Seasonal changes in the activity of certain enzymes in crude tissue extracts of two common cirripedes, Balanus balanoides (L.) and B. balanus (L.).

The activity of glutamate-oxaloacetate transaminase (GOT), glutamate-pyruvate transaminase (GPT), lactate dehydrogenase (LDH), malate dehydrogenase (MDH), isocitrate dehydrogenase (ICDH), and aldolase in tissue extracts of Balanus balanoides (L.) and B. balanus (L.) have been determined at regular intervals over a year, and an attempt made to relate the results to known biochemical changes in the animals.The work was ecologically orientated. Preliminary studies on the effects of extractant, dialysis, and possible endogenous interference were made and the subsequent procedure rigorously standardized.Transamination was investigated by TLC. LDH and aldolase show striking seasonal changes; an abundance of the former is associated with the production of semen. MDH, concerned in carbohydrate and lipid metabolism, was present in considerable quantities but there were no marked seasonal changes. GPT activity is high when reproductive products are being produced from reserves of food and the activity is also related to the production of semen. GOT showed no clear seasonal trends.The results are discussed relative to the metabolism of crustaceans: the part played by proteins and lipids is stressed.