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Thermal impairment of reproduction is differentially expressed in maiden and repeat spawning Atlantic salmon


Pankhurst, NW and King, HR and Anderson, KC and Elizur, A and Pankhurst, PM and Ruff, N, Thermal impairment of reproduction is differentially expressed in maiden and repeat spawning Atlantic salmon, Aquaculture, 316, (1-4) pp. 77-87. ISSN 0044-8486 (2011) [Refereed Article]

Copyright Statement

Copyright 2011 Elsevier B.V.

DOI: doi:10.1016/j.aquaculture.2011.03.009


Groups of maiden or repeat spawning Atlantic salmon were maintained during vitellogenesis in austral autumn at either 14C or 22C through until April when all fish were transferred to a spawning temperature of 8C. There was no difference in body weight within groups for maidens and repeats, with repeats being consistently larger than maidens, no difference in condition factor amongst groups, but consistently higher gonad weight in repeats than maidens. Gonadosomatic index (GSI) and follicle diameter were suppressed in both maidens and repeats at 22C, with the effect being most marked in repeat spawners. Relative fecundity (eggkg−1) determined from ovarian tissue samples also showed depression in repeats at 22C. Fish from both age classes held at 22C had a higher proportion of atretic follicles. Plasma levels of estradiol-17β (E2) were strongly depressed in both maidens and repeats exposed to 22C throughout autumn but there was some evidence of recovery amongst maiden fish by late April. A similar effect was seen on plasma testosterone (T) levels. Plasma cortisol levels were generally low and typical of levels in unstressed fish indicating that stress did not account for the inhibitory effects observed. Hepatic zona pellucida protein gene expression was significantly inhibited in both maiden and repeat spawning fish reared at 22C, but with some evidence of recovery after temperature reduction to 8C. Hepatic vitellogenin (Vtg) gene expression was also lower in both maiden and repeat spawning fish exposed to 22C and this was accompanied by reduced plasma Vtg levels in maidens, but not repeats at 22C. Maidens at 14C began ovulating first followed by repeats at 14C, then repeats at 22C followed by maidens at 22C. There was reduced fertility in maidens at 22C relative to both maidens and repeats at 14C, whereas repeats at 22C showed intermediate fertility between 14C fish and 22C maidens. Survival to the eyed egg stage was highest in maidens at 14C, significantly suppressed at 22C in maidens, and at intermediate levels in repeats at both temperatures. This suggests that repeat spawning Atlantic salmon may be more robust in the face of thermal insult which combined with their larger size and egg production, could make their use desirable under production situations where there was any threat of exposure to higher than normal temperature.

Item Details

Item Type:Refereed Article
Keywords:Atlantic salmon, temperature, reproduction, fertility, gonadal steroids
Research Division:Agricultural, Veterinary and Food Sciences
Research Group:Fisheries sciences
Research Field:Aquaculture
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - aquaculture
Objective Field:Aquaculture fin fish (excl. tuna)
UTAS Author:Anderson, KC (Dr Kelli Anderson)
UTAS Author:Elizur, A (Professor Abigail Elizur)
ID Code:122074
Year Published:2011
Web of Science® Times Cited:26
Deposited By:Fisheries and Aquaculture
Deposited On:2017-10-30
Last Modified:2018-08-06

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