Age Estimation and Post-Natal Growth in the Bat Myotis lucifugus

Kunz, Thomas; Anthony, Edythe L. P.

doi:10.2307/1380667

Cited by 197 publications

(180 citation statements)

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“…Bats were always captured before or as they left their roost. Individuals were sexed, weighed and their adult status determined as previously described [Kunz and Anthony 1982;León-Galván et al 2005]. In total 16 adult male bats were examined.…”

Section: Methodsmentioning

confidence: 99%

Spermatozoa Epididymal Maturation in the Mexican Big-Eared Bat (Corynorhinus Mexicanus)

Cervantes

Arenas‐Ríos

Ángel

et al. 2008

Systems Biology in Reproductive Medicine

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Prolonged epididymal sperm storage in vespertilionid and rhinolophid bats, provides an interesting experimental model for the study of spermatozoa epididymal maturation. We examined the presence of the cytoplasmic droplet, and the sequential induction of capacitation and the acrosome reaction in spermatozoa obtained from different epididymal regions (caput, corpus, cauda) throughout the annual reproductive cycle of Corynorhinus mexicanus (C. mexicanus). This is a vespertilionid bat that stores spermatozoa in the epididymis for several months after testes regression. The number of sperm recovered from the different epididymal regions indicate that epididymal transit in C. mexicanus is rapid. The persistence of a high percentage of sperm cells with cytoplasmic droplet in cauda epididymis was observed in addition to a low index of capacitation and acrosome reaction in sperm cells obtained from the corpus epididymis. There was a significant increase in the percentage of capacitated and acrosome reacted spermatozoa during the storage of sperm cells in the cauda epididymis and the percentage of capacitated spermatozoa was consistently, and significantly, higher (p < 0.05) in cauda compared to the corpus epididymis at all studied dates. Tthe process of epididymal maturation in C. mexicanus is completed in the caudal region of this organ encompassing a significant period. Our results also indicate that in C. mexicanus, and in other vespertilionid and rhinolophid bats that show the same temporal asynchrony in the function of male reproductive organs, the final phases of epididymal maturation and storage are, apparently, independent of testicular function.

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Section: Methodsmentioning

confidence: 99%

Spermatozoa Epididymal Maturation in the Mexican Big-Eared Bat (Corynorhinus Mexicanus)

Cervantes

Arenas‐Ríos

Ángel

et al. 2008

Systems Biology in Reproductive Medicine

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“…molossus adult males (n = 18) weighing 15-20 g were collected during the four neotropical annual seasons: summer (January and March, n = 5), fall (April and June, n = 5), winter (July and August, n = 4) and spring (October, n = 4). The identification of adult bats was done based on the fusion zone region of the cartilaginous epiphysis of the fourth metacarpal-phalangeal joint (Kunz and Anthony, 1982). The animals were captured in Viçosa, southeastern of Minas Gerais, Brazil (20°45'4" S and 42°52'53" W).…”

Section: Animalsmentioning

confidence: 99%

Seasonal variation of energy reserves and reproduction in neotropical free-tailed bats Molossus molossus (Chiroptera: Molossidae)

et al. 2013

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Seasonal variation is a key factor regulating energy metabolism and reproduction in several mammals, including bats. This study aimed to track seasonal changes in the energy reserves of the insectivorous bat Molossus molossus associated with its reproductive cycle. Adult males were collected during the four neotropical annual seasons in Viçosa -MG, Brazil. Blood and tissues were collected for metabolic analysis and testes were removed for histology and morphometry. Our results show that liver and breast muscle glycogen concentrations were significantly lower in winter. The adiposity index was significantly higher in the fall compared to winter and spring. Seminiferous tubules were greater in diameter in animals captured in fall and winter, indicating a higher investment in spermatic production during these seasons. The percentage of Leydig cells was higher in summer compared to fall and winter. We suggest that M. molossus presents a type of seasonal reproduction with two peaks of testicular activity: one in fall, with higher sperm production (spermatogenesis), and another in summer, with higher hormone production (steroidogenesis). The metabolic pattern may be associated with reproductive events, especially due to the highest fat storage observed in the fall, which coincides with the further development of the seminiferous tubules.Keywords: spermatogenesis, histology, insectivorous, males, metabolism. Variação sazonal das reservas energéticas e a reprodução do morcego neotropical de cauda livre Molossus molossus (Chiroptera: Molossidae) ResumoA variação sazonal é um fator chave na regulação do metabolismo energético e da reprodução em vários mamíferos, incluindo os morcegos. O objetivo deste estudo foi avaliar as reservas energéticas do morcego insetívoro Molossus molossus ao longo das estações anuais associadas ao seu ciclo reprodutivo. Foram coletados machos adultos durante as quatro estações anuais na cidade de Viçosa -MG, Brasil. Para as análises metabólicas foram coletados tecidos e sangue, e os testículos foram removidos para análises histológicas e morfométricas. Os resultados mostram que as concentrações de glicogênio no fígado e músculo peitoral foram significativamente menores no inverno. O índice adiposo foi significativamente maior no outono em relação ao inverno e primavera. Os túbulos seminíferos apresentaram maiores diâmetros nos animais coletados no outono e inverno, indicando um maior investimento na produção espermática durante estas estações. A porcentagem de células de Leydig foi maior no verão em comparação com outono e inverno. Sugere-se que M. molossus apresenta um tipo de reprodução sazonal com dois picos de atividade testicular: uma no outono, com maior produção de espermatozóides (espermatogênese), e outra no verão, com maior produção de hormônio (esteroidogênese). O padrão metabólico pode estar associado a eventos reprodutivos, especialmente devido ao maior armazenamento de gordura observado no outono, que coincide com o desenvolvimento dos túbulos seminíferos.Palavras-chave: e...

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“…The age group was determined based on the presence of bone or cartilage epiphysis on the metacarpal-phalangeal joint from the left forth digit (Burnett and Kunz, 1982;Kunz and Anthony, 1982;Anthony, 1988). …”

Section: Samplementioning

confidence: 99%

Sexual size dimorphism in Myotis nigricans (Schinz, 1821) (Chiroptera: Vespertilionidae) from south Brazil

2008

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Among Vespertilionidae species, sexual size dimorphism is very well documented, in which females are larger than males. The differences are mainly in body weight, skull measurements and forearm length. Studies have discussed some hypothesis for this phenomenon. However, very little information is known about sexual size dimorphism in Myotis nigricans (Schinz, 1821) in Brazil. In this sense, the goal of this paper is to present a study of this phenomenon in the species. For this, we present a quantitative analysis of sexual size dimorphism assessed by traditional morphometrics. Ten skull measurements in addition to the forearm length of adult specimens were taken. Results of traditional morphometrics revealed sexual size dimorphism in five skull measurements and in the forearm length. Females were larger than males. These differences can be attributed to natural selection on large female size for increase fecundity. Bat females of the Vespertilionidae family are usually larger than males in order to perform parental care appropriately and to provide a successful reproductive process.Keywords: Chiroptera, Vespertilionidae, Myotis nigricans, sexual size dimorphism, morphometrics.Dimorfismo sexual no tamanho do crânio de Myotis nigricans (Schinz, 1821) (Chiroptera: Vespertilionidae) no sul do Brasil ResumoEntre as espécies de Vespertilionidae, o dimorfismo sexual, no qual as fêmeas são maiores que os machos, é bem documentado. As diferenças aparecem principalmente no peso do corpo, nas medidas cranianas e no comprimento do antebraço. Estudos têm discutido algumas hipóteses para este fenômeno. Contudo, poucas são as informações conhecidas sobre dimorfismo sexual de tamanho para a espécie Myotis nigricans (Schinz, 1821) no Brasil. O objetivo deste artigo é apresentar um estudo deste fenômeno na espécie. Para isso, apresentamos uma análise quantitativa do dimorfismo sexual através da morfometria tradicional, no qual 10 medidas cranianas e o comprimento do antebraço foram tomados. Resultados da morfometria tradicional revelaram dimorfismo sexual em cinco das dez medidas cranianas e no comprimento do antebraço. Em todas as medidas, as fêmeas foram maiores que os machos. As diferenças podem ser atribuídas à seleção natural, favorecendo tamanho maior para as fêmeas para aumentar a fecundidade. Fêmeas da família Vespertilionidae são geralmente maiores a fim de desempenhar adequadamente o cuidado parental e prover processo reprodutivo com sucesso.Palavras-chave: Chiroptera, Vespertilionidae, Myotis nigricans, dimorfismo sexual no tamanho, morfometria tradicional.

show abstract

Age Estimation and Post-Natal Growth in the Bat Myotis lucifugus

Cited by 197 publications

References 14 publications

Spermatozoa Epididymal Maturation in the Mexican Big-Eared Bat (Corynorhinus Mexicanus)

Spermatozoa Epididymal Maturation in the Mexican Big-Eared Bat (Corynorhinus Mexicanus)

Seasonal variation of energy reserves and reproduction in neotropical free-tailed bats Molossus molossus (Chiroptera: Molossidae)

Sexual size dimorphism in Myotis nigricans (Schinz, 1821) (Chiroptera: Vespertilionidae) from south Brazil

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