We caught this grouper in deep water off Kona. What can you tell me about it?
Mark, this fish appears to be a Hawaiian grouper, Hyporthodus
quernus. A member of the family Serranidae, this species was known for many years as Epinephelus quernus until recent genetic studies suggested a number of deep-sea grouper species should be separated from the shallowwater grouper groups. This was done by placing several deepwater groupers (including the Hawaiian) into the resurrected genus Hyporthodus.
Hawaiian grouper have a rather restricted distribution, recorded only from the Hawaiian archipelago and Johnston Island. Within this area, genetic studies suggest this species shows little evidence of population structure, indicating that eggs and larvae are widely distributed by ocean currents. The Hawaiian grouper is a reasonably large and probably long-lived species that reaches a little over 4 feet long and 50 pounds or so. Juveniles are gray-brown in color, with a pretty mottled pattern with numerous white blotches over the flanks. They occur on the bottom over reefs and ledges, in waters as shallow as 30 feet or so. In contrast, adults like the one captured here live on the bottom, in deep waters, down to more than 1,100 feet. As adult fish mature, they lose the mottled coloration, becoming almost uniformly dark brown, with a few faint, scattered lighter spots. Like many other groupers, Hawaiians feed mainly on crustaceans, such as shrimp and crabs, but also eat smaller fish.