syn. Epinephelus dispar, Epinephelus goldmani, Epinephelus microdon, Epinephelus polyhekadion, Epinephelus polyphekaidon, Serranus dispar var. b +3 more
90 cm1-50 mPoisonousVulnerable
1044
A grouper does not chase anything down. It sits still, sometimes for an hour, and then the water in front of it disappears.
The strike is a suction event. The fish drops its lower jaw, flares its gill covers and expands the floor of its mouth all at once, and the volume inside the head increases so fast that water is pulled in through the open mouth at high speed, carrying whatever was in front of it. The whole thing takes about twenty milliseconds. A prey fish that has begun to react is already inside.
That is why the mouth on these fish is so large and why the head looks oversized in proportion to the body: the mouth is not a pair of jaws for gripping, it is the aperture of a pump, and how much water it can move sets how big a meal it can take. It also explains the sitting: the pump has a range of about one body length, so everything depends on the prey coming to the grouper rather than the other way around.
This one is built for exactly that, dark brown spots over the whole body and head, up to ninety centimeters, waiting beside coral. Large groupers concentrate ciguatera and this species appears in the records, so it is best left where it is.
The genus.Epinephelus Bloch 1793 - epinéphelos (ancient Greek for clouded over). ETYFish
The species.Epinephelus polyphekadion (Bleeker 1849) - poly (many) + phekadion (presumably from phakoeides). ETYFish
How to recognise it
head and body covered in close-set dark brown spots and blotches
heavy-bodied, up to 90 cm
usually motionless beside a coral head or in the mouth of a cave
Overfishing by commercial and recreational fisheries is a major threat to this species. Spawning aggregation sites and timing are often widely-known by fishers, and easily accessed in outer reef passages. In some locations, the species utilizes predictable reproductive migratory corridors to and from aggregation sites, which increases its susceptibility to exploitation. Given its continued high-value in the international market, and the fact that fishing is insufficiently managed in most areas, it is inferred that populations will continue to decline, especially due to heavy fishing of spawning aggregations and the high frequency of juveniles in the catch (Sadovy de Mitcheson and Colin 2012). Secondarily, degradation of the coral reefs that this species inhabits is expected to increase due to impacts from climate change, including rising water temperatures. Land-based activities, such as logging and coastal development also contribute to reef degradation.
Threat classification from the IUCN Red List.
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