Effects of Habitat Fragmentation on the Amphidromous Freshwater Shrimp, Caridina Leucosticta (Decapoda, Atyidae) in a Rice Paddy Drainage Channel
Effects of Habitat Fragmentation on the Amphidromous Freshwater Shrimp, Caridina Leucosticta (Decapoda, Atyidae) in a Rice Paddy Drainage Channel
复制标题
稻田排水沟生境破碎化对双性淡水虾 Caridina Leucosticta(十足目,Atyidae)的影响
DOI:
10.1163/001121610x521190
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发表时间:
2010
期刊:
影响因子:
0.6
通讯作者:
T. Hamano
中科院分区:
文献类型:
--
作者:
K. Nakata;Kunihiko Amano;M. Denda;Junji Miwa;T. Hamano
[Agricultural channels can be important habitats for aquatic species inhabiting agricultural areas. However, water supply in agricultural channels can vary substantially with types of agriculture and irrigation/drainage system, and thereby affect the viability of local populations of aquatic species. In this study, we focused on the amphidromous freshwater atyid shrimp Caridina leucosticta. To clarify whether C. leucosticta utilizes agricultural channels as a habitat in relation to fluctuations in the water supply, we conducted a series of field surveys on the distribution of this shrimp in a rice paddy drainage channel (spring-fed channel) around the Furu River, central Japan, during July and December 2008. Large numbers of C. leucosticta had migrated into that drainage channel. Water from the adjacent rice paddies had disappeared by October, because irrigation was stopped, but the water level in the drainage channel was maintained by a supply of spring water. By mid-November the supply of spring water had almost disappeared, then the channel nearly dried up, and many shrimps were concentrated in an isolated water pool in the channel. Thus, habitat fragmentation of C. leucosticta occurred in terms of water (dis-)continuity. This water pool dried up completely by mid-December. We found many dead individuals of C. leucosticta in the dried-up area of the channel. These results indicate that agricultural channels can be an important temporal habitat for amphidromous freshwater shrimps, but that the drying-up of the channels can lethally affect migrating atyid shrimps. Les canaux agricoles peuvent etre des habitats importants pour les especes aquatiques rurales. Cependant l'alimentation en eau des canaux agricoles peut varier substantiellement avec le type d'agriculture, les systemes d'irrigation/drainage et en consequence affectent la viabilite des populations locales des especes aquatiques. Cette etude est centree sur la crevette atyidee amphidrome d'eau douce Caridina leucosticta. Pour eclaicir si C. leucosticta utilise les canaux agricoles comme habitat en relation avec la fluctuation de l'apport en eau, nous avons conduit une serie de releves de terrain sur la distribution de cette crevette dans un canal de drainage de riziere (eau de source) pres de la riviere Furu, Japon central, durant Juillet et Decembre 2008. Un grand nombre de C. leucosticta ont migre dans ce canal de drainage. L'eau des rizieres adjacentes a disparu en Octobre, car l'irrigation a stoppe, mais le niveau de l'eau a ete maintenu par un apport d'eau de source. Mi-Novembre l'apport d'eau de source a presque disparu, ce qui a pratiquement asseche le canal, et de nombreuses crevettes etaient concentrees dans des flaques isolees du canal. Ainsi la fragmentation de l'habitat de C. leucosticta est due a la discontinuite en eau. Ces flaques d'eau ont seche completement mi-Decembre. De nombreux individus morts ont ete trouves dans parties assechees du canal. Ces resultats indiquent que les canaux agricoles peuvent etre un important habitat temporaire pour les crevettes d'eau douce amphidromes, mais que l'assechement de ces canaux peut affecter de facon letale les crevettes atyides migratrices., Agricultural channels can be important habitats for aquatic species inhabiting agricultural areas. However, water supply in agricultural channels can vary substantially with types of agriculture and irrigation/drainage system, and thereby affect the viability of local populations of aquatic species. In this study, we focused on the amphidromous freshwater atyid shrimp Caridina leucosticta. To clarify whether C. leucosticta utilizes agricultural channels as a habitat in relation to fluctuations in the water supply, we conducted a series of field surveys on the distribution of this shrimp in a rice paddy drainage channel (spring-fed channel) around the Furu River, central Japan, during July and December 2008. Large numbers of C. leucosticta had migrated into that drainage channel. Water from the adjacent rice paddies had disappeared by October, because irrigation was stopped, but the water level in the drainage channel was maintained by a supply of spring water. By mid-November the supply of spring water had almost disappeared, then the channel nearly dried up, and many shrimps were concentrated in an isolated water pool in the channel. Thus, habitat fragmentation of C. leucosticta occurred in terms of water (dis-)continuity. This water pool dried up completely by mid-December. We found many dead individuals of C. leucosticta in the dried-up area of the channel. These results indicate that agricultural channels can be an important temporal habitat for amphidromous freshwater shrimps, but that the drying-up of the channels can lethally affect migrating atyid shrimps. Les canaux agricoles peuvent etre des habitats importants pour les especes aquatiques rurales. Cependant l'alimentation en eau des canaux agricoles peut varier substantiellement avec le type d'agriculture, les systemes d'irrigation/drainage et en consequence affectent la viabilite des populations locales des especes aquatiques. Cette etude est centree sur la crevette atyidee amphidrome d'eau douce Caridina leucosticta. Pour eclaicir si C. leucosticta utilise les canaux agricoles comme habitat en relation avec la fluctuation de l'apport en eau, nous avons conduit une serie de releves de terrain sur la distribution de cette crevette dans un canal de drainage de riziere (eau de source) pres de la riviere Furu, Japon central, durant Juillet et Decembre 2008. Un grand nombre de C. leucosticta ont migre dans ce canal de drainage. L'eau des rizieres adjacentes a disparu en Octobre, car l'irrigation a stoppe, mais le niveau de l'eau a ete maintenu par un apport d'eau de source. Mi-Novembre l'apport d'eau de source a presque disparu, ce qui a pratiquement asseche le canal, et de nombreuses crevettes etaient concentrees dans des flaques isolees du canal. Ainsi la fragmentation de l'habitat de C. leucosticta est due a la discontinuite en eau. Ces flaques d'eau ont seche completement mi-Decembre. De nombreux individus morts ont ete trouves dans parties assechees du canal. Ces resultats indiquent que les canaux agricoles peuvent etre un important habitat temporaire pour les crevettes d'eau douce amphidromes, mais que l'assechement de ces canaux peut affecter de facon letale les crevettes atyides migratrices.]