Fish skin pigmentation in aquaculture: the influence of rearing conditions and its neuroendocrine regulation

Skin pigmentation pattern is a species-specific characteristic that depends on the number and the spatial combination of several types of chromatophores. This feature can change during life, for example in the metamorphosis or reproductive cycle, or as a response to biotic and/or abiotic environmental cues (nutrition, UV incidence, surrounding luminosity, and social interactions). Fish skin pigmentation is one of the most important quality criteria dictating the market value of both aquaculture and ornamental species because it serves as an external signal to infer its welfare and the culture conditions used. For that reason, several studies have been conducted aiming to understand the mechanisms underlying fish pigmentation as well as the influence exerted by rearing conditions. In this context, the present review focuses on the current knowledge on endocrine regulation of fish pigmentation as well as on the aquaculture conditions affecting skin coloration. Available information on Iberoamerican fish species cultured is presented

Analysis of truncated growth hormone receptor 1 in the differential growth of fine flounder Paralichthys adspersus

Differences in body size within a fish population are a recurring problem in aquaculture. In fish farms, a higher growth rate is one of the most important selection traits, so growth dispersion with smaller batch sizes leads to increased production costs. Despite the importance of this dispersion in growth, the understanding of the molecular basis of these differences is still largely unknown. In the present work, we firstly determined that in the fine flounder Paralichthys adspersus the variant of the growth hormone receptor 1 (ghr1tr) is in agreement with a transcript truncation product of an alternative polyadenylation signal (APAs) embedded in an intronic region of ghr1 full length nucleotide sequence. Additionally, we observed that this region possesses a high identity with homologous regions in other Pleuronectiformes with documented differences in body size. Finally, our quantitative expression analysis, focusing on liver and muscle tissues, reveals that ghr1tr of P. adspersus was less expressed in bigger adult individuals. In this sense, this study proposes ghr1tr as the modulator of size dimorphism growth and that it could be a useful target for genetic studies on fine flounder breeding improvement.Fil: Marín, Alan. Universidad Nacional del Santa; PerúFil: Alonso, Andrés Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Delgadin, Tomás H.. Universidad Nacional del Santa; PerúFil: López Landavery, Edgar A.. Universidad Nacional del Santa; PerúFil: Cometivos, Lise Jara. Universidad Nacional del Santa; PerúFil: Saavedra Flores, Anaid. Universidad Nacional del Santa; PerúFil: Reyes Flores, Lorenzo E.. Universidad Nacional del Santa; PerúFil: Yzásiga Barrera, Carmen G.. Universidad Nacional del Santa; PerúFil: Fernandino, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Zelada Mázmela, Eliana. Universidad Nacional del Santa; Per

Digestive enzyme activities during pejerrey (Odontesthes bonariensis) ontogeny

The first step for assessing and refining the nutritional requirements during the larval and early juvenile stages of a fish is the study of the ontogeny of digestive system functionality. The combination of these studies with ecological and anatomical knowledge of the species of interest establishes the base for facing one of the major aquaculture challenges: promoting larvae growth and survival. Considering this, changes in the activity of the main digestive (pancreatic and intestinal) enzymes during larval development of the agastric South America pejerrey (Odontesthes bonariensis) were described in the present work. Digestive enzymes for protein, lipid, and carbohydrate hydrolysis were present from the first-week post-hatching (6.85 ± 0.07 mm total length, TL). Changes in the activity of trypsin, chymotrypsin, and alkaline protease indicated that the exocrine pancreas in pejerrey achieves its functional development at the 2nd week post-hatching (9.22 ± 0.17 mm TL). Interestingly, α-amylase and maltase total activity progressively increased over development, suggesting that gradual incorporation of dietary carbohydrates in a feeding protocol may have a protein-sparing effect, as well as a cheap and fast way to obtain energy for the development and growth of pejerrey. The analysis of intestinal enzymes revealed that the typical shift between intracellular and luminal protein digestion that occurs during larval development in gastric species does not take place in pejerrey, indicating that in agastric species intracellular protein digestion plays a major role in comparison to luminal digestion during larval development. Contrary to gastric species, our results suggest that the ratio of alkaline phosphatase to leucine-aminopeptidase for evaluating gut maturation in agastric species is not recommended, and other parameters should be measured when evaluating the maturation process in fish larvae from this group of species.info:eu-repo/semantics/acceptedVersio