I.Fishes - Overview B.Chondrichthyes (Cartilaginous fishes) 2.Rays and Skates Body dorsoventrally flattenedBody dorsoventrally flattened Often live on/near

I.I. Fishes - OverviewFishes - Overview

B.B. Chondrichthyes (Cartilaginous fishes)Chondrichthyes (Cartilaginous fishes)2.2. Rays and SkatesRays and Skates

• Body dorsoventrally flattenedBody dorsoventrally flattened• Often live on/near bottom (Often live on/near bottom (demersaldemersal))• Gill slits (five pairs) on ventral surfaceGill slits (five pairs) on ventral surface• Pectoral fins flat and greatly expanded, often fused Pectoral fins flat and greatly expanded, often fused

with headwith heada.a. StingraysStingrays• Whip like tail with hollow spine (poisonous) at Whip like tail with hollow spine (poisonous) at

basebase• Eat small animals, including mollusks, Eat small animals, including mollusks,

crustaceans and fishescrustaceans and fishesb.b. Electric raysElectric rays• Stun prey and defend against predatorsStun prey and defend against predatorsc.c. Swimming raysSwimming rays• Eagle, manta raysEagle, manta raysd.d. SkatesSkates• No whip-like tailNo whip-like tail• No stinging spinesNo stinging spines• Lay egg cases (rays bear live young)Lay egg cases (rays bear live young)

Fig. 8.7


B.B. Chondrichthyes (Cartilaginous fishes)Chondrichthyes (Cartilaginous fishes)3.3. RatfishesRatfishes

• Most common in deep waterMost common in deep water• Single pair of gill slitsSingle pair of gill slits• Feed on benthic crustaceans and mollusksFeed on benthic crustaceans and mollusks

Fig. 8.7


C.C. Osteichthyes (Bony fishes)Osteichthyes (Bony fishes)• About 26,000 speciesAbout 26,000 species• Skeleton made of boneSkeleton made of bone• CycloidCycloid (round, smooth) or (round, smooth) or ctenoidctenoid (spiny) scales (spiny) scales

made of bonemade of bone• Thin, flexible, overlapThin, flexible, overlap

• Bony operculum covers gill chamber on each sideBony operculum covers gill chamber on each side• Caudal fin usually Caudal fin usually homocercalhomocercal (vs. (vs. heterocercalheterocercal in in

sharks)sharks)• Fins composed of fin rays connected by thin Fins composed of fin rays connected by thin

membranesmembranes• Mouth typically terminalMouth typically terminal

• Jaws have more freedom of movement than in sharksJaws have more freedom of movement than in sharks• Swim bladder to regulate buoyancySwim bladder to regulate buoyancy

• Helps to compensate for dense bony skeletonHelps to compensate for dense bony skeleton

Fig. 8.8

II.II. Fishes - BiologyFishes - Biology

A.A. Body ShapeBody Shape• Strongly related to lifestyleStrongly related to lifestyle1.1. Fusiform, streamlinedFusiform, streamlined

• Sustained high speed (up to 50+ mph)Sustained high speed (up to 50+ mph)• ExEx – Tunas, mackerels, marlins – Tunas, mackerels, marlins

2.2. Laterally compressedLaterally compressed• Slow cruising, occasional burst swimmingSlow cruising, occasional burst swimming• ExEx – Snappers, wrasses, butterflyfishes – Snappers, wrasses, butterflyfishes

3.3. FlattenedFlattened• Sedentary, often demersalSedentary, often demersal• ExEx – Flatfishes (flounders, halibuts, soles), sea robins – Flatfishes (flounders, halibuts, soles), sea robins

4.4. Elongate, eel-likeElongate, eel-like• Cryptic, living in tunnels, crevicesCryptic, living in tunnels, crevices• Ex Ex – Moray eels, pipefishes, trumpetfishes– Moray eels, pipefishes, trumpetfishes

5.5. Unusual, irregularUnusual, irregular• Often with camouflage color/patternOften with camouflage color/pattern• ExEx – Sargassum fishes, seahorses, trunkfishes, – Sargassum fishes, seahorses, trunkfishes,

stonefishesstonefishes

Fig. 8.9



• Sustained high speed (up to 50+ mph)Sustained high speed (up to 50+ mph)• ExEx – Tunas, mackerels, marlins – Tunas, mackerels, marlins

2.2. Laterally compressedLaterally compressed• Slow cruising, occasional burst swimmingSlow cruising, occasional burst swimming• Ex – Snappers, wrasses, butterflyfishesEx – Snappers, wrasses, butterflyfishes

3.3. FlattenedFlattened• Sedentary, often demersalSedentary, often demersal• Ex – Flatfishes (flounders, halibuts, soles), sea robinsEx – Flatfishes (flounders, halibuts, soles), sea robins

4.4. Elongate, eel-likeElongate, eel-like• Cryptic, living in tunnels, crevicesCryptic, living in tunnels, crevices• Ex – Moray eels, pipefishes, trumpetfishesEx – Moray eels, pipefishes, trumpetfishes

5.5. Unusual, irregularUnusual, irregular• Often with camouflage color/patternOften with camouflage color/pattern• Ex – Sargassum fishes, seahorses, trunkfishes, Ex – Sargassum fishes, seahorses, trunkfishes,


Ch. 15, p. 326

Fusiform

Video



• Sustained high speed (up to 50+ mph)Sustained high speed (up to 50+ mph)• Ex – Tunas, mackerels, marlinsEx – Tunas, mackerels, marlins

2.2. Laterally compressedLaterally compressed• Slow cruising, occasional burst swimmingSlow cruising, occasional burst swimming• ExEx – Snappers, wrasses, butterflyfishes – Snappers, wrasses, butterflyfishes





Laterally CompressedVideo





3.3. FlattenedFlattened• Sedentary, often demersalSedentary, often demersal• ExEx – Flatfishes (flounders, halibuts, soles), sea robins – Flatfishes (flounders, halibuts, soles), sea robins




FlattenedHilburt






4.4. Elongate, eel-likeElongate, eel-like• Cryptic, living in tunnels, crevicesCryptic, living in tunnels, crevices• Ex Ex – Moray eels, pipefishes, trumpetfishes– Moray eels, pipefishes, trumpetfishes



ElongateVideo







5.5. Unusual, irregularUnusual, irregular• Often with camouflage color/patternOften with camouflage color/pattern• ExEx – Sargassum fishes, seahorses, trunkfishes, – Sargassum fishes, seahorses, trunkfishes,


Irregular

Video

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I.Fishes - Overview B.Chondrichthyes (Cartilaginous fishes) 2.Rays and Skates Body dorsoventrally flattenedBody dorsoventrally flattened Often live on/near