Morphological Variation of Primary Reproductive Structures in Males of Five Families of Neotropical Bats

Abstract

Bats present unique features among mammals with respect to reproduction, and although neotropical bats do not have a hibernation period, many of their reproductive characteristics vary seasonally and interspecifically. Thus, this work aimed to examine the reproductive structures of 18 species belonging to five families of Brazilian bats. The gross anatomy of the testes varied little; however, the epididymis of Emballonuridae and Vespertilionidae showed exceptional structures with a large elongation of the caudal region. We observed a wide variation in the positioning of the testes: Phyllostomidae and Noctilionidae presented external testes; Emballonuridae and Molossidae presented migratory testes that may be in intra-abdominal or external positions; and Vespertilionidae displayed scrotal testes. In the histological evaluation, we observed a different pattern in vespertilionid species, with testicular regression and sperm retention/storage in the cauda epididymis in the five species analyzed. Similar testicular regression was observed in Molossops temminckii; however, sperm retention/storage was not observed in this species. These data suggest that although the species analyzed are tropical species that do not present a prolonged period of torpor (hibernation), they still maintain a period of seminiferous tubule regression and sperm storage very similar to that observed in hibernating bats. Anat Rec,

Impact of the processes of testicular regression and recrudescence in the prostatic complex of the bat Myotis nigricans (Chiroptera: Vespertilionidae)

“…levis (Araújo et al, ), Eptesicus furinalis (Bueno et al, ), Histiotus velatus, Lasiurus blossevillii, Myotis. albescens (Beguelini et al, ) and M. nigricans (Beguelini et al, , ).…”

Structure, histochemistry and seasonal variations of the male reproductive accessory glands in the Pallas’s mastiff bat, Molossus molossus (Chiroptera: Molossidae)

“…It is the most common bat in the urban areas of Brazil. It is known to be polyestric with two annual reproductive breeding seasons in Brazil, one in March-April and another in November, and sexually active males are found almost year round (Fabián and Marques 1989;Beguelini et al 2010Beguelini et al , 20122013a;Morais et al 2012Morais et al , 2013. However, information about the reproductive process in males is still scarce.…”

Comparative analysis of the male reproductive accessory glands of bat species from the five Brazilian Subfamilies of the family Phyllostomidae (Chiroptera)

“…The wide geographic distribution and consequent variation in abiotic factors, such as latitude, temperature, humidity, rainfall, and food availability; directly influence the reproductive characteristics and patterns of bats (Fleming et al, ), and lead to the development of many reproductive specializations. Examples of these features are: testicular regression during hibernation; testicular regression in a tropical habitat, without a period of hibernation; an extended duration of sperm storage in the cauda epididymis in males and in the uterine cornua in females; asynchrony between spermatogenesis and the mating period; delayed ovulation, fertilization, and implantation in the female reproductive tract; major differences in the position and morphology of the testes and epididymis and in the ultrastructural morphology of the spermatozoa; and large seasonal variations in reproductive patterns (Fawcett and Ito, ; Gustafson, ; Krutzsch, ; Breed and Leigh, ; Phillips et al, ; Sang‐Sick et al, ; Crichton and Krutzsch, ; Beguelini et al, , , a, b, c, d, a, b; Christante et al, 2014; Negrin et al, ).…”