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Of the family Pteropodidae (Megachiroptera), only the placentae of Rousettus and Pteropus have been examined ultrastructurally. Recently, the interhemal membrane characteristics of some members of this family have been questioned. We report here on the fine structure of the interhemal membrane of Rousettus leschenaulti and Cynopterus sphinx gangeticus. Contrary to earlier reports of a consistent endotheliochorial nature of the membrane until mid-gestation in Rousettus, such a condition is found to be restricted to the trilaminar blastocyst stage. Thereafter, the placental membrane was hemodichorial. We also document how the trophoblast surface has been modified to create honeycombed intrasyncytial desmosomes in Rousettus. The intrasyncytial lamina and maternal endothelium are lacking in the hemodichorial interhemal membrane of Cynopterus.
The detailed reproductive patterns and their associated endocrine characteristics have been documented only for a few species of bats. The objective of this study was to examine seasonal changes in plasma concentrations of leptin and compare it with the changes in body mass, circulating concentrations of testosterone, androstenedione and its correlation with prolonged survival of sperm during winter dormancy in the male sheath-tailed batTaphozous longimanus Hardwicke, 1825. Six bats were captured every month for three consecutive years during 2002 to 2005 from Varanasi, a subtropical part of India. The changes in the body mass were positively correlated with circulating concentration of leptin. Leptin concentration reached a peak (14 ng/ml) in November coinciding with peak body mass. Leptin levels declined during other months of the year except for a rise in March and August. Plasma leptin was positively correlated with androstenedione concentration, but did not show significant correlation with testosterone level. We noticed a significant increase in testosterone secretionin vitro in response to leutinizing hormone (LH) stimulation. However, we did not notice any increase in testosterone or androstenedione secretionin vitro in response to leptin stimulation. Plasma leptin concentration did not show any correlation with testis mass in this study. The higher concentration of testosterone and androstenedione may be responsible for the prolonged survival of sperm in the epididymidies and higher levels of leptin in November may be responsible for maintaining reproductive function during winter dormancy. We suggest that inT. longimanus, higher leptin concentrations in November may be responsible for the gonadal recrudescence and reproductive response during winter dormancy is modified by energy availability and by changing leptin concentrations during this period.
Among adult bats, a vomeronasal organ (VNO) is known only for the New World families Phyllostomidae and Mormoopidae, and for the Old World vespertilionid subfamily Miniopterinae. However, Koike (1924) reported the presence of a well-developed VNO in embryos of Scotophilus kuhlii (= S. temmincki), a vespertilionid from Java of the subfamily Vespertilioninae. Given that a VNO has not been described for any other member of Vespertilioninae, we collected and serially sectioned adults and embryos of two species of Scotophilus (S. kuhlii and S. heathi) from Varanasi, India to check Koike's observation. A careful search revealed the complete absence of the VNO in the adults and embryos of both species. We conclude that the embryos described by Koike as having a well-developed VNO were attributed to S. kuhlii in error. The specimens described by Koike may have been confused with other bats from Java, whose adults and embryos are known to have a well-devel- oped VNO (i.e., the miniopterine Miniopterus schreibersii) or a rudimentary VNO, an epithelial tube without neuroepithelium (i.e., various rhinolophids).
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