The tiger grouper, Mycteroperca tigris, is the most common grouper on Cayman’s reefs.
These fish can be found in a wide area of the ocean, from Bermuda south to Brazil, and grow to about three feet in length. They can also change colours – from gray to dark brown – featuring stripes and blotches.
Tiger groupers are usually solitary hunters of small fish, except during mating when they form large aggregates. Like the Nassau grouper, they too take on a dark anterior and light posterior just before mating.
I have only witnessed this once in over 25,000 dives in Cayman.
One large study showed them to be protogynous hermaphrodites, with all of the larger specimens being male.
Tom Byrnes is the owner/operator of Cayman Marine Lab. He acquired his Coast Guard Captain’s Licence when he was a teenager and worked as a commercial fisherman in his youth. He got his first diving certificate in 1974 with the YMCA. He has worked in the local dive industry for more than 35 years and has a PhD in marine biology.