1 0 0 0 OA ヤドカリの個体群生態学(総説)
- 著者
- 朝倉 彰
- 出版者
- 日本ベントス学会
- 雑誌
- 日本ベントス研究会誌 (ISSN:18838898)
- 巻号頁・発行日
- vol.1984, no.27, pp.1-13, 1984-10-31 (Released:2009-08-07)
- 参考文献数
- 74
- 被引用文献数
- 2 2
Hermit crabs are anomuran decapod crustaceans which have evolved the behabiour of utilizing empty gastropod shells as portable shelters. This paper briefly reviewed various aspects of population ecology of the hermit crabs. Hermit crabs in the field are generally unable to procure empty shells from living snails. Rather they are dependent ultimately upon snail mortality for shells. Snail size affects some parameters of the population through the individual-level processes of the crabs. Some studies indicate that crab growth is slowed by occupation of too small or too large shells. Fecundity is also affected directly by shell occupancy. Reduced clutch size is correlated with reduced shell size, even after the effects of crab size are taken in account. The flexibility in life history traits which shells regulated trade-off between growth and reproduction was reported. Crabs with large shells put effort to growth, while crabs in shells too small to permit growth allocate more time and energy into reproduction. There are considerable inferential and some direct evidences that hermit crab population are limited by supplies of empty shells. Adding many empty shells to the crab population in the field resulted in increasing the crab density. Finally, some problems of life history tactics of hermit crabs and other marine invertebrates are discussed.
1 0 0 0 OA アメリカ・スミソニアン自然史博物館研究員に聞く : 博物館の研究体制
- 著者
- 朝倉 彰
- 出版者
- 日本動物分類学会
- 雑誌
- タクサ:日本動物分類学会誌 (ISSN:13422367)
- 巻号頁・発行日
- vol.12, pp.20-27, 2002-02-20 (Released:2018-03-30)
1 0 0 0 OA カブトヤドカリとモンバンイソギンチャクの共生継続様式
- 著者
- 朝倉 彰
- 出版者
- 日本動物分類学会
- 雑誌
- タクサ : 日本動物分類学会誌 (ISSN:13422367)
- 巻号頁・発行日
- no.21, pp.33-39, 2006-08-20
In 1997, Masatsugu Takano and the applied population genetics research group at Tohoku University published a ground-breaking paper on biochemical and morphological evidence indicated that there were two sympatric forms, interpreted as sibling species, of the common crab Hemigrapsus penicillatus (De Haan). This species is very common in intertidal rocky shores, pebble beaches and mud flats in Japan, Korea and China, but prior to Takano et al., no one had noticed that the species comprised two different forms. A recent intensive study by Prof. Seiichi Watanabe, Tokyo University of Marine Science and Technology, and his research group revealed further differences between the two forms, including coloration, allometry, egg size and number, and geographical distribution. Watanabe and myself recognized these as two distinct species and described one of them as a new species Hemigrapsus takanoi in 2005.