First record of spine malformation of the round stingray Urobatis halleri off the Western Coast of Baja California Sur, México

Abstract

Background: Malformations of the Round stingray Urobatis hallerii, Cooper 1863 captured off the southwestern coast of Baja California Sur, México are reported in this study. Methods: The ray was an adult male captured by artisanal fishery in the area of Estero Banderitas. Size measurements of total length and disk width were taken; the organism could be photographed when captured. Results: Malformations of U. hallerii were found in the posterior part of the spine, a distortion in the upper part of the tail and in the left fin close to the tail. The specimen was considered able to reach the adult size usually reported in other specimens of this species despite the spine malformations because of its benthic habits and not losing its mobility completely. Conclusions: The observed malformations were likely due to genetic alterations although other studies are needed to see if other environmental factors could cause malformations in marine organisms mainly in fish and elasmobranchs.

Primer registro de albinismo en la raya redonda enana, <i>Urotrygon nana</i> (Urotrygonidae: Elasmobranchii), en el Pacífico oriental

“…Las malformaciones pueden atribuirse a varias causas, siendo la contaminación del agua, por el aporte de agentes químicos, la más importante debido a las grandes descargas de aguas residuales de las zonas urbanas y las rurales (Haaker, 1977); además del aporte de afluentes cálidos de agua por parte de estaciones generadoras de electricidad, que incluso afecta la distribución de algunas especies de rayas (Hoisington & Lowe, 2005). Se ha observado un mayor grado de afectación en las especies de rayas de hábitos costeros (De Jesús-Roldan, 1990;Ben-Souissi et al 2007;Wakida-Kusunoki, 2015) y al igual que otros organismos que viven enterrados en el sustrato como los peces planos (Gracian-Negrete & Del Moral-Flores, 2013) presentan altas probabilidades de tener afectación en su descendencia al estar en contacto con altas concentraciones de metales pesados (Ochoa et al 2016).…”

New report of malformations in blue shark embryos (Prionace glauca) from the western coast of Baja California Sur, Mexico

“…Additionally, malformations may be the result of genetic alterations during embryonic development or by pollution in the area of species distribution (Whitehead et al , 2012). Early studies on malformations in sharks have reported deformities mainly in skeletal traits, such as pectoral fins not fused to the head, albinism and dicephaly and trunk rolled in the case of rays (Heupel et al , 1999; Mancini et al , 2006; Ochoa-Diaz et al , 2016). This study reports for the first time four malformations of blue shark embryos from the western coast of BCS, Mexico.…”

First record of monoclasper in the Banded guitarfish, Zapteryx exasperata in the Gulf of California, Mexico

“…Worldwide, several malformations have been reported in elasmobranchs (e.g., Delpiani et al, 2011;Mejía-Falla et al, 2011;Muñoz-Osorio et al, 2013;Wakida-Kusunoki, 2015;Anislado-Tolentino et al, 2016;Ehemann et al, 2016). In the Mexican Pacific bicephalic embryos (Galván-Magaña et al, 2011), albinism and morphological abnormalities (Escobar-Sánchez et al, 2009;Escobar-Sánchez et al, 2014;Ochoa-Díaz et al, 2016) have been reported. However, pelvic fin abnormalities are uncommon compared to those of pectoral fins (Orlov, 2011), and five cases of a single clasper are know for batomorphs.…”