Carbohydrate metabolism during embryonic and larval development of Odonthestes humensis(De Buen, 1953) (Pisces—Atherinidae)

Changes in glucose and glycogen concentrations during embryonic and larval development of Odonthestes humensis (De Buen, 1953) (Pisces—Atherinidae) were followed. Glycogen decreased immediately after fertilization but remained constant throughout the embryonic period, suggesting that although present glycogenolisis may not be the most important energetic pathway during this period. Glucose levels only show a significant increase on the fifth day of development coincident with the beginning of heart activity. In fed larvae glycogen utilization increases during development, resulting in an increase in glucose concentration. Such a pattern does not occur in starved animals, where glycogen and glucose are present respectively at high and low concentrations similar to embryos. The change of pattern seems to be associated with the first larval feeding.