Question

Why cartilagenous fishes in hypertonic conditions accumulate urea inside the body?

Answer 1

marine fishes excrete urea,,,but not ammonia as the nitrogenous wastesthe body fluid in these marine fishes are to maintained hypertonic to the sea water

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Answer 2

• Cartilagenous fishes has organic compound called urea inside their body to make the environment stable i.e isotonic as the environment outside the body of fishes is hypertonic.
• This does not means that their body has huge of urea and their blood composition is similar to that of sea water but they have the ability to accumulate the urea in their body to maintain the isotonicity with the sea water animals screating urea are called ureotelic animals.
• These animals or we can say cartilagenous fishes have a special gland called rectal gland to secrete salt and this gland helps in osmoregulation.