Question

Marine teleost fishes excrete
A. Uric acid
B. Ammonia
C. Urea
D. None of these.

Answer 1

Hint: The nitrogenous waste is excreted in three forms - ammonia, uric acid, and urea. They are known as ammonotelic, uricotelic, and ureotelic in nature respectively. Most marine vertebrates are uricotelic i.e. they excrete urea.

Complete answer:
Uric acid is excreted by arthropods like terrestrial insects, reptiles, birds, etc. The term guanine is also used in place of uric acid. These are uricotelic in nature and they convert the toxic nitrogenous compounds into uric acid.
Ammonia is excreted by most of the invertebrate marine fishes. They are ammonotelic in nature. The aquatic invertebrates and cephalopods are examples of this kind of excretion.
Urea is excreted by ureotelic animals. This includes most of the marine fishes which are vertebrates. As teleost fishes are found in most of the aquatic habitat. They are adaptive to different aquatic conditions. They excrete urea to give up the nitrogenous waste. They are vertebrates. Many amphibians also excrete urea. Urea is highly soluble in water. It is also colourless.

Hence, the correct answer is option (C).

Note: Most of the Invertebrate fish are ammonotelic in nature. Uricotelic animals are terrestrial animals.
-Human is also an example of a uricotelic animal.
-Most of the Vertebrate fish are ureotelic in nature.
-Marine teleost fish are very adaptive to different aquatic conditions and are vastly found in nature.
-Teleost fish are vertebrate fish.