Organic, inorganic, and caloric composition of eggs, pentaculae, and adults of the brooding sea cucumber Cucumaria curata cowles (Echinodermata: Holothuroidea)

Abstract

Levels (percentage composition) of water, ash, carbohydrate, lipid, protein, and calories were determined for eggs, pentaculae, and adults of the sea cucumber Cucumaria curata Cowles. Component contents (μg/individual) were calculated for eggs and pentaculae. During the 28 days of development to hatching, the large yolky eggs gain water and ash, the total dry weight increasing from 169 to 190 μg/egg during embryogenesis. There were no statistically significant changes in lipid, protein, and caloric contents during embryogenesis, but carbohydrate decreased by 0.82 μg/egg. The decrease in carbohydrate is sufficient to account for estimated embryonic energy requirements. Based on the utilization of carbohydrate, embryos of C. curata show a nutritional pattern similar to that of the planktonic embryos of sea urchins and different from that of embryos developing from terrestrial eggs, freshwater eggs, and planktonic and demersal marine eggs. Although broods varied widely in egg number and mean egg dry weight, C. curata gives eggs which contain a constant proportion of organic components. Levels of ash, water, and protein in the adults exceeded those in the pentacula, and lipid comprises a much smaller proportion of the adult body than it did of the pentacula.