Honeycomb grouper Epinephelus merra

Honeycomb Grouper – Facts and Photographs

Honeycomb Grouper 1

The Honeycomb grouper Epinephelus merra is also known as the Dwarf-spotted Grouper, the Honeycomb Rock Cod and the Wire-netted Rock Cod. They are one of the eight species of reticulated groupers that live on coral reefs. They are not as common as some of the other smaller groupers in Tanzanian waters, perhaps because of overfishing. It can be fairly difficult to distinguish the reticulated groupers due to their ability to lighten and darken their colors.


The Honeycomb grouper has a fairly typical grouper shape perhaps not quite as robust as other groupers with the body being proportionally slightly slimmer. It’s typical coloration is a light brown body with a large number of darker brown blotches which on some specimens more than others forms a distinctive  honeycomb pattern.  They grow up to 26 cm in length. The males are slightly larger than the females.

 Honeycomb grouper Epinephelus merra 2


The Honeycomb grouper is very shy in the Tanzanian coastal waters and as a rule tends to head for cover at the first sign of a diver. This is undoubtedly due to the practice dynamite fishing now fortunatey stopped as of 2017. On the offshore islands of Mafia and Zanzibar they are not as shy. They are almost always found solitary and it is speculated that the group spawn on the new moon.

 Honeycomb grouper Epinephelus merra 3


Honeycomb grouper are found on the East African coast from South Africa to Kenya across to Japan and south to Northern Australia and to the east in the Pacific islands. They are not found in the Red Sea and on the Asian mainland.

In 1956 they were introduced to Hawaii as a possible new food source.   In Tanzanian waters they are usually seen on coral reef from 12 meters downwards.

 Epinephelus merra 1


The main diet of the Honeycomb grouper is small fishes, small cephalopods and crustaceans.  They are ambush predators who vary their diet according to location and availability and as with most groupers pretty much anything moving that can fit into their mouths they will eat given the opportunity.

 Epinephelus merra 2


Honeycomb grouper are usually found solitary and spawning is thought to take place in group spawning events but his is not confirmed as a certainty.  They are protogynous hermaphrodites and even the adult males have the ability to change to a female if necessary. This allows them to be more resilient to overfishing. They also mature at younger ages than most other groupers. When the female is ready for mating the lower body swells with eggs as can be seen in the image above.

 Epinephelus merra 4


The Honeycomb grouper is certainly over fished by subsistence fishermen in Tanzania. Most inshore areas of the Tanzanian coast are heavily over fished. They have been cultured in experiments in the Philippines.


Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Serranidae
Genus: Epinephelus
Species: E. merra



Heemstra, P.C. and J.E. Randall, 1993. FAO Species Catalogue. Vol. 16. Groupers of the world (family Serranidae, subfamily Epinephelinae). An annotated and illustrated catalogue of the grouper, rockcod, hind, coral grouper and lyretail species known to date.


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