Variabilità spaziale di una Tanato-Malacocenosi dell’area marina protetta di Torre Guaceto (Adriatico sud-occidentale)
Abstract
It
I campioni di sedimento raccolti da tre stazioni di una spiaggia dell’Area Marina Protetta di Torre Guaceto contenevano un totale di 7292 conchiglie appartenenti a 114 specie (86 Gastropoda, 27 Bivalvia ed 1 Scafopoda). Le specie più abbondanti erano i Gastropoda Tricolia pullus, Alvania cimex, Bittium latreillii ed i Bivalvia Striarca lactea e Glans trapezia. Sono state riscontrate differenze statisticamente significative fra i sedimenti delle tre stazioni: lungo il gradiente Est-Ovest diminuisce il numero delle specie e la densità delle conchiglie, mentre aumentano le loro dimensione medie. La deposizione differenziale di conchiglie lungo la spiaggia è ascrivibile alla forma della baia, unitamente ai movimenti prevalenti delle acque.
En
The shell assemblage of Mollusca on a beach of the Torre Guaceto Marine Protected Area was examined in three different sites to detect possible differences in the shell composition in terms of species, size, and abundance. Samples collected from the three stations (600 cc of sediment per station) contained a total of 7292 shells belonging to 114 species (86 Gastropoda, 27 Bivalvia and 1 Scafopoda). The most abundant species were the Gastropoda Tricolia pullus, Alvania cimex, Bittium latreillii and the Bivalvia Striarca lactea and Glans trapezia. Statistically significant differences were found between the three station samples: the density of shells and the number of species decrease from East to West, whereas the mean shell size increases along the same direction. The sediment grain size increases from East to West too. Such differences are possibly due to the shape of the bay sheltering the beach and the prevalent water movements. Studies of Mollusca shell assemblages are deemed useful to obtain information on neighbouring living biocoenoses; however this note shows that the fidelity of shell assemblages may fluctuate according to several factors, including the position of the beach.
I campioni di sedimento raccolti da tre stazioni di una spiaggia dell’Area Marina Protetta di Torre Guaceto contenevano un totale di 7292 conchiglie appartenenti a 114 specie (86 Gastropoda, 27 Bivalvia ed 1 Scafopoda). Le specie più abbondanti erano i Gastropoda Tricolia pullus, Alvania cimex, Bittium latreillii ed i Bivalvia Striarca lactea e Glans trapezia. Sono state riscontrate differenze statisticamente significative fra i sedimenti delle tre stazioni: lungo il gradiente Est-Ovest diminuisce il numero delle specie e la densità delle conchiglie, mentre aumentano le loro dimensione medie. La deposizione differenziale di conchiglie lungo la spiaggia è ascrivibile alla forma della baia, unitamente ai movimenti prevalenti delle acque.
En
The shell assemblage of Mollusca on a beach of the Torre Guaceto Marine Protected Area was examined in three different sites to detect possible differences in the shell composition in terms of species, size, and abundance. Samples collected from the three stations (600 cc of sediment per station) contained a total of 7292 shells belonging to 114 species (86 Gastropoda, 27 Bivalvia and 1 Scafopoda). The most abundant species were the Gastropoda Tricolia pullus, Alvania cimex, Bittium latreillii and the Bivalvia Striarca lactea and Glans trapezia. Statistically significant differences were found between the three station samples: the density of shells and the number of species decrease from East to West, whereas the mean shell size increases along the same direction. The sediment grain size increases from East to West too. Such differences are possibly due to the shape of the bay sheltering the beach and the prevalent water movements. Studies of Mollusca shell assemblages are deemed useful to obtain information on neighbouring living biocoenoses; however this note shows that the fidelity of shell assemblages may fluctuate according to several factors, including the position of the beach.
DOI Code:
10.1285/i15910725v31p67
Full Text: PDF
