Black Grouper
Black Grouper (Mycteroperca bonaci) is a saltwater species. The first thing to check: rectangular, chain-link-like dark blotches arranged in regular rows over an olive-grey body. The look-alike to rule out is Gag Grouper: gag have irregular worm-like markings and a wavy tail margin with a white inner line. Regulations often differ between the two, so the tail margin is worth checking properly.
Last updated
| Scientific name | Mycteroperca bonaci |
|---|---|
| Also called | marbled rockfish, cherna |
| Water | Saltwater |
| Group | Grouper |
| Temperature | Found between about 65 and 82 °F. |
How to identify a Black Grouper
- Rectangular, chain-link-like dark blotches arranged in regular rows over an olive-grey body.
- A square-cut tail with a plain dark margin and no wavy white inner line.
- Brassy or bronze spotting between the blotches, and a slightly convex rear edge to the tail.
If you would rather not work through a key on a wet deck, photograph the fish and let the app name it — you get the common and the scientific name back, and the record is filed before you release.
Fish it is mistaken for
| Species | How to tell them apart |
|---|---|
| Gag Grouper | Gag have irregular worm-like markings and a wavy tail margin with a white inner line. Regulations often differ between the two, so the tail margin is worth checking properly. |
| Yellowfin Grouper | Yellowfin grouper have bright yellow outer edges on the pectoral fins. |
Side-by-side comparisons
Read the full entry for Gag Grouper.
Where it lives
South Florida, the Keys, the Gulf and the Caribbean. Holds on high-relief coral reef, ledges, wrecks and drop-offs, generally in deeper and more structured water than gag.
Temperature
Found between about 65 and 82 °F.
The conditions that matter
Black grouper hold on high-relief structure and feed on current, moving up off the bottom when flow brings bait past a ledge. Current speed and tide stage decide the window; depth and structure decide the spot.
Global Fishing League records 18 weather and water readings against every catch automatically — tide stage, barometric pressure, water temperature, salinity, dissolved oxygen, chlorophyll, swell, current, moon phase and more, taken at your GPS position at the moment you log the fish. Over a season that turns a hunch about black grouper into a pattern you can read.
See every reading recorded with a catch, or the guides to what each reading means.
Size limits, bag limits and seasons
Size limits, bag limits, slot limits and seasons are set by your state wildlife agency — and for many offshore and migratory species by federal regulators — and on many waters they differ from the statewide rule. They also change between seasons. Check the current regulations for the exact water you are fishing before you keep a fish — we do not republish limits here, because a number that is a season out of date is worse than no number.
What the app does do is make your side of it accurate: every catch carries a length measured from the photograph, a GPS position and a timestamp, exportable if you ever need to show your work for a tournament or a record claim. It is also what a Global Fishing League entry is built from — a record that verifies itself, without publishing where you caught the fish.