|Scientific Name:||Chiloscyllium plagiosum|
|Species Authority:||(Anonymous [Bennett], 1830)|
|Taxonomic Notes:||Dingerkus and DeFino (1983) synonymized C. caerulopunctatum with this species, an action tentatively (and reluctantly) followed by Compagno (2001). However, C. caerulopunctatum is considered to be distinct from C. plagiosum and appears to be restricted to Madagascar (B. Séret pers. comm.). Chiloscyllium caerulopunctatum differs from C. plagiosum in a number of characters including dorsal fin size, snout length, coloration and possibly mouth width (Compagno 2001). Resolution of this issue is presently underway by B. Séret of the Muséum national d?Histoire naturelle, Paris based on new material recently collected from Madagascar (B. Séret pers. comm.).|
|Red List Category & Criteria:||Near Threatened ver 3.1|
|Assessor/s:||Kyne, P.M. & Burgess, G.H.|
|Reviewer/s:||Cavanagh, R.D. & White, W.T. (Shark Red List Authority)|
A reef-dwelling, shallow water bamboo shark with a relatively wide distribution in the Indo-West Pacific from India east to Indonesia and north to southern Japan. Reaches 95 cm total length, but little is known of its biology, although some information is available from captive animals. The majority of its distribution is under substantial and generally unregulated fishing pressure, and this bamboo shark is landed and utilised for human consumption in nearly all countries within its range. It is also prized for the aquarium trade as it survives well for long periods in captivity. Furthermore, pressure on coral reef systems is high over much of its range, with the amount of available habitat for this and similar species being reduced due to extensive degradation/destruction of coral reefs through practices such as dynamite fishing and pollution from terrestrial runoff. Given human population increases, habitat degradation and continued, increasing exploitation of marine resources in the region, the conservation status of this coral reef species is of concern, warranting a Near Threatened assessment. Lack of detailed catch and aquarium trade data precludes a higher threat listing at this time, but the species should be carefully monitored throughout its range, particularly as the threats described are likely to continue to increase.
|Range Description:||Indo-West Pacific: India to southern Japan. Has not been confirmed between India and Thailand (e.g., Bangladesh and Myanmar).|
Native:China; India; Indonesia; Japan; Malaysia (Peninsular Malaysia, Sabah, Sarawak); Philippines; Singapore; Sri Lanka; Taiwan, Province of China; Thailand; Viet Nam
|FAO Marine Fishing Areas:||
Indian Ocean – eastern; Indian Ocean – western; Pacific – northwest; Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||No knowledge of population size or structure.|
|Habitat and Ecology:||
A shallow water tropical reef-dwelling species. Biology is poorly known. A nocturnal feeder, resting by day in reef crevices (Compagno 2001). Reaches a maximum size of 95 cm TL; adolescent males to 64 cm TL and adult males 50 to 83 cm TL; smallest free-living individuals 9.8 to 12.5 cm TL (Compagno 2001).
Oviparous. Information on reproduction and growth is only available from captivity (Masuda and Teshima 1994, Miki 1994, Masuda 1998). Females deposit two egg capsules at a time, on average every 6 to 7 days from spring to summer (Masuda 1998), or about every six days from winter to spring (Miki 1994). Hatching period: range 110 to 135 days (Miki 1994); average 128.2 days (Masuda 1998); and, average 126 ± 9.2 days, range 116 to 144 days (Tullis and Peterson 2000). Average length at birth was 16.6 cm TL (Miki 1994, Masuda 1998). The maximum laying season reported by Miki (1994) of 87 days yielded 26 eggs from an individual, 11 of which failed to develop.
In captivity, some variation in growth rates have been reported. Masuda (1998) reported individuals reaching 30 cm TL after one year, while Miki (1994) reported 42.1 cm TL after five months! The species has been reported to live in captivity for 25 years (Michael 1993).
Life history parameters
Age at maturity (years): Unknown.
Size at maturity (total length): Female: unknown; Male: 50 to 64 cm TL.
Longevity: Uncertain, but reported to 25 years in captivity (Michael 1993).
Maximum size (total length): 95 cm TL.
Size at birth: 9.8 cm TL or smaller (Compagno 2001); 16.6 cm TL (average in captivity; Miki 1994, Masuda 1998).
Average reproductive age (years): Unknown.
Gestation time: Hatching period (in captivity): range 110 to 135 days (Miki 1994); average 128.2 days (Masuda 1998); and, average 126 ± 9.2 days, range 116 to 144 days (Tullis and Peterson 2000).
Reproductive periodicity: Unknown.
Average annual fecundity or litter size: In captivity: maximum of 26 eggs per laying season (Miki 1994).
Annual rate of population increase: Unknown.
Natural mortality: Unknown.
The majority of the distribution of the Whitespotted Bamboo Shark is under substantial, generally unregulated and unmanaged fishing pressure. The species is landed and utilised for human consumption in nearly all countries within its range. The species is known to be taken regularly in India, Thailand and China (Compagno 2001) and is landed in Borneo (Manjaji 2002), Philippines (Compagno et al. 2005), Taiwan (both on the mainland and the Penghu Islands) (P. Kyne pers. obs., D. Ebert pers. comm.) and irregularly in Indonesia (W. White pers. comm.). It is also prized for the aquarium trade as it is hardy in captivity and known to survive for long periods in aquaria (Michael 1993, Compagno 2001).
Pressure on coral reef systems is high over much of the species? range with the amount of available habitat being reduced in recent history due to the degradation/destruction of coral reefs through such practices as dynamite fishing (e.g., Indonesia and elsewhere) and terrestrial runoff (e.g., through logging in Philippines).
Given human population increases in the Asian region and continued and increasing exploitation of marine resources the conservation status of this coral reef species is of concern.
Harvest and trade management is required where this species is taken and marketed. The extent to which the species is exploited from the wild for the marine aquarium trade needs to be investigated and the industry should be encouraged to be self-regulated, ensuring stock is drawn from sustainable sources. Chiloscyllium species breed well in captivity and captive reared individuals rather than wild animals should be used to supply the expanding market.
Any measures to protect, maintain and restore coral reef habitats in Asia will benefit this and other species of reef-dwelling elasmobranchs.
The development and implementation of management plans (national and/or regional e.g., under the FAO International Plan of Action for the Conservation and Management of Sharks: IPOA-Sharks) are required to facilitate the conservation and sustainable management of all chondrichthyan species in the region. At the time of writing, development of a regional Plan of Action (under the IPOA-Sharks) was underway by Brunei Darussalam, Indonesia, Japan, Malaysia, Myanmar, Philippines, Singapore, Thailand and Vietnam. In addition, Malaysia has a separate draft National Plan of Action (NPOA) available, and the Philippines and Indonesia are also taking steps towards developing their separate NPOAs. India stated its intention to prepare a NPOA in the near future; China stated it was working towards development and implementation; and Taiwan and Sri Lanka had not yet stated any intention to develop NPOAs. In developing these management plans, it is vital for countries not to overlook the main aims of the IPOA-Sharks: to improve species-specific catch and landings data collection, and the monitoring and management of shark fisheries. This will not be achieved if the plans do not include adequate data collection, monitoring and management measures. Improved management of shark fisheries will not occur if even the most detailed of the management plans are simply not implemented once prepared (Anon. 2004).
|Citation:||Kyne, P.M. & Burgess, G.H. 2006. Chiloscyllium plagiosum. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 09 December 2013.|
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