|Scientific Name:||Thelenota ananas|
|Species Authority:||(Jaeger, 1833)|
|Red List Category & Criteria:||Endangered A2bd ver 3.1|
|Assessor/s:||Conand, C., Gamboa, R. & Purcell, S.|
|Reviewer/s:||Polidoro, B., Knapp, L., Carpenter, K.E. & Harwell, H.|
This species is commercially exploited throughout its range for its medium-high value as beche-de-mer to supply the Asian consumers around the world. Based on a number of quantitative and qualitative studies, populations are estimated to have declined by 80-90% in at least 50% of its range, and are considered overexploited in at least 30% of its range although exact declines are difficult to estimate. Declines and overexploitation have occurred primarily since the 1960s, and although generation length is not known, echinoderms are not considered to go through senescence and therefore may be greater than several decades. Additionally, this species may be more vulnerable to overfishing given its low fecundity and late sexual maturation. This species is therefore listed as Endangered. However, better and more quantitative data are needed to better estimate the impact of fishing on this species.
|Range Description:||This species has a wide distribution range throughout the Indo-Pacific, excluding Hawaii. In Madagascar, this species is observed on the west coast from the south of Toliara to Nosy-be (Rasolofonirina pers. comm. 2010). It occurs from South Africa north to India, southeast to Australia, north to Japan and China, and southeast to Palau, Guam, Tonga, Tuvalu, and the Cook Islands.
This species can be found in the Western Central Pacific (Kinch et al. 2008) and in the Africa and Indian Ocean, it can be found in Comoros, Mayotte (including Geyser Banks), Madagascar, Kenya and Seychelles. It is very rare in Réunion (Conand 2008).
Native:Australia; Bangladesh; Brunei Darussalam; Cambodia; China; Cocos (Keeling) Islands; Comoros; Cook Islands; Djibouti; Egypt; Eritrea; Fiji; French Polynesia; Guam; India; Indonesia; Iran, Islamic Republic of; Israel; Japan; Jordan; Kenya; Kiribati; Madagascar; Malaysia; Maldives; Marshall Islands; Mauritius; Mayotte; Mozambique; Myanmar; New Caledonia; Niue; Northern Mariana Islands; Oman; Pakistan; Palau; Papua New Guinea; Philippines; Réunion; Samoa; Saudi Arabia; Seychelles; Singapore; Solomon Islands; Somalia; South Africa; Sri Lanka; Sudan; Taiwan, Province of China; Tanzania, United Republic of; Thailand; Tonga; Tuvalu; Vanuatu; Viet Nam; Yemen
|FAO Marine Fishing Areas:|
|Range Map:||Click here to open the map viewer and explore range.|
This species is common compared to Thelenota rubrilineata.
In the Gulf of Manner and Pal Bay, India, CPUE and size of specimens has dramatically declined (Bruckner et al. 2003).
In the Maldives, export of this species, Holothuria nobilis, and Bohadschia marmorata increased from 3t in 1986 (start of the fishery) to 740t in 1990 (Bruckner et al. 2003).
In Tuvalu, this species was part of a small fishery between 1979 and 1982 with exports of 1800kg in 1979, 805kg in 1980, 90kg in 1981, and 198.5kg in 1982. The fishery was more active between 1993 and 1995 with exports of over 3000kg each year. The fishery includes Holothuria fuscogilva (50-70% of export); this species (14-20% of export); H. nobilis (0-10% of export); H. fuscopunctata (5-13.4% of export); and 4 other species (2.8-12.8%) (Bruckner et al. 2003).
Kalaeb et al. (2008) used transect data to calculate a population density of 3.5 individuals of this species per hectare in near shore waters of Eritrea, East Africa.
In FSM, surveys in 1985 found great abundances of this species, whereas in Marshall Islands it was scarce. In Solomon Islands, it was seen in low numbers and in New Caledonia it was in low densities (Kinch et al. 2008). In the Mou Box: Ashmore reef, this species was relatively abundant (Choo 2008). In Madagascar and Seychelles, it is becoming increasingly rare (Conand 2008).
In New Caledonia, 10-30 individuals were commonly found per hectare and up to 120 individuals in the early 1980s (Conand 1989), compared to an average of 6 per hectare in the most preferred habitat in the most recent survey (Purcell et al. 2009). This is a 60% decline in abundance.
In PNG, densities went from 8 to 1.4 individuals per hectare (Kaly et al. 2007).
In the Torres Strait where it is fished, densities of 1-2 individuals have been found and have been relatively stable in the past 15 years (Skewes 2010). There is a quota for this species in this area (20 tonnes per year for the fishery).
This species is considered to be depleted in at least 50% of many parts of its range (Philippines, PNG, India, Indonesia, Madagascar), and is considered overexploited in the South Pacific, and the majority if its range. For example, there has been a more than 60% decline over the past 30 years in at least one region (New Caledonia). In East Africa, it is heavily exploited, but the statistics are unreliable. No data from western Australia is available. Depletion refers to commercially unviable, and estimated to represent an approximately 90% loss or greater. In areas where it is considered overexploited, populations are difficult to estimate based on regional and local fishing effort, but harvests have declined and based on traditional fisheries definitions, overexploited is estimated to be at least 30% above maximum sustainable yield.
|Habitat and Ecology:||
This species is found along slopes and passes within reef zones (Skewes et al. 2004) and along outer reef flats (Conand and Mangion 2002) to depths of 35 m, but is more common in waters from 10-20 m. It is a large, conspicuous species, with relatively lower fecundity and relatively low weight gonads and sexual maturity, making it more vulnerable to overfishing (Conand 1998).
They are distributed mainly in shallow coral reef areas, on reef flats, reef slopes and near passes on sandy or hard bottoms with large rubble and coral patches. It is common in shallow waters of reef bottom where there is no terrigenous action, at depths from 0 to 20 m. They prefer rubble and hard bottoms covered with a layer of coral sand.
Larvae are planctonic, juveniles and adults are benthic epibiontic (Rasolofonirina pers comm. 2010).
Generation length is unknown for this species. Body size is not a good indicator of age or longevity. There is some indication, however, that many echinoderms do not go through senescence, but simply regenerate. Therefore generation length cannot be estimated, but is assumed to be greater than several decades in a natural, undisturbed environment.
In the Western Central Pacific, this species prefers reef slopes and near passes, hard bottoms with large rubble and coral patches between 0 and 25 m (Kinch et al. 2008). In the Africa and Indian Ocean, it prefers coral slopes over hard substratum between 5 and 35 m (Conand 2008). In Comores, it prefers hard bottoms or coral rubble (Samyn et al. 2006).
In Guam, this species reproduces almost all year long, with the exception of March, September and October; and in New Caledonia, it has an annual reproductive cycle from January to March (Kinch et al. 2008). It has a late sexual maturity (Conand 2008).
This species is host to the pearl fish Carapus homei, C. boraborensis, Encheliophis vermicularis, and E. gracilis. (Eeckhaut et al. 2004).
This species has a medium-high market value. It is targeted throughout its range, and fishing pressure has dramatically increased in the past 25 to 50 years, since the 1960s, and is expected to continue, even as stocks are depleted. When this occurs, other species are often targeted in their place. Even as a high value species for fishery purposes, this species has been targeted as a result of the decrease in Holothuria scabra (Choo 2008).This species is one of the most exploited holothurian species in Madagascar. It is classified in the category of medium commercial value species. Its exploitation reaches semi-industrial levels, and fishermen use scuba diving to collect this resource (Rasolofonirina pers. comm. 2010).
|Conservation Actions:||In PNG, there is a minimum size limit of 25 cm TL live and 10 cm TL dry; in New Caledonia 45 cm TL live and 20 cm TL dry; in Torres Strait, Northern Territory and Western Australia 30c m TL live and in the Great Barrier Reef of 50 cm TL live (Kinch et al. 2008).|
|Citation:||Conand, C., Gamboa, R. & Purcell, S. 2013. Thelenota ananas. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 23 April 2014.|
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