The The Tomato Grouper (Cephalopholis sonnerati) is also known as the Tomato Rockcod, the Tomato Hind, the Red Coral Grouper and the Tomato Cod. All these specimens were photographed on the Tanzanian coast. They were first described by Valenciennes in 1828 with the holotype originating in India.
Because of their ability to both darken and lighten their coloration , these Tomato grouper can be difficult to distinguish at times. A full range of their colors can be seen in the images in the post. They seem to darken their colors for breeding and when stressed, additionally they change color at night. I once viewed a fisherman catching one and as he pulled it out the water it went a bright tomato red color. They were very common in Tanzania twenty years ago but today one hardly sees larger specimens.
TOMATO GROUPER APPEARANCE
The Tomato Grouper has a fairly typical grouper shape with a large head and mouth. As can be seen in the images they have quite a variety of color variations, possibly as a result of their color changing abilities. The common factor across the color variations/changes seems to be the fairly large red spots across the lower face. More often than not they display their colors as seen in the image immediately above. They grow up to 57 cm in length but 25 cm is more common. The adult males are slightly larger than the females. A specimen photographed at night is pictured below.
TOMATO GROUPER IN THE WILD
The Tomato Grouper is very reclusive 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 of dynamite fishing now fortunately stopped as of 2017. On the offshore islands of Mafia and Zanzibar they are not as shy. They are invariably found perched on a rock with a good field of view around them, from which they can spot potential prey. Quite possibly they are territorial as one always finds them in the same spots.
In Tanzanian waters we typically find the adults in 10 to 18 meters of water with around the ten meter mark being more common. This is similar to findings in Madagascar. The adults seem to prefer shallow flat unprotected offshore reefs whereas the juveniles of around 10 cm or so are found closer inshore.
TOMATO GROUPER HABITAT
Tomato Grouper are found on the East African coast from South Africa to Djibouti across to Southern Japan and south to Southern Queensland in Australia. They are not found in the Red Sea or Persian Gulf and on the Chagos Archipelago. In Tanzania adults are commonly found between 10 and 20 meters.
TOMATO GROUPER DIET
The main diet of the Tomato Grouper is crustaceans, stomatopods and small fish. They are ambush predators who vary their diet according to location and availability and as with most groupers are opportunistic and will take bait indicating that they will scavenge to some extent.
TOMATO GROUPER REPRODUCTION
Tomato Grouper are usually found solitary. Spawning is thought to take place in group spawning events. They are protogynous hermaphrodites and even the adult males have the ability to change to a female if necessary. The females mature at around 28 cm and the males at around 34 cm .
TOMATO GROUPER COMMERCIAL EXPLOITATION
The Tomato Grouper is certainly over fished by subsistence fishermen in Tanzania. Unfortunately much of the catch is in the 10 cm range, meaning that very few make it to adult size for breeding. Similar problems have been experienced in Sri Lanka. They are caught on hook and line and in fish traps and are speared by divers with a metal pole. Most grouper are susceptible to over fishing by line because of their scavenging habits. Almost all inshore areas of the Tanzanian coast are heavily over fished. One seldom sees these fish these days and they were once very common.
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.