Gonad development and blood plasma profile of female bada fish (Rasbora sp.) by giving a combination of the hormones estradiol and spirulina in the feed

This study aimed to evaluate the effect of the combination of estradiol-17β hormone and spirulina in feed on blood plasma biochemistry, histology, and gonad development of female bada fish (Rasbora argyrotaenia). The research method were an experimental study using a completely randomized design with four treatment combinations and four replications, namely without the addition of the estradiol-17β hormone and spirulina (P0), the addition of the estradiol-17β hormone at 7 g kg-1 feed (P1), the addition of spirulina at 30 g kg-1 feed (P2) and the addition of the estradiol-17β hormone at 7 g kg-1 feed and spirulina at 30 g kg-1 feed. Female bada fish (4.22±1.28 g) were kept in an aquarium measuring 100x50x50 cm3 with a density of seven individuals per aquarium. Fish were fed the treatment twice daily, with 3% of the biomass for six weeks. The test parameters were estradiol-17β hormone concentration, egg diameter, blood plasma glucose concentration, blood plasma total cholesterol concentration, and gonadal histology observations. The experimental results showed that the concentration of the estradiol-17β hormone in the body plasma of treatments P1 and P3 was statistically significantly different (P<0.05) compared to treatments P0 and P2. The combination of estradiol-17β hormone and spirulina added to the feed gave not significantly different results (P>0.05) on blood plasma biochemistry and egg diameter of bada fish broodstock. A combination of estradiol-17β hormone and spirulina hormones in the feed resulted in better P1 and P3 treatments with higher plasma concentrations of the estradiol-17β hormone. Observations of gonadal development from histology showed that the bada fish gonads belonged to the asynchronous type.

Sablefish (Anoplopoma fimbra Pallas, 1814) plasma biochemistry and hematology reference intervals including blood cell morphology

Plasma biochemistry and hematology reference intervals are integral health assessment tools in all medical fields, including aquatic animal health. As sablefish (Anoplopoma fimbria) are becoming aquaculturally and economically more important, this manuscript provides essential reference intervals (RI) for their plasma biochemistry and hematology along with reference photomicrographs of blood cells in healthy, fasted sablefish. Blood cell morphology can differ between fish species. In addition, blood cell counts and blood chemistry can vary between fish species, demographics, water conditions, seasons, diets, and culture systems, which precludes the use of RI’s from other fish species. For this study, blood was collected for plasma biochemistry and hematology analysis between June 20 and July 18, 2019, from healthy, yearling sablefish, hatched and reared in captivity on a commercial diet. Overnight fast of 16–18 hours did not sufficiently reduce lipids in the blood, which led to visible lipemia and frequent rupture of blood cells during analysis. Therefore, sablefish should be fasted for 24 to 36 hours before blood is collected to reduce hematology artifacts or possible reagent interference in plasma biochemistry analysis. Lymphocytes were the most dominant leukocytes (98%), while eosinophils were rare, and basophils were not detected in sablefish. Neutrophils were very large cells with Döhle bodies. In mammals and avian species, Döhle bodies are usually signs of toxic change from inflammation, but no such association was found in these fish. In conclusion, lipemia can interfere with sablefish blood analysis, and available removal methods should be evaluated as fasting for up to 36 h might not always be feasible. Also, more studies are required to establish RI for different developmental stages and rearing conditions.