getting the most out of your underwater experience · * descriptions taken from reef fish...

Getting the Most Out of Your Underwater Experience:

An introduction to identifying the fish, creatures, and coral of the Virgin Islands

Part II: Creatures and Coral

Brian Naess, Research AssociateInstitute for the Environment, UNC-Chapel Hill

Credits• All photos taken by ENST 259 instructors: Brian Naess,

Liz Naess, Andrew George, Kolya Lachinsky• All identifications for class photos based on the 3 book

series by Paul Humann and Ned Deloach: Reef Fish Identification, Reef Creature Identification, and Reef Coral Identification of Florida, Caribbean, and Bahamas published by New World Publications, Inc.

• Disclaimer: Visual identification of many creatures like sponges and tunicates is at best an educated guess!

3 Main Divisions

• Fish – sharks, eels, rays• Creatures – crabs, shrimp, clams, starfish,

anemones, lobsters, squid, octopus, worms, cucumbers, tunicates, sponges, urchins, turtles

• Coral – hard and soft varieties, marine plants and algae

Creatures

* Images scanned from Reef Creature Identification: Florida, Caribbean, Bahamas by Paul Humann and Ned DeLoach

We’ll Focus On• Cnidarians: Hydroids, Anemones, Zoanthids,

and Corallimorphs• Segmented Worms: Fireworms, Feather duster

worms, Calcareous tube worms• Crustaceans: Shrimp, Lobsters, and Crabs• Mollusks: Snails, Bivalves, Squid, and

Octopuses• Echinoderms: Sea stars, Urchins, and

Cucumbers• Tunicates and Sponges• Sea Turtles: Green and Hawksbill turtles

What to Look For

0) What Kind of Creature Is It?1a) Shape1b) Distinctive Traits2) Color3) Behavior4) Location5) Size

Cnidarians: Hydroids, Anemones, Zoanthids, and Corallimorphs

• Hydroids– Usually colonial; branched skeleton

resembling feathers or ferns– Arrangement of stalk, branches, and

polyps key to identification• Anemones

– Solitary polyps attached to bottom– Tentacles vary in length, shape, color,

and number• Zoanthids

– Usually smaller than anemones– Oral disc has no tentacles except two

rings of tentacles around outer edge• Corallimorphs

– Tentacles radiate out from center and form concentric circles

– Protruding mouth

* Descriptions taken from Reef Creature Identification: Florida, Caribbean, Bahamas by Paul Humann and Ned DeLoach. Page 62-66

Where to LookHydroids – All areas of reefAnemones – All areas of reef. Bodies often hidden in recesses.Zoanthids - Many live on sponges. Others found on all areas of reef.Corallimorphs – Most attach to solid structure, often in protected areas.

Cnidarians: Hydroids, Anemones, Zoanthids, and Corallimorphs

Christmas tree hydroid Giant Anemone

Giant Anemone

Mat Zoanthid

Warty CorallimorphFeather plume hydroid

Segmented Worms• Fireworms

– Bundles of sharp, white bristles that will penetrate the skin and break off

• Feather Duster Worms– Bodies hidden inside

parchment-like tubes attached to reef

– Feather-like radioles that extend from tube act as gills and capture plankton

• Calcareous Tube Worms– Tubes often hidden in rock or coral– Colorful radioles form spirals and

whorls


Where to LookFireworms – Can be found crawling all over, especially on gorgonians and fire coralFeather duster worms – All reef and near-reef areas. Often shy and retract in tubeCalcareous tube worms – All areas of reef. Tubes often encased in live coral.

Segmented Worms

Christmas tree worm

Bearded fireworm

Star horseshoe worm

Crustaceans: Shrimp, Lobsters, and Crabs

• Shrimp– Long, hair-like antennae

• Lobsters– Bottom-dwellers, clawless– Spiny lobsters have long, conical

antennae– Slipper lobsters have plate-like

antennae

• Crabs– Claws, three to four pairs of legs– Usually secretive, hiding in recesses

and in association with anemones and urchins


Where to LookShrimp – Under overhangs, recesses and in association with anemones. Usually more than one.Lobsters – Caves, recesses. Look for antennae. Often more than one.Crabs – Caves, recesses, behind urchins. If you see long-spined urchin next to wall, look behind urchin for nimble spray crab.


Pederson cleaner shrimp

Banded coral shrimpPeppermint shrimp

Spotted cleaner shrimp


Spanish lobster

Spotted spiny lobster

Caribbean spiny lobster


Nimble spray crabYellowline arrow crab

Blotched swimming crab

Mollusks: Snails, Bivalves, Squid, and Octopuses

• Snails/Gastropods– Identified by shell shape, sculpturing,

color pattern, etc.– Snail’s body normally hidden, but you

may see tube-like mouth and/or two tentacles with eyes

• Bivalves– Two shells hinged together by a

ligament• Squid

– Eight arms with two longer tentacles. Stabilizing swim fins along the sides. Usually in groups of 3 or more.

• Octopuses– Eight arms of equal length,

globular/bag-like body– Incredible ability to camouflage


Where to LookSnails – Sea grass, sand, shallow reef areas. Some attach/feed on gorgoniansBivalves – Cracks, recesses, attached to structure like pilings, sometimes attached to gorgoniansSquid – Usually shallow, reef/near-reef areas.Octopuses – Hard to spot unless moving. Can be in recesses. Look for piles of shells.


Crown conch Rough fileclam

Atlantic wing-oyster


Caribbean reef squid Common octopus

Echinoderms: Sea stars, Urchins, and Cucumbers

• Sea stars– Central disc with typically five

triangular arms– Incredible regenerative abilities

• Brittle stars– Long, thin arms with flattened central

disc

• Sea urchins– Spherical bodies with long, protective

spines

• Sea cucumbers– Sausage shaped bodies crawling

across reef or sand


Where to LookSea stars – Sea grass, sandy areasBrittle stars – Sponges, fire coral, under rocksSea urchins – Everywhere, particularly in shallow reef/near reef areas.Sea cucumbers – Sandy areas, sea grass beds, and reef rubble areas.


Cushion sea star

Common comet star

Banded arm brittle star

Sponge brittle star


West Indian sea egg

Long-spined urchin

Rock-boring urchin

Donkey dung sea cucumber

Tunicates and Sponges• Tunicates

– Attached to substrate on one end, two siphons at the other end for food and oxygen

– Can close their siphons quickly when disturbed

– Highly evolved with nervous system and complex muscles

• Sponges– Water passes through numerous

small pores where food and oxygen are filtered out, then exits out one or more large excurrent openings

– Many different sizes, colors, and shapes (barrel, ball, tube, rope, encrusting, etc.)

– Simplest multicellular animal

* Descriptions taken from Reef Creature Identification: Florida, Caribbean, Bahamas by Paul Humann and Ned DeLoach. Pgs 14,400

Where to LookTunicates– Reef areas, sometimes attached to gorgonians. Often bodies are hidden in crevices.Sponges – Usually near/on reefs, reef walls, overhangs, sometimes attached to substrate like gorgonians, mangrove roots, etc.

TunicatesBlue bell tunicates

Painted tunicates

Overgrowing mat tunicates

Strawberry tunicates

SpongesBlack ball sponge

Branching tubesponge

Brown bowl sponge

Orangeicing sponge

Red-orange encrusting sponge

Scattered pore ropesponge

Sea Turtles• Marine reptiles that only come

ashore to lay eggs• All species of turtles are

endangered• We’ll see hawksbill and green

turtles

* Descriptions taken from Reef Fish Identification: Florida, Caribbean, Bahamas by Paul Humann and Ned DeLoach. Pg 481

Where to LookSea turtles will most often be found in sea grass areas, feeding on turtle grass. You may find them swimming over deeper water, and you may spot them surfacing for air from the beach.

• Hawksbill turtles have generally brown shells with mottled markings, overlapping plates on their shells, and an overhanging upper beak• Hawksbill turtles have two pairs of plates between the eyes• Green turtles have brown to dark brown shells that are generally unmarked, though they can have mottled markings like the hawksbill or wave-like/brush-stroke patterns• Green turtles have only two plates between the eyes.

Sea Turtles

Green turtle Hawksbill turtle

Quiz

Banded tube-dwelling anemone*

Visual ID: Translucent brown-and-white banded outer tentacles, whitish oral disc and central tentacles.

Habitat and Behavior: Inhabit areas of sand and coral rubble. Nocturnal, solitary polyps extend from parchment-like tube buried in sand.

* Description taken from Reef Creature Identification: Florida, Caribbean, Bahamas by Paul Humann and Ned DeLoach. Pg 118

Quiz

Reticulated brittle star*

Visual ID: Reticulated network of fine dark lines on bone white to bluish disc. Arms whitish to pale yellow with brownish bands and short spines.

Habitat and Behavior: Inhabit sandy areas around reefs. Hide under slabs of coral and rubble.


Quiz

Flamingo tongue*

Visual ID: Cream-white mantle covered with orangish, often somewhat rectangular spots with black outlines. Shell is lustrous cream to white.

Habitat and Behavior: Attach to and feed on gorgonians in all types of habitats.


3 Main Divisions

• Fish – sharks, eels, rays• Creatures – crabs, shrimp, clams, starfish,

anemones, lobsters, squid, octopus, worms, cucumbers, tunicates, sponges, urchins, turtles

• Coral – hard and soft varieties, marine plants and algae

Coral

* Images scanned from Reef Coral Identification: Florida, Caribbean, Bahamas by Paul Humann and Ned DeLoach

We’ll Focus On

• Hydrocorals: Fire coral• Gorgonians: Sea rods, Sea plumes, and

Sea fans• Stony corals: Branching & pillar corals,

Finger corals, Star corals, Brain corals, and Cup corals

• Marine plants and Algae

Hydrocorals• Fire Coral

– Actually member of hydroid family

– Two types of polyps: sensory/stinging encircling stout feeding polyps

– Sting caused by nematocysts on tentacles

– 3 different flavors: blade, branching, and box

– Look for “mustard” color with white ends; white hairs

Gorgonians

• Polyps have 8 tentacles• Stems and branches all have central

“trunk”• Entire coral colony attached at a single

point• Pay special attention to arrangement of

polyps, as it can be helpful in identification

Gorgonians

• Sea Rods

Knobby sea rod

Porous sea rod

Gorgonians

• Sea Plumes

Rough sea plume

Sea plume forest

Gorgonians

• Sea Fans

Wide mesh sea fan

Common sea fan

Stony Corals

• Hermatypic – “reef-building”• Colonies increase size by asexual budding• Tentacles in multiples of six

Stony Corals

• Branching and pillar corals

Staghorn coral

Elkhorn coral

Pillar coral

Stony Corals

Branched finger coral Clubtip finger coral

• Finger corals

Stony Corals

Blushing star coral

Boulder star coral

• Star corals

Elliptical star coral

Lobed star coral

Stony Corals

Boulder brain coral Symmetrical brain coral

• Brain corals

Grooved brain coral

Stony Corals

• Cup corals

Orange cup coral

Marine Plants and Algae

• Photosynthetic• Marine plants have roots, stems, leaves,

and flowers– Example: Sea grasses

• Algae attach to substrate using rhizoids, have stalks rather than stems, and blades instead of leaves– Examples: Brown, green, and red algae

* Descriptions taken from Reef Coral Identification: Florida, Caribbean, Bahamas by Paul Humann and Ned DeLoach. Pgs188-9


• Sea grassTurtle grass


• Brown algae

White scroll algaandY Branched alga


• Green algae

Green grape alga

Green feather alga

Bristle ball brush


• Red algae

Y-Twig alga

Fuzz ball alga

Quiz

Black-ball sponge, elliptical star coral, etc.

Quiz

Bluestriped grunt (juv.), erect rope sponge, smooth star coral, etc.

Quiz

Clubtip finger coral, elkhorn coral, turtle grass, watercress alga

Quiz

Common octopus, orange ball sponge, some type of vase sponge, long-spined urchin, etc.

Tips for Productive Snorkeling

• Good fitting mask• Take your time• Reefs are 3D – swim down and explore• Don’t use fins in shallow water• Stay horizontal in water less than 20’ deep• Look for overhangs, openings, caves• Focus on one thing at a time• Spend some time in the shallows• Little fish are just as cool as big fish!

getting the most out of your underwater experience · * descriptions taken from reef fish...

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