Microcrustacean abundance as potential food resources for larval and juvenile fishes in a reed zone of Lake Biwa [Japan]
2004
Yamamoto, T. (Toyota Yahagi River Inst., Aichi (Japan)) | Nozaki, K.
Abstract: To evaluate a reed zone as a nursery ground for fishes, temporal changes in the abundance of 8 groups of microcrustaceans were examined from April to July 1994 in shallower and deeper parts of a reed zone in Lake Biwa (Shiga Prefecture, Japan) , and compared with the microcrustacean abundance recorded at the same reed zone in the 1960s. In the shallower part, total microcrustacean abundance ranged 188 - 3290 ind./l and had two peaks in late April and late May, whereas the lowest density was observed in June. Of the 8 groups, Bosmina longirostris, nauplii, Chydoridae, Podocopida and Scapholeberis kingi were dominant. Both the total abundance in the shallow and the deeper part in 1994 were significantly higher than in 1960s. Additionally, Podocopida and Harpacticoida were not collected in the 1960s. These large changes may reflect recent drastic alterations in the environment and bio-community in the littoral zone.
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