l o r i d a land ings i nc lude some l o b s t e r s caught i n f o r e i g n waters. b Domestic landings i nc lude waters of t h e e n t i r e S ta te of F l o r i d a .

Table 3. Size and m o r t a l i t y est imates f o r t h e unf ished popu la t i on o f sp iny l o b s t e r s a t Dry Tortugas and the, f i s h e d popu la t ions o f t h e lower F l o r i d a Keys and t h e midd le t o upper F l o r i d a Keys (adapted from GMSAFMC 1982).

Locat i on L r L c Z A F E Data source

Dry Tortugas 100 115 1.00 63 -- - - Davis (1977)

Lower F l o r i d a Keys 65 78 1.72 82 1.32 0.77 Warner e t a l . ( 1975-76) (1977)

Middle t o upper F l o r i d a 73 81 2.73 94 2.33 0.85 L y o n s e t a l . Keys (1978-79) (1981

L r = Size (m CL) a t f u l l r ec ru i tmen t LC = Average s i z e of f u l l y r e c r u i t e d popu la t i on Z = K ( L - Lc ) / (Lc - L r ) = To ta l m o r t a l i t y c o e f f i c i e n t A = 1 - e-Z = Annual m o r t a l i t y r a t e (%) F = Z - M = F i sh ing m o r t a l i t y c o e f f i c i e n t E = F/Z = E x p l o i t a t i o n r a t i o

where L = 190 mm CL, growth c o e f f i c i e n t (K) = 0.2, n a t u r a l m o r t a l i t y (M) =O

12% o f t he number o f eggs of an un f ished popu la t i on o f equal number because the f i s h e r y se lec ted and e f f e c t i v e l y removed t h e 1 arger, more fecund females. I f t h e decrease i n eggs spawned causes a decrease i n l a r - vae and rec ru i tmen t i n t o t h e f i s h e r y , then spawning s tocks w i l l have t o be b e t t e r p ro tec ted . If l o c a l l y spawned l a r vae are s i g n i f i c a n t c o n t r i b u t o r s , suggested ac t i ons i nc lude i nc reas ing t h e minimum l e g a l s i z e and e s t a b l i s h i n g sanc tuar ies where l a rge , fecund females are pro tec ted . I f l a r - vae f rom F l o r i d a support l o b s t e r f i s h e r i e s ou ts ide o f F l o r i d a waters and v i c e versa, coopera t ive i n t e r - n a t i o n a l management agreements may be r e q u i r e d (Lyons 1981; V i l l e g a s e t a l . 1982 1.

Fishery-Induced Juven i l e M o r t a l i t y / Growth Reduction

Laws enacted i n 1976 a l l o w f ishermen i n F l o r i d a t o use smal l , i 1 l e g a l l o b s t e r s ( l o c a l l y termed "sho r t s " ) as decoys i n t r aps . Fishermen p r e f e r " sho r t s " over conven- t i o n a l b a i t s such as cowhide o r f i s h heads. S tud ies c o n f i r m t h a t ca tch r a t e s increase w i t h t he number o f " sho r t s " used per t r a p (Lyons and Kennedy 1981). Th i s p r a c t i c e causes s u b s t a n t i a l m o r t a l i t y among j u v e n i l e stocks. Major s t resses a re boa ts ide t r a n s p o r t and s t a r v a t i o n d u r i n g con- f i nement ( Lyons and Kennedy 1981 ). Loss t o t h e f i s h e r y may be s u b s t a n t i a l because i n t h e 1980's over 500,000 t r a p s are be ing f i shed, and f ishermen t y p i c a l l y use t h r e e t o f i v e " sho r t s " per t r a p (Lyons and Kennedy 1981). Attempts a re underway t o develop a r t i - f i c i a l l u r e s as a low-cost a l t e r n a t i v e (Ache and Hami l ton 1982). Another approach would be t o r e q u i r e openings o f s u f f i c i e n t s i z e among t h e s l a t s (escape gaps) t o a l l ow a l l unders ized l o b s t e r s t o escape (Lyons and Kennedy 1981 1.

I n j u r i e s t o j u v e n i l e l o b s t e r s ( l o s s o f antennae and l e g s ) are com- monly caused by a t t acks f rom predators

and f rom hand1 i n g by commerci a1 f ishermen and s p o r t d i ve rs . I n Biscayne Bay, the f requency of i n j u r i e s increased as much as 50% d u r i n g t h e f i s h i n g season (Davis and D o d r i l l 1980). Less f requent i n j u r i e s were repo r ted f o r t h e midd le and upper F l o r i d a Keys (Lyons e t a l . 1981). I n j u r e d l o b s t e r s grow slower (Davis 1981; Waugh 1981) than un in ju red l o b s t e r s presumably because they are l e s s e f f i c i e n t f o rage rs and because growth i s r e d i r e c t e d i n t o 1 imb regen- e r a t i o n . Davis (1979) es t imated t h a t i n j u r i e s f rom commercial hand l ing i n Biscayne Bay caused an annual l o s s o f 31,000 l o b s t e r s . Lyons e t a l . (1981) presented evidence t h a t i n j u r i e s cause h i g h m o r t a l i t y among smal l ( l e s s than l e g a l s i z e ) l o b s t e r s i n t he F l o r i d a Keys. The F l o r i d a S ta te L e g i s l a t u r e es tab l i shed a l o b s t e r sanctuary i n Biscayne Bay i n 1979, and t h e Everglades Na t i ona l Park p o r t i o n o f F l o r i d a Bay was c losed t o r e c r e a t i o n a l l o b s t e r i n g i n 1980; bo th measures were designed t o p r o t e c t j u v e n i l e s .

Maximum sus ta inab le y i e l d (MSY) f o r l o b s t e r land ings i n Monroe County i s es t imated t o be 5.9 m i l l i o n I b , on t h e bas i s o f ca t ch and f i s h i n g i n t e n - s i t y da ta ob ta ined f rom 1952 t o 1975 (GMSAFMC 1982). I f domestic catches (0.2 m i l l i o n I b ) , unrecorded landings, and losses due t o ha rves t i ng p r a c t i c e s (es t imated a t 5.9 m i l l i o n 1b) were inc luded, t h e ac tua l MSY would be nearer t o 12 m i l l i o n I b .

ECOLOGICAL ROLE

The d i e t o f s p i n y l o b s t e r p h y l l o - somes has n o t been s u f f i c i e n t l y descr ibed. Phyllosomes i n c u l t u r e e a t chaetognaths, euphausi ids, f i s h 1 a r - vae, medusae, and ctenophores (Provenzano 1968; Inoue 1978; P h i l l i p s and Sas t r y 1980). There are no i n d i - c a t i o n s t h a t p u e r u l i feed a t a l l (Lyons 1980).

Lobsters are noc turna l fo ragers throughout t he ben th i c phase, l o c a t i n g food w i t h chemoreceptive setae l i n i n g t h e antennules and d a c t y l s o f t h e wa lk ing legs (Ache and Macmil lan 1980). They prey upon a wide v a r i e t y o f slow-moving and sedentary animals, i n c l u d i n g gastropod and b i v a l v e mollusks, crustaceans, and echinoderms (F igu re 4) . Powerful mandibles crush o r c h i p away a t molluscan she1 1s and o ther types o f p r o t e c t i v e armor. Va r ia t i ons i n t h e d i e t s among recent- l y s e t t l e d j u v e n i l e s i n concent ra t ions o f algae, o lde r . j u v e n i l e s i n inshore bays, and a d u l t s on c o r a l r e e f s proba- b l y r e f l e c t d i f f e r i n g prey avai l a b i 1- i t y among h a b i t a t s . Spiny 1 obs ters of ten are t h e dominant carn ivores (as i nd i ca ted by t o t a l biomass) i n t h e i r h a b i t a t and probably have impor tan t eco log i ca l e f f ec t s on marine ben th i c communities (Ber ry and Smale 1980).

a l g a l O c o m m . a b a y r e e f

8 O r

F igu re 4. Frequency o f occurrence o f food i tems among samples o f e a r l y benth ic l o b s t e r s ( i nsho re a l g a l community), l a t e r j u v e n i l e s (bay), and adu l t s ( ree f ) (Herrnkind e t a l . 1975; Andree 1981).

Subs tan t i a l numbers o f l a r vae and pos t l a rvae are probably eaten by pe la- g i c f i shes ( P h i l l i p s and Sast ry 1980). P u e r u l i are eaten by benth ic ( o r ep iben th i c ) fauna as w e l l (Gracia and Lozano 1980; L i t t l e and Mi lano 1980). Octopods and p o r t u n i d crabs prey on r e c e n t l y s e t t l e d j uven i l es (Andree 1981 1. Experiments i n aquar ia i n d i - ca te t h a t small f i s h e s (e.g., gray snappers) are probably t h e most impor- t a n t p redators on e a r l y ben th i c stages ( B e r r i l l 1976). Because o f t h e i r r e l a t i v e l y l a r g e s ize, sp iny exoskele- ton, r a p i d t a i 1 - f l i p escape response, and defense by group format ion, l a t e j u v e n i l e s and adu l t s are w e l l p ro- t ec ted from small predators. Large predators, p r i m a r i l y groupers, jewf ish , sharks, loggerhead t u r t l e s , and octopods, p rey on both j u v e n i l e and a d u l t l o b s t e r s (Kanciruk 1980). Stomachs of 1 arge jewf i s h o f t e n con- t a i n l a r g e l o b s t e r s (Crawford and De Smidt 1922).

Competi t ion among l o b s t e r species i n F l o r i d a waters appears t o be incon- sequent ia l . The o the r l o c a l shal low- d w e l l i n g species, Panu l i r us laevicauda and P. gu t ta tus , are r e l a t i v e l y sca rce and are r e s t r i c t e d main ly t o r e e f h a b i t a t s .

ENVIRONMENTAL REQUIREMENTS

H a b i t a t

Phyl losoma la rvae i n h a b i t t he ep ipe l ag ic zones o f t h e open ocean, which are charac ter ized by r e l a t i v e l y constant temperature and s a l i n i t y , low l e v e l s o f suspended sediments, and few p o l l u t a n t s . R e l a t i v e l y stable, n a t u r a l cond i t i ons are apparent ly r e q u i r e d f o r optimum s u r v i v a l . I n g l e and Witham (1968) noted t h a t "sp iny l o b s t e r 1 arvae are extremely de l i ca te , phys i ca l ly, and i n o r d i n a t e l y f a s t i d - ious, p h y s i o l o g i c a l l y . " Larvae are p a r t i c u l a r l y s e n s i t i v e t o s i l t par - t i c l e s , which can, i n extreme ins tan - ces, lodge on t h e i r setae, weigh them down, and cause death (Crawford and De

Smidt 1922). Because n u t r i t i o n a l requi rements change th roughout t h e l i f e o f t h e l a r v a e (Provenzano 1968; Phi 11 i p s and Sas t r y 1980), enhanced growth and s u r v i v a l r e q u i r e a d iverse , p r o d u c t i v e oceanic p l ank ton community. P o s i t i v e c o r r e l a t i o n s between p lank ton biomass and d e n s i t y o f l a t e - s t a g e phy l losomes were repo r ted by R i t z (1972).

A l though p u e r u l i s e t t l e on i s o - l a t e d oceanic banks where t h e minimum depth exceeds 1 0 m (Munro 19741, p ro - d u c t i v e f i s h e r i e s appa ren t l y r e q u i r e w e l l -vegetated sha l low h a b i t a t f o r j u v e n i l e development. Biscayne Bay and F l o r i d a Bay a re c r i t i c a l n u r s e r i e s f o r F l o r i d a l o b s t e r s (Davis and D o d r i l l 1980). These bays a re charac- t e r i z e d by ex tens i ve meadows of ben th i c veqeta t ion . p r i m a r i l y t u r t l e g r a s s f i ha lass ia testudinum), shoalgrass (Ha lodu le w r i g h t i i ), and va r i ous a lqae (Tabb e t a l . 1962; Hudson e t '81. 1970; E ld red e t a l . 1972). Macroalgal cormnuni t i e s i n te r spe rsed among these areas appa ren t l y are impor tan t f o r t h e e a r l i e s t ben th i c staqes. Red alqae, Laurenc ia spp., a re abundant i n waters s u ~ ~ o r t i n q concen t ra t i ons o f vounci j u v e n i l e s " (E ld red e t a l . 1972; ~ n d r e e 1981; Marx 1983). I n t r i c a t e a l g a l branching p rov ides young l o b s t e r s w i t h c r y p t i c s h e l t e r and suppor ts a d i v e r s e assemblage o f smal l gastropods, crustaceans, and o t h e r prey.

Juven i l es l a r g e r than 20 mm CL take refuge i n b o t h b i o t i c (sponges, smal l c o r a l heads, sea u r c h i n s ) and a b i o t i c ( ledges, s o l u t i o n ho les ) s t r u c t u r e s . The importance o f s h e l t e r a v a i l a b i l i t y on p o p u l a t i o n d i s t r i b u - t i o n i s magn i f ied because, u n l i k e clawed l obs te rs , sp iny l o b s t e r s can mod i fy b u t n o t c o n s t r u c t dens (Kanci ruk 1980). S u b s t a n t i a l a d d i t i o n o f a r t i f i c i a l s h e l t e r s i n Biscayne Bay caused popu la t i on r e d i s t r i b u t i o n b u t d i d n o t inc rease t h e numbers o f l o b s t e r s i n t h e area (Davis 1979). The south F l o r i d a j u v e n i l e l o b s t e r p o p u l a t i o n may be 1 i m i t e d by r e c r u i t -

ment, emigra t ion , food, and perhaps o the r f a c t o r s (Dav is 1979).

Adu l t s i n h a b i t c o r a l r e e f c r e v i - ces o r overhangs, r o c k y outcroppings, ledges, and o the r d i s c o n t i n u i t i e s i n hard subs t ra te . R e s i d e n t i a l p a t t e r n s o f h a b i t a t i o n a re apparent i n 1 arge, permanent d w e l l i ngs near ex tens i ve f e e d i n g grounds (Her rnk ind e t a l . 1975). S o f t - s u b s t r a t e she l t e r s , l i k e grass-bed ledges, a re occupied p r i - mar i l y d u r i n g nomadic movements. Muddy, t u r b i d i t y - p r o n e subs t ra tes a r e u s u a l l y avoided (Her rnk ind e t a l . 1975; Kanc i ruk 1980).

Throughout ben th i c l i f e sp iny l o b s t e r s use o the r h a b i t a t s besides those p r o v i d i n g s h e l t e r . Lobs te rs concent ra ted d u r i n g t h e day i n l oca - l i z e d dens d i spe rse a t n i g h t t o f o rage over ad jacent grass beds, sand f l a t s , and a l g a l p l a i n s (Her rnk ind e t a l . 1975). I n t e r a c t i o n s between popula- t i o n d e n s i t y o f s p i n y l o b s t e r and food a v a i l a b i l i t y have n o t been s t u d i e d i n sou th F l o r i d a . Extreme v a r i a t i o n i n growth ra tes , b o t h among i n d i v i d u a l s and by h a b i t a t , suggests t h a t food abundance i s a c r i t i c a l f a c t o r , as demonstrated i n sp iny l o b s t e r species elsewhere (Chi t t l e b o r o u g h 1976).

Temperature

Spiny l o b s t e r s g e n e r a l l y i n h a b i t waters w i t h annual minimum month ly temperatures t h a t exceed 20° C (George and Main 1967). Along t h e n o r t h e r n edge o f t h e i r d i s t r i b u t i o n i n F l o r i d a , mean month ly water temperatures r a r e l y f a l l below 160 C (Witham e t a l . 1968; Hudson e t a l . 1970; E ld red e t a l . 1972; L i t t l e 1977; Davis 1979). Th i s i s j u s t above r e p o r t e d minimum su r - v i v a l temperatures f o r b o t h l a r v a l and b e n t h i c l i f e staqes. Phvllosomes o f t h e s l i p p e r l o b s t e r , s c y i l a r u s ameri- canus, which has a geographic range s i m i l a r t o t h e s p i n y l o b s t e r (Lyons 19701, show r e t a r d e d development a t water temperatures below 16O C (Robertson 1968). P o s t l a r v a l and young j u v e n i l e sp iny l o b s t e r grow

slower and demonstrate h igher mor- t a l i t y a t temperatures susta ined below 16O C (Witham 1974). Post1 a rva l t o le rance o f short-term, sharp tem- pe ra tu re dec l i nes t o 13O C ( L i t t l e and M i l ano 1980) p r o t e c t s them aga ins t severe bu t s h o r t - l i v e d c o l d f r o n t s t h a t sometimes f requent south F l o r i d a .

A t water temperatures near 13O C, sp iny l o b s t e r s 65-85 mm CL demonstrate reduced locomotor a c t i v i t y and an i na - b i l t y t o capture and manipulate prey (Wynne 1979). D i r e c t mor ta l i ty may occur, especi a1 l y f o r l o b s t e r s undergoing ecdysis, du r i ng r a p i d water temperature dec l ines t o as low as 100 C (Davis 1979). Poor s u r v i v a l a t low temperatures, e s p e c i a l l y i f they are susta ined f o r several days, p robab ly l i m i t s bo th t h e l a t i t u d i n a l and depth d i s t r i b u t i o n s o f sp iny l o b s t e r s as we1 1 as prevent ing m ig ra t i on across deep ocean basins l i k e t h e F l o r i d a S t r a i t s (Witham 1974; Wynne 1979).

The annual water temperature range i n l o b s t e r h a b i t a t s i n south F l o r i d a i s about 18O-31° C. Sharp temperature f l u c t u a t i o n s w i t h i n t h i s range may a l t e r t h e normal r a t e o f growth o f l o b s t e r s and t h e i r t ime o f set t lement. From November t o A p r i l , t h e growth o f j u v e n i l e s i n Biscayne Bay i s reduced by as much as 59%, con- c u r r e n t w i t h water temperature dec l i nes o f 80 C (Davis 1979). Growth i s r a p i d b u t s u r v i v a l i s poor a t tem- pera tures exceeding 32O C (Witham 1974; Aiken 1980). Growth i s op t ima l between 260 and 28O C. Newly s e t t l e d pos t l a rvae are p a r t i c u l a r l y vu lne rab le du r ing temperature extremes and disturbances by hur r icanes and w i n t e r storms. F luc tua t i ons i n j u v e n i l e abundance probably a re caused by i n t e r a c t i o n s between t h e r a t e o f se t t lement and seasonal environmental cond i t i ons .

Seasonal temperatures and tem- pera ture changes r e g u l a t e t h e t ime o f spawning, 1 a rva l development, and t h e growth o f adu l t s and matura t ion and growth o f j uven i l es , which va ry

markedly throughout t h e geographic range o f t h e sp iny l o b s t e r (Kanciruk 1980). Year-round spawning occurs i n t r o p i c a l waters (e.g., Venezuela), extended spawning ( s p r i n g through f a l l ) i n t h e Bahamas, and r e s t r i c t e d spawning (March through June) i n t h e F l o r i d a Keys. These v a r i a t i o n s may be caused by a phys io log i ca l adjustment t o d i f f e r i n g photoperiods and tem- pera tures (Quackenbush and Herrnkind 1981).

Sal i n i t y

Pos t l arvae do no t u s u a l l y t o l e r a t e s a l i n i t i e s below 19 p a r t s per thousand ( p p t ) (Witham e t a1 . 1968). Along t h e no r the rn Gu l f o f Mexico, adverse s y n e r g i s t i c e f f e c t s o f reduced temperature and v a r i a b l e s a l i n i t i e s probab ly prevent rec ru i tmen t i n t o nearshore h a b i t a t s (Aus t i n 1972). Recruitment p a t t e r n s were d i s rup ted i n bo th 1966 and 1968 i n t h e St. Luc ie Es tuary when heavy freshwater i n f l o w reduced s a l i n i t y t o below 19 pp t (Witham e t a l . 1968; L i t t l e 1977). Older j u v e n i l e s are ab le t o use mar- g i na l inshore h a b i t a t s because they a re h i g h l y mob i le and can r e t r e a t from unsu i tab le phys i ca l cond i t i ons (Her rnk i nd 1980).

Hydrodynamics

Throughout ben th i c l i f e , l o b s t e r s are i n f 1 uenced by hydrodynamic fo rces and s t i m u l i ( cu r ren ts , wave surge, tu rbu lence) . Puerulus se t t lement i s reduced i n areas o f s t rong cur ren ts , e.g., channels between t h e F l o r i d a Keys ( L i t t l e 1977). The pos t - se t t lement p e r i o d may be d i s rup ted by d is turbances t h a t a1 t e r she1 t e r , i n t e r f e r e w i t h foraging, o r cause b o d i l y abrasion. Subadults and adu l t s respond t o sha rp l y increased cu r ren ts and tu rbu lence caused by t h e f i r s t autumnal storms by mass m ig ra t i on (Her rnk ind and Kanciruk 1978; Kanciruk and Herrnkind 1978; Herrnkind 1980). Mass movements are p a r t i c u l a r l y s t r i k i n g . The l o b s t e r s form s i n g l e - f i l e l i n e s , o r queues, and march i n

l o c a l l y p r e c i s e d i r e c t i o n s day and n i g h t f o r up t o 1 week. The r o l e o f sha rp l y increased hydrodynamics i n t r i g g e r i n g m ig ra to ry queuing has been expe r imen ta l l y demonstrated (Her rnk ind 1982 1. Mass m ig ra t i on by sp iny l o b s t e r may r e d i s t r i b u t e migran ts i n t o s t a b l e ove rw in te r i ng h a b i t a t i n deeper r e e f areas near t h e Gu l f Stream (Her rnk ind and Kanci ruk 1978). Current f l o w prov ides a d i r e c t i o n a l cue bo th f o r general o r i e n t a t i o n and f o r l o c a t i n g food by chemosenses (Her rnk ind 1980).

Oceanic C i r c u l a t i o n

Because t h e movement o f p h y l l o - soma l a r v a e i s r e s t r i c t e d t o v e r t i c a l m i g r a t i o n (Phi 11 i p s and Sas t r y 1980), ocean c i r c u l a t i o n p a t t e r n s are respon- s i b l e f o r spreading l a r v a e i n t o

d i s t a n t waters. These p a t t e r n s con- s i s t o f ( 1 ) i n i t i a l d i s p e r s a l o f l a r - vae f rom spawning s i t e s ; ( 2 ) long- d i s tance t r a n s p o r t o r r e t e n t i o n o f la rvae; and ( 3 ) t r a n s p o r t o f l a r v a e t o nu rse ry grounds. Mechanisms i nvo l ved i n l a r v a l t r a n s p o r t t o south F l o r i d a are p o o r l y understood because o f complex i n t e r a c t i o n s o f major cu r ren ts o f t h e G u l f o f Mexico and Caribbean Sea, seasonal v a r i a t i o n i n c u r r e n t p a t t e r n s o f f t h e F l o r i d a coast, and u n c e r t a i n t y o f t h e e x t e n t t o which phyllosomes r e g u l a t e t h e i r h o r i z o n t a l d i s t r i b u t i o n by v e r t i c a l m i g r a t i o n i n t o and o u t o f d i ve rgen t water masses (Sims and I n g l e 1967; L i t t l e 1977; Menzies and Ke r r i gan 1979; Lyons 1981 1. T ranspor t models proposed f o r o the r s p i n y l o b s t e r species cannot be s t r i c t l y app l i ed t o sp iny l o b s t e r s i n F l o r i d a ( P h i l l i p s 1981).

LITERATURE CITED

Ache, B.W. , and K.A. Hamil ton. 1982. Development o f an a r t i f i c i a l t r a p b a i t f o r sp iny l o b s t e r s . Page 25 i n W.G. Lyons, ed. Proceedings o f a - workshop on F l o r i d a sp iny l o b s t e r research and management, 13-14 August 1981. F l o r i d a Department o f Natura l Resources, St . Petersburg.

Ache, B. W. , and D. L. Macmil l ian . 1980. Neurobio l ogy. Pages 215-268 i n J.S. Cobb and B.F. P h i l l i p s , eds. - The b i o l o g y and management o f l obs te rs , Vol. 1. Academic Press, New York.

Aiken, D.E. 1980. M o l t i n g and growth. Pages 91-147 i n J.S. Cobb and B. F. P h i l l i p s , eds: The b i o l o g y and management o f l o b s t e r s , Vol. 1. Academic Press, New York.

Andree, S.W. 1981. Locomotory a c t i v i t y p a t t e r n s and food i tems o f benth ic p o s t l a r v a l sp iny l o b s t e r s , ~ a n u l i r us ' argus. 'M. 5 . ~ h e s i s : F l o r i d a S ta te U n i v e r s i t v . ., ,

T a l l ahassee.

Aust in, C.B. 1981. D i f f i c u l t i e s o f l i m i t i n g e n t r y i n t o t h e over- c a p i t a l i z e d F l o r i d a sp iny l o b s t e r f i s h e r y . Proc. G u l f Caribb. F ish. I n s t . 33:184-199.

Aust in , H.M. 1972. Notes on d i s - t r i b u t i o n o f phyllosoma o f t h e sp iny l o b s t e r Panu l i rus spp. i n t h e G u l f o f Mexico. Proc. N a t l . S h e l l f i s h . Assoc. 62: 26-30.

B e r r i l l , M. 1976. Aggressive be- hav io r o f pos tpueru l us 1 arvae o f t h e western rock l o b s t e r Panul i rus

long ipes ( M i lne-Edwards). Aust. J. Mar. Freshwater Res. 27: 83-88.

Berry, P.F., and M. J. Smale. 1980. An es t imate o f p roduc t i on and con- sumption r a t e s i n t h e sp iny l o b s t e r Panul i r u s homarus on a shal low 1 i t t o r a l r e e f o f f t h e Nata l coast, South A f r i c a . Mar. Ecol. Prog. Ser. 2: 337-343.

Chi ttl eborouqh. R. G. 1976. Growth o f j uven i 1 e Panul i r u s 1 ongipes cygnus George on coasta l ree fs compared w i t h those reared under opt imal environmental cond i t ions . Aust. J. Mar. Freshwater Res. 27: 279-295.

Crawford, D. R. 1921. Spawning h a b i t s o f t h e sp iny l o b s t e r (Panul i r u s argus) w i t h notes on a r t i f i c i a l spawning. Trans. Am. F ish. Soc. 50: 312-319.

Crawford, D.R., and W. J.J. De Smidt. 1922. The sp iny l o b s t e r , Panul i rus argus, o f southern F l o r i d a : i t s n a t u r a l h i s t o r y and u t i 1 i z a t i o n . B u l l . Bur. F ish. (U. S. ) 38: 281-310.

Creaser, E. P. 1950. R e p e t i t i o n o f egg l a y i n g and number o f eggs o f Bermuda sp iny l o b s t e r . Proc. G u l f Caribb. F ish. I n s t . 230-31.

Davis, G.E. 1971. Aggregations o f Spiny sea urch ins , Diadema a n t i l l a r u m , as s h e l t e r f o r young sp iny 1 obsters, Panul i r u s argus. Trans. Am. F ish. Soc. 100: 586-587.

Davis, G.E. 1975. Minimum s i z e o f mature sp iny l o b s t e r s , Panul i rus argus, a t Dry Tortugas, F lo r i da . Trans. Am. F ish. Soc. 104: 675-676.

Davis, G.E. 1977. E f f e c t s o f recrea- t i o n a l harves t on a sp iny l o b s t e r , Panul i rus argus, popujat ion. B u l l . Mar. Sci . 27: 233-236.

Davis , G. E. 1979. Management recom- mendations f o r j u v e n i l e s ~ i ny . - 1 obsters , Panul i r i s argus , i n Biscavne Nat iona l Monument. F l o r i d a . U.S. bep. I n t e r . So. F la. * ~ e s . Rep. M-530. 32 pp.

Davis, G.E. 1981. E f f e c t s o f i n j u r i e s on sp iny l o b s t e r , Panul i rus argus, and imp1 i c a t i o n s f o r f i s h e r y management. U. S. N a t l . Mar. F ish. Serv. F ish. B u l l . 78: 979- 984.

Davis, G.E., and J.W. D o d r i l l . 1980. Marine parks and sanctuar ies f o r sp iny l o b s t e r f i s h e r y management. Proc. G u l f Caribb. F ish. I n s t . 32: 194-207.

Dawson, C. E., and C. P. I d y l l . 1951. I n v e s t i g a t i o n s on t h e F l o r i d a s ~ i n v . "

1 obster; Panul i r u s argus ( L a t r e i 1 l e ) . F la. Board Conserv. ~ e c h . Ser.-NO. 2. 39 pp.

Eldred, B., C.R. Futch, and R.M. I ng le . 1972. Studies o f j u v e n i l e spiny 1 obsters , Panul i r u s argus, i n Biscavne Bav, F l o r i d a . F la. Dep. Nat. -~esou r : - Mar. Res. Lab. spec. Sci. Rep. 35. 15 pp.

George, R.W., and A. R. Main. 1967. The e v o l u t i o n o f sp iny l o b s t e r s (Pal i nuridae): s tudy o f e v o l u t i o n i n t h e marine environment. Evolu- t i o n 21: 803-820.

Gracia, A., and E. Lozano. 1980. A1 imentacion de l baare marino - Netuma platypogon y su impor tanc ia como ind i cado r de recru tamiento de post1 arves de langosta (Decapoda: Pal i nur idae) , Guerrero, Mexico. An. Centro Cienc. Mar. Limnol. Univ. Nac. Auton. , Mexico 7(2): 199-206.

G u l f o f Mexico and South A t l a n t i c F ishery Management Counci 1 s

(GMSAFMC) . 1982. F i shery management p lan , environmental impact statement and r e g u l a t o r y ana l ys i s f o r sp iny l o b s t e r i n t h e G u l f o f Mexico and South A t l a n t i c . March 1982. U.S. Dep. Commer. , Washington, D. C. , N a t l . Oceanic Atmos. Adm.

Her rnk i nd, W. F. 1980. Spiny 1 obsters: p a t t e r n s o f movement. Pages 349-407 J.S. Cobb and B.F. P h i l l i p s , eds. The b i o l o g y and management o f l o b s t e r s , Vol. 1. Academic Press, New York.

Herrnkind, W. F. 1982. Environmental f a c t o r s t r i g g e r i n g mass m i g r a t i o n i n sp iny l o b s t e r , ~ a n u l i r u s -argus: A progress r e p o r t . Pages 11-12 fi W.G. Lyons, ed. Proceedings o f a workshop on F l o r i d a sp iny - l o b s t e r research and management, 13-14 August 1981. F l o r i d a Department o f Natura l Resources, St . Petersburg.

Herrnkind, W.F., and P. Kanciruk. 1978. Mass m i g r a t i o n o f s ~ i n v . - l o b s t e r , ~ a n u l i r& argus (Crustacea: Pal inur idae) : s v n o ~ s i s and o r i en - t a t i o n . Pages - 430-439 i n K. Schmidt-Keonig and W. T. ~ e e t o K eds. Animal m ig ra t i on , nav iga t ion , and homing. S p r i nger-Verl ag, New York.

Herrnkind, W. F. , J. Vanderwal ker , and L. Bar r . 1975. Popu la t ion dynam- i c s , ecology, and behavior o f sp iny l o b s t e r , Panu l i r us argus, o f S t . John, U.S. V i r g i n Is lands: habi- t a t i o n and p a t t e r n o f movements. Resu l ts o f t h e T e k t i t e Program, Vol. 2. Nat. H i s t . Mus. Los Ang. Cty. Sci. B u l l . 20: 31-45.

Hudson, J.H., D.M. A l l en , and T.J. Cos te l l o . 1970. The f l o r a and fauna o f a b a s i n i n c e n t r a l F l o r i d a Bay. U.S. F i s h W i l d l . Serv. Spec. Sci. Rep. F ish. No. 604. 14 pp.

I n g l e , R.M., and R. Witham. 1968. B i o l o g i c a l cons ide ra t i ons i n sp iny l o b s t e r c u l t u r e . Proc. G u l f Caribb. Fish. I n s t . 21:158-162.

Inoue, M. 1978. Studies on the c u l - t u r e d phyllosoma la rvae o f t he Japanese sp iny 1 obster , Panul i rus japonicus. I. Morphology o f t he phyllosoma. B u l l . Jpn. Soc. Sci. Fish. 44:457-475.

Kanciruk, P. 1980. Ecology o f juve- n i l e and a d u l t Pal i nur idae (sp iny lobs ters) . Pages 59-92 i n J.S. Cobb and B.F. P h i l i p s , eds. The b io logy and management o f l obs te rs , Vol. 2. Academic Press, New York.

Kanciruk, P., and W.F. Herrnkind. 1976. Autumnal reproduct ion o f sp iny 1 obster , ~ a n u l i rus argus, a t B imin i . Bahamas. B u l l . Mar. Sci.

Kanciruk, P. , and W.F. Herrnkind. 1978. Mass m i g r a t i o n o f sp iny l obs te r , Panu l i rus argus (Crustacea: Pal i nuridae): behavior and env i ron- mental co r re la tes . B u l l . Mar. Sci. 28: 601-623.

Kennedy, F. S. , J r . 1982. Catch r a t e s o f l o b s t e r t r a p s b a i t e d w i t h shor ts , w i t h notes on e f f e c t s o f conf ine- ment. Page 20 i n W.G. Lyons, ed. Proceedings o f a workshop on F l o r i d a sp i ny 1 obster research and manage- ment, 13-14 August 1981. F l o r i d a Department o f Natura l Resources, St. Petersburg.

Lewis, J.B. 1951. The phy l losoma la rvae o f t h e spiny l o b s t e r , Panul i rus argus. B u l l Mar. Sci . 1: 89-103.

Lewis, J. B. , H. B. Moore, and W. Babi s. 1952. The p o s t l a r v a l stages o f t h e spiny l o b s t e r Panul i r u s argus. B u l l . Mar. Sci. 2:324-337.

L ipc ius , R. N., M. L. Edwards, W. F. Her rnk i nd, and S. A. Waterman. 1983. I n s i t u mat ing behavior o f the sp iny -- l o b s t e r Panul i r u s argus. J. Crust. B i o l . 3: 217-222.

L i t t l e , E. J. 1972. Tagging o f sp iny l o b s t e r s (Panul i rus argus) i n t h e

F l o r i d a Keys, 1967-69. Fla. Dep. Nat. Resour. Mar. Res. Lab. Spec. Sci. Rep. 31. 23 pp.

L i t t l e , E. J. 1977. Observations on recru i tment o f p o s t l a r v a l spiny 1 obsters , ~ a n u l i rus argus , t o ' the south F l o r i d a coast. F la. Mar. Res. Publ. No. 29. 35 pp.

L i t t l e , E.J., and G.R. Milano. 1980. Techniques t o moni tor recru i tment o f ~ o s t l a r v a l s ~ i nv 1 obsters. ~ a n u l i r u s argus, t o - t h e ~ l o r i d a Keys. Fla. Mar. Res. Publ. No. 37.

Lyons, W. G. 1970. Scyl l a r i d l obs te rs (Crustacea, Decapoda) . Memoirs o f t h e Hourglass Cruises 1: 1-74.

Lyons, W.G. 1980. The p o s t l a r v a l stage o f scy l l a r i d e a n lobs ters . F i she r ies 5:47-49.

Lyons, W. G. 1981. Poss ib le sources o f F l o r i d a ' s sp iny l o b s t e r popula- t i o n . Proc. Gu l f Caribb. Fish. I n s t . 33:253-266.

Lyons, W.G. , and F. S. Kennedy, J r . 1981. E f fec ts o f harvest techniques on sublegal sp iny l obs te rs and on subsequent f i s h e r y y i e l d . Proc. Gu l f Fish. I n s t . 33: 290-300.

Lyons, W.G., D.G. Barber, S.M. Foster, F. S . Kennedy, J r . , and G. R. M i lano. 1981. The sp iny l o b s t e r , Panul i rus argus, i n t h e middle and upper F l o r i d a Keys: popu la t i on s t ruc tu re , seasonal dynamics, and reproduct ion. Fla. Mar. Res. Publ. No. 38. 38 pp.

Marchal , E.G. 1968. Sur l a capture de l ong des cotes A f r i c a i n e s de deux specimens de Panul i r u s argus ( L a t r e i l l e ) . B u l l . Mus. Nat l . H i s t . Nat. 2 ser. 39:1120-1122.

Marx, J. M. 1983. Macroalgal communi- t i e s as h a b i t a t f o r e a r l v benth ic spiny l obs te rs , ~ a n u l i r u s argus. M.S. Thesis. F l o r i d a Sta te U n i v e r s i t y , T a l l ahassee.

Menzies, R.A. 1981. Biochemical popula t ion genetics and the spiny 1 obster 1 arva l recrui tment problem: an update. Proc. Gul f Caribb. Fish. I n s t . 33:230-243.

Menzies, R.A., and J.M. Kerrigan. 1979. Impl ica t ions o f spiny l o b s t e r recrui tment pat terns o f the Caribbean -- a biochemical genet ic approach. Proc. Gul f Caribb. Fish. I n s t . 31: 164-178

Mota-A1 ves , M. I. , and R. C. F. Bezerra. 1968. Sobre o numero de ovos da lagosta Panul i rus argus (Lat r . ). Arq. Estac. B i o l . Mar. Univ. Fed. Ceara 8: 33-35.

Munro, J. L. 1974. The b io logy, ecol- ogy, e x p l o i t a t i o n , and management o f Caribbean r e e f f ishes. Sci. Rep. ODA/UWI Fish. Ecol. Res. Pro j . , 1969-1973. Par t 6. The b io logy, ecology, and bionomics o f Caribbean r e e f f ishes: 6. Crustaceans (spiny lobs te rs and crabs). Univ. W. Ind ies Zool. Dep. Res. Rep. No. 3. Kingston, Jamaica. 57 pp.

Newman, G. G. , and D. E. Pol 1 ock. 1974. Growth o f the rock l o b s t e r Jasus l a l a n d i i and i t s r e l a t i o n s h i p t o benthos. Mar. B i o l . (N.Y.) 24: 339- 346.

Olsen, D.A. , and I . G . Kobl i ck . 1975. Population dynamics, ecology, and behavior o f spiny lobs te r , Panul i rus argus, o f S t . John, U.S. V i r g i n Is lands: growth and mor- t a l i t y . Results o f the T e k t i t e program, Vol. 2. Nat. H i s t . Mus. Los Ang. Cty. Sci. B u l l . 20: 17-21.

01 sen, D. A. , W. F. Herrnkind, and R. A. Cooper. 1975. Populat ion dynamics, ecoloav. and behavior o f s ~ i n v l o b s t e r - Panu1 i rus argus, o f ' st: John. U.S. V i r a i n Is lands: i n t r o - duction. Nat. %s t . Mus. Los Ang. Cty. Sci. B u l l . 2O:ll-16.

P h i l l i p s , B. F. , 1981. The c i r c u l a t i o n o f the southeastern Ind ian Ocean and

the p lankton ic l i f e o f the western rock lobs te r . Oceanogr. Mar. B i o l . Annu. Rev. 19: 11-39.

P h i l l i p s , B. F., and A.M. Sastry. 1980. Larval ecology. Pages 11-48 i n J.S. Cobb and B.F. P h i l l i p s , eds. - The b io logy and management o f lobsters , Vol. 2. Academic Press, New York.

Provenzano, A .J . 1968. Recent expe- r iments on the labora to ry r e a r i n g o f t r o p i c a l l o b s t e r larvae. Proc. Gul f Carr ib. Fish. I n s t . 21:152-157.

Quackenbush, L. S. , and W. F. Herrnki nd. 1981. Regulation o f mo l t and gonadal development i n the spiny lobs te r , Panul i rus argus (Crustacea: Pal inur idae): e f f e c t o f eyestal k ab la t ion. Comp. Blochem. Physiol. 69A: 523-527.

Richards, W. J., and T. Po t tho f f . 1981. D i s t r i b u t i o n and seasonal occurrence o f 1 arva l pe lag ic stages o f spiny lobs te rs (Pal inur idae, Panul i r u s ) i n the western t r o p i c a l A t l a n t i c . Proc. Gul f Caribb. Fish. I n s t . 33:244-252.

R i t z , D.A. 1972. Factors a f f e c t i n g the d i s t r i b u t i o n o f rock l o b s t e r 1 arvae (Panul i rus 1 ongipes cygnus) , w i t h reference t o v a r i a b i l i t v o f Plankton-net catches. Mar. B i o l . 13: 309- 317.

Robertson, P. B. 1968. The complete l a r v a l develo~ment o f the sand lobs te r , ~ c i l l arus ameri canus (Smith) (Decapoda: Scyl 1 ar idae) i n the 1 aboratory , w i t h notes on 1 arvae from the plankton. B u l l . Mar. Sci. 18: 294-342.

Sims, H.W., and R.M. Ing le . 1967. Caribbean recru i tment o f F l o r i d a ' s spiny l o b s t e r populat ion. Q. J. Fla. Acad. Sci. 29: 207-242.

Sutc l i f f e , W. H. 1952. Some observa- t i o n s o f the breeding and m ig ra t ion o f the Bermuda sp i ny 1 obster,

Panul i r u s argus. Proc. Gu l f Caribb. Fish. I n s t . 4: 64-69.

Sweat, D. E. 1968. Growth and tagg ing s tud ies on Panu l i rus argus ( L a t r e i l l e ) i n t h e F l o r i d a Keys. Fla. Board Conserv. Mar. Res. Lab. Tech. Ser. No. 57. 30 pp.

Tabb, D.C., D. L. Dubrow, and R.B. Manning. 1962. The ecology o f nor thern F l o r i d a Bay and adjacent es tuar ies . F la. S ta te Board Con- serv. Tech. Ser. No. 39. 8 1 pp.

V i l l egas , .L. , A.C. Jones, and R. F. Labi sky. 1982. Management s t r a t e g i e s f o r t h e spiny l o b s t e r resources i n t h e western c e n t r a l At1 a n t i c : a cooperat ive approach. N. Am. J. Fish. Manage. 2:216-223.

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Yang, M.C. K. , and B. Obert. 1978. Selected s t a t i s t i c a l analyses o f Key West spiny l o b s t e r data. Pages 4-7 i n R.E. Warner, ed. Spiny l o b s t e r - research review; proceedings o f a conference h e l d December 16, 1976 i n Key West, F lo r i da . Sea Grant Tech. Pap. No. 4. 56 pp.

Species P r o f i l e s : L i f e Hi s t o r i e s and Envi ronmental Requi rements o f Coastal Fishes and Inver tebra tes (South F l o r i da ) -- Spiny Lobster

SO171 -101

7. Author(%)

James M. Marx and W i l l i am F. Herrnk ind 9. Pstfomlng Orpnlzatlon Narne and Address

Department of B i o l o g i c a l Science F l o r i d a S ta te U n i v e r s i t y T a l l ahassee, FL 32306

3. Rec~p~ant's Accession NO.

5. Rewrt Oate

REPORT DOCUMENTATION PAGE

11. Gontract(C) or Grant(G) No.

I(C1 I

'a REmRT 2.

B i o l o g i c a l Report 82(11.61)

12. Sponsorin. Organization Narne and Addnss

4. TRIO and Subtitle

Nat ional Wetlands Research Center U. S. Army Corps o f Engineers F ish and W i l d l i f e Serv ice Waterways Experiment S ta t i on U.S. Department o f the I n t e r i o r P.O. Box 631 Washington, DC 20240 Vicksburg, MS 39180

15. Supplementary Notes _I I *U.S. Army Corps o f Engineers Report No. TR EL-82-4 I I .IS. Abstract (Umit: 200 words) I

The F l o r i d a sp iny l o b s t e r (Panul i rus argus) supports major commercial f i s h e r i e s i n south F l o r i d a and t he Caribbean Sea. I t s l i f e h i s t o r y inc ludes several l i f e stages t h a t l i v e i n the open ocean, inshore bays, and coas ta l reefs . The F l o r i d a popu la t ion spawns a long deeper o f f shore r ee f s i n sp r i ng and e a r l y summer. Fate o f l o c a l l y spawned la rvae i s uncer ta in , b u t s i g n i f i c a n t p o s t l a r v a l rec ru i tment may o r i g i n a t e from la rvae spawned i n f o re i gn waters. A f t e r set t lement i n inshore vegetated hab i t a t s , j u ven i l es reach l ega l harvestab le s i z e i n about 2 years. The onset o f m a t u r i t y i s co i nc i den t w i t h a marked emigrat ion of fshore. Subsequent seasonal movements cued by reproduc t i ve a c t i v i t y and weather disturbances a re pronounced. Excessive f i s h i n g has caused a dec l i ne i n t he s i z e o f t he south F l o r i d a popu la t ion and a corresponding r educ t i on i n t o t a l spawn. The relevance o f spawn reduc t ion i s unce r t a i n because o f quest ions regard ing l a r v a l o r i g i n s and s tock-recru i tment r e l a t i o n s . Water temperatures probably r egu la te popu la t ion d i s t r i b u t i o n and t he seasonal dynamics o f growth and reproduct ion. Pos t l a r va l r e c r u i t - ment i s l i m i t e d t o h i gh s a l i n i t y inshore environments. Hydrodynamic s t i m u l i and water c i r c u l a t i o n pa t t e rns p l a y c r i t i c a l r o l e s throughout the l i f e cyc le .

17. Document Analmis a. Deurieton --I Lobsters L i f e cyc les Feeding hab i t s Growth F isher ies Depth Temperature Sal i n i t y

I b. IdentlhenlOpen.Endad Terms

Spiny 1 obster Panul i rus argus Environmental requirements

I c. GOSATI FieldlGmup I I & Availsbility Statement ' 19. Sccunty Class CThis Repart) 21. NO. of Pages

Unl imi ted d i s t r i b u t i o n 2 1

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