Seasonal variation in the abundance and distribution of Anomalocardia flexuosa (Mollusca, Bivalvia, Veneridae) in an estuarine intertidal plain.

Jacqueline S Silva-Cavalcanti,Luis H.B Alves,Monica F Costa

doi:10.7717/peerj.4332

Jacqueline S Silva-Cavalcanti, Luis H.B Alves + Show 1 more

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https://doi.org/10.7717/peerj.4332

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Abstract

Spatial and temporal density and biomass of the infaunal mollusk Anomalocardia flexuosa (Linnaeus, 1767) evaluated a tidal plain at Goiana estuary (Northeast Brazil). Three hundred and sixty core samples were taken during an annual cycle from three intertidal habitats (A, B and C). Shell ranged from 2.20 to 28.48 mm (15.08 ± 4.08 mm). Recruitment occurred more intensely from January to March. Total (0–1,129 g m−2) differed seasons (rainy and dry), with highest values in the early rainy season (221.0 ± 231.44 g m−2); and lowest values in the late dry season (57.34 ± 97 g m−2). The lowest occurred during the late rainy (319 ± 259 ind m−2) and early dry (496 ± 607 ind m−2) seasons. Extreme environmental situations (e.g., river flow, salinity and water temperature) at the end of each season also affected density ranges (late dry: 0–5,798 ind m−2; late rainy: 0–1,170 ind m−2). A. flexuosa in the Goiana estuary presented a dominance of juvenile individuals (shell length < 20 mm), with high biomass main the recruitment period. Average shell length, density and biomass values suggest overfishing of the stock unit. A. flexuosa is an important food and income resource along its whole distribution range. The species was previously also known as Anomalocardia brasiliana (Gmelin, 1791).

Highlights

Estuarine intertidal areas support a large number of clam species of varying ecologic guilds, and have been used by humans as important fishing grounds for millenia
Spawning occurs in the late rainy season and might extend up to the late dry season
Seasonal differences were observed for biomass and density, with the early rainy season presenting higher values

Summary

Introduction

Estuarine intertidal areas support a large number of clam species of varying ecologic guilds, and have been used by humans as important fishing grounds for millenia. Edible bivalves are widely collected around the World and became the basis of many coastal communities’ livelihoods (Silva-Cavalcanti & Costa, 2011). On the tropical and sub-tropical littoral of the Eastern South America and Caribbean, Anomalocardia flexuosa (Linnaeus, 1767), an infaunal clam distributed from the Western Indies to Uruguay (Rios, 1985), is one of the main shellfish fisheries product, especially from the 19th century. A. flexuosa is an important food and income resource along its whole distribution range. How to cite this article Silva-Cavalcanti et al (2018), Seasonal variation in the abundance and distribution of Anomalocardia flexuosa (Mollusca, Bivalvia, Veneridae) in an estuarine intertidal plain.

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