Effect of starvation and subsequent feeding on glycogen concentration, behavior and mortality in the golden mussel Limnoperna fortunei (Dunker, 1857) (Bivalvia: Mytilidae

Abstract

<p>The success of <em>Limnoperna fortunei</em> as an invasive species is related to its physiological plasticity that allows them to endure adverse environmental conditions. Starvation tolerance is considered to be an important trait associated with bivalve invasiveness. In natural ecosystems, food resources can vary during the year, exposing mussels to variable periods of starvation or limited food availability. Thus, mussels have developed physiological strategies to tolerate and survive fluctuations in food availability. Glycogen concentration has been used in different monitoring studies as an indicator of the nutritional condition of bivalves. The aim of this study was to investigate the physiological responses of <em>L. fortunei</em> based on the glycogen concentrations of specimens under four treatments, comprising different combinations of feeding and starvation, during 125 days. The experiment was carried out in two phases. In the phase I, mussels were divided in two treatments: starvation (S) and feeding (F). After 100 days, tissue samples were collected to quantify glycogen concentrations and, each phase I group was divided in two subgroups: starvation (S) and feeding (F), resulting in four treatments. In the phase II, that lasted 25 days, starvation specimens (S) from phase I were allowed to feed (starvation-feeding treatment , or S-F), or continued to undergo starvation (starvation-starvation treatment , or S-S) and the feeding specimens (F) continued feeding (feeding-feeding group, or F-F), or were subjected to starvation (feeding-starvation treatment , or F-S). Behavior (valve-closing) and mortality were recorded in 24 h intervals. After the 25 days (phase II) all specimens were killed, and their soft tissue was removed to quantify glycogen concentrations. The glycogen concentration of the S-F treatment was lower than that of the F-S treatment, which was initially allowed to feed (phase I) and then subjected to starvation (phase II). Stability in the glycogen concentrations was observed when the phase II feeding conditions were maintained during the experiments, as observed in the S-S (continued starvation) and F-F (continued feeding) treatments. Based on our glycogen concentrations results, the golden mussel shows a higher tolerance to starvation (125 days) than has previously been published, which suggests that its tolerance strongly influences its invasive behavior.<strong></strong></p>

Effect of temperature on behavior, glycogen content, and mortality in Limnoperna fortunei (Dunker, 1857) (Bivalvia: Mytilidae)

“…The use of metabolic reserves, or the depletion of glycogen concentrations, has been associated with the nutritional conditions of the mussels and is a good parameter for assessing their physiological conditions (Widdows and Bayne, 1971;Gabbott and Bayne, 1973;Patterson et ., 1999;Chen et al, 2001;Nandurkar and Zambare, 2012;Anacleto et al, 2013;Cordeiro et al, 2016Cordeiro et al, , 2017. In fact, stressors (e.g., extreme temperatures, starvation) cause severe changes in their metabolism and contribute to mortality (Patterson et al, 1999;Lee et al, 2008;Anacleto et al, 2013;Cordeiro et al, 2016).…”

“…In fact, stressors (e.g., extreme temperatures, starvation) cause severe changes in their metabolism and contribute to mortality (Patterson et al, 1999;Lee et al, 2008;Anacleto et al, 2013;Cordeiro et al, 2016).…”

“…To gain a more comprehensive understanding of the effects of temperature and considering that mussels may respond differently to stressors (i.e., physiological response, behavioral response, mortality or some combination of these) (Dowd and Somero, 2010;Palais et al, 2011;Perepelizin and Boltovskoy, 2011;Cordeiro et al, 2016Cordeiro et al, , 2017, we attempted to examine the effects of different temperatures on L. fortunei responses. These data may contribute to (i) a better understanding of the physiological and behavioral responses of the golden mussel to different temperatures, which may be related to their ability to adapt to temperature changes,…”

“…Valve movement is easily measurable and is one of the most important bivalve behaviors; it was monitored in experiments involving chemical (Di Fiori et al, 2012;Montresor et al, 2013) and nutritional stressors (Riisgård and Larsen, 2015;Cordeiro et al, 2016) and temperature changes (Perepelizin and Boltoskoy, 2011). In general, filter-feeding bivalves such as L. fortunei reduce their filtration rate by closing their valves when exposed to lower temperatures or abrupt temperature changes (Kittner and Riisgård, 2005;Perepelizin and Boltoskoy, 2011).…”

“…This species has successfully increased its geographic distribution in South America, chiefly through its physiological plasticity, rapid growth and sexual maturation and its ability to colonize several natural and artificial substrates Boltovskoy et al, 2015;Nakano et al, 2015;Barbosa et al, 2016;Cordeiro et al, 2016). Considering these factors, several studies investigated the roles of abiotic factors (e.g., calcium, temperature and salinity) on the establishment, abundance and risk of further spread of the golden mussel to several areas Damborenea, 2005, 2011;Oliveira et al, 2010Oliveira et al, , 2011Darrigran et al, 2012).…”