|Scientific Name:||Diplobatis colombiensis Fechhelm & McEachran, 1984|
|Taxonomic Notes:||The dorsal colour pattern consist in brown spots ranging from ¼ to 1 times the size of the orbits, arranged fairly symmetrically on the disc, pectoral fins and tail, which distinguish it from the sympatric D. guamachensis.|
|Red List Category & Criteria:||Vulnerable A2bd+3bd+4bd ver 3.1|
|Assessor(s):||Caldas, J.P., de Carvalho, M.R. & McCord, M.E.|
|Reviewer(s):||Caldas, J.P., De Carvalho, M.R.& McCord, M.E. (Shark Red List Authority)|
Diplobatis colombiensis has a very restricted distribution in the Western Central Atlantic, where it is known only off the Caribbean coast of northern Colombia at depths of 30 to 100 m. Little information is available on this small (to 17 cm total length) batoid, and information concerning biology, population dynamics and status are generally lacking. The Colombian electric ray is sympatric with the more common Diplobatis guamachensis in parts of its range and due to identification difficulties between these species, it may be more heavily fished than currently thought. However, most of the range of D. colombiensis is distinct from that of D. guamachensis. The species is taken as bycatch in trawl fisheries and the genus Diplobatis has been shown to have a 27.5% occurrence in the captures of the offshore trawl fishery in the region. Even though little information is available on the species, its high level of endemicity indicates that this species is threatened by high levels of incidental fishing mortality and it is assessed as Vulnerable as a precautionary measure given its restricted distribution in mostly heavily trawled areas.
|Range Description:||Known only from the coast of northern Colombia, in the Caribbean Sea.|
|FAO Marine Fishing Areas:|
Atlantic – western central
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This species has a limited distribution. Caldas et al. (in prep.) show evidence of intra-populational variation in coloration patterns and geographical range for specimens collected throughout the northern coast from Colombia. There are shared regions (Tayrona National Natural Park-La Guajira) between D. colombiensis and D. guamachensis, where individuals show color patterns that are intermediate between the characteristics of each species. This intermediate coloration suggests that populations of this species are genetically mixed in some areas, resulting in interactions between individuals with specific characteristics that combine in this region.|
|Current Population Trend:||Unknown|
|Habitat and Ecology:||This species is benthic on the continental shelf at depths of 30 to 100 m (McEachran and Carvalho 2002).The region inhabited by D. colombiensis is characterized by hard sand with zones of soft mud and areas with coral reef development. The area has limited fluctuations in salinity. |
Very little known of the species' biology. Reaches a maximum size of 17 cm TL (McEachran and Carvalho 2002) and maturity in males is estimated to be 10 cm TL (Caldas et al. in prep.).
Demersal trawl fisheries operate over the species' limited area of occurrence. Medina (2002) reports Diplobatis pictus as bycatch in shrimp trawl fisheries. These catch surveys were in the geographic range of both D. guamachensis and D. colombiensis, and so specific information on D. colombiensis is not available (D. pictus does not occur in Colombia, being known from southeastern Venezuela to northern Brazil).
Because of identification problems, the species may be more frequently caught than suspected.
Diplobatis colombiensis occurs in the Tayrona National Natural Park area, a Colombian nature reserve. This area is closed to fishing with trawl nets and only an artisanal fishery exists. However, there are no known documents records of this species from fishermen at Tayrona Park.
An adequate conservation program for the Colombian Guajira peninsula is needed. This area supports extraordinary species richness, including several southern Caribbean endemics. Plans for developing and exploiting mineral resources in the Guajira continental shelf and slope during the 21st century must consider this fact (Caldas et al. in prep.).
Caldas, J.P., Acero, A. and Mejia, L.S. (in prep.) Evidence of sympatric distribution in the Dwarf electric rays of the genus Diplobatis (Torpediniformes: Narcinidae) in the southern Caribbean: are they really difference species?
Fechhelm, J.D. and McEacharn, J.D. 1984. A revision of the electric ray genus Diplobatis with notes on the interrelationships of Narcinidae (Chondrichthyes, Torpediniformes). Bulletin of the Florida State Museum 29(5): 171–209.
IUCN. 2006. IUCN Red List of Threatened Species.
IUCN SSC Shark Specialist Group. Specialist Group website. Available at: http://www.iucnssg.org/.
McEachran, J.D. and de Carvalho, M.R. 2002. Batoid fishes. In: K.E. Carpenter (ed). The Living Marine Resources of the Western Central Atlantic. Volume 1. Introduction, molluscs, crustaceans, hagfishes, sharks, batoid fishes and chimaeras. pp: 508–589. FAO Species Identification Guides for Fishery Purposes. FAO, Rome.
Medina, J.A. 2002. Ensamblajes de peces demersales explotados por la flota industrial camaronera en la plataforma continental de La Guajira (Caribe colombiano). Tesis pregrado Biólogo Marino. Universidad Jorge Tadeo Lozano, Facultad de Biología Marina. Santa Marta, 2002.
|Citation:||Caldas, J.P., de Carvalho, M.R. & McCord, M.E. 2006. Diplobatis colombiensis. The IUCN Red List of Threatened Species 2006: e.T61401A12471224.Downloaded on 22 October 2017.|
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