Histomorphology of the glans penis in Vespertilionidae and Phyllostomidae species (Chiroptera, Mammalia)

Abstract

The penises of bats are taxonomically distinctive in size and shape. In addition, they are variable in microscopic anatomy, indicating that histomorphological studies of copulatory organs of bats may help understanding their successful reproductive strategies. We studied adult males of 13 species of vespertilionid and phyllostomid bats.Both families exhibited the basic structure of the vascular penis of mammals: the hydrostatic elements of the corpora cavernosa and the corpus spongiosum surrounding the urethra, as well as accessory cavernous tissue. Variation in the position and amount of the tissues were observed in these families. Vespertilionid bats have a small glans penis with abundant accessory cavernous tissue on the prepuce and a highly variable baculum. The baculum varied in size and morphology, even among congeneric species, such as the three Lasiurus species and the two Myotis species.Phyllostomid species possess no bacula, but vascular structures are present to produce penile stiffening, particularly on the glans. Variation in the microscopic anatomy of the phyllostomid prepuce was observed, for example, Artibeus species had accessory cavernous tissue surrounded by a tunica albuginea, but Carollia perspicillata had two bundles of striated musculature and some adipose tissue; abundant pigments were present in the prepuce of most species. K E Y W O R D S baculum, bat, male reproductive tract

Morphological changes associated with Nile crocodile (Crocodylus niloticus) phallic glans inflation

“…Glans structures among vertebrates are likely to share a number of functional similarities related to producing specific and repeatable shapes, such as extensible tissues and elements that locally restrict expansion (Kelly, 2016). Glans anatomy has been generally described for mammals, where it is typically an inflatable, cap‐shaped expansion of the corpus spongiosum found at the distal end of the penis (Jubilato et al, 2019; Weiss et al, 2012), but it is more poorly understood for other amniote taxa. Studies of the male turtle reproductive anatomy have, until recently, focused on the gross morphologies of noncopulatory glans, not characterizing glans inflation, internal structures, or histological details (Fernandes Araujo Chaves, Viana, Chaves, Miglino, & de Sousa, 2020; Gradela et al, 2019; Larkins & Cohn, 2015; Zug, 1966).…”