Big eyes are the diagnostic characters of the family:

Correct option is A

Correct Answer: (a) Priacanthidae
Explanation:
→ Priacanthidae (big-eye fishes) are characterized by disproportionately large eyes adapted for dim-light environments.
→ Usually deep-red in color and inhabit deeper reef areas.
→ Enlarged eyes enhance vision in low-light habitats.
Information Booster:
→ Commonly called catalufas or bigeyes.
→ Nocturnal predators feeding on crustaceans & small fishes.
→ Occur in tropical/subtropical waters.
Additional Information (Other Options):
(b) Trichiuridae – ribbonfishes.
(c) Scomberidae – mackerels/tunas.
(d) Rachycentridae – cobia.