Chondrichthyes General Characteristics and Examples | Free Biology Notes

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Chondrichthyes General Characteristics

• These are all marine and cartilaginous fishes
• Skin covered with minute placoid scales
• Mouth and nostrils ventral
• Five to seven pairs of gill slits present but not covered with operculum. Except in the chimaeras
• Lungs or air bladder absent in these fishes
• Spiral valves present in intestine
• Paired fins are broad. The caudal fin is mostly heterocercal
• Males with claspers, fertilization is internal.
• They are oviparous or ovoviviparous

Chondrichthyes Examples

Chimaera

• It is commonly called rabbit fish, rat fish or ghost fish
• Its connecting link between cartilaginous fish and bony fishes
• Cartilaginous fish characters – Cartilage skeleton, Claspers and placoid scales
• bony fishes characters – Operculum, distinct anus and urogenital aperture.

Scoliodon

• It is commonly called dog fish or Indian shark
• Ampulla of lorenzini help to receives information of temperature fluctuations in water
• Heterocercal tail is present
• The claspers help in the copulation
• It is ovoviviparous
• Liver oil get from this fish

Torpedo

• It is commonly called electric ray
• They are bottom living fish
• A pair of electric organs are situated on the dorsal side of trunk
• Both pectoral fins are fused with trunk

Trygon

• It is commonly called sting ray
• It is resembles the electric ray in many aspects but don’t have eclectic organs
• The tail bearing a spine.
• the spine makes a severe wound on the victim