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Tsukasa OKANO Katsuhi NAKATA Yumiko NAKAYA Takashi NAGAMINE Manabu ONUMA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(6):637-642
The Ryukyu long-furred rat, Diplothrix legata, is a large rodent
distributed only on Amami-ohshima Island, Tokuno-shima Island and Okinawa-jima Island,
Japan. This animal is endangered as a result of deforestation, predation by introduced
carnivores and mortality caused by vehicles. We performed theriogenological examinations
of 32 male and 25 female Ryukyu long-furred rats carcasses collected from wild populations
on northern Okinawa-jima Island from December 2005 to September 2013. Adult males had
remarkably large preputial glands. Seminiferous diameter of adult was significantly small
(136 ± 28 µm, n=8) from April to August. Numerous spermatozoa were
observed from September through February, and seminiferous diameter was significantly
large (216 ± 27 µm, n=12) during this time in adults; testes length
changed in a similar pattern. These findings indicate that the mating season may occur
from September through February. Size (body length) at sexual maturity was estimated to be
>560 mm in both sexes. From observation of corpora lutea and placental scars, litter
size was estimated to range from 2 to 12 (average=6, n=4). These results provide
fundamental knowledge that will be beneficial for in situ and ex
situ conservation of this rare species. 相似文献
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