The prevalence of skeletal deformity throughout the development of different populations (all-female triploid, mixed-sex triploid, all-female diploid and mixed-sex diploid) of Tasmanian Atlantic salmon (Salmo salar L.) was determined to elucidate the possible effects of ploidy or sex status on the incidence of deformity. Populations were produced and maintained under commercial conditions in freshwater until individuals had attained a wet weight of approximately 80 g, at which time each population was divided and either retained in freshwater (FW smolt) or transferred to seawater (SW smolt), where fish were held for a further 2 months. Whole fish were sampled throughout this period from hatching (470° days post-fertilisation). The prevalence of skeletal deformities was significantly higher in triploid populations. Jaw deformity, including lower jaw deformity syndrome (LJD), occurred in up to 2% of triploid fry, 7% of triploid FW smolt, 14% of triploid SW smolt and 1% of diploid FW smolt. The prevalence of LJD was highest in triploid FW smolt. Short opercula were observed in up to 22% of triploids and 16.6% of diploids. Up to 60% of triploids and 4% of diploids suffered from the absence of primary gill filaments (gill filament deformity syndrome (GFD)) during FW development prior to SW transfer, then, up to 50% of triploid FW smolt and 60% of tripioid SW smolt suffered from GFD. There was no significant difference in the sex ratio of each deformity type. An index of gill surface area (GSA) was significantly reduced in normal triploids and triploids afflicted with GFD, compared to diploid counterparts. It is likely that the reduction of GSA affects an individual's capacity for metabolic gas exchange under vigorous exercise or suboptimal environmental conditions. © 2001 Elsevier Science B.V.

Item Type:	Refereed Article
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:	Fisheries - aquaculture not elsewhere classified
UTAS Author:	Sadler, J (Dr Joanne Sadler)
UTAS Author:	Pankhurst, PM (Dr Tish Pankhurst)
ID Code:	21155
Year Published:	2001
Web of Science® Times Cited:	126
Deposited By:	TAFI - Aquaculture
Deposited On:	2001-08-01
Last Modified:	2011-09-20
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