Premium
Food Habits of the Mountain Whitefish, Prosopium williamsoni (Girard)
Author(s) -
Pontius Richard W.,
Parker Michael
Publication year - 1973
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(1973)102<764:fhotmw>2.0.co;2
Subject(s) - food habits , geography , fishery , zoology , ecology , biology , medicine , environmental health
Quantitative and qualitative analyses of organisms eaten by mountain whitefish in the Snake River were undertaken. Abundance of an organism in a whitefish stomach appears to be dependent upon the organismˈs overall availability. The stomach contents of all size classes differed in taxonomic composition. Overlap in the taxonomic categories of food organisms eaten by fish of size classes II and III was about 50%. Larger fish were more generalized feeders and could utilize a greater size range of prey organisms than could smaller fish. This was reflected in the increase of food length diversity (FLD) and food taxa diversity (FTD) with increasing fish size. FTD was correlated most closely with the taxonomic richness of stomach contents rather than relative abundance of items in each taxonomic category. Hence, merely counting the taxa in stomachs gave some measure of FTD. This suggests that choices concerning the type of food eaten (species richness component of diversity) are most important in affecting FTD. Comparison of stomach contents with drift and bottom samples showed that fish could not have fed randomly solely from the drift or solely from the bottom. Morphology of the whitefish and the occurrence of sand and gravel in stomachs are an indication of bottom feeding.