Tag: Duskytail Grouper (Epinephelus bleekeri)

Growing to a maximum length of over 70cm, the Duskytail Grouper (Epinephelus bleekeri) bares a striking similarity to its close relative, the Areolate Grouper.

With an overall pale greyish colouration (often with 4 - 5 brown vertical bars) and numerous yellow - redish/brown spots, the main distinguishing feature is the partially spotted caudal fin (tail).

Whereas the Areolate Grouper has spots across the whole caudal fin, with a distinctive white margin, the caudal fin of the Duskytail Grouper has spots and white margin present only on the upper 30% or so. The lower area is unmarked, instead having a plain grey/blueish colouration.

Whilst the dorsal fin also retains the spot markings, the pectoral and anal fins are largely unmarked, tending to be yellowish or semi-transparent. The ventral fins also lacks spots, however the fin rays may have a yellow/blueish striped appearance.

Similarities between the Duskytail and Areolate Grouper continue in their preferred habitat and even behaviour.

Although both species may be found around local reefs, they appear to prefer the outer reef slopes with a mud or silt substrate.

An unusual trait shared both species, certainly when compared to most of their locally occurring relatives, is their boldness and apparent curiosity towards divers.

Particularly when lying stationary on the bottom, whilst taking photographs for example, it is not uncommon to be approached and observed at very close quarters by one or more curious individuals.

Growing to a maximum length of over 70cm, the Duskytail Grouper (Epinephelus bleekeri) bares a striking similarity to its close relative, the Areolate Grouper.

With an overall pale greyish colouration (often with 4 - 5 brown vertical bars) and numerous yellow - redish/brown spots, the main distinguishing feature is the partially spotted caudal fin (tail).

Whereas the Areolate Grouper has spots across the whole caudal fin, with a distinctive white margin, the caudal fin of the Duskytail Grouper has spots and white margin present only on the upper 30% or so. The lower area is unmarked, instead having a plain grey/blueish colouration.

Whilst the dorsal fin also retains the spot markings, the pectoral and anal fins are largely unmarked, tending to be yellowish or semi-transparent. The ventral fins also lacks spots, however the fin rays may have a yellow/blueish striped appearance.

Similarities between the Duskytail and Areolate Grouper continue in their preferred habitat and even behaviour.

Although both species may be found around local reefs, they appear to prefer the outer reef slopes with a mud or silt substrate.

An unusual trait shared both species, certainly when compared to most of their locally occurring relatives, is their boldness and apparent curiosity towards divers.

Particularly when lying stationary on the bottom, whilst taking photographs for example, it is not uncommon to be approached and observed at very close quarters by one or more curious individuals.

Alan's picture
Duskytail Grouper (Epinephelus Bleekeri)

In this photograph of a Duskytail Grouper (Epinephelus Bleekeri), photographed on the outer reef slope at Mae Haad/Koh Ma reef, the translucent pectoral fin, unmarked anal fin and the yellow/blueish colouration of the

Alan's picture
Duskytail Grouper (Epinephelus Bleekeri)

This Duskytail Grouper (Epinephelus Bleekeri), photographed at Aow Leuk Bay demonstrated a trait which seems to be almost exclusive to this species, and the closely related