Protein synthesis in wild-caught Norway lobster (Nephrops norvegicus L.)

Although protein metabolism has been studied in fish and other crustaceans, this is the first study to measure protein synthesis rates for Norway lobster Nephrops norvegicus. This research aimed to assess the nutritional status of wild caught Nephrops by measuring tissue rates of protein synthesis and comparing these with rates from fed and starved Nephrops maintained in aquaria. Rates of protein synthesis were measured in the hepatopancreas, gill and tail muscle tissue. A time-course validated the use of a flooding-dose of 3H phenylalanine to measure protein synthesis in Nephrops and showed that the flooding-dose method is suitable for the study of protein turnover in Nephrops. The relationship between the measured rate of protein synthesis and capacity for protein synthesis (Cs) showed differences between tissues and between nutritional history. Measures of protein metabolism were generally higher in hepatopancreas, then gill and then tail muscle and generally lower in starved animals. Although individual variation meant there were few significant differences in tail muscle values between treatments, RNA concentration was higher in wild-caught than starved and suggested they were not starving. This was supported by hepatopancreas protein synthesis in wild-caught being intermediate between fed and starved, indicating relatively recent feeding had increased hepatopancreas protein synthesis due to increased RNA activity at constant RNA capacity. This study will add to our current but limited understanding of the effects of environmental variations on nutritional status and on protein metabolism and deposition in Nephrops species. Knowledge of the mechanisms enabling their survival is required to understand their ability to adapt to environmental variables.