Effects of elevated temperatures on the embryonic development and corpus luteum activity in the Japanese long-fingered bat, Miniopterus schreibersii fuliginosus

Abstract

Gravid female Japanese long-fingered bats were kept in captivity without hibernation at elevated temperatures (23-25 degrees C) in winter. The embryonic growth rate was accelerated and consequently parturition was advanced by a period equivalent to that of exclusion from hibernation as compared with that in the wild population. The corpus luteum became active, as indicated by an increase in the 'light' lutein cells in an experimental bat pregnant with a 15-mm embryo, but was less active (more 'dark' cells) in 2 hibernating control bats with an implanting blastocyst.

Changes in progesterone concentrations in the Japanese long-fingered bat, Miniopterus schreibersii fuliginosus

“…These results support our belief that the corpus luteum is less active during delayed development in this bat (Kimura & Uchida, 1983;Uchida et al, 1984). The so-called delayed development was first described in the California leaf-nosed bat, Macrotus californicus (Bradshaw, 1962), and occurs also in the Mexican fruit bat, Artibeus jamaicensis (Fleming, 1971).…”

“…Embryonic development, however, proceeds rapidly after arousal from hibernation in early April , and the young are born in late June or early July (Uchida, 1957). Uchida et al (1984) showed that elevated temperatures (23-25°C) and abundant food supply during winter accelerated the rate of embryonic development and that the corpus luteum cells in bats kept at an elevated temperature (25°C) became active while those in hibernating bats were less active. However, information which might explain an hormonal regulation of such a reproductive mechanism is scarce.…”

A comparative study of prenatal development in Miniopterus schreibersii fuliginosus, Hipposideros armiger and H. pratti

“…Although accelerated development could be the result of individual variation in the population, it is most likely due to the fact that the bats captured on 19 Feb 2009 and 4 March 2008 were artificially aroused from hibernation, kept in an elevated ambient temperature and supplied with food. Similar phenomena also occurred in other bat species, including M. schreibersii fuliginosus [20,21]. …”

Reproductive synchrony and annual variation in foetal growth rate in the long‐fingered bat (Miniopterus schreibersii)

“…Elevated ambient temperature accelerates post-implantation development in the pipistrelle (Pipistrelfus pipistrelfus) in Great Britain (Racey, 1973) and in the long-fingered bat ( M . schreihersii) in Japan (Kimura & Uchida, 1983;Uchida, Inoue & Kimura, 1984), while reduced ambient temperature coupled with food deprivation has the opposite effect in the pipistrelle in Great Britain (Racey, 1969(Racey, , 1973. Racey & Swift (1 98 1) have used the results from these experiments to explain a 1 O-day variation in gestation length of the pipistrelle over two consecutive years when weather conditions in early pregnancy varied.…”