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

Abstract

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 À3 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.

The hematological response to exhaustive exercise in ‘all-fish’ growth hormone transgenic common carp (Cyprinus carpio L.)

“…Resting plasma glucose and lactate concentrations did not differ between transgenic and non-transgenic carp, and values were comparable to those from other studies on carp (Pottinger, 1998;Ruane et al, 2001Ruane et al, , 2002. Both groups exhibited a typical secondary metabolic stress response to exhaustive exercise, as indicated by elevated plasma glucose and lactate concentrations (Barton, 2002;Iwama et al, 2004;Portz et al, 2006), but transgenic fish appeared to clear lactate more quickly than controls.…”

“…Several studies have reported that crowding (Yin et al, 1995;Ruane et al, 2002) or infection by pathogens (Harikrishnan et al, 2003) reduce total plasma protein concentrations in carp. Significant changes in the amounts and activities of the serum proteins in fish during stress suggest that stressed fish may have decreased disease resistance and become more susceptible to infection (Yin et al, 1995).…”

The effect of transport on biochemical and haematological indices of common carp (Cyprinus carpio L.)

“…However, quantifying stressful conditions proved difficult with many authors reporting a transient increase in plasma cortisol levels during stress, e.g. during crowding (Tort et al, 1996;Ruane et al, 2002) while others reported no effect (Procarione et al, 1999) or reduced cortisol levels (Leatherland and Cho, 1985).In this study, the plasma cortisol level in fish increased slightly during transport (from 258.57 ng per ml in Hluboká to 301.94 ng/ml in Boheľov), but the increase was not significant. At the beginning of the experiment, carp responded to netting and catching during pre-transport manipulation with a mild cortisol response, similarly to results reported by Ruane et al (2002).…”

“…However, quantifying stressful conditions proved difficult with many authors reporting a transient increase in plasma cortisol levels during stress, e.g. during crowding (Tort et al, 1996;Ruane et al, 2002) while others reported no effect (Procarione et al, 1999) or reduced cortisol levels (Leatherland and Cho, 1985).…”

The effect of allostatic load on hypothalamic–pituitary–interrenal (HPI) axis before and after secondary vaccination in Atlantic salmon postsmolts (Salmo salar L.)

“…Many researchers reporting transient elevation of cortisol levels during crowding stress (Barcellos et al 1999;Ruane et al 2002), while others report no effect (Da Rocha et al 2004;Fanouraki et al 2007;Vijayan and Leatherland 1990) or even a reduction (Leatherland and Cho 1985).…”