Distinctive Characters: Dorsal fin with 11 spines and 15-17 rays. Anal fin with 3 spines and 8 rays. Pectoral fin with 16-18 rays. Body depth 2.8-3.3 in standard length. Body oblong, somewhat compressed. Maxillary extending behind the hind border of eye. Pectoral fin shorter than head. First dorsal spine shorter than others, dorsal rays longer than dorsal spines. Caudal fin rounded.
Colour: Body, head and all fins with dark brown spots, with narrow pale inter-space. Dots on fins and lower sides of body more widely spread. Pectoral fin covered with small black spots that are largely confined to the rays; outer half of the fin dark.
Habitat and Biology: A shallow water coral reef species typically found on patch reefs in lagoons usually at depths of less than 20 m. Feeds primarily on crustaceans (crabs and shrimps) but also fishes.
Remarks: Epinephelus merra is the most common grouper on protected shallow lagoon reefs. It is also one of the “reticulated groupers�?, which comprise 9 shallow water coral reef species that have a rounded caudal fin and a close-set dark brown spots with pale interspaces forming a network on the body. However, E. merra can be distinguished from others by its pectoral fin pattern.