Number of barbels in Heteroneustes fossilis:

Correct option is D

Correct Answer: (d) 4 pair
Explanation:
→ Heteropneustes fossilis (stinging catfish) possesses eight barbels = 4 pairs (maxillary + several mandibular and nasal pairs), characteristic of the species.
→ Barbels are sensory organs aiding in foraging in turbid waters.
Information Booster:
→ High barbel count helps benthic feeding and detection of food in low-visibility habitats.
Additional Information (Other Options):
(a–c) Underestimate the species’ barbel morphology.