Seasonal changes in functional parameters of the hemolymph of Mytilus galloprovincialis

Abstract

n bivalves, many functional parameters show seasonal changes in relation to both abiotic (such as temperature and salinity) and biotic factors (such as gonad maturation, food availability). Available data indicate that also immune parameters can show seasonal fluctuations in the marine mussel Mytilus spp.. In this work we report data on hemocyte lysosomal membrane stability (LMS) and phagocytic activity, as well as on soluble lysozyme activity, in the hemolymph of mussels (Mytilus galloprovincialis) collected over a 24 month period in the Adriatic Sea (2006-2007). The results indicate that all the parameters measured show seasonal fluctuations over the year, with lysozyme activity showing the largest changes. Lowest LMS values were observed in early winter and early autumn, whereas maximal values of phagocytic activity were observed in winter and increasing serum lysozyme activities were recorded in autumn. The observed seasonal fluctuations are discussed in relation to both abiotic (temperature) and biotic (changes in endogenous modulators) factors.

Keywords

• Mytilus
• hemocytes
• lysosomal membrane stability
• phagocytosis
• lysozyme
• immune parameters
• seasonal variation