I Fishes Overview B 2 Chondrichthyes Cartilaginous fishes

I. Fishes - Overview B. 2. Chondrichthyes (Cartilaginous fishes) • • Rays and Skates Body dorsoventrally flattened Often live on/near bottom (demersal) Gill slits (five pairs) on ventral surface Pectoral fins flat and greatly expanded, often fused with head a. Stingrays • Whip like tail with hollow spine (poisonous) at base • Eat small animals, including mollusks, crustaceans and fishes b. Electric rays • Stun prey and defend against predators c. Swimming rays • Eagle, manta rays d. Skates • No whip-like tail • No stinging spines • Lay egg cases (rays bear live young)

Fig. 8. 7

I. Fishes - Overview B. Chondrichthyes (Cartilaginous fishes) 3. Ratfishes • • • Fig. 8. 7 Most common in deep water Single pair of gill slits Feed on benthic crustaceans and mollusks

I. Fishes - Overview C. Osteichthyes (Bony fishes) • • • About 26, 000 species Skeleton made of bone Cycloid (round, smooth) or ctenoid (spiny) scales made of bone • • • Thin, flexible, overlap Bony operculum covers gill chamber on each side Caudal fin usually homocercal (vs. heterocercal in sharks) Fins composed of fin rays connected by thin membranes Mouth typically terminal • • Jaws have more freedom of movement than in sharks Swim bladder to regulate buoyancy • Helps to compensate for dense bony skeleton

Fig. 8. 8

II. Fishes - Biology A. • 1. 2. 3. 4. 5. Body Shape • • • Strongly related to lifestyle Fusiform, streamlined Sustained high speed (up to 50+ mph) Ex – Tunas, mackerels, marlins Laterally compressed Slow cruising, occasional burst swimming Ex – Snappers, wrasses, butterflyfishes Flattened Sedentary, often demersal Ex – Flatfishes (flounders, halibuts, soles), sea robins Elongate, eel-like Cryptic, living in tunnels, crevices Ex – Moray eels, pipefishes, trumpetfishes Unusual, irregular Often with camouflage color/pattern Ex – Sargassum fishes, seahorses, trunkfishes, stonefishes

Fig. 8. 9

II. Fishes - Biology A. • 1. 2. 3. 4. 5. Body Shape • • • Strongly related to lifestyle Fusiform, streamlined Sustained high speed (up to 50+ mph) Ex – Tunas, mackerels, marlins Laterally compressed Slow cruising, occasional burst swimming Ex – Snappers, wrasses, butterflyfishes Flattened Sedentary, often demersal Ex – Flatfishes (flounders, halibuts, soles), sea robins Elongate, eel-like Cryptic, living in tunnels, crevices Ex – Moray eels, pipefishes, trumpetfishes Unusual, irregular Often with camouflage color/pattern Ex – Sargassum fishes, seahorses, trunkfishes, stonefishes

Fusiform Video Ch. 15, p. 326

II. Fishes - Biology A. • 1. 2. 3. 4. 5. Body Shape • • • Strongly related to lifestyle Fusiform, streamlined Sustained high speed (up to 50+ mph) Ex – Tunas, mackerels, marlins Laterally compressed Slow cruising, occasional burst swimming Ex – Snappers, wrasses, butterflyfishes Flattened Sedentary, often demersal Ex – Flatfishes (flounders, halibuts, soles), sea robins Elongate, eel-like Cryptic, living in tunnels, crevices Ex – Moray eels, pipefishes, trumpetfishes Unusual, irregular Often with camouflage color/pattern Ex – Sargassum fishes, seahorses, trunkfishes, stonefishes

Laterally Compressed Video

II. Fishes - Biology A. • 1. 2. 3. 4. 5. Body Shape • • • Strongly related to lifestyle Fusiform, streamlined Sustained high speed (up to 50+ mph) Ex – Tunas, mackerels, marlins Laterally compressed Slow cruising, occasional burst swimming Ex – Snappers, wrasses, butterflyfishes Flattened Sedentary, often demersal Ex – Flatfishes (flounders, halibuts, soles), sea robins Elongate, eel-like Cryptic, living in tunnels, crevices Ex – Moray eels, pipefishes, trumpetfishes Unusual, irregular Often with camouflage color/pattern Ex – Sargassum fishes, seahorses, trunkfishes, stonefishes

Flattened Hilburt

II. Fishes - Biology A. • 1. 2. 3. 4. 5. Body Shape • • • Strongly related to lifestyle Fusiform, streamlined Sustained high speed (up to 50+ mph) Ex – Tunas, mackerels, marlins Laterally compressed Slow cruising, occasional burst swimming Ex – Snappers, wrasses, butterflyfishes Flattened Sedentary, often demersal Ex – Flatfishes (flounders, halibuts, soles), sea robins Elongate, eel-like Cryptic, living in tunnels, crevices Ex – Moray eels, pipefishes, trumpetfishes Unusual, irregular Often with camouflage color/pattern Ex – Sargassum fishes, seahorses, trunkfishes, stonefishes

Elongate Video

II. Fishes - Biology A. • 1. 2. 3. 4. 5. Body Shape • • • Strongly related to lifestyle Fusiform, streamlined Sustained high speed (up to 50+ mph) Ex – Tunas, mackerels, marlins Laterally compressed Slow cruising, occasional burst swimming Ex – Snappers, wrasses, butterflyfishes Flattened Sedentary, often demersal Ex – Flatfishes (flounders, halibuts, soles), sea robins Elongate, eel-like Cryptic, living in tunnels, crevices Ex – Moray eels, pipefishes, trumpetfishes Unusual, irregular Often with camouflage color/pattern Ex – Sargassum fishes, seahorses, trunkfishes, stonefishes

Irregular Video