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Relationship between F ulton's condition factor and proximate body composition in three freshwater fish species
Author(s) -
Mozsár A.,
Boros G.,
Sály P.,
Antal L.,
Nagy S. A.
Publication year - 2015
Publication title -
journal of applied ichthyology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 62
eISSN - 1439-0426
pISSN - 0175-8659
DOI - 10.1111/jai.12658
Subject(s) - biology , lepomis , composition (language) , proximate , centrarchidae , perciformes , zoology , ecology , freshwater fish , fish <actinopterygii> , fishery , food science , linguistics , philosophy , micropterus
Summary Morphometric‐based condition indices are widely used to assess proximate body composition and, collaterally, feeding and living conditions of fish. However, the exact relationship between condition indices and proximate body composition of fish and its relatedness to life history traits and seasonality has yet to be fully explored. Therefore, the aim of this study was to examine how the F ulton's condition factor ( K ‐factor) is related to the chemical composition (i.e. lipid, protein, water and carbon content, and molar carbon : nitrogen ratio), length and gonadal development of fish, and how these relationships are influenced by gender and seasonality in three freshwater fish species: Amur sleeper ( P erccottus glenii ), pumpkinseed ( L epomis gibbosus ) and rudd ( S cardinius erythrophthalmus ). It was found that the strength and direction of association between the K‐factor and proximate body composition can vary markedly among fish species. The K‐factor correlated positively with gonadal development in pumpkinseed and Amur sleeper, while no such relationship existed in rudd. Condition factor can be a reliable measure of lipid content; however, the relationship was stronger in species with higher and more variable lipid contents. Moreover, a striking and consistently negative linkage was found between the K‐factor and water content of the fish body, which corresponds to the findings of several other studies. In turn, any relationship between the K ‐factor and the protein content of fish was not detected. Gender seemed to exert a negligible effect on the relationship between the K ‐factor and proximate body composition, while seasonal variance was obvious in most relationships.