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Stress‐induced changes in concentrations of plasma sex steroids in black bream
Author(s) -
Haddy J. A.,
Pankhurst N. W.
Publication year - 1999
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.1095-8649.1999.tb02077.x
Subject(s) - medicine , endocrinology , biology , testosterone (patch) , sparidae , sexual maturity , plasma levels , fish <actinopterygii> , fishery
Cortisol levels of black bream Acanthopagrus butcheri at capture did not change with time of day, gonadal stage or season and were 1·9±0·2 and 2·8±0·4 ng ml −1 for male and female fish, respectively. Confinement resulted in significantly elevated cortisol levels at all time periods; however, levels after 24 h of confinement were significantly lower than peak cortisol levels (15 min for males and 1 h for females). Confinement stress resulted in reduced levels of 17β‐oestradiol (E2) and testosterone (T) within 1 h in sexually mature females. In mature males, suppression of T and 11‐ketotestosterone (11KT) occurred after 30 min and 6 h of confinement, respectively. The relationship between confinement stress and levels of 17,20β‐dihydroxy‐4‐pregnen‐3‐one (17,20β P) was more complex, with levels in males being elevated after 15 min and 24 h and suppressed after 6 h of confinement. In contrast, 17, 20β P levels in females were elevated after 1 h of confinement. In regressed females, plasma E 2 and T concentrations were low at capture and were not affected by confinement stress whereas plasma 17, 20β P was elevated within 1 h. This study indicates that stress exerts a rapid inhibitory effect on gonadal steroidogenesis.