FISH
Jan 02, 2016
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