河川環境におけるカニ類の分布様式と生態　生態系における役割と現状

• 小林 哲

  京都大学大学院農学研究科

書誌事項

タイトル別名

• Distribution pattern and ecology of brachyuran crabs in the riverine environment
• 生態系における役割と現状

抄録

I reviewed the ecology of brachyuran crabs distributed in rivers flowing in central Japan. Ecological information on 20 crab species is introduced. Six life history types were classified according to their distribution in rivers and migration patterns. Regarding types A and B, the distribution of crabs is restricted to brackish areas, without migration (Type A) or with a seaward migration for reproduction (Type B). Regarding types C and D, crabs are widely distributed in the terrestrial environment along rivers, with hatching in the wide area (Type C) or only in the sea (Type D). Regarding type E, crabs grow in the freshwater area of rivers and reproduce in the estuarine area after a downstream migration. In these types, larvae are dispersed in the sea. Regarding type F, crabs complete their life history within the freshwater area, with an abbreviated larval development.<BR>The distribution of crabs tends to concentrate in the estuarine area. Many ocypodids dig burrows in the tidal flat with habitat segregation mainly according to the granularity of substratum, and many sesarminae (grapsid) crabs occur around reed marshes. In the lower and middle regions of the freshwater area, Eriocheir japonica is distributed in aquatic habitats, and three sesarmid crabs (Sesarmops intermedium, Chiromantes dehaani, Chiromantes haematocheir) live in habitats along the river. In the upper reaches, Geothelphusa dehaani occurs in both aquatic and terrestrial environments.<BR>Crabs are important members of the detritus food chain in the tidal area. Ocypodids and grapsids consume particulate organic matter deposited on the substrate and support the decomposition of nutrients by digging burrows into the substrate. In recent years, however, their habitat tends to be lost due to changes in the sediment environment. Construction of weirs also affects their migration process. The loss of natural vegetation around the watershed due to riverworks decreases their habitat.

収録刊行物

• 応用生態工学

  応用生態工学 3 (1), 113-130, 2000

  応用生態工学会

キーワード

• brachyuran crabs
• distribution in the river
• life history
• habitat
• riverine environment

詳細情報

• CRID: 1390282679448254848
• NII論文ID: 130003441737
• DOI: 10.3825/ece.3.113
• ISSN: 18825974
• ISSN: 13443755
• ISSN: http://id.crossref.org/issn/13443755
• 本文言語コード: ja
• データソース種別:
  • JaLC
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可