Male external genitalia morphology of the solo ex situ pacarana Dynomis branickii (mammalia: Rodentia: Dinomyidae)

Abstract

Little is known regarding the biology and behavior of the pacarana (Dinomys branickii) in both in situ and ex situ environments. A comprehensive morphological analysis of the male pacarana's genital organ is presented in this study, along with comparisons to other species belonging to the suborder Hystricomorpha. The study was conducted assessing the reproductive health of the sole ex situ male in Brazil. The findings revealed subcutaneous ellipsoidal tests and a cylindrical penis covered with distinct penile spines that was enveloped by a foreskin. The discussion draws comparisons between the aforementioned findings and those of other Neotropical rodents, emphasizing the lack of a scrotum and the existence of penile spines. This research offers vital insights into the pacarana's biology, establishing a groundwork for forthcoming reproductive biotechnological efforts that seek to safeguard the genetic diversity of little-known species and emphasizing the significance of ex situ conservation efforts.