Ammonia is generally excreted by diffusion across body surfaces or through gill surfaces as ammonium ions. Which of the following organisms primarily exhibits this mode of nitrogenous waste excretion?

Step-by-step solution

Ammonia is the most toxic form of nitrogenous waste and requires large amounts of water for its elimination. Organisms that excrete ammonia are called ammonotelic. Many bony fishes, aquatic amphibians, and aquatic insects are ammonotelic in nature. Ammonia, being readily soluble, is generally excreted by diffusion across body surfaces or through gill surfaces (in fishes) as ammonium ions. Among the given options: Catla is a bony fish and is ammonotelic. Scoliodon is a cartilaginous fish and is ureotelic. Testudo is