- 著者
- Yuki OKADA Takashi YABE Sen-Ichi ODA
- 出版者
- The Herpetological Society of Japan
- 雑誌
- Current Herpetology (ISSN:13455834)
- 巻号頁・発行日
- vol.30, no.1, pp.53-61, 2011 (Released:2011-07-01)
- 参考文献数
- 27
- 被引用文献数
- 3
We investigated sex ratio in seven populations of the Japanese pond turtle, Mauremys japonica, inhabiting ponds in the central region of Aichi Prefecture, Japan. The sex ratio, calculated as a numerical proportion (%) of males to total individuals sexed, was highly variable among the populations, ranging from no more than 20.0% to no less than 92.9%. Since M. japonica shows a temperature-dependent sex determination (TSD) with eggs producing more males under a relatively low incubation temperature and more females under a higher temperature, we hypothesized that the observed remarkable inter-population variation in sex ratio reflects that in the nest temperature. Our field observations indicated that the nesting sites of male-biased populations were largely shaded by wood, thus supposedly under a relatively low ambient temperature, while those of female-biased populations were located in open environments with direct exposure to solar heat. These results offer a circumstantial support to the above hypothesis. Remarkably skewed sex ratios observed in some populations might reflect the effect of substantial habitat fragmentation and severe nesting site limitation caused by recent artificial land development and changes in agricultural land use. If this is actually the case and the effect continues to operate, many of the M. japonica populations may eventually disappear.
- 著者
- Reiko USUI Yuki OKADA Emiko FUKUI Atsuhiko HASEGAWA
- 出版者
- 公益社団法人 日本獣医学会
- 雑誌
- Journal of Veterinary Medical Science (ISSN:09167250)
- 巻号頁・発行日
- pp.14-0072, (Released:2014-10-16)
- 被引用文献数
- 1 5
Otitis media of the left ear was diagnosed by video otoscopic examination in a 7-year-old, intact male Shih-tzu dog (weight, 5.1 kg), that also had three complex ceruminous adenomas and a Pseudomonas aeruginosa infection in the left ear canal. In such cases, total ear canal ablation is usually required. However, a complete cure was achieved in the present case without total ear canal ablation. The complex ceruminous adenomas were excised using a diode laser, and repeated cleansing of the tympanic cavity and ear canal was implemented using a video otoscope. As a result, the ear canal was closed in a U-form, and the otitis media was cured.