Effect of Selection for High Growth on Resilience of Giant Freshwater Prawn Macrobrachium rosenbergii

Resilience is the capacity of an animal to be minimally affected by disturbances or to rapidly return to its pre-disturbance state. To the best of our knowledge, no previous study has investigated resilience in the giant freshwater prawn (GFP, Macrobrachium rosenbergii). In this study, we aimed to estimate the genetic parameters of resilience indicators, the correlations between resilience and growth and survival traits, and the correlated genetic responses to selection for high growth in the present GFP line. A resilience indicator based on standardised body weight (BW) deviation was analysed in 39,134 individuals (offspring of 810 females and 515 males), specifically the logarithm-transformed variance (LnVar). The heritability estimate for the resilience indicator (LnVar) was low (0.09 ± 0.03) but statistically significant. The genetic correlations between LnVar and body weight (BW) and total length (TL) were moderate and positive (0.33 ± 0.04 and 0.18 ± 0.01, respectively), whereas those between LnVar and body and carapace widths were negative (-0.28 to -0.32). The correlated response of the resilience indicator (LnVar) to selection for high growth was low but favourable, averaging 0.77%-2.89% over eight generations, or only 0.002 and 0.006 phenotypic and genetic standard deviation units, respectively. In conclusion, this study demonstrates the presence of heritable genetic variation in the resilience indicator derived from BW deviations in the giant freshwater prawn. Selection for high body weight has slightly improved resilience in this species, highlighting the potential to enhance resilience through selective breeding, albeit at a slow rate.