FISH

I. Characteristics of Fish

A. Fish are over A. Fish are over 1/2 the 1/2 the

vertebrates on vertebrates on Earth.Earth.

•The internal skeleton The internal skeleton allows vertebrates to allows vertebrates to grow larger than grow larger than invertebrates.invertebrates.

•The backbone of The backbone of vertebrates vertebrates provide support provide support and protect the and protect the dorsal nerve corddorsal nerve cord..

B. The study of B. The study of fish is called fish is called

ichthyology.ichthyology.

C. Fish are C. Fish are adaptive for adaptive for living in water.living in water.

•SchoolSchool–fish have comfortable fish have comfortable swimming room.swimming room.

•PodPod–fish bodies touch as fish bodies touch as they swim.they swim.

•EctothermicEctothermic–cold-blooded.cold-blooded.

•Cannot control their body Cannot control their body temperature.temperature.

•EndothermicEndothermic–warm-blooded.warm-blooded.

•Maintain a constant body Maintain a constant body temperature.temperature.

1. have 1. have gillsgills for for breathing.breathing.

2. have 2. have paired fins & paired fins & streamlined shapestreamlined shape for easy movement.for easy movement.

3. have skin covered 3. have skin covered with scaleswith scales

4. Most have 4. Most have lateral lateral line systemline system

a. Lateral line a. Lateral line system is a row of system is a row of sensory structures sensory structures that run the length that run the length of the body on each of the body on each side.side.

b. Lateral line b. Lateral line system detects system detects vibrations & vibrations & chemicals in the chemicals in the water.water.

II. Three II. Three Classes of Classes of FishFish

A. A. Class Class Agnatha - Agnatha - Jawless FishJawless Fish

1. Examples1. Examples

a. Lampreya. Lamprey

1. parasites1. parasites

2. feed on blood2. feed on blood

3. locate prey 3. locate prey with sense of smellwith sense of smell

Lamprey

b. Hagfishb. Hagfish

1. 1. scavengersscavengers

2. feed on 2. feed on dead or dead or dying fishdying fish

2. Characteristics of 2. Characteristics of Class AgnathaClass Agnatha

a. mouth is a ringa. mouth is a ring

b. slimy skin with b. slimy skin with no no scales scales

c. Good sense of c. Good sense of smellsmell

d. some are parasitesd. some are parasites

e. some are e. some are scavengersscavengers

B. B. Class Class Chondrichthyes - Chondrichthyes - Cartilage FishCartilage Fish

1. Examples1. Examples

a. Sharksa. Sharks

b. Raysb. Rays

2. General 2. General Characteristics of Characteristics of Class Class ChondrichthyesChondrichthyes

a. skeleton made of a. skeleton made of cartilage not bonecartilage not bone

b. most are b. most are carnivores - meat carnivores - meat eaterseaters

c. skin is covered c. skin is covered with with placoid placoid scalesscales - tooth like - tooth like spines which make spines which make it feel like it feel like sandpapersandpaper

Hammerhead

3. Characteristics of 3. Characteristics of SharksSharks

a. upper portion of a. upper portion of tail is longer tail is longer

than than lower lower portion.portion.

b. has 6 to 20 rows b. has 6 to 20 rows of backward of backward pointing teeth pointing teeth which can be which can be replaced if worn replaced if worn down or brokendown or broken

Megalodon Teeth

c. sharp sense of c. sharp sense of smell- can detect smell- can detect blood in water up blood in water up to 500 meters to 500 meters (546 yards) away(546 yards) away

d. most must move d. most must move constantly to pass constantly to pass water over their water over their gills gills (NO swim bladder).(NO swim bladder).

e. eggs are fertilized e. eggs are fertilized internallyinternally..

1. Males have 1. Males have modified fins modified fins called called claspersclaspers that carry sperm that carry sperm through grooves through grooves into the female.into the female.

2. Most females 2. Most females give live births; give live births; others lay large others lay large yolky eggs.yolky eggs.

4. Characteristics 4. Characteristics of Raysof Rays

a. have flattened a. have flattened bodies with bodies with

wing-wing- like finslike fins

b. b. are bottom dwellersare bottom dwellers

c. feed on mollusks & c. feed on mollusks & crustaceanscrustaceans

d. have barbed stinger d. have barbed stinger on the end of its tail on the end of its tail for defensefor defense

Puffer Fish

C. C. Class Class OsteichthyesOsteichthyes

1. Examples1. Examples

a. percha. perch b. bassb. bass

c. troutc. trout d. d. tunatuna

Poisonous Lion Fish

2. About 95% of all 2. About 95% of all fish belong to this fish belong to this class.class.

3. Types of bony fish3. Types of bony fish

a. Lobe-finneda. Lobe-finned

1. have paddle like 1. have paddle like finsfins

2. Example - 2. Example - a.a. CoelacanthsCoelacanths

b. Lung Fishb. Lung Fish

1. have lungs & gills1. have lungs & gills

2. live in shallow 2. live in shallow tropical ponds that tropical ponds that dry up in summerdry up in summer

3. bury themselves 3. bury themselves in mud until in mud until

ponds ponds refillrefill

c. Ray - finnedc. Ray - finned

1. live in all waters1. live in all waters

2. most numerous 2. most numerous of all fishof all fish

FINS

•Dorsal-keeps upright.Dorsal-keeps upright.•Caudal- propels.Caudal- propels.•Pelvic- steers.Pelvic- steers.•Pectoral- steers.Pectoral- steers.•Anal- steers.Anal- steers.

•Raising and Raising and lowering the lowering the fins help fish fins help fish regulate body regulate body temperaturetemperature..

SWIM BLADDER

•a.k.a. gas bladdera.k.a. gas bladder–acts like a float as it fills acts like a float as it fills up with gas to go higher up with gas to go higher and lower in the water.and lower in the water.

–Lacking in cartilage fish.Lacking in cartilage fish.

External Adaptations•ChromatophoresChromatophores-- color pigments. color pigments.

•CountershadingCountershading-- dark on top;light dark on top;light on bottom.on bottom.

•OperculumOperculum-- shield over the gills. shield over the gills.

HEART (2 chambers)

•ATRIUMATRIUM–receives blood from receives blood from the body.the body.

•VENTRICLEVENTRICLE–pumps the blood.pumps the blood.

BRAIN•Cerebrum- instincts.Cerebrum- instincts.•Cerebellum- muscle coordination.Cerebellum- muscle coordination.•Olfactory-smell.Olfactory-smell.•Optic- sight.Optic- sight.•Medulla oblongata- internal Medulla oblongata- internal

organs.organs.

DIGESTIVE

•Liver- makes bile.Liver- makes bile.•Gall bladder- balloon-like Gall bladder- balloon-like

sac that stores bile.sac that stores bile.•Spleen- blood reservoir. Spleen- blood reservoir. •Pancreas- secretes insulin.Pancreas- secretes insulin.

REPRODUCTION

•SPAWNINGSPAWNING–process of laying eggs process of laying eggs by the female and by the female and releasing sperm (MILT) releasing sperm (MILT) over them by the male.over them by the male.

GoneFishing