Semen cryopreservation in golden-headed lion tamarin, Leontopithecus chrysomelas

Wild animal genetic resource banking (GRB) represents a valuable tool in conservation breeding programs, particularly in cases involving endangered species such as the golden‐headed lion tamarin (Leontopithecus chrysomelas). Thus, we aimed to assess a sperm freezing protocol for golden‐headed lion tamarins using two different exenders: BotuBOV® (BB) and Test Yolk Buffer® (TYB). Ejaculates were collected by penile vibrostimulation from animals housed at São Paulo Zoological Park Foundation, São Paulo, Brazil, and after immediate analysis, two aliquots were diluted in BB and TYB. Postthawing samples were evaluated for total and progressive motility, plasma membrane and acrosome integrities, mitochondrial activity, suscept- ibility to oxidative stress, and sperm–egg‐binding. No differences between BB and TYB were found for most seminal parameters, except for acrosome integrity and susceptibility to oxidative stress (in both cases BB showed higher values). However, in spite of these differences and regardless of the extender used, postthaw sperm motility and viability with the described protocol were encouraging (on average >50% and >80%, respectively), indicating that sperm cryopreservation may be a short‐term measure for the conservation of golden‐headed lion tamarins.

Testicular volume and semen characteristics in the endangered southern muriqui (Brachyteles arachnoides)

Background: The southern muriqui (Brachyteles arachnoides) is an endangered Neotropical primate. Semen collection and description of its traits, as well as testicular morphometry, have never been reported for this species. Methods: Testicles from five healthy adult captive southern muriqui were measured, and semen was collected by rectal probe electrostimulation (RPE). Results and Conclusions: A solid coagulum was identified in all ejaculates, and none of them liquefied, spontaneously or non-spontaneously. It was possible to collect semen using RPE, and although solids coagula did not liquefy, we managed to describe ejaculates characteristics and also confirmed that southern muriqui have relatively large testes size. Further investigations are needed to improve coagulum handling, to achieve a better spermatozoa recovery aiming its application in assisted reproductive technologies.