Chapter 25: Fishes 1

Jawless Fishes (Agnatha) Cartilaginous Fishes (Chondrichthyes) Bony Fishes (Osteichthyes) Lamprey Whale shark Scorpion fish 3

Gills Single-loop Blood Circulation Vertebral column (backbone) Boxfish Pygmy seahorse 4

Organs used breathing Used oxygen that is dissolved in water Large surface area Why do fish always open their mouths? Countercurrent flow 5

Countercurrent flow Water passes over gills one direction Blood flows through capillaries in opposite direction Gills can extract upto 85% of oxygen from the water 6

Simple chamber-pump system 1. Sinus venosus Collection area Reduces blood flow resistance 2. Atrium Thin walled chamber Collection 3. Ventricle Thick walled primary pump 4. Conus arteriosus Smooth pulses secondary pump 7

2 chambered heart Evolutionary advantage : chamber that pumps oxygenated blood through a single loop! 8

How can they have problems with water loss? They live in water! Marine Fish Salt ion concentration 3x greater in water Fish loses water via osmosis Drink sea water and pump out excess ions Freshwater Fish Salt ion is greater in body Fish gains water by osmosis 9

Nephrons Regulate salt and water balance Removed via urine Marine Fish excrete small amounts concentrated Freshwater Fish excrete large amounts dilute 10

Most Fish Separate sexes Spawn Large number of eggs Sharks, Skates & Rays are different Have live young Males use claspers to inject sperm into the female Trout Spawning (1 min) Shark Mating Video (4 min) Mouth Brooders (3 min) 11

Primitive Lampreys & Hagfishes Scaleless, eel-like bodies Multiple gills Unpaired fins Skeletons of cartilage and connective tissue Notochord in all stages of life Hagfish Lamprey 12

Hagfish vultures of the sea Produce large amounts of slime when threatened Live on ocean floor Not well understood 13

Parasitic on other fish Suction cup-like structure with raspy teeth Feeds on blood and flesh Marine and freshwater All reproduce in freshwater 14

Stingray Sharks, rays, and skates Basking Shark Light and strong skeletons made of cartilage Layer of calcium carbonate for strengthening Skates Manta Ray 21

Light, streamlined body Cone-shaped placoid scale 6-10 rows of serrated teeth (teeth are modified scales) 20,000 replaced in a lifetime NO swim bladder Spotted Wobbegong Shark Great White Shark Leopard Shark 22

Lesser Electric Ray Mega Ray Clip Flat bodies Live primarily of sea floor Rosette River Stingray Flattened teeth to eat fish and invertebrates Little Skate Thornback Skate 23

Most numerous of all fishes Internal skeleton made completely of bone Unique Structural Adaptations 1. Lateral line system 2. Gill cover (operculum) 3. Swim bladder Leafy Sea Dragon Frogfish Luring Clip Mandarin 24

Sensory system that extends along fish s body Detects vibrations and sends info to the brain Nerve impulses from ciliated sensory cells Similar to human ears 25

Hard plate which protects gills Moves muscles and opercula to draw water over gills while stationary Conserves energy 26

Special gas sac to regulate buoyancy in fish When the gas sac fills, a fish will? When swim bladder empties, the fish will? Puffer fish clip Gas is exchanged between the bloodstream and swim bladder 27

Bluegill Two Groups 1. Ray Finned 2. Lobe-finned Triggerfish Australian Lungfish 28

Fins are supported by bony structures called rays. Teleosts (like the perch) Most advanced of ray-finned fishes Highly mobile fins Thin scales Symmetrical tails 95% of all fish species 29

Nares (nostrils) Operculum (Gill covering) Spiny Dorsal Fin Soft Dorsal fin Caudal fin Eye mouth Peduncle Pectoral fin Pelvic fin Scales Anus Anal fin Lateral Line 30

Lateral Line 31

Only 7 species 6 species are lungfishes 1 species is a Coelacanth Physical Characteristics: Paired fins Long, fleshy, muscular lobe supported by joints Bony rays at tips of each lobed fin 32

Pipefish Needlefish Crappie Tuna Flounder 33

Which fish accelerates faster based upon morphology? Why do catfish have an extra fin? 36

Black Crappie Yellow Perch Bluegill 37

Largemouth Bass Northern Pike Black Bullhead 38

Walleye Muskellunge Round Goby 39

Lake Sturgeon Paddlefish White Sucker 40

Brook Stickleback Rainbow Trout Smallmouth Bass 41

Basic Arrangement of all vertebrates Mouth Esophagus Stomach Short Intestine Liver secretes bile & pancreas secretes enzymes into short intestine Food is broken down and absorbed through intestine lining Undigested material exits through the anus 43

Scales Ootilith bone (ear bone) Spine 45