Descripción morfológica de estructuras dérmicas en batoideos distribuidos en el Pacífico Ecuatoriano.

Abstract

Batoids are a group that present a great variety in their dermal structures, which are fundamental for taxonomic identification and understanding their ecology. However, research on dermal structures is limited and focused on selachians. This study focuses on the morphological variations of the dermal structures in four species of batoids Urobatis tumbesensis (n = 10), Zapteryx xyster (n = 11), Rostroraja equatorialis (n = 10) and Rostroraja velezi (n = 8), in the Manabí region, Ecuador, with the aim of identifying distinctive characteristics in their structures from different regions of the body, and if there is presence of sexual dimorphism across them. Individuals were obtained from incidental capture and 2 cm2 of skin tissue was extracted, selecting seven sections of each organism; Dermal structures were removed from the tissue using 5% sodium hypochlorite for further analysis. Different types of structures were identified, such as thorns, prickles, and cutaneous tubercles, which varied in shape and size depending on the species, sex, and stage of maturity. Two types of structures were present per organism, with significant variability in the morphology of the dermal structures, with differences in the coverage and development of prickles and thorns based on the stage of maturity and sex. This work demonstrates the importance of dermal structures as a tool for taxonomic recognition of batoids from both predatory and fossil records and highlights the need for further research in other regions and orders of elasmobranchs.