Which of the following is not a bony fish ? A Labeo rohita B Anabas C Hippocampus D Chimera

To determine which of the options is not a bony fish, we need to understand what a bony fish is. Bony fish, also known as osteichthyes, are a group of fish that have skeletons made of bone. They are the most common type of fish and include familiar species such as trout, salmon, and goldfish.

Now, let's analyze each option:

A) Labeo rohita: Labeo rohita, also known as the Rohu, is a species of fish that belongs to the carp family. Carp are indeed bony fish, so option A is a bony fish.

B) Anabas: Anabas, also known as the climbing perch, is a species of fish that can breathe air and survive in oxygen-depleted waters. It belongs to the family Anabantidae, which includes labyrinth fish. Labyrinth fish are also bony fish, so option B is a bony fish.

C) Hippocampus: Hippocampus, commonly known as seahorses, are a group of fish that have a unique appearance with their horse-like heads and curled tails. Despite their unique characteristics, seahorses are still bony fish, so option C is a bony fish.

D) Chimera: Chimera, also known as ghost sharks or ratfish, are a group of cartilaginous fish. Unlike bony fish, cartilaginous fish have skeletons made of cartilage instead of bone. Therefore, option D, Chimera, is not a bony fish.

In conclusion, the correct answer is option D, Chimera, as it is not a bony fish.