Docosahexaenoic acid (DHA) is the most critical and least available omega-3 fatty acid in the Western human diet. Currently, the source of omega-3 long chain polyunsaturated fatty acids (LC-PUFA) is mainly dependent on wild fisheries, making this resource unsustainable in the foreseeable future. In recent years, a high rate of biosynthesis and accumulation of DHA has been discovered in a freshwater species (Chirostoma estor) belonging to the Atherinopsidae family. Interest in evaluating fatty acid composition in other members of the family has emerged, so this study compiles original data of flesh composition of eight atherinopsid species from freshwater and brackish environments, either wild or cultured. High levels of DHA (16 to 31%) were found in all analyzed members of the family, except in C. grandocule, independently of their habitat or origin. The analyzed species of the Jordani group (C. estor, C. promelas and C. humboldtianum) showed high DHA and low EPA levels (<0.5%) as previously reported for cultured C. estor. The low trophic niche of these atherinopsids and their fatty acid accumulation capabilities are factors that make these species noteworthy candidates for sustainable aquaculture.

Protein-rich microalgae have been increasingly recognized as viable alternatives to fish meal (FM) in aquaculture diets. In this study, we evaluated the effects of partial or total replacement of FM with the microalga Arthrospira platensis (Spirulina, SM) on the growth performance, reproductive parameters, and transcriptomic profile of zebrafish. Six isoproteic, isoenergetic experimental diets were formulated with increasing levels of SM (0, 10, 20, 30, 40, and 50 g kg⁻¹ feed) replacing FM. Fish were randomly assigned to six groups (five replicates each) and fed for 60 days. The diet containing 50 g kg⁻¹ SM resulted in the highest final body weight, weight gain, specific growth rate, and protein efficiency, as well as increased gonadosomatic index, eggs per female, fertilization rate, and hatching rate compared to the results for the control group (0 g kg⁻¹ SM). RNA-Seq transcriptomic analysis identified 2299 differentially expressed genes in the SM50 group, mainly associated with muscle development and energy metabolism. These findings offer new insights into the underlying molecular mechanisms and underscore the potential of Spirulina as a sustainable alternative for cultured fish nutrition.

La biotecnología acuícola se basa en el conocimiento generado por investigaciones científicas multidisciplinarias aplicadas a la producción de organismos acuáticos. Las enfermedades infecciosas, el cambio climático y la sostenibilidad, son los principales retos actuales de la acuicultura. En este trabajo se hace una revisión de las posibles soluciones biotecnológicas a estos retos, a través del mejoramiento de las dietas, del uso de nuevas tecnologías de análisis, como son las ciencias ómicas y finalmente se discute la integración de especies nativas a la acuicultura. Todas estas actividades, con políticas públicas adecuadas, promoverán el desarrollo de una acuicultura más rentable, sostenible y acorde con las condiciones regionales, garantizando la seguridad alimentaria.

A feeding trial was performed to assess dietary protein:lipid ratios for the grow-out phase of the bullfrog (Lithobates catesbeianus). Nine balanced isoenergetic diets were formulated, combining three different protein levels (300, 400, and 500 g kg−1) with three different lipid levels (50, 100, and 200 g kg−1), designated as P300/50L, P300/100L, P300/200L, P400/50L, P400/100L, P400/200L, P500/50L, P500/100L, and P500/200L. Additionally, a commercial fish feed, commonly used in Mexico to feed bullfrogs, was also tested during the experiment. Growth performance, [...] ABSTRACT A feeding trial was performed to assess dietary protein:lipid ratios for the grow-out phase of the bullfrog (Lithobates catesbeianus). Nine balanced isoenergetic diets were formulated, combining three different protein levels (300, 400, and 500 g kg−1) with three different lipid levels (50, 100, and 200 g kg−1), designated as P300/50L, P300/100L, P300/200L, P400/50L, P400/100L, P400/200L, P500/50L, P500/100L, and P500/200L. Additionally, a commercial fish feed, commonly used in Mexico to feed bullfrogs, was also tested during the experiment. Growth performance,

The Mexican pike silverside (Chirostoma estor) is a zooplanktivorous, agastric short-intestined species, and it has been found that increased-frequency feeding (twelve feedings a day) improved feed efficiency and promoted growth by 70%. This work determined the effect of different juvenile feeding frequencies upon the C. estor liver transcriptome. The level of the expression of appetite-regulating peptides was analyzed in silico to understand the mechanisms involved in appetite control in this species. Differential expression analysis showed that up-regulated genes between treatments were related to metabolism, digestive processes, immune system response, apoptosis, growth, and oxidative stress. This information explains the better performance of pike silverside fed 12 times daily. Appetite regulatory peptides were identified for the first time in the liver of C. estor in response to high feeding frequencies, contributing to the general knowledge of the roles of each family of neuropeptides in this agastric, short-intestined fish. The information presented here emphasizes the need to explore further the complex physiological processes involved in appetite regulation in C. estor. Additionally, it will serve as a basis for more specific targeted studies of appetite control to elucidate the mechanisms behind this process.