|The biology and ecology of a brackish lagoon bivalve, Cerastoderma glaucum Bruguière, in Lago Lungo, Italy|
Ivell, R. (1979). The biology and ecology of a brackish lagoon bivalve, Cerastoderma glaucum Bruguière, in Lago Lungo, Italy. J. Moll. Stud. 45(3): 364-382
In: Journal of Molluscan Studies. Oxford University Press: Reading. ISSN 0260-1230, more
Cerastoderma glaucum (Poiret, 1789) [WoRMS]; Brackish water
Population and individual parameters of an Italian population of the brackish lagoon bivalve, Cerastoderma glaucum Bruguière, living in a mixohaline lagoon with typical summer dystrophy, were assessed over a one year period. Mortality and recruitment were both high, such that productivity and turnover were also high. Individual production was considerable; one cohort achieved 27 mm mean shell height and 375 mg mean dry flesh weight in 9 months. Accompanying the summer dystrophy, however most of the population had a very low “condition index”. The reproductive cycle followed a polycyclic pattern with up to three spawnings in a single year. Circumstantial evidence suggests that the cycle is environmentally controlled, and that spawning is not a necessary consequence of gametogenic activity. The chemical composition largely reflected the reproductive state and the “condition index”, with large fluctuations in water, ash and glycogen contents. Calorific content also fluctuated, as a function of ash content and lipid content; a formula is presented to predict such variation from the latter parameters. Finally, a simple production model is presented, indicating improvements to exploit further the high productivity of these lagoons.