FISH

Phylum ChordataVertebrates

Animals which have a spinal cord protected by a backbone

Fish, amphibians, reptiles, birds & mammals

Internal skeletons

The fishLive in water

Gills for gas exchange

Fins for locomotion

Skeleton made of cartilage or bone

Most are covered by scales

Cold-blooded – body temp. depends on environment

3 classes of fish

1. Jawless fish - agnatha

Oldest group – very primitive

Scale-less skin

Some Parasitic / some filter feed

Circular mouth with fleshy teeth

Cartilaginous skeleton

Hagfish & lamprey

Circular mouth

Gill slits

3 classes of fish

2. cartilaginous fish condrichthyes

Skeleton made of cartilage

Sharks, rays, skates

All are predatory except 4 species!

The 4 exceptions are filter feeders

Whale sharks – warm shallow water

THE LARGEST FISH IN THE SEA!!!

The 4 exceptions are filter feeders

Basking sharks – cold shallow water

THE SECOND LARGEST FISH IN THE SEA!!!

The 4 exceptions are filter feeders

megamouth shark – cold deep water

The 4 exceptions are filter feeders

manta ray– shallow warm water

3 classes of fish

3. bony fish - osteichthyes

Skeleton of bone

Most numerous of fish species

Greatest diversity in shape and feeding habits

Body forms of fishes1. fusiform

Sharks, tuna, bluefish

Streamlined, torpedo shaped

Fast long distance swimmers

Open water predators

Body forms of fishes2. compressed

Perch, butterfly fish, angelfish

Flattened laterally

Quick bursts of speed - short distance

Easily move in tight spaces

Body forms of fishes

3. depressed

Flounder, fluke, stingray

Dorso-ventrally flattened

Live on the bottom

Eyes on top of body

Body forms of fishes

4. attenuated

Eels, lamprey, pipefish

Elongated, tubular shape

Many Live in holes / burrows

Many secrete heavy mucus

Body parts of fishGet ready to draw a fish!!!

1. Caudal fin - tail fin

Used for forward motion and acceleration

2. Dorsal fin & 3. Anal fin

Singular finsUsed to prevent rolling/tipping

4. pectoral fin &

5. pelvic fin

paired fins (left & right)

Used to balance, stop & turn

6. Spines Used for protection

Some contain poison sacs

7. operculum Covers & protects gillsNot found in sharks

8. Lateral line Sensory canals used to detect changes in water pressure around the fish (similar to human ear)

COMPARISON OF CARTILAGINOUS & BONY FISHES

TRAIT CARTILAGINOUS BONY_____

EXAMPLESSHARKS, RAYS, SKATES

TUNA, COD, SALMON,

SKELETON CARTILAGE BONE

SWIM BLADDER

ABSENT – OILY LIVER PROVIDES BUOYANCY

PRESENT – AIR FILLED FOR BUOYANCY

COMPARISON OF CARTILAGINOUS & BONY FISHES

TRAIT CARTILAGINOUS BONY_____

FERTILIZATION

INTERNAL – HAVE FEW LARGE YOUNG IN LIFE TIME

EXTERNAL – LAY MILLIONS OF SMALL EGGS

SCALES PLACOID – SPINY EMBEDDED IN SKIN

GANOID – PLATELIKE CTENOID & CYCLOID ARE FLAT, FLEXIBLE, OVERLAP

COMPARISON OF CARTILAGINOUS & BONY FISHES

TRAIT CARTILAGINOUS BONY_____ GILLS NO OPERCULUM

HAVE GILLS SLITS

HAVE OPERCULUM COVER & PROTECT GILLS

FEEDING BEHAVIOR

ALL PREDATORS FOUR EXCEPTIONS

GREAT VARIATION IN FOOD SOURCES

FINS RIGID AND UNSEGMENTED

FLEXIBLE AND SEGMENTED

TEETH NOT FUSED TO JAW -REPLACEABLE

FUSED TO JAW - IRREPLACEABLE