Title of article
A seasonal survey on feeding diet, breadth and feeding niche overlap of the native brown trout (Salmo trutta) and the exotic rainbow trout (Oncorhynchus mykiss) in Haraz River, in the southern Caspian Sea basin
Author/Authors
ABEDI ، Ahmad Department of Fisheries - Faculty of Animal Sciences and Fisheries - Sari Agricultural Sciences and Natural Resources University , RAHMANI ، Hossein Department of Fisheries - Faculty of Animal Sciences and Fisheries - Sari Agricultural Sciences and Natural Resources University , HAGHPARAST ، Sara Department of Fisheries - Faculty of Animal Sciences and Fisheries - Sari Agricultural Sciences and Natural Resources University , MOGHADAS ، Daryoush Expert/Protected areas and Biodiversity division - Department of Environment
From page
114
To page
125
Abstract
Diet composition and feeding strategies of two native and non- native trout species i.e. the brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) were investigated from autumn 2018 until summer 2019 in the uppermost of Emamzadeh Ali Lake (Haraz River, North of Iran). A total of 79 individuals including 59 brown trouts and 20 rainbow trouts were caught and studied. Digestive contents of feeding indices including CV (coefficient of vacuity), RLG (relative length of gut) and IF (intensity of feeding) revealed that both trout species were voracious carnivores, and showed a desirable nutritional status at all sampling seasons. Rainbow trout had a wider niche breadth than the brown trout in autumn, winter, and summer, except for spring. Feeding niche of the both trouts was highly overlapped in autumn and winter i.e. feeding on the same common resources. Percentage of overlap of both trouts was the most in autumn and winter and similar with the results of Morisita′s overlap index.
Keywords
Diet , Niche overlap , Rainbow trout , Brown trout
Journal title
Iranian Journal of Ichthyology
Journal title
Iranian Journal of Ichthyology
Record number
2768600
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