Increased stocking density influences the acute physiological stress response of common carp (Cyprinus carpio (L.))

• Published in: Aquaculture research Vol. 33
• Main Authors: Ruane, N.M, Carballo, E.C, Komen, J
• Format: Journal Article
• Published: 2002
• Subjects: Aquaculture and Fisheries; Aquacultuur en Visserij; Bioprocess Engineering; Bioprocestechnologie; Leerstoelgroep Aquacultuur en Visserij; Leerstoelgroep Bioprocestechnologie; VLAG; WIAS
• ISSN: 1355-557X; 1365-2109

The physiological response of common carp, Cyprinus carpio (L.) to increased stocking density and an additional acute net confinement stressor was investigated. Stocking densities were increased from 28.4 to 56.8 or 113.6 kg m¿3 by the use of crowding screens and fish were sampled from the crowded groups after 15, 39 and 87 hours of crowding (hc). A transient elevation of plasma cortisol was found in the higher density group after 15 hc before values returned to control levels. Increased stocking density also increased plasma levels of glucose, free fatty acids (FFA) and lactate during the experimental period. No effect was found on oxygen radical production in the blood, haemoglobin or haematocrit levels, but leucocrit values were lower after 39 hc in both groups. Net confinement resulted in a significant increase in plasma cortisol levels in all groups. However, after 15 hc, cortisol and FFA levels in both crowded plus confinement groups were higher than in the control and confined groups. Confinement resulted in increased oxygen radical production in the crowded plus confined groups at all times. Results indicate that although carp responded with a mild stress response to increased stocking density and adaptation occurred by 87 hc, the crowded fish were more sensitive to an additional acute stressor