Question

Scoliodon is also called
A. Dog fish
B. Cuttlefish
C. Jellyfish
D. Whale fish

Answer 1

Hint: The gill bearing aquatic animals are called as Fish. They lack limbs with digits. Most fish are ectothermic. Fish are the source of food for humans. Most fish exchange gases using gills. The jaw of fish helps them to eat a wide variety of food. The fish excretes nitrogenous wastes as ammonia.

Complete Answer:
- Scoliodon has a spindle shaped body tapered at the ends. The body is made of exoskeleton of placoid scales. The mouth is bound on both sides by jaws.
- Scoliodon has unpaired and paired fins. Scoliodon has an alimentary canal and digestive glands.
- The scoliodon is also known as dog fish because of its highly developed sense of smell like a dog. The smell helps it to find food.
- The scoliodon is found in Srilanka, Bay of Bengal, eastern pacific and eastern coasts of south America. The longitudinal muscle fibres and fins help in locomotion.
- The coelom of the scoliodon is divided into pericardial and abdominal cavity. The heart of Scoliodon is a bent muscular tube between the two series of gill pouches.
- The central nervous system consists of the brain and spinal cord. The brain of dog fish is highly organised. The olfactory sense organs are well developed in scoliodon.

So the correct answer is Dog fish.

Note: The Cuttlefish is the common name for Sepiida. They are marine molluscs. Jelly fish are free swimming marine animals. Jelly fish is a name given to the medusa phase of some members of phylum Cnidaria.