Influence of Grain Size on Burrowing and Alongshore Distribution of the Yellow Clam (Amarilladesma mactroides)

Abstract

The yellow clam Amarilladesma mactroides (Reeve, 1854), is an intertidal species that prospers mainly on dissipative sandy beaches along the temperate Atlantic coast of South America, from Brazil to Argentina (24-41°S). This large clam is considered a fast burrower, which lives buried in the sediment, migrating seasonally into the intertidal zone. The present study explores the effect of sediment grain size on the burrowing performance of this species, to elucidate the influence of granulometry on the alongshore distribution of the A. mactroides population. Laboratory trials were performed with clams of different sizes, to study the influence of grain size on the burial rate. Clam distribution was analyzed along a 32 km coastal fringe whose granulometric composition varies from very fine to coarse sand. The values of the mean burrowing rate index, a measurement of clam mobility, suggest that burrowing is fast to very fast in fine and medium sand and becomes slower toward areas with extreme particle size (very fine and coarse sand). The burial time of A. mactroides was positively correlated with shell length: small animals can burrow into substrates that may exclude larger animals. Adults clams burrowed in a very limited range of sand grain sizes. They displayed fastest burial times in grain sizes typical of dissipative beaches, i.e., fine to medium sand. Patchy distribution and density variation of A. mactroides alongshore reflect the relation between grain size and burrowing performance: the population is absent in sites with the highest proportion of coarse sands, its density increases in patches with the highest proportion of fine and medium sand and peaks at a site with the highest proportion of fine sand. Results indicate that the discontinuous distribution of A. mactroides along its range could be due to a postsettlement process. Clams can potentially recruit on a wide morphodynamic range, but only may thrive in beaches which sand grain size allows them a rapid reburial during migratory and local movements.

Growth and morphometric relationships of the bean clam Donax punctatostriatus Hanley, 1843 in a sandy beach of southern Sinaloa, Mexico

“…The species of the genus Donax presented different growth types. The effect of sediment particle size on shell growth (positive or negative allometry) has been recognized in other bivalve species; the shape of the bivalve determines its capacity for penetration of the substrate, as is the case with Tellina tenuis, Macoma balthica, Donax vittatus and Cerastoderma edule (Trueman et al, 1966;Brown &Trueman, 1991), Donax faba, D. serra, D. sordidus, D. hanleyanus, Mesodesma mactroides, Tivela stultorum andSiliqua patula (McLachlan et al, 1995;Nel et al, 2001;Fiori & Carcedo, 2015), as well as Mactra violacea (Laxmilatha, 2008) and Ruditapes philippinarum (Caill-Milly et al, 2012). In this type of study, it is important to consider local environmental conditions (i.e., sediment type, exposure to waves, the incidence of currents), since these can differ markedly.…”

The role of temperature and oxygen availability on the distribution ofCorbicula largillierti

“…Burrowing is a mechanism that allows bivalves to continue feeding while avoiding harmful environmental factors or predators. Temperature influences bivalve burial behavior (Amyot & Downing, 1997), affecting their ability to evade predators, or to reestablish contact with water after burial by sediment deposition (Alexander et al., 1993; Fiori & Carcedo, 2015; McKeon & Barshis, 2015). Evaluating burial behavior in C. largillierti may thus represent a good proxy for performance at different granulometries and temperatures.…”

“…One day after SMR evaluation, burial performance in sediments of different grain sizes was evaluated following the methods of Fiori and Carcedo (2015) and Nel et al. (2001).…”

“…One day after SMR evaluation, burial performance in sediments of different grain sizes was evaluated following the methods of Fiori and Carcedo (2015) and Nel et al (2001). Because the amount and type of organic matter in sediments may directly influence oxygenation and pH, and thus affect bivalve burial behavior (Cottrell et al, 2016;Cummings et al, 2009), the sediment used was first placed in a muffle furnace for 5 hr at 450°C to remove any remaining…”

Vulnerability assessment of nearshore clam habitat subject to storm waves and surge

“…On the other hand, clams would suffer significant smothering mortality due to the sediment overburden that exceeds their adaption limits 26 . The survival rate depends on factors such as burrowing ability, burial depth, sediment properties, and tolerance of anoxia 32 , 33 . The response of clams to sudden burial is vertically migrating upward until where the siphon may reach out the sediment layer.…”