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Port Lincoln, Australia

Nguyen N.H.,University of The Sunshine Coast | Whatmore P.,University of The Sunshine Coast | Whatmore P.,The Australian Seafood Cooperative Research Center | Miller A.,Clean Seas Tuna Ltd | Knibb W.,University of The Sunshine Coast
Journal of Fish Diseases

The main aim of this study was to estimate the heritability for four measures of deformity and their genetic associations with growth (body weight and length), carcass (fillet weight and yield) and flesh-quality (fillet fat content) traits in yellowtail kingfish Seriola lalandi. The observed major deformities included lower jaw, nasal erosion, deformed operculum and skinny fish on 480 individuals from 22 families at Clean Seas Tuna Ltd. They were typically recorded as binary traits (presence or absence) and were analysed separately by both threshold generalized models and standard animal mixed models. Consistency of the models was evaluated by calculating simple Pearson correlation of breeding values of full-sib families for jaw deformity. Genetic and phenotypic correlations among traits were estimated using a multitrait linear mixed model in ASReml. Both threshold and linear mixed model analysis showed that there is additive genetic variation in the four measures of deformity, with the estimates of heritability obtained from the former (threshold) models on liability scale ranging from 0.14 to 0.66 (SE 0.32-0.56) and from the latter (linear animal and sire) models on original (observed) scale, 0.01-0.23 (SE 0.03-0.16). When the estimates on the underlying liability were transformed to the observed scale (0, 1), they were generally consistent between threshold and linear mixed models. Phenotypic correlations among deformity traits were weak (close to zero). The genetic correlations among deformity traits were not significantly different from zero. Body weight and fillet carcass showed significant positive genetic correlations with jaw deformity (0.75 and 0.95, respectively). Genetic correlation between body weight and operculum was negative (-0.51, P < 0.05). The genetic correlations' estimates of body and carcass traits with other deformity were not significant due to their relatively high standard errors. Our results showed that there are prospects for genetic selection to improve deformity in yellowtail kingfish and that measures of deformity should be included in the recording scheme, breeding objectives and selection index in practical selective breeding programmes due to the antagonistic genetic correlations of deformed jaws with body and carcass performance. © 2016 John Wiley & Sons Ltd. Source

Sanchis-Benlloch P.J.,University of The Sunshine Coast | Nocillado J.,University of The Sunshine Coast | Ladisa C.,University of The Sunshine Coast | Aizen J.,University of The Sunshine Coast | And 5 more authors.
General and Comparative Endocrinology

Biologically active recombinant yellowtail kingfish follicle stimulating hormone (rytkFsh) was produced in yeast Pichia pastoris and its biological activity was demonstrated by both in-vitro and in-vivo bioassays. Incubation of ovarian and testicular fragments with the recombinant hormone stimulated E2 and 11-KT secretion, respectively. In-vivo trial in immature female YTK resulted in a significant increase of plasma E2 levels and development of oocytes. In males at the early stages of puberty, advancement of spermatogenesis was observed, however plasma 11-KT levels were reduced when administered with rytkFsh. © 2016 Elsevier Inc. Source

Knibb W.,University of The Sunshine Coast | Miller A.,Clean Seas Tuna Ltd | Quinn J.,University of The Sunshine Coast | D'Antignana T.,Clean Seas Tuna Ltd | Nguyen N.H.,University of The Sunshine Coast

Recently, aquaculture and captive breeding have commenced for a raft of large fish species, including bluefin tuna (Thunnus orientalis), kingfish (Seriola lalandi) and giant grouper (Epinephelus lanceolatus). With captive breeding, there is often interest to conduct selection and genetic improvement, but these large species present many and substantial challenges to selective breeding. Indeed there are no reports or examples that selection response and forward genetic gain has been achieved for such large and problematic species. These large species, typified by kingfish, are characterized by immense fecundity with ensuing opportunity for intense domestication selection, either adverse or synergistic, that can impact on planned selection response. Moreover, because of size and logistics, typically few broodstock are held and chance sampling of few broodstock individuals has the potential to confound selection response and the repeatability of response.The main objective here was to assess if forward selection response could be achieved after selection for adult weight of kingfish in sea cages. Selection response was estimated by comparing the performance of F1 offspring from wild parents with F2 offspring from selected parents during the larval rearing and adult growout. Pedigree data, from genotyping approximately 1000 individuals using up to 17 DNA microsatellite loci, was added to the larval and adult performance data to resolve the contributions of different sire and dam lineages.For most traits measured, whether larval survival, incidence of larval deformity, adult weights or adult condition factor, the offspring of selected parents outperformed those from wild parents, whether animals were grown separately in replicate (larval rearing tanks) or communally as adults in tanks. Larval survival was not deliberated selected, yet the dropout of specific parental sire or dam lineages suggest in part genetic differences account for some of the differences between the F1 and F2. Observed selection responses for adult weights and condition factor were greater than those predicted from covariances of relatives. Either (synergistic) domestication selection or some type of magnification of line differences under communal rearing may account for these data.The chance sampling of particularly good or bad broodstock sires or dams did not seem to have been a major contributor to the strain testing results. Whether this means that selection responses are repeatable even when using few broodstock, a situation unavoidable for large marine species, is discussed in terms of how intense deliberate and possible domestication selection could narrow the variances of breeding values of selected broodstock. Statement of relevance: Can we select large marine species with few broodstock? © 2015 Elsevier B.V. Source

Whatmore P.,University of The Sunshine Coast | Whatmore P.,Australian Seafood Cooperative Research Center | Nguyen N.H.,University of The Sunshine Coast | Miller A.,Clean Seas Tuna Ltd | And 6 more authors.

The aim of the present study was to estimate genetic parameters for body and carcass traits, visual condition score, and deformity in yellowtail kingfish Seriola lalandi, an emerging aquaculture species in Australia. These novel data and genetic parameters are required to solve the problem of how to conduct efficient selection in this and related species. Analyses were performed on a total of 400 data records collected from a yellowtail kingfish breeding population at Cleanseas Tuna Ltd. farm. They were progeny of 22 full- and half-sib families (eight sires and six dams). Six newly developed and four published microsatellite markers were used to construct the pedigree. Genetic parameters were estimated using average information algorithm in ASReml with a multiple trait model. Fixed effects included sex, seal bite and deformity status. Random effects were the additive genetics of individual animal, and maternal and common environmental effects (i.e., dam-tank effect arising from a short period of separate rearing of offspring that came from two different broodstock tanks). The estimates of heritability for body and carcass traits were moderate (h2=0.15 to 0.30, s.e. ranging from 0.09 to 0.19). Fillet fat content showed an unusually high heritability (0.94±0.21) with a standard animal model, but was only moderate (0.41±0.26) when tank and dam were included as random effects. The estimate for condition score was 0.15±0.11, whereas the heritability for deformity was close to zero (h2=0.02). The genetic correlations between body and carcass (fillet weight and fillet yield) traits were high and positive (0.57 to 0.94, s.e. 0.05 to 0.46). Genetic correlations between body traits and condition score were moderate to high and positive (i.e. favourable). These results suggest that selection for high growth would result in concomitant increase in fillet weight, a carcass trait of paramount importance. It is concluded that there is substantial potential for genetic improvement of economically important traits especially growth performance and fillet weight in the current population of yellowtail kingfish. © 2013 Elsevier B.V. Source

Clean Seas Tuna Ltd | Date: 2008-01-08

Aquaculture produced fish including mulloway, kingfish and tuna.

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