Sperm morphology and comparison morphometry measurements of two species of bats, Molossus molossus and Molossops temminckii (Chiroptera: Molossidae)

Abstract

Sperm morphology is considered a species-specific character and has been used as atool in the classification of numerous mammalian taxa. Neotropical bats have beenpoorly studied, and important aspects on sperm morphology have not been elucidated.The aim of the present study was to describe and compare the sperm morphologyand morphometry of Molossus molossus and Molossops temminckii. A total of14 adults specimens were analyzed from the Coleccion Mamíferos Lillo, UniversidadNacional de Tucumán: five M. molossus and nine M. temminckii. The epididymis wereextracted and macerated in Farmer´s solution, followed by a coloration with differentstains. To carry out the description and morphometric analysis, microphotographswere taken under an optical, epifluorescence, and scanning electron microscope(SEM). A total of 50 sperm from each individual were measured for morphometricanalysis. The length and width of the head, midpiece and tail were taken as variables.Sperm from M. molossus and M. temminckii were practically identical, both morphologicallyand morphometrically. In both species, a distal bulge was observed at theend of the intermediate piece in a percentage greater than 85%. The main characteristicsshared between the species were: presence of acrosomal blebs in the upperhalf of the head of the spermatozoa; cephalic equatorial segment with filiform ornamentations;intermembrane space of head apex wedge-shaped; helical middle pieceand annulus at the end of middle piece. In the present study, SEM allowed us to visualizestructures, such as acrosomal vesicles, that were not detected with other typesof microscopy.