Influence of abiotic factors on the fecundity and ecological plasticity of a freshwater prawn in estuary and river environments.

Context: Macrobrachium amazonicum is a freshwater prawn of socioeconomic importance in the Amazon region, whose growth, reproduction and fecundity vary according to the environment. Aims: To determine which abiotic factors influence the size and fecundity of populations of M. amazonicum in estuary and river environments. Methods: To do so, we captured a total of 255 ovigerous females, 181 from the estuary and 74 from the river, and measured temperature, total dissolved solids, turbidity, salinity, pH, dissolved oxygen and precipitation. Key results: We found that turbidity, precipitation and dissolved oxygen explained the variation in M. amazonicum size, and that the estuarine females were larger and had more and smaller eggs than riverine females. Conclusions: Precipitation, turbidity and dissolved oxygen were found to bedetermining factors for the ecological plasticity of M. amazonicum females in different environments. Implications: Freshwater prawn species display different reproductive strategies for distinct environments, and understanding their fecundity is important to establish efficient management policies. In addition, this information should be useful to improve the cost–benefit ratio of freshwater prawn farming in the Amazon region. In this study, we sought to determine which abiotic factors influence the fecundity and size of populations of M. amazonicum in estuary and river environments. Precipitation, turbidity and dissolved oxygen are determining factors for the differences found in the fecundity and size of M. amazonicum females in different environments. This information should be useful for improving the cost-efficiency of prawn culture. (Image credit: Breno Silva and Juan Caldas.) [ABSTRACT FROM AUTHOR]