Q. With reference to ‘Cat Fish’ consider the following statements:
1.They are one of the smallest groups of fishes found in the sea-water.
2.Most species of catfish are nocturnal.
3.Catfish are primarily benthic.
Which of the statements given above are correct?
Answer: B
Notes:
Statement 1 is incorrect. Catfish represent one of the largest groups of freshwater fishes.
Statement 2 and 3 are correct. Most species of catfish are nocturnal. Catfish are primarily benthic or bottom-dwellers.
Source: ForumIAS

