Comparison of semen characteristics and sperm cryopreservation in common marmoset (Callithrix jacchus) and black-tufted-ear marmoset (Callithrix penicillata).

BACKGROUND: The common marmoset (Callithrix jacchus) is one of the most studied Neotropical primates regarding reproduction. However, little has been reported on the black-tufted-ear marmoset (Callithrix penicillata), which may produce fertile hybrids with other Callithrix. This is the first study to evaluate sperm freezing from black-tufted-ear marmoset. METHODS: Testicles from all animals were measured, and semen was collected by penile vibrostimulation. Samples were analyzed after collection, after chilling and addition of glycerol, and after thawing. RESULTS AND CONCLUSIONS: Fresh semen from both species was similar in many aspects. Additionally, there is a relationship between total motility, plasma membrane integrity, and acrosome integrity observed in sperm samples from both species. We managed to evaluate fresh and thawed sperm with suitable methods for use under zoo or field conditions. However, TEST egg yolk with glycerol at 4% and 6% concentration was not effective for sperm protection in both species during cryopreservation.

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, susceptibility 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.

Collection, Evaluation, and Coagulum Dissolution of Semen from Goeldi's Monkey, Callimico goeldii.

Research on Neotropical primates' reproduction is necessary due to the lack of available information and the increasing threat to these species. Callimico goeldii is listed as Vulnerable on the IUCN Red List of Threatened Species. This study aimed to test rectal electrostimulation for semen collection and evaluate seminal characteristics. Therefore, semen from 6 captive Goeldi's monkeys was collected and, for the first time, seminal characteristics are described. Coagulum formation was noted in all ejaculates, and we obtained partial or complete liquefaction of the samples. Results were (means ± SD): volume = 26.9 ± 11.87 µL; pH = 7.61 ± 0.28; concentration = 143.18 ± 174.96 × 106 spermatozoa/mL; total sperm motility = 83.33 ± 5.16%; linear progressive motility = 46 ± 24.08%; plasma membrane integrity = 36.38 ± 16.11%; acrosome integrity using fast-green/bengal-rose staining = 63.41 ± 11.72%, and kit Spermac® = 69.36 ± 11.81%; abnormal sperm = 72.5 ± 17.7%, with 16.2 ± 7.7% major defects and 56.3 ± 10% minor defects; sperm with high mitochondrial activity class I = 16.45 ± 22.25%. Rectal electrostimulation was an efficient method for semen collection in this species. Investigations are required to improve semen collection and handling, including cryopreservation methods.

Semen characteristics of captive common marmoset (Callithrix jacchus): a comparison of a German with a Brazilian colony.

BACKGROUND: The common marmoset (Callithrix jacchus) is of interest for reproductive studies because of their high and variable fertility in captivity. However, to understand this variability, much basic information still needs to be gathered. This study is the first to characterize marmoset semen comparing a German and a Brazilian colony. METHODS: All animals were weighted, and semen samples were collected by penile vibratory stimulation and analyzed according to standard criteria. RESULTS AND CONCLUSIONS: The German animals had a higher mean and maximum weight than the Brazilian. Further, sperm concentration tended to be higher with heavier animals in the German population, but not in the Brazilian. Additionally, major defects tended to be more frequent with higher weight but also only in German sample. In spite of these differences, the total range and variability in sperm concentration were similar in both populations, suggesting that this is characteristic for the species.

Pelvimetria em macacos-da-noite (Aotus azaraiinfulatus – KUHL, 1820 / Pelvimetry on owl monkeys (Aotus azarai infulatus – KUHL, 1820)

Analisou-se os diâmetros pelvicos de 72 Aotus azarai infulatus, adultos, 42 machos e 30 fêmeas não prenhes, correlacionando-os com o dimorfismo sexual, a biometria corpórea e a origem dos animais por meio de radiografias em projeção ventro-dorsal, digitalizadas. As médias verificadas foram: para o comprimento do corpo 30,94 cm; comprimento da cauda 35,63 cm; perímetro do tórax 18,97 cm; perímetro da pelve 17,11 cm e o peso 0,96 Kg, em média. As médias dos diâmetros pélvicos foram de 2,64 cm para o diâmetro diagonal direito; 2,66 cm para o diâmetro diagonal esquerdo; 1,97 cm para o diâmetro biilíaco médio; 1,41 cm para o diâmetro biilíaco superior;1,58 cm para o diâmetro biilíaco inferior; 2,48 cm para o diâmetro sacro-púbico e 3,85 cm(elevado a 2) para a área de entrada da pelve. Concluiu-se que, tanto nos machos quanto nas fêmeas, a pelve de Aotus azarai infulatus pode ser classificada como dolicopélvica, tendo-se verificado dimorfismo sexual pélvico nos adultos.

Related data to the diameters of the pelvis from 72 Aotus azarai infulatus, owl monkeys, 42 adult males and 30 adult non-pregnant females, were obtained in vivo by ventrodorsal projection radiographic exams, correlated with sex, the measures of the body and their origin.The mean values of the body length (30.94 cm), tail length (35.63cm), thoracic perimeter (18.97 cm), hip perimeter (17.11 cm) and the weight (0.96 Kg) were verified. The radiographic images were digitalized and measured, and the mean values were 1.41 cm for the superior biiliac diameter; 1.58 cm for the inferior biiliac diameter; 1.97cm for the medium biiliac diameter; 2.64 cm for the right diagonal diameter; 2.66 cm for the left diagonal diameter; 2.48 cm for thesacrum-pubic diameter; 3.85 cm2 for the inlet pelvic area. In conclusion, the pelvis from males and females Aotus azarai infulatus can be classified as dolicopelvic and there is pelvic sexual dimorphism in adult owl monkeys (Aotus azarai infulatus).