Animals that develop within an egg, must rely on the egg yolk for nutrition for healthy development. While we have known that proteins and fats in the egg are important for development, the role of carbohydrates in the development of molluscs is a bit vague.
A new study published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology examined the role of carbohydrates in the development of Pacific abalone (Haliotis discus hannai). The reason for examining this relationship in abalone is that these molluscs are commercially grown for human consumption as well as making decorative items. Moreover, developing abalone experience high mortality rates in traditional aquaculture farming.
The new study found increases in both glucose and glycogen, the storage form of glucose, within developing Pacific abalone larvae. By examining gene expression patterns, they found that larval abalone are able to produce and use carbohydrates for energy. The researchers experimented with adding glucose to the water but they found that the animals were able to produce enough carbohydrates on their own through a process called gluconeogenesis, which uses amino acids and glycerol to make new glucose molecules.
This is the first study to report the importance of carbohydrates, and not just fats and proteins, in the development of Pacific abalone. The hope is that by understanding how these molluscs utilize energy, farming practices may be refined to improve survival and health of these animals.
M Koyama, F Furukawa, Y Koga, S Funayama, S Furukawa, O Baba, C-C Lin, P-P Hwang, S Moriyama S Okumura. Gluconeogenesis and glycogen metabolism during development of Pacific abalone, Haliotis dicsus hannai. American Journal of Physiology – Regulatory, Integrative and Comparative Physiology. 2020.