Survival, Growth, and Metabolic Changes in Eastern School Prawn (Metapenaeus macleayi) across a Spectrum of Salinities

Abstract

Variation in salinity is one of the principal changes in estuarine physicochemistry that can impact the productivity of estuarine species. The effect of salinity on the mortality, growth, and metabolite profiles of juvenile Eastern School Prawn (Metapenaeus macleayi) was evaluated across a salinity gradient ranging from 0.2–36 over 60 days. Survival was >70% for salinity treatments other than the lowest salinity. Survival was 0% in the lowest salinity and all prawns had died within 3 days. Salinity did not appear to impact relative growth across the range of salinities examined. In contrast, relative somatic condition was greater at lower salinities and was negatively correlated with salinity, indicating lower salinities promote enhanced somatic condition in School Prawn. Total fatty acid concentration showed no relationship with salinity or somatic condition index. However, total fatty acid concentration did have a significant positive relationship with total amino acid concentration. Total amino acid concentration showed no linear relationship with salinity or somatic condition index. Quantitative profiling of individual fatty acids and amino acids showed some changes in response to salinity. Alpha-aminoadipic acid showed a significant positive relationship with salinity. These complex patterns suggest several shifts in cellular chemistry may occur throughout the salinity range investigated, potentially with metabolic consequences. These results highlight the complex responses of estuarine crustaceans to changes in salinity.