Abstract: We determined and compared the contents of nutritional and functional ingredients in males and females from two major seahorse species, Hippocampus erectus and H. trimaculatus, and we also evaluated their nutritional values. The results showed that: 1) the major component of the seahorses was crude protein (on a dry mass basis), which averaged at (60.61 ± 2.83)%, and the crude fat (on a dry mass basis) was relatively lower with an average of (3.04 ± 0.26)%, no significant differences being seen between the genders within a species; 2) the male and female seahorses were similar in amino acid composition, of which the seven essential amino acids were slightly lower as compared with the FAO/WHO recommended pattern. Within a species, the amino acids score, chemical score and essential amino acid index of the females were higher than those of the males. We also found the limited amino acids, including valine, isoleucine, methionine and cysteine, in the seahorses; 3) the fatty acid compositions in the seahorses were consistent regardless of gender, and the total contents of saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids (PUFA) of the females were significantly higher than those of the males within a species. The ratios of n-6/n-3 PUFA of the two species were 0.14–0.18, and they were n-3 PUFA-rich food. The indexes of atherosclerosis and thrombosis were significantly higher than those in the Eskimo diets, which are considered as healthy food for preventing coronary heart disease; 4) the contents of cholesterol and hypoxanthine in the female seahorses were significantly higher than those in the males, while the uridine content in the females was lower than in the males. These results indicate that H. erectus and H. trimaculatus can be used as superior sources of protein and n-3 PUFA. In addition, the gender difference in the contents of nutrients and main functional components (e.g. cholesterol and hypoxanthine), suggests that monosex culture may be a good practice in seahorse aquaculture.

Key words: male and female, seahorses, nutritional components, nutritional value, functional compositions