The study, the results of which have just been published in Aquaculture Research, investigated short‐term effects of increasing water temperature from 27 to 41°C on survival and feed consumption of Penaeus indicus at three different ages: PL25 (postlarvae 25 days old), PL50 and PL90.
For each age group, water temperature was maintained at 27°C in the control, but increased to 32, 35, 38 and 41°C at a rate of 1°C every eight hours. The temperature was then kept stable until the end of the 7‐day experiment. Results showed that increasing water temperature affected both survival and feed consumption of the experimental shrimps (p < .01). Survival was highest at 32 and 35°C (ranging from 93.8 percent to 100 percent), but significantly reduced (to 40.0 percent – 81.6 percent) at 38°C. No shrimp survived the 41°C treatment.
PL25 were more tolerant to 38–41°C than PL50 and PL90 in terms of survival. Increasing water temperature had no effects on feed consumption of PL25 (p > .05). For PL50 and PL90, feed consumption significantly increased at 38 and 41°C (p < .01) and was similar within the range of 27–35°C.
According to FAO statistics, global production of the species peaked at just over 40,000 tonnes in 2009, but had fallen to 5,202 tonnes by 2016. However, the new study suggests that Indian white shrimp might have a future, particularly if water temperatures in many areas continue to rise.
The authors of the study conclude that “P. indicus in tropical areas can tolerate water temperatures of at least 35°C and should be considered for farming during the summer time.”