Abstract

RAMOS-SOCHA, Herly Bibiana  and  GRIJALBA-BENDECK, Marcela. BIOECOLOGY OF THE FRESHWATER STINGRAY Potamotrygon magdalenae (Duméril, 1865) (MYLIOBATIFORMES) FROM THE CIÉNAGA DE SABAYO, GUAIMARAL, COLOMBIA. rev.udcaactual.divulg.cient. [online]. 2011, vol.14, n.2, pp.109-118. ISSN 0123-4226.

One of the most abundant fishes in Colombia is Potamotrygon magdalenae, from the Magdalena River and its tributaries, however, no previous studies on this species exist, unknowing therefore the main bio-ecological aspects. No commercial interest exists on this ray that is caught as bycatch by artesian fishery at Ciénaga de Sabayo (Guaimaral, Magdalena). Between October (2007) and May (2008) 488 individuals of P. magdalenae were captured using gillnet and trawl net. The catch per unit effort was calculated as 1.43 ± 0.37 ind/h for gillnet and 59.30 ± 9.00 ind/h for trawl net, and for biomass estimation 0.38 ± 0.06kg/h and 81.70 ± 13.30kg/h, respectively. Medium maturity size was estimated as 240mm disk width for females and 202mm for males, while minimum maturity size was 164mm (females) and 160mm (males). The right ovary of females was less developed than the left one, both uterus were functional containing 1 to 5 embryos, which birth size was estimated between 87 and 95mm AD. A total of 39 empty stomachs were registered (14,6%), and food content was observed on 227 (85,3%). Polymitarcidae (55,6%) and its larvae (30,8%) were the most important preys, indicating that P. magdalenae is an insectivore and detritivore benthonic species.

Keywords : Potamotrygonidae; freshwater stingray; biology; fishery; Magdalena; Colombia.

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