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Food Habits and Prey Selection of Coho Salmon (Oncorhynchus kisutch) and Cisco (Coregonus artedii) in Relation to Zooplankton Dynamics in Pallette Lake, Wisconsin
Author(s) -
Engel Sandy
Publication year - 1976
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/1548-8659(1976)105<607:fhapso>2.0.co;2
Subject(s) - zooplankton , coregonus , biology , fishery , predation , oncorhynchus , abundance (ecology) , epilimnion , ecology , zoology , fish <actinopterygii> , hypolimnion , nutrient , eutrophication
Insects, large zooplankton, and some fishes were the main diet of coho salmon (Oncorhynchus kisutch) stocked in Pallette Lake, Wisconsin. From May to early July, coho (117–210 mm total length) were found inshore and in the epilimnion offshore and ate mostly winged flies, ants, and beetles. In late July and August they were primarily captured in the metalimnion and selected some underyearling cisco (Coregonus artedii) and numerous large, rare zooplankton. The latter included Chaoborus punctipennis larvae and pupae, Leptodora kindtii, and Holopedium gibberum. Coho were captured mainly inshore in November and consumed some underyearling cisco and adult hemipterans. Native cisco (129–260 mm) fed on small, seasonally abundant zooplankton. Copepods (chiefly Cyclops bicuspidatus thomasi) reached peak abundance in May‐June and October‐November, when they were the most important items in cisco stomachs. Cladocerans (especially Chydorus sphaericus, Bosmina longirostris, and Daphnia spp.) reached peak abundance between June and August and were then the most abundant items eaten by cisco in the metalimnion. Rotifers, which reached peak abundance in June, were rarely eaten by cisco.