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Observations on the reproduction and the biometry of Cerastoderma glaucum (POIRET, 1789) (Bivalvia, Cardiidae) in the Lagoon of Grado (High Adriatic Sea). The reproduction and biometry of a population of Cerastoderma glaucum (Poiret, 1789) from Morgo Island, in the Lagoon of Grado have been studied. The sexes are separate and the first gametogenesis of reproductive cycle starts from December to February (in concomitance with the lowest temperatures of water), while the maturity and the spawn take place from March to November. Anyway, samples in spent stage can be found during all periods of the year. The average shell-lenght of population has shown tendency to increase from October to June. In July on, this feature shows a remarkable decreasing, due to incoming juvenile samples, in relation with the progressive loss of the oldest ones. Key words: Cerastoderma glaucum, Bivalvia, reproduction, biometry, Lagoon of Grado. |
