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The ingestion of bacteria in suspension by the common carp Cyprinus carpio L.
Author(s) -
Beveridge M. C. M.,
Sikdar P. K.,
Frerichs G. N.,
Millar S.
Publication year - 1991
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/j.1095-8649.1991.tb04412.x
Subject(s) - cyprinus , biology , bacteria , carp , ingestion , common carp , microbiology and biotechnology , zoology , fish <actinopterygii> , food science , fishery , endocrinology , genetics
Groups of large (65 ‐75 g) and small (8‐17 g) common carp ( Cyprinus carpio L.) fingerlings were exposed to the bacterium Chromobacterium violaceurn in order to establish whether they could detect and ingest unattached bacteria. Small fish exposed to both bacteria and to cell‐free bacterial extracts showed a significant increase in opercular beat rates, thus demonstrating that they are able to detect the presence of unattached bacteria in suspension. Examination of carp gut contents showed that the proportion of small fish ingesting bacteria increased with exposure time although no significant relationship was observed among larger fish. Significant, positive correlations between numbers of viable bacteria isolated from the intestinal tracts and concentration in the environment were observed. Possible mechanisms of bacterial ingestion are discussed.