Cultured Senegalese sole (Solea senegalensis) breeders fail to spawn fertilized eggs. The implantation of large-scalein vitrofertilization protocols, to solve this problem, has been frustrated by low production of poor quality sperm. Cultured females were induced to ovulate with a 5 µg kg⁻¹single injection of gonadotropin-releasing hormone agonist (GnRHa) and viable eggs (82.6 ± 9.2% fertilization) were stripped 41:57 ± 1:46 h after the injection. Sperm was collected from cultured males, diluted in modified Leibovitz and used fresh to fertilize the eggs. Males were not treated with hormones. A nonlinear regression, an exponential rise to a maximum (R= 0.93,p< 0.0001) described the number of motile spermatozoa required to fertilize a viable egg and 1617 motile spermatozoa were sufficient to fertilize 99 ± 12% (±95% CI) of viable eggs. Similar, spermatozoa egg⁻¹ratios of 592 ± 611 motile spermatozoa egg⁻¹were used in large-scalein vitrofertilizations (190 512 ± 38 471 eggs). The sperm from a single male (145 ± 50 µl or 8.0 ± 6.8 × 10⁸spermatozoa) was used to fertilize the eggs. The mean hatching rate was 70 ± 14% to provide 131 540 ± 34 448 larvae per fertilization. The viability of unfertilized eggs stored at room temperature decreased gradually, and the sooner eggs were fertilized after stripping, the higher the viability of the eggs. The collection of sperm directly into a syringe containing modified Leibovitz significantly increased the percentage of motile spermatozoa (33.4 ± 12.2%) compared with other collection methods. The spz egg⁻¹ratios for Senegalese sole were at the lower end of ratios required for fish. Senegalese sole have a pair-spawning reproductive behaviour characterized by gamete fertilization in close proximity with no sperm competition. The provision of a large-scalein vitrofertilization protocol (200 µl of sperm per 100 ml of eggs) will enable the industry to operate sustainably and implement breeding programmes to improve production.

The aim of this study was to evaluate the zootechnical performance, macronutrient composition, physicochemical analysis of the water, and hematological parameters of the L. pardalis at different densities (5, 7, 10 fish m-2), during four-month period. A total of 660 fish were utilized in the study, with an initial mean weight of 54.89 ± 0.18 g. They were distributed across nine earthen ponds, with the number of fish allocated to each treatment as follows: T1 (150 fish), T2 (210 fish), and T3 (300 fish). The most efficacious treatment, exhibiting optimal growth, was T2 (7 fish m-2). The FW was 198.24 ± 0.69 g, and the TL was 18.2 ± 0.44 cm. These values were significantly different (p < 0.05) from those observed in the other treatments. The physicochemical parameters of the water demonstrated fluctuations at higher stocking densities. The findings demonstrate that L. pardalis modifies its lifestyle to a low metabolic capacity, resulting in alterations to the red series hematological parameters (Ht, HGB, ERIT, VCM, CHCM, HCM) in response to the increase in temperature and decrease in oxygen. Significant differences (p < 0.05) were observed between the initial and final samples. Nevertheless, this work demonstrates the importance of relating zootechnical and hematological parameters as indicators of productivity and health. Further studies are recommended on fish of the family Loricariidae to establish differences between genera, habitat, and production systems. This will facilitate the development of sustainable Amazonian aquaculture. El objetivo de este estudio fue evaluar los rendimientos zootécnicos, composición de macronutrientes, análisis fisicoquímicos del agua y parámetros hematológicos del L. pardalis a diferentes densidades 5, 7, 10 peces m-2, durante 4 meses, un total de 660 peces con peso promedio inicial de 54,89 ± 0,18 g, fueron distribuidos en 9 estanques de tierra, cuya distribución por tratamiento fue T1 (150 peces), T2 (210 peces) y T3 (300 peces). El mejor tratamiento que mostro un buen crecimiento fue T2 (7 peces m-2); peso final de 198,24 ± 0,69 g y longitud total 18,2 ± 0,44 cm, siendo significativamente diferente (p < 0,05) a los demás tratamientos, los parámetros fisicoquímicos del agua manifestaron variaciones a una mayor densidad de siembra. Demostrando que L. pardalis modifica su estilo de vida a una capacidad metabólica baja, de tal manera que los parámetros hematológicos de la serie roja (Ht, HGB, ERIT, VCM, CHCM, HCM) se vieron afectados por ese aumento de temperatura y disminución del Oxígeno, encontrándose diferencias (p < 0,05) frente a las muestras iniciales y finales. No obstante, este trabajo demuestra la importancia de relacionar los parámetros zootécnicos y hematológicos como indicadores de productividad y salud, es recomendable hacer más estudios en peces de la familia Loricariidae, para establecer diferencias entre géneros, habitad y sistemas de producción, para una acuicultura amazónica sostenible.

Crustacean shell waste, exceeding 6–8 million tons annually, represents a largely underexploited source of chitin and chitosan, biopolymers of recognized functional and economic value. Despite growing interest in sustainable production, eco-friendly extraction routes remain constrained by the lack of integrated frameworks addressing extraction efficiency, polymer quality, environmental performance, and industrial scalability simultaneously. This review critically evaluates conventional and emerging chitin/chitosan extraction technologies from crustacean biomass across six dimensions: yield, degree of deacetylation, molecular weight retention, energy and chemical demand, effluent burden, and technology readiness level (TRL). Enzymatic and fermentation-based routes (TRL 4–6) preserve higher molecular weight but require extended processing times (48–120 h) and face unresolved enzyme-cost barriers. Deep eutectic solvent systems (TRL 3–5) achieve purities exceeding 96% under mild conditions, although scalability and solvent recovery remain limiting. Hybrid integrated configurations emerge as the most technically and economically viable transition pathway. Feedstock diversity, including the underutilized regional resource Grimothea monodon from the Humboldt Current System, was discussed as a candidate resource within circular bioeconomy principles. By linking techno-economic analysis, life-cycle perspectives, and TRL maturity into a unified, decision-oriented framework, this review identifies hybrid biorefinery configurations as the most viable pathway toward scalable, industrially competitive chitin-based production.