Abstract Scientific data on the influences of salinity shifts on the survival and behavioural attributes of marine animals is valuable to select potential coastal aquaculture candidates/commercial cultivation sites and to devise conservation strategies in the climate change scenario. This study establishes the survival ranges following gradual and abrupt salinity shifts for a high-value marine lobster species, Panulirus homarus. Lethal concentration limits differed between gradual and abrupt salinity shifts, with a broader tolerance observed under gradual shifts. There was 100% survival between 17 and 44‰ and between 26 and 41‰ following gradual and abrupt salinity shifts. As behavioural responses are critical in understanding the physiology and welfare status of animals, behavioural attributes, viz. antennule flicking per minute (AFM) and feed response time (FRT) were evaluated upon salinity shifts from the control (35‰). The sudden increase in AFM was the first visible reaction to the salinity shifts followed by a sustained decline beyond particular ranges in both gradual and abrupt shifts. FRT was significantly decreased beyond specific salinity ranges on gradual and abrupt salinity shifts and the animals became completely anorectic beyond 44–14‰, and beyond 44–23‰, respectively, on gradual and abrupt shifts. A better coping mechanism and a wider range of salinity tolerance were observed for gradual shifts than abrupt shifts.
Raveendran et al. (Thu,) studied this question.