|Scientific Name:||Mobula tarapacana|
|Species Authority:||(Philippi, 1892)|
|Red List Category & Criteria:||Data Deficient ver 3.1|
|Assessor(s):||Clark, T.B., Smith, W.D. & Bizzarro, J.J.|
|Reviewer(s):||Kyne, P.M., Notarbartolo-di-Sciara, G., Fowler, S.L. & Compagno, L.J.V. (Shark Red List Authority)|
Mobula taracapana is probably circumglobal in temperate and tropical waters but at present is known from scattered locations in the Indian, Pacific and Atlantic Oceans. A large devil ray (reaching 370 cm disc width) of primarily oceanic occurrence, but occasionally found in coastal waters. The threat from coastal fisheries in México, Indonesia, the Philippines and elsewhere where mobulids are captured is more limited for this species given its apparent offshore habitat. However, the species is landed in Indonesia where the catch of mobulids is increasing due to the high value of gill rakers for the Asian medicinal market. Apart from being taken as bycatch of the inshore pelagic tuna gillnet fisheries and purse seine fisheries, mobulids are increasingly being targeted in Indonesia. Although information is lacking it is most likely taken elsewhere in its Asian range (for example Taiwan). In studies of mobulid catches in the Gulf of California, México and the Philippines, M. taracapana represented a minor part of landings. Given its more pelagic occurrence than other mobulids and its apparent ichthyophagous diet, its capture on longlines requires investigation. The affect of the long-term use of high-seas gillnet and longline fisheries is not known for this species but the deleterious impacts of such fishing practices on populations of other large elasmobranchs is well known. This is however one of the least known mobulids and the lack of population data and exploitation rates preclude a global assessment beyond Data Deficient at this time. Increasing catches of mobulids in Indonesia, which may mirror increases elsewhere, is of great concern for a species not likely to be able to tolerate high catch levels due to its low reproductive potential (fecundity of one pup/litter). As such, present catch levels in Southeast Asia together with increasing demand in that region warrant a Vulnerable listing there.
|Range Description:||Probably circumglobal in temperate and tropical waters but at present known from scattered locations in the Indian, Pacific and Atlantic Oceans (Compagno and Last 1999). Mostly oceanic, but occasionally in coastal waters.|
Native:Brazil; Cape Verde; Chile; Côte d'Ivoire; Egypt; Indonesia; Japan; Mexico; Palau; South Africa; Taiwan, Province of China; United States (Texas); Venezuela, Bolivarian Republic of
|FAO Marine Fishing Areas:||
Atlantic – eastern central; Atlantic – southeast; Atlantic – southwest; Atlantic – western central; Indian Ocean – eastern; Indian Ocean – western; Pacific – eastern central; Pacific – northwest; Pacific – southeast; Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Reported to be uncommon (Compagno and Last 1999).|
|Habitat and Ecology:||
Mostly oceanic, but occasionally in coastal waters. Extremely limited information is available for this broadly distributed ray. Mode of reproduction is aplacental viviparity. Embryos feed initially on yolk, then through absorption of enriched uterine fluid from the mother (Wourms 1977). Only the left ovary is functional and litter size is one pup (Wourms 1977, Notarbartolo-di-Sciara 1988). Females of 270 cm DW were found to be transitional or mature in the southern Gulf of California, México (Notarbartolo-di-Sciara 1988). It is observed only in the summer and fall months in this region and is usually solitary, but sometimes seen in small groups (Notarbartolo-di-Sciara 1988).
Limited evidence pertaining to the feeding ecology is available, but it has been suggested that the species may be a more general feeder than other mobulids or possibly ichthyophagous (Notarbartolo-di-Sciara 1988). This possibility is supported by occasional catches of this species on pelagic longlines.
There is no published information on the age and growth of this species.
Life history parameters
Age at maturity (years): Unknown.
Size at maturity (disc width): Female: 270-280 cm DW (Gulf of California; Notarbartolo-di-Sciara 1988); Male: 240 to 250 cm DW (Indonesia; W. White pers. comm.), 240 to 250cm DW (Gulf of California; Notarbartolo-di-Sciara 1988).
Longevity (years): Unknown.
Maximum size (disc width): 370 cm DW (Compagno and Last 1999).
Size at birth: >105 cm (Compagno and Last 1999).
Average reproductive age (years): Unknown.
Gestation time (months): Unknown.
Reproductive periodicity: Unknown.
Average annual fecundity or litter size: 1 pup/litter (Notarbartolo-di-Sciara 1988).
Annual rate of population increase: Unknown.
Natural mortality: Unknown.
The threat from coastal fisheries in México, Indonesia, the Philippines and elsewhere where mobulids are captured is more limited for this species given its apparent offshore habitat. Mobula taracapana is however, susceptible to pelagic gillnets together with purse seines and longline. It has been shown to be only minor components of catches in the Gulf of California and the Philippines, but is more regularly taken in Indonesia. Although information is lacking it is likely taken elsewhere in its Asian range (for example Taiwan) and probably in West Africa. Its pelagic occurrence and apparent ichthyophagous diet, raises concern for its capture on longlines and this requires investigation. The affect of the long-term use of high-seas gillnet and longline fisheries is not known for this species. The deleterious impacts of such fishing practices on populations of other large elasmobranchs are well known.
The species is landed in Indonesia where the catch of mobulids is increasing due to the high value of gill rakers for the Asian medicinal market. Apart from being taken as bycatch of the inshore pelagic tuna gillnet fisheries and purse seine fisheries in Indonesia, mobulids are increasingly being targeted. During the shark fishing off-season (December to March) fishers are landing more mobulids as an alternative (W. White pers. comm.). Apart from gill rakers which are dried and exported, the flesh is also utilized both for human consumption and as bait and chum for longlines.
During a study on the mobulid catch in the Gulf of California by artisanal fisheries, M. taracapana was the rarest species observed, comprising 3% of the observed mobulid catch (seven individuals captured over a four-month period) (Notarbartolo-di-Sciara 1988). There is still an active mobulid fishery in the southwest Gulf of California, south of La Paz and devil rays are also landed in nearshore artisanal elasmobranch fisheries throughout the Gulf of California.
In a study of the mixed Manta/Mobula fishery in the Philippines, M. tarapacana comprised 2% of the total catch in 2002 (Bureau of Fisheries and Aquatic Resources, unpublished study). There is currently a ban on fishing for manta rays in the Philippines, but the effectiveness of this ban is questionable due to limited enforcement ability and mobulids are still being taken illegally.
Mobula taracapana is not likely to be able to tolerate high catch levels, given its low reproductive potential. Increasing catches of mobulids in Indonesia, which may mirror increases elsewhere, is of great concern.
Additional research is needed to quantify the extent of target and non-target fisheries take for this species and to determine if they pose a serious threat to the species. Available life history information is limited and more research is required to make a more accurate assessment of the threat posed by fisheries.
In México, a moratorium on the issue of elasmobranch fishing permits was issued in 1993, but no formal management plan has been implemented for Mobula taracapana specifically or most other chondrichthyans. However, legislation is currently being developed in México to establish national elasmobranch fishery management.
Elasmobranch landings in generally lack species-specific details (for example in México, batoids are broadly grouped as "manta raya"). Improved clarity in catch records would provide a basis for detecting potential trends in effort and landings.
In the Philippines, fishing for mobulids was banned in 1998, however it was lifted in 1999 to study the fishery. The ban was put back in place in 2002, and currently it is illegal to fish for any Manta or Mobula in Philippine waters. However, enforcement is insufficient and mobulids are still being taken illegally.
Elasmobranch fisheries are generally unmanaged throughout Central America and Southeast Asia and indeed elsewhere in the range of this species, and attempts to regulate fisheries in these regions would greatly improve conservation of M. taracapana and other chondrichthyans.
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 across the regions where this ray occurs.
The vulnerability of mobulids and increasing catches requires urgent international conservation measures. These will need to focus on harvest and trade management.
|Citation:||Clark, T.B., Smith, W.D. & Bizzarro, J.J. 2006. Mobula tarapacana. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 29 November 2014.|
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