- 著者
- Komai Tomoyuki Mishima Shinji
- 出版者
- Japanese Association of Benthology
- 雑誌
- Benthos research (ISSN:02894548)
- 巻号頁・発行日
- vol.58, no.1, pp.15-30, 2003-06-01
- 被引用文献数
- 1
- 著者
- HIROMICHI IMABAYASHI HIDETOSHI SAITO CHIAKI OHMASA KOICHIRO KAWAI
- 出版者
- JAPANESE ASSOCIATION OF BENTHOLOGY
- 雑誌
- BENTHOS RESEARCH (ISSN:02894548)
- 巻号頁・発行日
- vol.1996, no.50, pp.11-17, 1996-02-15 (Released:2009-08-07)
- 参考文献数
- 20
- 被引用文献数
- 1 9
A unique foraging behavior of the carnivorous polychaete Halla okudai (Lysaretidae) is described in detail. Living bivalves, Ruditapes philippinarum were supplied to adult H. okudai, which were burrowing in sandy sediment in aquariums. The foraging behavior was divided into 4 stages ; responding, searching, handling, and feeding. Responding and searching were considered to be dependent on the olfactory sense, and searching was significantly responsible for the variation in total foraging time. Handling was performed by inhibiting the escape of the bivalve and then opening its shell while secreting a jelly-like material. Bivalve size (23.8-26.3mm shell length) showed a significant correlation to handling time, which ranged from 0.87 to 6.67hr. During feeding, the ploychaete continued to secrete the jelly-like material, which was different in hue from that secreted during handling.
- 著者
- Youichi Seto Yukiko Moriyama Daisuke Fujita Mieko Komatsu
- 出版者
- JAPANESE ASSOCIATION OF BENTHOLOGY
- 雑誌
- BENTHOS RESEARCH (ISSN:02894548)
- 巻号頁・発行日
- vol.55, no.2, pp.85-93, 2000-12-31 (Released:2011-11-11)
- 参考文献数
- 17
- 被引用文献数
- 2 4
Abstract: Sexual and asexual reproduction of the fissiparous asteroid Coscinasterias acutispina(Stimpson)was studied in two populations(Kurosaki and Uozu)in Toyama Bay, Sea of Japan, during April 1998-March 1999(Kurosaki)and April 1998-October 1999(Uozu). A total of 96% and 87% of all starfish collected at Kurosaki and Uozu, respectively, showed signs of asexual reproduction by fission. Monthly changes in the ratio of regenerated arm length to maximum arm length revealed that starfish in these populations split most frequently in summer. There was a marked difference in the development of gonads between the two populations. In the Kurosaki population, monthly changes of gonad indices and histological observations on gonads indicated a distinct annual cycle, with a winter spawning season in both males and females. In the Uozu population, gonad indices remained low, and no starfish with mature gonads were observed during the study. An unbalanced sex ratio was observed in both populations; the Uozu population was composed entirely of males. The absence of mature gonads and the extremely biased sex ratio suggest that larval recruitment was low or absent in the Uozu population.
- 著者
- Minoru Ikeda Toshiya Suzuki Yoshihisa Fujio
- 出版者
- JAPANESE ASSOCIATION OF BENTHOLOGY
- 雑誌
- BENTHOS RESEARCH (ISSN:02894548)
- 巻号頁・発行日
- vol.53, no.1, pp.47-52, 1998 (Released:2009-08-07)
- 参考文献数
- 20
- 被引用文献数
- 5
Genetic differentiation among five populations of the Japanese freshwater crab Geothelphusa dehaani, each comprising one of three different body color types, dark brown (RE), dark purplish brown (DA), and grayish blue (BL), was examined by means of electrophoretic analysis of 16 enzyme loci. Allelic replacement was observed between the BL-type population and populations of the other two types (RE and DA) at three loci (α Gpd, Gpi, and Sod-1), but not between the RE-and DA-type populations. The average of Nei's genetic distance (D) was 0.035 between the RE and DA populations (range of 0.013-0.061), 0.251 between the RE and BL populations (0.244-0.260), and 0.296 between the DA and BL populations. These results suggest that the BL type is only distantly related to the other two color types (RE and DA).