Aquatic Animals | MCQs

Explanation

Sharks, along with other cartilaginous fish-like rays, retain urea in their bodies as part of their osmoregulatory strategy.

This helps them maintain osmotic balance in marine environments by making their internal body fluids isotonic with the surrounding seawater. 

Explanation

A cephalopod is any member of the molluscan class Cephalopoda such as a squid, octopus, cuttlefish, or nautilus.

Class: Cephalopoda; Cuvier, 1797

Scientific name: Cephalopoda

Domain: Eukaryota

Kingdom: Animalia

Explanation

Seahorse is a true fish; it has gills, fins, and lives in water.

Jellyfish, cuttlefish, and starfish are not true fish despite their names.

Explanation

Amphibians can live both in water and on land (e.g., frogs, salamanders).

They typically begin life in water and later adapt to live on land.

Explanation

Aquatic animals may breathe air or extract oxygen that dissolved in water through specialized organs called gills, or directly through the skin.

Explanation

Aquatic arthropods like crabs, prawns, and some aquatic insects use gills to extract oxygen from water.

Gills provide a large surface area for gas exchange in an aquatic environment.

Explanation

Explanation

Fishes have only two chambers of the heart

01. Atrium

02. Ventricle