Luis Brain Carrasco-Martínez; Luis Fernando Del Moral-Flores; Rafael Emiliano Quintanar-Zúñiga & Francisco Sancho-Vázquez

The dermal denticles are dermal structures present in the group of chondrichthyans, they have a very important role in their biology and they have been used as a taxonomic character that allows to recognize groups or species. Therefore, in the present work, the dermal morphology of the juveniles of two species of shovel sharks, Sphyrna tiburo and S. vespertina, whose evolutionary origin is related to the closure of the Central American isthmus, is compared. For this, dermal samples (1 cm2) from three body regions were obtained and processed to obtain high resolution images by means of scanning electron microscopy (SEM). The denticles of both species have a common morphological pattern, with variations in the length of the ridge extensions, free area and overlapping of the denticles, and the degree of notoriety of the microstructural ornamentation.

KEY WORDS: Dermal denticle; Elasmobranch; Spyrnidae; Scale; Scanning electron microscopy.

CARRASCO-MARTÍNEZ, L. B.; DEL MORAL-FLORES, L. F.; QUINTANAR-ZÚÑIGA, R. E. & SANCHO- VÁZQUEZ, F. Dermal microstructural morphology in juveniles of two sister species of Bonnethead shark, Sphyrna tiburo and S. vespertina. Int. J. Morphol., 39(4):1160-1163, 2021.