This study evaluated the effects of dietary astaxanthin on sperm quality and physiological indicators of pubertal male Nile tilapia, Oreochromis niloticus (Linnaeus, 1758). Fish (32.42 ± 0.51 g) were allocated to 16 tanks in recirculating aquaculture system (220 L; 5 fish tank-1), with four replicate tanks per dietary treatment, and fed for 45 days with diets containing 0, 50, 100, and 150 mg kg-1 astaxanthin derived from microalgae Haematococcus pluvialis. Astaxanthin supplementation markedly improved seminal traits: males receiving 50-150 mg kg-1 exhibited significantly greater semen volume, sperm concentration and motility, and a higher proportion of morphologically normal sperm than controls (P 0.05). Hematologically, astaxanthin, particularly at 100-150 mg kg-1, increased lymphocyte proportions while decreasing circulating neutrophils, monocytes, and thrombocytes (P -1, with reduced glucose, total cholesterol, triglycerides, alanine aminotransferase, and aspartate aminotransferase, and elevated total protein, albumin, and globulin (P -1, supports semen quality and physiological status in pubertal male Nile tilapia without compromising growth.
Avelino et al. (Wed,) studied this question.