Abstract:
Perna canaliculus is one of the most important aquaculture export industries in New Zealand, with total exports in 2009 of $NZD202 million. The behavioural responses to common intertidal stressors of desiccation, heat shock and starvation have been examined in P. canaliculus juveniles and include secondary settlement, increased mortality and reduced growth that greatly effect production in the New Zealand mussel aquaculture industry. The aim of this study was to examine if preconditioning juvenile P. canaliculus with an acute pre-stress of heat shock, desiccation or starvation can confer an increased resistance to more intensive future stress via adjusting molecular processes. The physiological effects of thermal and desiccation stress through the induction Hsp70 in juvenile P. canaliculus is reported here for the first time. There was an increase in Hsp70 levels following a heat shock of 32 °C but not at a significant level due to large variation in the samples. Desiccation trials showed no significant difference for Hsp70 in juvenile P. canaliculus but there was high mortality. There was a clear trend of increasing mortality with smaller shell length of juvenile P. cancliculus. How these common environmental stressors can affect juvenile P. canaliculus on a molecular level that may not be obvious from observation of the whole organism could be an important tool to assessing the overall quality of both hatchery and wild caught P. canaliculus juveniles. Understanding molecular responses can help predict the level of stress of that a behavioural response such as secondary settlement may occur.
