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Brycon moorei is an endemic species of the Magdalena River basin with a strong commercial, sports and consumption fishing pressure; however, knowledge of ontogeny is scarce or non-existent. For this reason, the present study describes and compares early development in this species. Product of semi-natural induced reproduction, at established times, samples were taken from fertilization until day 15 after hatching to characterize the stages of zygote, cleavage, blastula, gastrula, segmentation, organogenesis, hatching and early juvenile. It was found that the latency time was 6 hours after the second dose at 26°C; hatching occurred at 13 hours post-fertilization (HPF). In the larval stage, cannibalism begins at 22 hours post-hatching (HPH); the maximum buccal opening was reached at 37 HPH with 1773.37 µm and the yolk sac was totally absorbed at 37 HPH. For the pre-bending stage, the mean weight was 3.14±0.36 mg and the length were 6.85±0.53 mm; in the final stage of post-flexion, the average weight and total length were 221.6±15.84 mg and 25.66±0.64mm, respectively. Finally, juveniles with the same characteristics as an adult were presented at 326 HPH. It is concluded that Brycon moorei presents an embryonic and larval development, like most of the species of the genus Brycon and others of the Characidae family; but with the shortest time to consume endogenous reserves and with the shortest time to start cannibalism. [ABSTRACT FROM AUTHOR]

The yellowtail (Seriola lalandi) has been farmed for many years and is becoming a promising aquaculture species. Knowledge of the intestinal microbiota of this species is very limited. Thus, the aim of this study is to describe the bacterial populations associated with the intestinal tract of Seriola lalandi reared in Chile. The microbiota composition was analyzed at two growth stages distinguished by weight and parameters such as Specific Growth Rate (SGR) and Feed Conversion Ratio (FCR). Juveniles (mean initial weight 7.33 ± 0.30 g) and pre-adults (81.7 ± 19.0 g) were fed with commercial diet for 33 and 50 days, respectively. The first intestinal samples were collected at the end of Trial 1 from specimens weighing approximately 50 g while the second samples were obtained at the end of Trial 2 from specimens weighing approximately 370 g. The microbiota composition was examined using conventional isolation in Tryptic Soy Agar (TSA) followed by 16S rRNA sequencing and identification. In total, 16 genera were identified. Pseudomonas, Vibrio and Staphylococcus were the predominant genera in fish at the 50 g stage, whereas Microbacterium and Francisella were the predominant genera in the 370 g stage. The microbiota composition showed different assemblages, depending on host size, with Bacillus and Vibrio being the only genera that were shared. Knowledge of the intestinal microbiota of Seriola lalandi is the first step in the exploration of microbiota management and the development of probiotics, as well as in the identification of the bacterial populations in healthy fish under cultured conditions. [ABSTRACT FROM AUTHOR]

In order to extract salt-soluble proteins, such as myofibrillar proteins, sodium chloride is added to restructured products that serve as a binding agent among fish particles. Various additives, such as microbial transglutaminase (MTGase), have been used to reduce NaCl level in restructured products to improve water holding capacity (WHC) and textural properties. The aim of this work was to study the effect of salt level in the physicochemical and mechanical properties of uncooked restructured fish products using MTGase as cold binding agent. Except adhesiveness, the mechanical properties were affected by both salt and MTGase levels (p < 0.05). Samples with regular-salt level (20 g/kg) showed higher values of hardness, springiness and chewiness than low-salt (10 g/kg) samples (p < 0.05). Expressible water ranged from 7% to 10% for low-salt samples and from 4.3% to 4.5% for regular-salt samples, a decrease of the salt level induced a decrease in the WHC. El cloruro sodico se adiciona a los productos reestructurados con el fin de extraer las proteinas solubles, como las miofibrilares, que sirven de agentes de union en la pasta de pescado. Algunos aditivos, como la transglutaminasa microbiana, han sido utilizados en productos reestructurados bajos en sal para mejorar la capacidad de retencion de agua y las propiedades texturales. En este trabajo se estudio el efecto del nivel de sal y transglutaminasa (MGTasa), sobre las propiedades mecanicas y las caracteristicas fisicoquimicas, de un producto reestructurado no cocido de dorada (Sparus arata). Las propiedades mecanicas, a excepcion de la adhesividad, presentaron valores mas altos en las muestras con un nivel regular de sal (p < 0,05). Los valores de los parametros del Analisis de Textura TPA se incrementaban de forma significativa (p < 0,05) al aumentar la MTGasa adicionada de 3 a 6 g/kg para muestras con nivel regular de sal. El agua extraible incrementaba con el nivel de MTGasa para muestras con un contenido bajo de sal indicando un descenso en la capacidad de retencion de agua. [ABSTRACT FROM AUTHOR]

This work focuses on the slaughtering and chilled storage (up to 14 days) related to the commercialization of fresh farmed gilthead seabream (Sparus aurata). A slurry ice (SI) system was applied and evaluated in comparison to traditional flake ice (FI). Lipid hydrolysis and oxidation were analyzed and compared to sensory acceptance and trimethylamine (TMA) formation. An important quality loss could be assessed in fish during slaughtering and chilling storage, according to sensory assessment and TMA formation. However, lipid damage development was found relatively low, in agreement to the different lipid quality indexes checked (lipid hydrolysis; primary, secondary and tertiary lipid oxidation). No development of rancid odor and no polyunsaturated fatty acid losses were detected. The employment of SI as a slaughtering and chilling strategy was found useful to inhibit quality loss in gilthead seabream resulting in a shelf life increase and a TMA and free fatty acid formation inhibition. [ABSTRACT FROM AUTHOR]