The Effect of Handling and Transport of the Concentration of Glucose and Cortisol in Blood Plasma of Common Carp

Z Svobodová,J Kolářová,B Vykusová,D Janoušková,P Kaláb,L Dušek

doi:10.2754/avb199968040265

Abstract

Svobodova Z., P. Kalab, L. Du‰ek, B. Vykusova, J. Kolafiova, D. Janou‰kova: The Effect of Handling and Transport on the Concentration of Glucose and Cortisol in Blood Plasma of Common Carp. Acta Vet. Brno 1999, 68: 265-274. The aim of this contribution was to assess the degree of stress in common carp (Cyprinus carpio, L.) exposed to handling and transport. Cortisol and glucose concentrations in blood plasma were used as stress indicators. In some cases, concentration of ammonia in blood plasma and relative weight of spleen (SSI) were used as well. Within handling, an effect of time pause (0; 2 and 5 min) between catching the fish from water and blood sampling for stress indicators was checked. Another goal was to assess the effect of Menocain anaesthetics on the stress indicators. An open system of a 10-hour transport in a special long-distance live fish transport truck (Transport I a II), and a 2-hour transport in classic transporting tanks (Transport III) were compared. Temperature and oxygen concentration in water was measured during transport. After handling the fish prior to blood sampling (2 and 5 min pause), the cortisol concentration dropped significantly (p < 0.001) and the glucose concentration significantly (p < 0.001) increased compared to values in fish sampled immediately after catching. No effect of anaesthetics on cortisol concentration was proved. On the contrary, the glucose concentration fell (p = 0.012) in the anaesthetized fish. After a 10-hour transport in a special truck (Transport I), a significant (p < 0.001) decrease of the cortisol concentration was found, as well as a significant (p < 0.001) increase in the glucose concentration in blood plasma. In the course of 10hour transport in a special truck (Transport II), the majority of carp was found dead. Suffocation and ammonia autointoxication due to loading the fish with full digestive tract were the most probable causes of the fish mortality. After a 2-hour transport in transporting tanks (Transport III) both the cortisol concentration and relative weight of spleen (SSI) dropped non-significantly while glucose concentration in blood plasma significantly (p < 0.001) increased. Results showed that both handling and transport are important stressors in the common carp. Preventive measures were proposed aimed at alleviating the negative effects of these stressors.

Highlights

Important fish species, as well as those living in open waters are being exposed to various stresses in the course of their life
As analysed by t-test and Mann-Whitney test, the time periods of 2 and 5 minutes between catching and blood sampling were reflected in significantly decreased cortisol concentration and increased glucose concentration in analysed blood plasma samples
Secondary reactions in our study were represented by changes in concentrations of glucose and ammonia in blood plasma and by changes in the relative weight of spleen (SSI)

Summary

Introduction

Important fish species, as well as those living in open waters are being exposed to various stresses in the course of their life. Common stressors are e.g. water level decrease (Fryer 1975; Thomas and Robertson 1991), fish catching in nets (Barton et al 1980), increased stocking density (Barton et al 1985), water temperature change (Barton and Peter 1982), artificial and natural reproduction (Hlavová 1992; Lusková and Lusk 1995ab; Svobodová et al 1997b), fish handling (Wurts 1995), etc. The concentration of glucose has a similar course but with a certain delay (Barry et al 1993; Carragher and Ress 1994) We utilized these indices (cortisol, glucose) in the present study to assess the stress of the common carp exposed to experimental handling and transport under field conditions, as well as for the assessment of anaesthesia

Methods

Results

Conclusion