Features of Behavioral Responses of the Mediterranean Mussel in Its Natural Habitat of the Black Sea.

Typical characteristics of the behavioral reactions of the Mediterranean mussel Mytilus galloprovicialis Lam, 1819 in its natural habitat of the Black Sea have been investigated using the originally developed automated biomonitoring complex of the aquatic environment. The valve movements exhibit a pronounced, clear solar diurnal rhythm, with maximum valve opening amplitude at night and minimum in the daytime at ambient natural environmental conditions throughout the year. Two types of valve movements are defined in the diurnal rhythm of the activity of the mussels inhabiting the Black Sea. Mollusks react acutely to abrupt fluctuations in the physical factors of the environment by closing the valves instantly for a short time, which is a manifestation of protective reflexes. The manifestation of stress signs is observed in behavioral reactions to an abnormal acute decrease in water temperature and prolonged exposure to a high water temperature. [ABSTRACT FROM AUTHOR]