Endocrine stress responses in elasmobranchs

AWRUCH C. A.; PANKHURST, N. W; SIMPFENDORFER, C.

Buenos Aires

Simposio; 7th International Symposium on fish endocrinology; 2012

In the last few years, studies to explore and understand stress responses in elasmobranchs have importantly increased. However, much of the research has focused in secondary stress responses (e.g. measurement of chemical metabolites such lactate and glucose) as the laboratory tools to measure the primary stress responses, involving steroid hormones, are very limited. Unlike teleosts fish, where cortisol is well known to play a crucial role in the stress response, elasmobranchs produce a unique steroid 1α-hydroxycorticosterone (1α-OH-B). The particular chemical nature of this steroid has presented distinct disadvantages as it has proven to be difficult to synthesise, and as a consequence studies examining the mineralocorticoid and glucocorticoid actions of this steroid are limited. Although 1α-OH-B is considered the main stress hormone, serum corticosterone was previously studied in numerous elasmobranch fishes but the role of this steroid has yet to be defined. The goal of this study was to test whether corticosterone varied in response to different stress levels, and across different elasmobranchs species. Serum levels of circulating steroid hormones in corticosterone units were quantified and correlated with lactate and glucose values during capture and release of different elasmobranch species, to determine the degree of variability in the steroid hormones and the relationship being found between the hormones and different levels of stress.