Experimental measurement of enzyme activity during initial crustacean growth using the ornamental shrimp, <i>Neocaridina denticulata</i> (De Haan, 1844) as a model and changes in activity with growth

This study examined the growth dynamics, enzyme activity, and histological development of Neocaridina denticulata juveniles in controlled aquaculture conditions. Individual body weight and length variations were attributed to microenvironmental factors and social interactions. Transparent tank systems and localized environmental niches likely influenced resource competition and growth. Despite suboptimal temperatures (16.9–19.1°C, below the ideal 22–26°C), juvenile development remained unaffected, indicating broader temperature tolerance than previously recognized. Histological analysis revealed that the digestive structures of juveniles (15–60 days after hatching, DAH) and adults (>75 DAH) were remarkably similar, supporting isometric growth and highlighting a robust digestive system across life stages. Enzyme activity analysis, conducted with minimal sample sizes (10 individuals), effectively detected growth-related trends. Amylase and lipase activities showed dynamic patterns shaped by developmental programs and environmental factors, while protease activity increased steadily, reflecting the nutritional demands of growing juveniles. Adults exhibited significantly higher lipase activity than shrimplets, likely due to reproductive and metabolic requirements. This study underscores the efficiency of direct development in N. denticulata, providing valuable insights into its physiological and behavioral adaptations. The findings offer significant implications for aquaculture practices, particularly in enhancing shrimplet growth and survival under controlled environmental conditions.