Abstract:

The nutrient compositions of different tissues of adult female tri-spine horseshoe crab Tachypleus tridentatus were determined and analyzed to explore the nutritional requirements during spawning period as well as to promote their gonadal development and egg cell maturation. The important nutrient components, including amino acids and fatty acids, of muscles, yellow connective tissues and eggs were measured using the Chinese national standard biochemical analysis methods. The results show that the compositions of common nutrients, amino acids and fatty acid, but not their levels, are similar among the tissues. The muscle tissues have the highest moisture level (77.5%), the egg crude protein content is the highest (27.9%), and the yellow connective tissues record the highest contents of crude lipid (16.5%), ash (1.6%), calcium (1220 mg/kg) and phosphorus (107 mg/100 g). There are 17 kinds of amino acids and 13 kinds of fatty acids in the three tissues, in which amino acid Glu, fatty acids palmitic acid (C_16:0) and oleic acid (C_18:1) are the highest. The relative contents of fatty acids DHA and EPA in the three tissues are the highest in eggs, followed by those of yellow connective tissue and muscle. These results indicate that the muscle of adult female T. tridentatus is characterized by the high protein and low lipid contents, while the eggs are rich in amino acids and unsaturated fatty acids. The findings are useful for the conservation and sustainable use of horseshoe crab stock resources, and their nutritional value evaluation.

Key words: Tachypleus tridentatus, histology, nutrient composition, amino acid, fatty acid