This contribution brings together current knowledge on the use of functional food additives affecting marine fish reproductive performance. This article reviews published studies by several authors who have worked with specialized diets and focused on the dietary needs of brood fish, with the objective of identifying the relevant functional additives with potential to improve reproductive performance. The use of commercial and experimental diets that may have an effect on egg viability, quantity, and quality are discussed, with reference to hatching rates, larval survival, and compositions of fatty acids and amino acids after feed supplementation with various nutritional compounds. The intention of this review is to highlight the benefits of the use of vitamins, carotenes, fatty acids, and proteins of animal origin in broodstock nutrition, all of which have been shown to improve the quality of progeny under captive conditions. Finally, consideration is given to future perspectives on the use of additives in marine fish nutrition.

Additives in fish feeds are used worldwide to provide better productivity and improve fish’s health in facing disease outbreaks. This study aimed to identify the protective effect of taurine on the immune-related parameters and antioxidant enzyme activities of Seriola rivoliana juveniles after being challenged with LPS (lipopolysaccharide). Previously, the fish were submitted to a feeding trial for 60 days with feed enriched with different doses of external taurine (0, 1%, and 2%). Juveniles fed on different doses of taurine were injected with LPS (0%, LPS+T0%; 1%, LPS+T1%; 2%, LPS+T2%), and a control group was injected with saline solution (LPS-). The immune-related mRNA expression was evaluated, as were lysozyme enzyme activity and antioxidant enzyme activities (superoxide dismutase—SOD; catalase). Regarding immune mRNA expression, all the treatments had a peak of expression at 24 h post-LPS-injection, with a sharp decrease at 72 h post-injection, reaching similar mRNA expression as at 0 h post-injection. The results showed that the LPS+T2% treatment improved the expression of il1-β, tnf-α, and tlr-3 at 24 h post-LPS injection. Antioxidant and lysozyme activities were higher in both treatments with taurine when compared to the LPS+T0% and LPS- groups after 72 h post-LPS injection. These results suggest using 2% of exogenous external taurine can improve immunocompetency and counteract the oxidative stress caused by exposure to LPS in S. rivoliana juveniles.

Taurine supplementation has shown survival and feeding efficiency in larval fish development. Thus, the present study aims to evaluate the effects of adding taurine to the longfin yellowtail (Seriola rivoliana) diet for 60 days. Fish (n = 270) were distributed in three treatments: T0 without taurine, T1, and T2, supplemented with taurine at 1 and 2%, respectively. Growth performance, blood serum biochemistry, fatty acid, and amino acid profiles in skeletal muscle were evaluated. Notable improvements (P < 0.05) were observed in T1 and T2 in terms of specific growth rate (SGR) and weight gain (WG). Survival rates (SR) did not show significant differences (P > 0.05). In addition, a decrease was observed in intraperitoneal fat (IPF). Still, an increase was observed in blood parameters, including higher total protein (TP) and globulin (GLO) concentration, as well as a reduction in cholesterol (CHO) levels. Changes in fatty acid profiles were also detected in skeletal muscle with an increase in omega-3 fatty acids (EPA and DHA) and elevation in taurine concentration in T2. The results showed that adding 20 g kg-1 of taurine to the diet improved growth, skeletal muscle, and blood serum biochemistry. Therefore, the use of higher taurine concentrations is recommended in future studies to understand fully the extent of the benefits to longfin yellowtail juveniles.

The advancement of biotechnology in cultivating the Pacific white snook (Centropomus viridis) is noteworthy. This study aimed to elucidate the reproductive biology of C. viridis during the early stages leading up to first sexual maturity, with particular focus on spermatogenesis. We evaluated several factors, including 1) weight and growth, with physiological indices such as the condition factor (K) and the gonadosomatic index (GSI); 2) gonadal development (GD); and 3) environmental influences, including water temperature and photoperiod. We identified four distinct phases of GD: phase I: immature, phase II: developing, phase III: spawning capable, and phase IV: regressing. The spermatogenesis process involved various cell types: 1) spermatogonia (diameter 5.01 ± 0.80 μm), 2) primary spermatocytes (3.29 ± 0.36 μm), 3) secondary spermatocytes (2.76 ± 0.30 μm), 4) spermatids (2.38 ± 0.48 μm), and 5) spermatozoa (1.48 ± 0.44 μm). Phase III, indicating sexual maturity, was first observed in July 2020 (approximately 3 years old). Almost a year later, in May 2021, K peaked (>1.0), and by July 2021, with the water temperature on the rise, GSI reached a value greater than 0.8. These findings provide the first documented description of early gonadal development and sexual maturation in captive-born male C. viridis.