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Cadiz, Spain

Garcia-Celdran M.,Technical University of Cartagena | Ramis G.,University of Murcia | Manchado M.,Centro IFAPA El Toruno | Estevez A.,IRTA - Institute of Agricultural-Alimentary Research and Technology | And 2 more authors.
Aquaculture | Year: 2015

Carcass quality traits such as visceral fat and fish morphology have a direct influence on final product and consumer preferences, especially in species as sea bream that are sold as whole fish. Nevertheless, strategies that involve the development of selection schemes for these traits of economic interest in gilthead sea bream are limited. In this study the effect of the origin of the broodstock on carcass quality traits was analyzed in harvest size (690. days post-hatching) gilthead sea bream for the first time. For this purpose, a population (. n=. 890) of farmed gilthead sea bream obtained by industrial mass-spawnings from broodstocks from three different origins [Cantabrian Sea (CAN), the Atlantic Ocean (ATL) and Mediterranean Sea (MED)] was analyzed for condition factor, visceral fat content, dressing weight, dressing percentage, fillet weight and fillet percentage. Moreover, with the goal of estimating genetic parameters (heritabilities and genetic correlations) for carcass quality traits as well as their correlations with growth (harvest weight and length), a reconstruction of pedigree was carried out a posteriori. The origin had an effect on several carcass traits. Fish from ATL showed the lowest visceral fat percentage, dressing weight and percentage and those form CAN the lowest condition factor. These differences among origins can be explained through their different genetic backgrounds but also by environmental conditions in the initial facilities, where each origin was reared, and the derivate genotype × environment interactions. All carcass traits showed medium heritabilities (ranging from 0.17 to 0.24) and were estimated with accuracy (standard errors from 0.05 to 0.07) except dressing (0.07. ±. 0.05) and fillet (0.11. ±. 0.05) percentage. Due to their genetic correlations, selection on weight could lead to an increase in condition factor (0.47. ±. 0.21) but, at the same, to an undesirable increase in visceral fat (0.42. ±. 0.20) and a decrease in fillet yield (-. 0.58. ±. 0.09). However, selection on length could improve dressing (0.87. ±. 0.07) and fillet weight (0.84. ±. 0.09). Alternatively, visceral fat content could be decreased by selection through condition factor (-. 0.46. ±. 0.16). All findings reported in this study should be relevant for the establishment of successful breeding programs in aquaculture of this species. Statement of relevance: This study proves the importance of the acquisition of a stock in sea bream since the studied origins of the broodstock had an effect on different carcass traits. Moreover, genetic parameters are estimated for these traits which are scarce for this species. © 2015 Elsevier B.V. Source


Garcia-Celdran M.,Technical University of Cartagena | Ramis G.,University of Murcia | Manchado M.,Centro IFAPA El Toruno | Estevez A.,IRTA - Institute of Agricultural-Alimentary Research and Technology | And 4 more authors.
Aquaculture | Year: 2015

Growth rates and the presence of deformities can be affected by the use of different rearing systems as well as by the different genetic origins of the stocks. At the same time, strategies that involve the development of selection schemes for these traits of economic interest are scarce. In this study the effect of the origin of the broodstock on growth traits and external deformities as well as genetic parameters (heritabilities and genetic correlations) for these traits were estimated at different ages (days post-hatching; dph). For this purpose, a population of farmed gilthead sea bream was obtained from three broodstock of different origins along the Spanish coasts [Cantabrian Sea (CAN), the Atlantic Ocean (ATL) and Mediterranean Sea (MED)] and reared under the same intensive conditions. Parental assignments between breeders and their offspring were carried out a posteriori using a microsatellite multiplex (SMsa1). Juveniles from MED showed the fastest growth while those from ATL showed the slowest growth and the highest incidence of vertebral column deformities. Differences among origins could be explained not only through their different genetic backgrounds but also by environmental conditions in the initial facilities, where different origins were reared separately, and by genotype. ×. environment interactions. Growth traits showed low heritabilities at 163. dph (0.11 ± 0.03) and medium at 690. dph (0.25 ± 0.06 for weight; 0.22 ± 0.07 for length) suggesting that selection at the later age would be more appropriate. Both traits were highly and positively correlated at both ages at the genetic and phenotypic levels. External deformities in the vertebral column as well as in the operculum showed medium-high heritability at both studied ages with higher values at 690. dph (0.56 [0.17-0.69] and 0.46 [0.20-0.90], respectively). These results revealed that the ontogenesis of deformities exhibits a partial genetic basis. Nevertheless, for those in the rest of the head the heritability was close to zero. Initially, positive genetic correlations between growth and deformities in the vertebral column were observed (83% probability of being positive for weight-vertebral column deformity; 81% for length-vertebral column deformity). However, these correlations seem to be negative at 690. dph (94.2% probability of being negative for weight-vertebral column; 80.6% for length-vertebral column). Results confirm that it could be recommended to eliminate deformed fish from a breeding nucleus and later, select on growth. All these findings should be relevant for the establishment of successful breeding programs in the aquaculture of this species. © 2015 Elsevier B.V. Source


Saez M.I.,University of Almeria | Suarez M.D.,University of Almeria | Cardenas S.,Centro IFAPA El Toruno | Martinez T.F.,University of Almeria
International Journal of Food Properties | Year: 2015

The effects of freezing and freezing-thawing cycles during cold storage have been studied in meagre (Argyrosomus regius) fillets. Fillets were subjected to three conservation protocols: fresh, freezing at -20°C, and repeated freezing-thawing cycles. Fresh fillets were stored (4°C, 15 days), and the same protocol was followed for freezing and freezing-thawing after the freezing period. Freezing and freezing-thawing fillets were softer and presented lower water holding capacity than fresh, mostly attributable to collagen solubilization, and partial myofibrillar protein degradation. Cold storage (4°C) during 15 days caused softening in fresh and frozen fillets attributable to myofibrillar protein hydrolysis. Freezing-thawing cycles increased proteolysis, this leading to unacceptable softening even from early stages of further cold storage, and this was also revealed by SDS-PAGE. Copyright © Taylor & Francis Group, LLC. Source


Saez M.I.,University of Almeria | Martinez T.F.,University of Almeria | Cardenas S.,Centro IFAPA El Toruno | Suarez M.D.,University of Almeria
Journal of Food Processing and Preservation | Year: 2015

The influence of two preservation strategies (vacuum [V] and modified atmosphere [MA]) on microbiological counts, lipid oxidation and color changes during cold storage of meagre (Argyrosomus regius) fillets was studied. Meagre fillets were stored in a cold room under aerobic (control, C), V and MA package systems. Samples were withdrawn at six sampling points throughout 15-day storage, and postmortem changes were assessed. Bacterial counts and lipid oxidation increased consistently with storage time, also changes in color parameters of fillet skin were observed, L* decreased, and a** and b* increased. V-stored fillets showed significantly lower mesophilic (P<0.0001) and psychrophilic (P<0.0001) loads up to 7days postmortem (7.0 and 6.3log cfu/g, respectively) compared with C and MA (7.5 and 6.8log cfu/g, respectively); however, no clear influence among conservation treatments could be noticed on lipid oxidation values and color parameters. © 2014 Wiley Periodicals, Inc. Source


Portela-Bens S.,University of Cadiz | Merlo M.A.,University of Cadiz | Rodriguez M.E.,University of Cadiz | Cross I.,University of Cadiz | And 4 more authors.
Chromosoma | Year: 2016

The evolution of genes related to sex and reproduction in fish shows high plasticity and, to date, the sex determination system has only been identified in a few species. Solea senegalensis has 42 chromosomes and an XX/XY chromosome system for sex determination, while related species show the ZZ/ZW system. Next-generation sequencing (NGS), multi-color fluorescence in situ hybridization (mFISH) techniques, and bioinformatics analysis have been carried out, with the objective of revealing new information about sex determination and reproduction in S. senegalensis. To that end, several bacterial artificial chromosome (BAC) clones that contain candidate genes involved in such processes (dmrt1, dmrt2, dmrt3, dmrt4, sox3, sox6, sox8, sox9, lh, cyp19a1a, amh, vasa, aqp3, and nanos3) were analyzed and compared with the same region in other related species. Synteny studies showed that the co-localization of dmrt1-dmrt2-drmt3 in the largest metacentric chromosome of S. senegalensis is coincident with that found in the Z chromosome of Cynoglossus semilaevis, which would potentially make this a sex proto-chromosome. Phylogenetic studies show the close proximity of S. senegalensis to Oryzias latipes, a species with an XX/XY system and a sex master gene. Comparative mapping provides evidence of the preferential association of these candidate genes in particular chromosome pairs. By using the NGS and mFISH techniques, it has been possible to obtain an integrated genetic map, which shows that 15 out of 21 chromosome pairs of S. senegalensis have at least one BAC clone. This result is important for distinguishing those chromosome pairs of S. senegalensis that are similar in shape and size. The mFISH analysis shows the following co-localizations in the same chromosomes: dmrt1-dmrt2-dmrt3, dmrt4-sox9-thrb, aqp3-sox8, cyp19a1a-fshb, igsf9b-sox3, and lysg-sox6. © 2016 Springer-Verlag Berlin Heidelberg Source

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