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Due to the scarcity of information about patterns of spermatogenesis in bats, this study aimed to provide information on the testicular activity of the bat Sturnira lilium along the annual seasons. Thus, a series of morphometrical and stereological analyses were made using the testes of adult S. lilium in order to achieve a better understanding of the sperm production dynamics. Light and transmission electron microscopy analyses were performed in testicular fragments of animals captured during dry and rainy seasons. The testes followed the pattern of organization described for other mammals, and there were no morphological differences between organs collected either in dry or in rainy seasons. Each tubular cross-section in stage 1 was made of 0.5 type-A spermatogonia, 4.4 primary spermatocytes in preleptotene/leptotene, 3.7 in zygotene, 11.9 in pachytene, 35.6 round spermatids and 8.5 Sertoli cells. The mitotic and meiotic indexes were 15.4 and 2.9 cells, respectively, while the spermatogenesis yield was 68.7 cells. The testicular sperm reserves was 37.61×106 cells, and daily sperm production per gram of testis averaged 209.68×106 cells, both highest averages occurring in the rainy season. S. lilium male bats have a continuous reproductive pattern, high spermatogenesis yield and low support capacity by the Sertoli cells.

Among all bat species, Desmodus rotundus stands out as one of the most intriguing due to its exclusively haematophagous feeding habits. However, little is known about their spermatogenic cycle. This study aimed at describing the spermatogenic process of common vampire bats through testicular histomorphometric characterization of adult specimens, spermatogenic production indexes, description of stages of the seminiferous epithelium cycle and estimative of the spermatogenic process duration. Morphometrical and immunohistochemical analyzes for bromodeoxiuridine were conducted under light microscopy and ultrastructural analyzes were performed under transmission electron microscopy. Vampire bats showed higher investment in gonadal tissue (gonadosomatic index of 0.54%) and in seminiferous tubules (tubulesomatic index of 0.49%) when compared to larger mammals. They also showed a high tubular length per gram of testis (34.70 m). Approximately half of the intertubular compartment was found to be comprised by Leydig cells (51.20%), and an average of 23.77x106 of these cells was found per gram of testis. The germline cells showed 16.93% of mitotic index and 2.51% of meiotic index. The overall yield of spermatogenesis was 60% and the testicular spermatic reserve was 71.44x107 spermatozoa per gram of testis. With a total spermatogenesis duration estimated at 37.02 days, vampire bats showed a daily sperm production of 86.80x106 gametes per gram of testis. These findings demonstrate a high sperm production, which is commonly observed in species with promiscuous mating system.

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RESUMORealizaram-se estudos morfológico e funcional da espermatogênese em 15 testículos de catetos adultos, provenientes de abatedouro comercial de animais silvestres. Foram estudados os estádios do ciclo do epitélio seminífero (CES), a população celular dos túbulos seminíferos, o rendimento intrínseco da espermatogênese, o índice das células de Sertoli, o diâmetro médio dos túbulos seminíferos e a proporção volumétrica dos componentes do parênquima testicular. O coeficiente de eficiência de mitoses espermatogoniais foi de 22,54, a eficiência da mitose de 22,54, o rendimento meiótico de 1:2,7 e o rendimento geral da espermatogênese de 1:64. Concluiu-se que a espermatogênese dos catetos é muito semelhante à espermatogênese de suínos. Palavras-chave: catetos, Tayassu tajacu, espermatogênese ABSTRACT

This study was designed to evaluate the efficiency of medetomidine anesthesia for semen collection through urethral catheter in wild and captive jaguars. Six captive and five wild jaguars were chemically restrained with a combination of medetomidine (0.08-0.1 mg/kg) and ketamine (5 mg/kg). After medetomidine administration the urethra was catheterized using a urinary tomcat catheter (1 mm diameter × 130 mm length) to collect semen from all animals. By using this technique, we could collect an average of 347.2 μl of semen containing 2,635.2 sperm/ml. Forward progressive motility, sperm progressive motility, and sperm morphology analysis demonstrated that the methodology did not affect sperm quality. Thus, urethral catheterization after medetomidine administration is a practical and efficient method to collect high-quality semen from wild and captive jaguars; this will enable the development of reproductive assisted technologies for jaguars.

RESUMO Morfometria testicular e de túbulos seminíferos do cachorro-do-mato (Cerdocyon thous, Linnaeus, 1766) adultoOs parâmetros de biometria corporal e testicular são de grande importância no estabelecimento dos padrões reprodutivos e, consequentemente, no desenvolvimento de protocolos para a reprodução assistida nas diferentes espécies. Uma correlação direta entre o peso do testículo e a população espermática é observada nas diferentes espécies já estudadas, uma vez que o tamanho do testículo reflete principalmente o volume total do túbulo seminífero, seu principal componente. O presente trabalho tem como objetivos definir parâmetros volumétricos testiculares e correlacionar os dados de morfometria testicular e do túbulo seminífero com a massa corporal em seis cachorros-domato adultos. O peso corporal médio dos cachorros-do-mato foi de 6,53 Kg, dos quais cerca de 0,068% são alocados em massa testicular e 0,042% especificamente em túbulos seminíferos, que representam 87,5% do parênquima testicular. A albugínea representa 12,5% da massa testicular. O diâmetro médio dos túbulos seminíferos em cachorro-do-mato foi de 236 μm, e a espessura média do epitélio seminífero foi de 62,9 μm, sendo encontrados em média 18 metros de túbulo seminífero por grama de testículo. Os valores para os parâmetros tubulares indicam uma produtividade espermática próxima àquelas observadas nos carnívoros já estudados. Body and testicular biometric parameters are very important for establishing reproductive patterns and, consequently, the development of protocols for assisted reproduction in different species. A direct correlation between the testis weight and the sperm population was observed in other studied species, because the testis size primarily reflects the total volume of the seminiferous tubule, its main component. The objective of this study was to determine the testicular volume parameters and correlate data from morphometry of testis and seminiferous tubules with body mass in six adult crab-eating foxes. The mean body weight of the crab-eating foxes in this study was 6.53 kg, with approximately 0.068% allocated to the testicular mass and 0.042% specifically to seminiferous tubules, which represented 87.5% of the testicular parenchyma. The albuginea comprised 12.5% of the testicular mass. The mean diameter of seminiferous tubules was 236 μm, and the mean thickness of the seminiferous epithelium was 62.9 μm. Values of tubular parameters indicate a sperm productivity close to those observed in previously studied carnivores. Palavras