Population biology and secondary production of the stout razor clam Tagelus plebeius (Bivalvia, Solecurtidae) on a sandflat in southeastern Brazil

Abstract

The population biology and production of the stout razor clam Tagelus plebeius Lightfoot, 1786 were investigated on an intertidal sandflat on the southeast coast of Brazil (Enseada Beach, São Sebastião, state of São Paulo) between April 1997 and April 1998. Two rectangular sites of 50 X 10 m parallel to the waterline were established, site A (upper intertidal level) and site B (middle intertidal level), where the samples were taken in an 0.5 x 0.5 m quadrat. High abundances were recorded in winter and spring, with no significant differences between the sites. The high bivalve abundances were related to the presence of very fine homogeneous sediment with low salinities. Tagelus plebeius had negative allometric growth, characteristic of deep burrowers for the relationships DM/SL and AFDM/SL. Parameters of the modified von Bertalanffy growth function were: L∞ = 67.01 mm, K = 1.73 year-1, t0 = -0.11 year, C = 0.43, WP = 0.96. The instantaneous mortality (Z) was 3.12 year-1, relatively high in comparison to other tropical bivalve populations. Secondary production was 1.53 g AFDM m-2 year-1, with a P/B ratio reaching 1.37 year-1. This high turnover ratio (P/B) was related to a rapid population replacement, connected with the short life span and high mortality of the species

Modelling present and future global distributions of razor clams (Bivalvia: Solenidae)

“…While regionally depth and distance to land may be correlated, they are not globally (r = −0.46, p ≥ 0.05, Additional file 1: Table S1) because of the variation in sizes of continental shelves and occurrence of mid-ocean islands. Sea surface temperature (SST), dissolved and saturated oxygen, and surface current may also affect the distribution, growth, reproduction, juvenile survival and mortality of Solen species [14,17,[26][27][28][29]. Razor clams are filter feeders and consume phytoplankton as a food source.…”

Population dynamics of two suspension-feeding bivalves on a sheltered beach in southeastern Brazil

“…Several studies have focused on community ecology and population dynamics of macrofauna from exposed beaches McLachlan 2005, 2011), while sheltered beaches have been a historically neglected area of sandy-beach ecology (Cardoso et al 2011). Surprisingly, few studies have analyzed population parameters of sheltered beach macrofauna (Denadai et al 2004;Abrahão et al 2010), even though these environments support a high diversity of species (Dexter 1992).…”

Population Structure, Growth, and Production of the Wedge ClamDonax hanleyanus(Bivalvia: Donacidae) from Northern Argentinean Beaches

“…On the other hand, in contrast to the significant number of studies on most temperate sandy-beach bivalves, there is a lack of information on clam-harvesting issues, including the social aspects of clammers, for most clam species worldwide and this is even more pronounced for smallsized tropical species (Narchi 1976;Schaeffer-Novelli 1980;Viegas 1981;Paes 1989;Lima et al 2000;Laudien et al 2003;Hartill et al 2005;Herrmann et al 2009;Abrahão et al 2010). This situation is often an important factor preventing the establishment of appropriate management strategies to allow sustainable use of these resources.…”