Tides, Topography, and Seagrass Cover Controls on the Spatial Distribution ofPinna nobilison a Coastal Lagoon Tidal Flat

Abstract

Pinna nobilis (Linneaus 1758), commonly known by the name of "noble pen shell" or "fan mussel," is the largest bivalve mollusk in the Mediterranean, where it has been present since the end of the Miocene (Gómez-Alba, 1988). Its large valves can exceed 100 cm in length (García-March & Vicente, 2006;García-March et al., 2002), and some individuals can reach 45 years of age (Rouanet et al., 2015).In the last two decades the population of P. nobilis has recolonized some lagoons along the Italian coast of the Adriatic Sea (Curiel et al., 2020;Marrocco et al., 2018;Russo, 2012), where the fan mussel disappeared in the 20th century. As reported by Russo (2012), in 2006/2007 a significant population of P. nobilis was observed in certain areas of the Venice lagoon (NE Italy) with a density of up to 12-16 individuals/m 2 (Russo, 2012). Since

Evidence of Warm Welcome From the Cymodocea nodosa (<em>Tracheophyta, Alismatales</em>) Meadow in the Seas of Taranto (Southern Italy, Mediterranean Sea)

“…In Spain, in the transitional system of the Ebro River (NW Mediterranean), the highest density of P. nobilis specimens were measured in zones where the C. nodosa meadow reached a covering of 80-100% [21]. In the Venice Lagoon (Adriatic Sea, northern Italy), the fan mussel density was the highest at the highest cover of the phanerogam, and it was preferably located at the border of the meadow, where the filtering activity can be enhanced [23]. Unfortunately, Figure 3 represents an historical relic, since starting from 2018, P. nobilis underwent mass mortality in the Taranto seas, due to an infection of the protozoic parasite Haplosporidium pinnae [24].…”

“…For several years, starting from 2014, it was common to see specimens of the fan mussel Pinna nobilis (Linnaeus 1758) among the shoots of C. nodosa [19] (Figure 3). The big bivalve mollusk shows a marked preference for this phanerogam in transitional waters, mainly due to the close bonds produced among the rhizomes, the sediments, and the byssus filaments [20][21][22][23]. Also of paramount importance is the protective effect of leaves against the hydrodynamics, which fosters the mollusk's larvae settlement [23].…”

“…The big bivalve mollusk shows a marked preference for this phanerogam in transitional waters, mainly due to the close bonds produced among the rhizomes, the sediments, and the byssus filaments [20][21][22][23]. Also of paramount importance is the protective effect of leaves against the hydrodynamics, which fosters the mollusk's larvae settlement [23]. In Spain, in the transitional system of the Ebro River (NW Mediterranean), the highest density of P. nobilis specimens were measured in zones where the C. nodosa meadow reached a covering of 80-100% [21].…”

Native and Non-Indigenous Biota Associated with the Cymodocea nodosa (Tracheophyta, Alismatales) Meadow in the Seas of Taranto (Southern Italy, Mediterranean Sea)

“…For several years, starting from 2014, it was common to see specimens of the fan mussel Pinna nobilis (Linnaeus 1758) among the shoots of C. nodosa [19] (Figure 4). The big bivalve mollusk shows a marked preference for this phanerogam in transitional waters, mainly due to the close bonds produced among the rhizomes, the sediments, and the byssus filaments [20][21][22][23]. Also of paramount importance is the protective effect of leaves against hydrodynamics, which fosters the mollusk's larvae settlements [23].…”

“…The big bivalve mollusk shows a marked preference for this phanerogam in transitional waters, mainly due to the close bonds produced among the rhizomes, the sediments, and the byssus filaments [20][21][22][23]. Also of paramount importance is the protective effect of leaves against hydrodynamics, which fosters the mollusk's larvae settlements [23]. In Spain, in the transitional system of the Ebro River (NW Mediterranean), the highest density of P. nobilis specimens were measured in zones where the C. nodosa meadow reached a cover of 80-100% [21].…”