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Cartilaginous
fishes (Chondricthyes)
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Bony fishes
(Osteichthyes)
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1.
Exclusively marine.
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Marine
& fresh water.
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2.
Heterocercal caudal fin.
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Homocercal caudal fin.
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3.
Cartilaginous endoskeleton.
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Bony endoskeleton
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4.
Gill slits without operculum.
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4
pairs of gills covered by an operculum on each side.
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5.
Crescent (half moon) shaped
ventral mouth
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Terminal
mouth
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6.
Skin with placoid
scales. Teeth are modified placoid scales which are backwardly directed.
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Scales are Cycloid,
ctenoid etc.
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7.
No air bladder so they have to swim constantly
to avoid sinking.
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Air bladder for buoyancy
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8.
Sexes are separate. In males pelvic fins bear claspers.
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Sexes
are separate. No claspers
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9.
Internal fertilization.
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Fertilisation
external
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10.
Many of them viviparous
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Mostly oviparous
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11.
E.g. Scoliodon
(Dog fish), Pristis (Saw fish), Carcharodon (Great white shark), Trygon (Sting ray), Torpedo (Electric ray)
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E.g.
Marine
fishes: Exocoetus (flying fish), Hippocampus (sea horse), Sardine, Mackeral, Tuna, Remora (sucker
fish), Pomfret, Cybium
Fresh water
fishes: Labeo (Rohu), Catla (Katla), Clarias (Magur), Tilapia,
Anabas (Climbing
perch)
Aquarium
fishes:
Betta (Fighting fish), Pterophyllum (Angel fish) etc.
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Really helpful
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