Question

Question 10

  Which of the following is not the characteristic feature of class Chondrichthyes

 A

They have cartilaginous endoskeleton

 B

Skin is tough, containing minute cycloid scales

 C

Air bladder is absent

 D

Some of them have electric organs and poison sting.

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Answer 1

Answer:

Which of the following is not the characteristic feature of class Chondrichthyes.

Explanation:

your answer is :-

B) Skin is tough, containing minute cycloid scales.

Answer 2

Skin is tough, containing minute cycloid scales is the characteristic feature among the following that is not found in Chondrichthyes.(option - b)

Chondrichthyes are cartilaginous fishes consisting of a cartilaginous endoskeleton belonging to Phylum Chordata and subphylum Vertebrata.

Some of the characteristic features of cartilaginous fishes are as follows:-

• The skin of cartilaginous fishes is smooth and consists of small placoid scales, not cycloid scales.
• These do not consist of an air bladder and hence swim continuously to prevent sinking or drowning and can swim for a longer period underwater.
• They have a ventral mouth.
• They are filter-feeders -- feed on small fishes, mollusks, and crustaceans(predators)and have a 2 chambered heart.
• examples are Shark, Trygon - stingray, which has a poison sting, Torpedo - Electric ray, which has electric organs.
• Cycloid scales are mostly found in bony fishes or Osteioicthyes i.e consisting of a bony endoskeleton such as carps, Herring, etc.