Epinephelus merra, commonly called Honeycomb grouper, is a species of marine fish in the family Serranidae. The Honeycomb grouper is widespread throughout the tropical waters of the Indo-Pacific but is not present in the Red Sea and the Persian gulf. It is one of the smaller fish species in the Epinephelus genus, with a maximum known length of 32 centimetres (13 in). The genus Epinephelus has the ability to change sexes, more specifically they are protogynous hermaphrodites what means females can turn into males at one point in their life. This sex change usually happens in the non breeding season and can be caused by social stimuli, age, growth, and body size. Females turn into males when they reach a length of approximately 20 cm, thus the size advantage model for sequential hermaphroditism applies in the case of the honeycomb grouper. The size advantage model states that if an individual can reproduce more effectively as one sex when small or young and as the other sex when larger or older, it should change sex at some point in its life history