Chapter 39 Fish

http://www.fishtalesportfishing.com/images/chartwithfish.jpg

With introduction to vertebrae classes

Sources: Modern Biology- Holt, Reinhart & Winstonhttp://www.epa.gov/waterscience/fishadvice/advice.htmlocw.tufts.edu/Content/5/Lecturenotes/215706

Mrs. Lori SchallesBiology IIRinggold High School

I. Introduction to Vertebrates

Phylum - Chordata. Subphylum – Vertebrata

Recall- All Chordates share the following characteristics:

-Notochord-Dorsal hollow nerve cord-Pharyngeal gill slits-Post-anal tail

www.anselm.edu

A. Vertebrate Characteristics:

• Vertebrae - bones or cartilage that surround the dorsal nerve cord and form the spine.

• Cranium - a skull that protects the brain – highly cephalized– well developed brain & sense organs

• Endoskeleton - internal skeleton made of bone or cartilage

• Closed circulatory system: heart, arteries and veins

• Paired appendages – (Usually)

• Sexes separate in most

B. Vertebrates are divided into nine classes:

• Myxini - hagfishes• Cephalaspidomorphi - lampreys• Chondrichthyes - sharks, rays, skates• Actinopterygii - ray-finned fishes• Sarcopterygii - lobe-finned fishes• Amphibia - frogs, toads, salamanders• Reptilia - lizards, snakes, and turtles• Aves - birds• Mammalia - mammals

Evolutionary relationships- vertebrates

The first fish were jawless.

About 450 million years ago, the first fishes with jaws and paired fins appeared.

Jaws are thought to have evolved from the first pair of gill arches, the skeletal elements that support the pharynx.

II. Fish A. Adaptations1. Paired fins -increase fish stability &

maneuverability in water

http://www.pbs.org/wgbh/nova/teachers/activities/images/3003_fish_2.gif

Fin functions• Dorsal fin :Stabilizer, Courtship, Defense • Pectoral fin : counteract • Pelvic fin : stabilizer • Caudal fin : Motor • Anal fin : Stabilizer, Gonopodium (modified for

transferring sperm in live bearers)                                                       

2. Fish Integument

• Bony scales of fish are overlapping plates of bone produced in the dermal layer. 3 kinds of scales:– Ctenoid- thin & hair –like ends– Cycloid- thin with smooth edges– Ganoid – thick & heavy

• Mucous (glycocalyx) – Full of antibiotic / antifungal enzymes and antibodies – Protective coating – Slough off pathogens – Can be detrimental in high amounts

• Alarm cells (pheromone)

3. Adaptations to life in water:

• Streamlined body plan – (allows fish to move rapidly in water)

• Adaptations for buoyancy – stored gases (swim bladder or lung) – lipids help maintain vertical position in water

• Efficient respiration - gills exchange gases

• Homeostasis - concentration of solutes – in a fish’s body usually differs from that of the water. – have adaptations to maintain ion and water concentration

4. Sensory Adaptations

• Sight: fish eyes like eyes of land vertebrates

• Sound: internal ears hear

• Nostrils & Tastebuds – chemoreception (detect chemicals) – senses of smell and taste. – Tastebuds may be located in

mouths, lips, fins, and skin, – and on whisker-like organs called

barbels.

• Lateral line: is a system of canals in the skin that allow fish to sense vibration in the water

picture from: http://static.howstuffworks.com/gif/shark-diagram1.jpg

• NOTE: some fish have the ability to detect electrical and magnetic fields: example-– Ampulae of Lorenzini: cartilaginous fishes have

sense organs that can detect weak electrical fields

Figure 24.10

Lateral line system(baroreception)

Electroreceptors(Amupullae of Lorenzini)

B. Types of Fish1. Jawless Fisha. Myxini (Hagfishes)

– Also known as “slime eels”– Hagfish burrow into

& eat dead fish

b. Cephalaspidomorphi (Lampreys)– Parasitic Lampreys attach themselves to their

host with disc-shaped mouth & feed on host’s blood.

oceanexplorer.noaa.gov/.../media/hagfish.html

www.answers.com http://www.ryanphotographic.com/chordates.htm

Class Cephalaspidomorphi - The Lampreys

Atlantic Hagfishhttp://www.seasky.org/monsters/sea7a1q.html

• Myxine glutinosa, is covered with

special glands that emit sticky slime• In fact, a single hagfish can produce enough slime at one time to fill a milk jug.• The slime covers enemy fish & chokes

them to death because they cannot breath.• Sometimes the hagfish makes so much slime it

covers its own body- then it ties itself into a knot to wipe off the slime.

Class Myxini - The Hagfishes

Characteristics of Cartilaginous Fish • Skeleton -composed of cartilage (soft, flexible lightweight

tissues made of cells & protein)

• Skin is covered with placoid scales- (small tooth-like spines which reduce turbulence, increase swimming efficiency)

• Respiration- gills• Excretion- convert ammonia to urea

• Reproduction-internal fertilization– Most lay eggs, some live birth– No parental care.

-

Figure 24.12

Clearnose Skate Southern Stingray

Shark

Shark Bite Facts:• Tens of thousands of people come in close contact with sharks each year

while swimming, surfing, or boating, numbers of shark attacks are negligible. In 2005, there were 58 confirmed "unprovoked" shark attacks in the world, resulting in 4 deaths. Good site:

http://www.infoplease.com/spot/sharks1.html

• 1,600 people are bitten in New York City, by other people, every year. • In the U.S., your chances of getting killed by lightning are 30 times greater

than dying of a shark attack.

• Bees, wasps, and snakes kill more people each year than sharksTips for Avoiding Attack•Stay out of the water at night, dusk, or dawn. Sharks are most active at night. •Swim in a group. Sharks prefer to attack lone victims. •Keep close to shore. It will be easier for help to reach you in an attack. •Avoid sandbars and sharp drop-offs where fish congregate. •Stay out of polluted or murky water. •Avoid areas being used by fishermen. •Be wary of feeding birds, or porpoises, which indicate the presence of fish. •Do not swim if you are bleeding. Sharks can detect tiny amounts of blood. •Do not wear shiny jewelry; underwater it resembles fish scales. •Avoid bright swimsuits and uneven tanning. Contrasts attract sharks. •Do not splash a lot, since it attracts sharks.

EUGENIE CLARK WITH BULL SHARK (MEXICO)

Figure 24.07

EMBRYO AND YOLK SAC - SWELL SHARK EGG CASE (JAPAN)

Shark from theInland Sea:

CretoxgrhinaMantelli

(NiobraraFormationIn Kansas)

3. Boney Fish• 3 Key features:

1. scales on body2. lungs or swim bladder3. bone in the skeleton

• 2 types:

A. Lobe-Finned FishesB. Ray-finned fishes

A. LOBE-finned fishes

• Have fleshy fins with bony axis

• Extinct lobe-fin fish may have been ancestors of amphibians

• Groups alive today– 1 species coelacanth– 6 species lungfish

(can gulp AIR into lung

as Oxygen source)

www2.dpi.qld.gov.au/far/12588.html

COELOCANTH - SUBCLASS SARCOPTERYGIILOBE-FINNED FISH

SINGLE SPECIES - LATIMERIA CHALUMNAE

B. RAY-Finned Fishes• Have thin, non-fleshy & flexible fins

• Includes most

familiar fish:

Yellow perch,

trout, salmon,

guppies, goldfish,

herring,& eels.

Bony fish anatomy & physiology• Operculum -a hard plate that opens at the

rear and covers & protects the gills.

• Circulatory system– heart has two chambers in a row– Blood from the body enters the sinus venosus, moves into

the atrium, then into the ventricle. – From the ventricle it enters the conus arteriosus, and then

goes to the gills. Note the thick walls of muscle for pumping.

Respiratory system• Gills for gas exchange.

• Countercurrent flow. – Water flows across the gill filaments in a direction opposite

to blood flow– Countercurrent flow allows more oxygen to diffuse into

the blood than if blood and water flowed in the same direction.

Figure 24.29a

Figure 24.29c

Construction of a single gill filament withnumerous, disc-shaped lamella oriented parallel to water flow

Water flow in oppositedirection to blood flow(counter-current flow)

Skeleton: The major parts of a fish’s skeleton are the skull, spinal column, pectoral girdle, pelvic girdle, and ribs

Internal structures:

What is a swim bladder?• Most boney fishes have a swim bladder• Adjusts fish overall density by regulating

gas in the swim bladder.• Thin walled sac in abdominal cavity

– Contains mix of gases (oxygen, CO2, Nitrogen) obtained from the Bloodstream.

• Probably evolved from balloon-like lungs• Can amplify sound in some fish.

Excretory system

• The kidneys – Have nephrons– filter chemical wastes from the blood – form urine, a solution containing ammonia,

ions such as salts, and water.

• The gills – also allow wastes to diffuse from the blood into

the water – help regulate ion and water balance in fish.

Nervous system• Includes brain, spinal cord, nerves &

sensory organs.

• See page 792 for location & function of olfactory bulbs, cerebrum, optic tectum, cerebellum & medulla oblongata.

2 methods of Reproduction1. spawning. -most bony fish reproduce by external fertilization (some internal)2. Some fish bear live young.Example- guppies-can store sperm & have up to 4 pregnancies from one deposit. Additional Info-

Atlantic Sturgeon - Eastern rivers in North America

Chondrostei : Sturgeons (think caviar…..)

Ray finned fish are a very diverse group

Paddlefish: 2 species (Mississippi River drainage andYangtze River drainage in China) - large bill used tostir bottom and expose food

JUVENILE LIONFISH (JAPAN)

C. Fish & Humans• Pollution/ poor water quality affect fish too.• For list of Endangered & Threatened Species

of Pennsylvania - Fish, Amphibians and Reptiles go to www.fish.state.pa.us/endang1.htm

•

• O2 is as important to fish as to terrestrial animals – If Oxygen poor water, fish will die– “Osmotically unfriendly”, (H2O is 800 times denser than

air)– Water is a “soup of pathogens” ocw.tufts.edu/Content/5/Lecturenotes/215706

Can fish be trained?

• http://kdka.com/video/?id=26064@kdka.dayport.com

• http://www.fish-school.com/

National Geographic Video-Over Fishinghttp://www7.nationalgeographic.com/ngm/0704/sights_n_sounds/index.html

http://www7.nationalgeographic.com/ngm/0704/feature1/online_extra.html

How to Help: Safe, Sustainable Seafood:

Pennsylvania Fishes• Pennsylvania is

home to many popular game fish, including trout, bass, musky, walleye, steelhead, panfish and many more!

•http://sites.state.pa.us/PA_Exec/Fish_Boat/pafish/fishhtms/chapindx.htm

Northern Snakehead• Snakeheads are native to parts of China, Russia, and Korea- alien to PA

The air-breathing, land-crawling, voracious predator found in a pond in Crofton, Maryland, is now multiplying into PA.

The fish's ability to breathe out of water and travel across land has increased the sense of urgency among wildlife officials.

• IF YOU CATCH ONE- dispose of them properly. Anglers suspecting they have caught a

snakehead are encouraged to NOT release it, and report it to theCommission at 610-847-2442 or via email. 

• PA REGULATIONS• It is unlawful for a person to possess, sell, purchase, offer for sale or

barter live snakehead species in Pennsylvania. http://www.fish.state.pa.us/water/fish/snakehead/000index.htm

Red Bellied Piranha Serrasalmus nattereri

• Weight -up to three pounds • Length -8 to 15 inches in length. • Can live up to 8 years. • Red-bellied piranhas live in the

warm fresh water regions of South America.

• Feed on fish, birds, reptiles, rodents, and small mammals.

• The name South American native language Tupi-guarani and means “cuts the skin.”

• It is illegal to keep piranhas in 21 states of the United States.

                                                         

By Pittsburgh Zoo Staff

''A school of these 8- to 12-inch fish, have been observed gnawing a 400-pound hog to the bone in minutes'' (from the “Book of Facts”)

Photo in the News: Century-Old Fish Caught in Alaska

April 6, 2007—A handful of Christians preparing rockfish as part of their traditional fish dinner this Good Friday might be feasting on one of the oldest creatures ever to live in Alaskan waters.

Commercial fishers in the Bering Sea recently hauled in the female shortraker rockfish seen above, which scientists say was between 90 and 115 years old.

Researchers at the National Oceanic and Atmospheric Administration (NOAA) used growth rings in the fish's ear bone, or otolith, to make their age estimate.

http://news.nationalgeographic.com/news/2007/04/070406-oldest-fish.html

Commonly eaten fish: http://www.eatwell.gov.uk/healthydiet/nutritionessentials/fishandshellfish/

Oily / fatty fish White / non-oily fish

Salmon Trout Mackerel Herring Sardines Pilchards Kipper Eel Whitebait Tuna (fresh only)Anchovies Swordfish Bloater Cacha Carp Hilsa Jack fish Katla Orange roughy Sprats

Parrot fishPollackPomfretRed and grey mulletRed fishRed snapperRohuSea bassSea breamSharkTilapiaTurbotTinned tunaMarlin

CodHaddockPlaiceColeyWhitingLemon soleSkateHalibutRock salmon/DogfishAyrCatfishDover soleFlounderFlying fishHakeHokiJohn DoryKalabasuLingMonkfish

Oily fish are all rich sources of omega 3 fatty acids, which help prevent heart disease.

Would you eat FUGU???

• Puffer fish (genus-Takifugu)(“Fugu” in Japanese) is an expensive delicacy.

• But more than just the money- it could cost your life!• It has a deadly poison (tetrodotoxin) in its organs. • Chefs must take intensive courses & pass exam to become licensed.

Only 30% of the applicants pass the test!• Several people die each year from eating this fish. If an ingested dose

of the fugu's poison is lethal, as more and more muscles are paralyzed, symptoms may include dizziness, exhaustion, headache, nausea or difficulty breathing. For 50 to 80% of the victims, death follows within four to 24 hours.

• To learn more on FUGU http://www.search.com/reference/Fugu

Eating FishIs eating fish healthy?• Fish and shellfish are an important part of a healthy diet. • Contain protein & omega-3 fatty acids, are low in saturated fat• However, nearly all fish and shellfish contain traces of mercury.

What is mercury and methylmercury?• Mercury occurs naturally in the environment • Can be released into air by industrial pollution. Mercury falls from

the air and can accumulate in streams and oceans and is turned into methylmercury in the water.

• This type of mercury can be harmful to unborn babies & young child.

• Fish absorb methylmercury as they feed & it builds up in them. It builds up more in some types of fish and shellfish than others.

http://www.epa.gov/waterscience/fishadvice/advice.html

Recommendations for eating fish

to reduce exposure to mercury.

• Do not eat Shark, Swordfish, King Mackerel, or Tilefish because they contain high levels of mercury.

• Eat up to 12 ounces (2 average meals) a week of a variety of fish and shellfish that are lower in mercury. – Five commonly eaten fish that are low in mercury are shrimp,

canned light tuna, salmon, pollock, and catfish. – Albacore ("white") tuna has more mercury than canned light

tuna..

• Check local advisories about the safety of fish caught by family and friends in your local lakes, rivers, and coastal areas.

http://www.epa.gov/waterscience/fishadvice/advice.html

http://www.purdue.edu/dp/envirosoft/mercury/slides/wc27new.gif