Resumen de Eyeless morphotype in the southern stingray (Dasyatis americana): a non-lethal and frequent abnormality from the southern Gulf of Mexico

Manuel Mendoza Carranza, Diego Santiago Alarcón, Juan Carlos Pérez-Jiménez, Chrystian Carolina Hernández Lazo

• español

  An eyeless morphotype in Southern Stingray (Dasyatis americana) is described and implications about its presence in tropical marine coastal zones are discussed based on the description of six individuals collected from commercial small-scale fisheries at southern Gulf of Mexico on the Campeche bank. Additionally to the eyeless characteristic, both regular (presence of eye) and eyeless (absence of eye) morphotypes have contrasting quantitative values and qualitative features for different phenotypic traits (color, teeth number, pelvic fin and spiracle form). Mature female and male eyeless morphotype had functional internal reproductive structures. Using the bar code gene we found conclusive evidence that the eyeless morphotype belongs to the species D. americana. This is the first report on reproductively functional eyeless individuals of this species or close relatives elsewhere, which live sympatrically with regular individuals in the southern Gulf of Mexico.  

• English

  Elasmobranchs are active predators that depend on a highly developed visual system. The eyes of the southern stingray, Dasyatis americana, are adapted to a changing light environment in coastal zones. In this study we use morphological characters and molecular methods (mtDNA COI) to describe an eyeless morphotype of D. americana from six individuals collected from commercial small-scale fisheries on the Campeche Bank (southern Gulf of Mexico). Additionally to the eyeless characteristic, both regular (presence of eye) and eyeless (absence of eye) morphotypes have contrasting quantitative values and qualitative features for different phenotypic traits (color, teeth number, pelvic fin and spiracle form). Mature female and male eyeless morphotype had functional internal reproductive structures. Using the bar code gene, we found conclusive evidence that the eyeless morphotype belongs to the species D. americana. This is the first report on reproductively functional eyeless individuals of this species or close relatives elsewhere, which live sympatrically with regular D. americana individuals in the southern Gulf of Mexico