Question

Which of the following animals is called a ‘waterdog’?
A. Axolotl larva
B. Necturus
C. Petromyzon
D. Dog fish

Answer 1

Hint:-Water dogs are the animals which are used to retrieve game from water. They are classified as aquatic salamanders. Necturus are commonly known aquatic salamanders. They have waterproof coats which help them to swim.

Complete Answer:-
The gun dog bred which is used to flush and retrieve game from water is called a water dog. They are considered as the most modern retriever dog breeds.
Axolotl larva has typical features of salamander larvae. They are closely related to waterdogs. The larval stage of Axolotl is closely related to Tiger salamanders Ambystoma tigrinum. They are commonly found in North America. Petromyzon belongs to the group of fishes. These are also called Agnathans.
Dog fish is the most widely known Squalus acanthias. They are also called spiny dogfish, spurdog or skittle dog. It is mostly found in the northern Atlantic and Pacific coast.
The genus of aquatic salamanders includes Necturus. They are commonly called water dogs and mudpuppies. They are mostly found in the eastern United States and Canada. They have entirely aquatic lifestyle in the eastern part of North America in lakes, rivers and ponds.
From the above information we have found that Necturus are called waterdogs.
Thus, the right option is B.

Note:- The size of the waterdog is usually medium sized. They have tight waterproof coats and they have a strong desire to swim. That’s the reason they are used to retrieve. Their hindquarters and long coat around their torso prevent them from thermal shock when jumping into freezing water. Other breeds such as American water spaniel, Barbet, Cantabrian etc. are also considered as water dogs.