Effects of starvation stress on growth, antioxidant system and biochemical substances of Pomacea canaliculata (Lamark 1822)

Pomacea canaliculata is a highly dangerous invasive alien species that threatens rice and aquatic crop production, thereby causing large economic and ecological losses. Starvation stress is an environmental pressure that organisms often face. Under starvation conditions, organisms slow down growth and development and consume energy storage substances to provide energy to maintain life activities. To investigate the physiological and ecological responses of P. canaliculata to short-term starvation stress, the effects of 10, 20, and 30 d of starvation stress on the growth, antioxidant system, and biochemical substances of P. canaliculata were studied. The results showed that the free water content of the snails continued to increase with the increased starvation time and was significantly higher than that of the control from 20 d onwards (P<0.05). The mean content of free water of the snails in the treatment group was 84.19% at 30 d, which was significantly higher than that of the control group at 81.60% (P<0.05). The growth and development of snails were inhibited by starvation stress, and shell height and shell mouth length were significantly smaller than those of the control after 20 d (P<0.05) and the inhibition persisted until the end of the experiment. Body weight, shell width, and shell mouth width were not significantly different from those of the control during the first 20 d. As the starvation period was extended to 30 d, all the growth indicators were significantly lower than those of the control (P<0.05). Under the starvation stress, the antioxidant capacity of the snails was improved, and the total superoxide dismutase activity was significantly higher than that of the control from 20 d until the end of the experiment (P<0.05). There was no significant difference in the catalase activity and malondialdehyde content between the first 20 d and the control; however, they were significantly higher than those of the control with the extension of the starvation time to 30 d (P<0.05). There was no significant difference in the peroxidase activity or reduced glutathione content between the starvation stress and control groups. The glycerol content showed a trend of increasing then decreasing; it was significantly higher than that of the control at 10 d (P<0.05), then decreased rapidly, and was significantly lower than that of the control at 20 d and 30 d (P<0.05). The lipid content was lower than that of the control at all three observation periods (P<0.05), the glycogen content was lower than that of the control at 20 d and remained low until the end of the experiment (P<0.05). The total protein content was significantly lower than that of the control at 30 d (P<0.05) but did not differ significantly from that of the control at the other observation periods. The results suggest that P. canaliculata can mitigate the effects of short-term starvation stress via a number of physiological mechanisms such as slowing growth, increasing antioxidant capacity, and depleting endogenous biochemicals. Limiting the food source can inhibit the outbreak and damage caused by P. canaliculata to a certain extent.