Epinephelus bleekeri 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Actinopterygii Perciformes Epinephelidae

Scientific Name: Epinephelus bleekeri (Vaillant, 1878)
Regional Assessments:
Common Name(s):
English Duskytail Grouper, Bleeker's Grouper, Bleeker's Rock Cod
French Merou Demideuil, Merou Demi-deuil
Spanish Mero Medioluto
Epinephelus bleekeri Valliant, 1878
Epinephelus dayi (non Bleeker, 1873)
Serranus coromandelicus Day, 1878
Serranus variolosus (non Valenciennes, 1828)
Serranus waandersi (non Bleeker, 1858)

Assessment Information [top]

Red List Category & Criteria: Near Threatened ver 3.1
Year Published: 2008
Date Assessed: 2008-01-01
Assessor(s): Russell, B., Samoilys, M., Cornish, A. & Carpenter, K.
Reviewer(s): Sadovy, Y. & Moss, K. (Grouper and Wrasse Red List Authority)
Epinephelus bleekeri is a widespread species, locally abundant in some areas. However, it is highly sought after as adults as food and also as fingerlings/juveniles for grow-out. Unrestricted exploitation has led to widespread local declines in the availability of fingerlings/juveniles for growout. The continuation of this practice may lead to further declines and this species should be closely monitored. From the trade in wild fingerlings/juveniles, a population decline throughout much of its range is inferred that may be close to meeting Criterion A4d.

Geographic Range [top]

Range Description:General
Epinephelus bleekeri is an Indo-West Pacific species ranging from the Persian Gulf to Taiwan, Indonesia and the northern coast of Australia. Currently it is not known from Japan, but it may occur there. It has not been found at any islands of Micronesia or Polynesia (Heemstra and Randall 1993).

Australia (Northern Territory, Western Australia), Bahrain, Brunei Darussalam, Cambodia, China (Fujian, Guangdong), Hong Kong, India (Andhra Pradesh, Karaikal, Kerala, Mahé, Pondicherry, Tamil Nadu, Yanam), Indonesia (Java, Kalimantan, Moluccas, Sulawesi, Sumatra), Iraq, Iran, Kuwait, Malaysia (Peninsular Malaysia, Sabah, Sarawak), Oman, Pakistan, Philippines, Qatar, Saudi Arabia, Singapore, Sri Lanka, Taiwan, Thailand, United Arab Emirates, and Viet Nam.
Countries occurrence:
Bahrain; Brunei Darussalam; Cambodia; China; Hong Kong; India; Indonesia; Iran, Islamic Republic of; Iraq; Japan; Kuwait; Malaysia; Myanmar; Oman; Philippines; Qatar; Saudi Arabia; Singapore; Sri Lanka; Taiwan, Province of China; Thailand; United Arab Emirates; Viet Nam
FAO Marine Fishing Areas:
Indian Ocean – western; Indian Ocean – eastern; Pacific – northeast; Pacific – western central
Additional data:
Lower depth limit (metres):104
Upper depth limit (metres):30
Range Map:Click here to open the map viewer and explore range.

Population [top]

Epinephelus bleekeri is widespread, but apparently no longer abundant in large parts of its range.

Fisheries-dependent data
In Hong Kong, declines are common to all medium-bodied groupers, including this species. There are inferred declines in the abundance of wild-caught fingerlings/juveniles for grow-out according to Hong Kong mariculturists. In southern China, fingerlings are near extirpated (Sadovy 2000). These declines suggest a reduction in the adult population in source areas throughout Southeast Asia (Min pers. comm. 2007). The species is still common in the markets of the Persian Gulf.

A minor part of the Western Ausrtalia trap fishery. A total of 55 kg caught in Onslow, Western Australia (1986 to 1987) and 46 kg in 1987 to 1988 (Moran et al. 1987).
Current Population Trend:Decreasing
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:General
Epinephelus bleekeri is a demersal species that occurs on shallow banks (30 to 104 m), but is not known from well-developed coral reefs (Randall 1995).

It is usually taken by trawling in 30 to 45 m or by hand-lining over rocky banks. Its maximum size is reported at 76.0 cm TL (Chan 1968). Epinephelus bleekeriis of minor commercial importance to fisheries. Wild caught juveniles are also utilized for aquaculture for live fish market in Hong Kong (Lee and Sadovy 1998, Donaldson et al. 2003).

Threats [top]

Major Threat(s): General
Perhaps the greatest threat to Epinephelus bleekeri is overfishing.

Epinephelus bleekeri is subject to commercial trawling of adults, including India (James et al. 1996) and in trap fishery in Western Australia (Moran et al. 1988).

Within the live reef food fish trade, there is a capture fishery of wild caught fingerlings and juveniles (fingerlings, hereafter) for grow out in sea cages and pens. Juveniles are commonly taken in estuaries in the Philippines (Pratt et al. 2000, Padilla et al. 2003) and Thailand (Vidthayanon and Premcharoen 2002), Malaysia, southern China, Vietnam and Indonesia. Fingerlings are either locally grown out or sold to Taiwan or Hong Kong (Sadovy 2000). The numbers can be substantial. For example, in one year 10 million fry were exported from Thailand to Hong Kong (Sadovy 2000). These fingerlings are grown out in open sea cages and big pens in Malaysia. Wild caught Epinephelus bleekeri fingerlings are raised in floating cages and ponds in Vietnam (Tuan 2003).

Among the fishing gears, seine net, scoop net and push net are mainly used for collecting small fish of 1 to 3 cm. Seine nets provide the highest yield (catch per unit effort) in terms of number of pieces per trip. For larger seed, encircling nets, used together with artificial reefs, were the most important in terms of quantity and quality of catch. The seasonality of use of different gears reflects the growth of the seed and their move to deeper water as the season progresses (Tuan and Hambrey 2000). No hatcheries are known for this species (Sadovy pers. comm.).

Epinephelus bleekeri was widely cultured in Hong Kong in the early 1990s when green groupers experienced disease problems that could not be overcome. Epinephelus bleekeri was not affected by the same disease, so fish farmers gave up farming green grouper and changed to this species. E. bleekeri Epinephelus bleekeri adapted very well to the new environment but grew much slower than green groupers. Disease problems with Epinephelus bleekeri began about three years ago. The diseased fish would consume excessive food one day, then stopped feeding the following day. By then an infection was noticeable on the fish’s body. Its condition would worsen very quickly and within three days most of the fish would die. Treatments with antibiotics, freshwater bath, malachite green, methylene blue and formalin have had no success with this problem. The situation was uncontrollable in 2001 with an almost 95% mortality rate for imported Epinephelus bleekeri. Researchers found that the disease was caused by a new vibrio (SPC Live Reef Fish Information Bulletin #9).

Listed in Life Reef Food Fish Trade in Hong Kong (Donaldson et al. 2003) and Philippines (Pratt et al. 2000 Padilla et al. 2003). Live reef fish import data from the Hong Kong Census and Statistics Department (HK CSD) record the largest quantities of "other groupers" and "other marine fishes" as being imported from Thailand. Thailand and Malaysia are important sources for so-called "cultured" species including Brown Spotted Grouper Epinephelus areolatus / Epinephelus bleekeri, which are amongst 12 most commonly available species imported to Hong Kong (

Conservation Actions [top]

Conservation Actions: Epinephelus bleekeri is listed as ‘Least Concern’ in Australia (Northern Territory), but there are no measures specific to this species. The species does occur in some marine protected areas within its range.

Citation: Russell, B., Samoilys, M., Cornish, A. & Carpenter, K. 2008. Epinephelus bleekeri. The IUCN Red List of Threatened Species 2008: e.T132826A3462138. . Downloaded on 26 September 2018.
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