|Scientific Name:||Potamotrygon magdalenae|
|Species Authority:||(Duméril, 1865)|
Taeniura, magdalenae Duméril, 1865
Trygon hystrix Müller & Henle, 1841
|Taxonomic Notes:||This species has been mistaken for P. yepezi from Lake Maracaibo (Rosa 1985). It is also pointed out as being easily mistaken for P. falkneri, P. signata and P. castexi in the ornamental trade (Ross and Schäfer 2000).|
|Red List Category & Criteria:||Near Threatened ver 3.1|
|Assessor(s):||Charvet-Almeida, P. & Pinto de Almeida, M.|
|Reviewer(s):||Kyne, P.M. & Fowler, S.L. (Shark Red List Authority)|
The Magdalena Freshwater Stingray (Potamotrygon magdalenae) is small freshwater stingray (adults 19-21 cm DW) that is restricted to the Magdalenae and Atrato River basins in Northern Columbia. The biological information available indicates that it has low fecundity (2-4 pups) and feeds on insect larvae, but further data are needed on its life history. This species enters the ornamental trade and is a bycatch species in other fisheries but no other information is available. Monitoring and specific management for the ornamental trade and bycatch are recommended. Habitat maintenance and conservation are also required conservation measures. Due to its restricted range, low fecundity and threats, this species is considered to be declining in abundance and is classified as Near Threatened.
|Range Description:||This species is restricted to the drainages of some rivers in Northern Colombia, including Magdalena, Cauca, San Jorge, Atrato and Catatumbo rivers. It has not been registered in the Sinú River but is also found in the headwaters and throughout the rivers Tibú, el Sardinata and el Zulia (Galvis et al. 1997). The extent of occurrence is very unlikely to be extended.|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This species was pointed out as common in the lower portion of the Catatumbo River (Galvis et al. 1997) but no further data are available on the population of this freshwater stingray.|
|Habitat and Ecology:||
Very little is known about the habitat and ecology of P. magdalenae.. This species was indicated to be found in both headwaters and lower drainages of some rivers within its distribution range (Galvis et al. 1997). These same authors reported that this species prefers muddy substrates, murky and shallow waters.
The stomach contents of specimens collected from the Catatumbo River contained insect larvae stages and detritus (Galvis et al. 1997).
Most reproductive biology information available comes from a single research study carried out by Teshima and Takeshita (1992). Apart from them, only Dahl (1971), in a general study of the fish in Northern Colombia, mentioned that this species reached maturity with less than 25 cm of disc width. The information available suggests that this species reaches sexual maturity at a small disc width size and presents a low fecundity. Since most potamotrygonids present a defined reproductive period (Charvet-Almeida et al. 2005), it is possible that Teshima and Takeshita (1992) could not observe this due to the short length of their sampling period.
There is little information regarding the threats for P. magdalenae but supposedly at least some of them are similar to ones indicated for P. yepezi, another freshwater stingray found in Colombia (Mojica et al. 2002). These same authors indicated P. magdalenae as being a vulnerable species (VU) in Colombia but no details are given concerning the criteria for the selection of this specific status.
This species is currently entering the ornamental trade (Gonella 1997, Ross and Schäfer 2000) without any specific regulation and monitoring. No information is available about how many specimens are exported and to what extent this might represent a threat for this species. Informal reports indicate that this species is also caught as bycatch in fisheries that target some bony fish of economic value in the river basins where P. magdalenae is found.
Intrinsic factors common to other elasmobranchs (Camhi et al. 1998) affect this species too and its restricted range must be taken into account.
Other threats for this species are not well know but considering the main known threats for other potamotrygonids (included the ones cited for P. yepezi by Mojica et al. 2002) it is expected that it is susceptible to water pollution of different origins (agricultural, industrial and sewage pollution mainly), mining, infrastructure development and human disturbances. As in other parts of the North region of South America, it is expected that persecution of this species also takes place.
Base-line studies are required to acquire more information regarding the life history aspects of this species. More information about the trade is also needed in order to implement management plans, trade management and specific legislation to guarantee that catches are sustainable.
Bycatch captures should also be monitored and quantified in order to determine to what extent target (bony fish) fisheries represent a threat.
Habitat maintenance and conservation should also be considered since freshwater elasmobranchs are more susceptible to impacts due to their more restricted distribution in comparison with their marine counterparts (Araújo 1998, Charvet-Almeida 2001, Charvet-Almeida et al. 2002).
Mojica et al (2002) indicated needed for habitat protection, base-line studies and population evaluation for P. yepezi, which are probably valid recommendations for P. magdalenae.
Public awareness is desired to minimize persecution, which probably occurs (as in other places where freshwater stingrays are present).
|Citation:||Charvet-Almeida, P. & Pinto de Almeida, M. 2009. Potamotrygon magdalenae. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 28 July 2015.|
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