著者

KATSUYUKI HAMASAKI HIDEYUKI IMAI NOBUHIKO AKIYAMA KYOHEI FUKUNAGA

出版者

The Japanese Society of Fisheries Science

雑誌

Fisheries science (ISSN:09199268)

巻号頁・発行日

vol.70, no.6, pp.988-995, 2004 (Released:2009-03-31)

参考文献数

22

被引用文献数

26

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Females of the swimming crab Portunus trituberculatus were cultured under natural temperature and high temperature (21°C) conditions to examine ovarian development and oviposition from autumn (October) to the beginning of breeding season in the following spring (May). Ovaries developed because of vitellogenesis of oocytes from October to December and their developmental state did not change during the overwintering period from December to March. In spring, from late March to mid May, some ovaries reached prematuration and maturation stages and ovipositions began from mid-late April under natural temperature conditions. Females reared in tanks of high temperature regimes oviposited earlier than those reared in tanks of natural temperatures. The number of days to oviposition tended to decrease with advancement of the beginning times (early February to late April) of culture of females under high temperature regimes; induced ovipositions were achieved more easily with increasing photoperiod from c. 12 h in early February to c. 14 h in late April. Therefore, it is inferred that the temperature and photoperiod are important environmental factors controlling ovarian development and oviposition.