I. I.Fishes – Overview B. B.Chondrichthyes (Cartilaginous fishes) 1. 1.Sharks Fusiform body Heterocercal tail Typically two dorsal fins Pectoral fins usually large and pointed Five to seven gill slits Most sharks swim continuously to ventilate gills Whale shark = Largest fish species (to 14+ m) Planktivorous (zooplanktivorous) – How? Most prevalent in tropical coastal waters Reproduction Internal fertilization (claspers) Viviparous Ovoviviparous Oviparous

Swell shark Horn shark Egg Cases Fig Claspers

I. I.Fishes – Overview B. B.Chondrichthyes (Cartilaginous fishes) 2. 2.Rays and Skates Body dorsoventrally flattened Often live on/near bottom (demersal) Dorsal spiracles, gill slits (five pairs) on ventral surface Pectoral fins flat and greatly expanded, often fused with head; no anal fin a. a.Stingrays Whip like tail with hollow spine (poisonous) at base Eat small animals, including mollusks, crustaceans and fishes b. b.Electric rays Stun prey and defend against predators c. c.Swimming rays (pectoral propulsion) Eagle, manta rays d. d.Skates No whip-like tail No stinging spines Lay egg cases - mermaid’s purse (rays bear live young) e. e.Sawfishes, guitarfishes Euryhaline Feed on benthic invertebrates Electroreceptors in “saw”

SawfishGuitarfish

I. I.Fishes – Overview B. B.Chondrichthyes (Cartilaginous fishes) 3. 3.Chimaeras Upper jaw attached to skull (unlike other cartilaginous fishes) Single pair of gill slits covered by operculum Most common in deep water Feed on benthic crustaceans, mollusks, fishes Bony plates; no teeth No cloaca Fig

I. I.Fishes – Overview C. C.Sarcopterygii (Lobefins) Coelacanths (marine) and lungfishes (freshwater) Pelvic & pectoral fins w/thick muscle around rod-shaped bone; similar to tetrapods Primitive; coelacanths thought to be extinct until early 20 th century Coelacanths Two extant spp. Only in deep water Ovoviviparous Lungfish

I. I.Fishes – Overview D. D.Actinopterygii/Osteichthyes (Bony fishes) More than 26,000 species Skeleton made of bone Ganoid (thick, rigid), Cycloid (round, smooth) or ctenoid (spiny) scales made of bone Cycloid, ctenoid: 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 Fig

Fig

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

Fig

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

Fusiform Video

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

Laterally Compressed Video

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

Flattened Halibut

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

Irregular Video

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

Elongate Eel Pipefish