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

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

doi:10.7717/peerj.4332

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

PeerJ. 2018 Feb 27:6:e4332. doi: 10.7717/peerj.4332. eCollection 2018.

Authors

Jacqueline S Silva-Cavalcanti^{1

2}, Monica F Costa², Luis H B Alves²

Affiliations

¹ Unidade Academica do Cabo de Santo Agostinho (UACSA), Universidade Federal Rural de Pernambuco, Cabo de Santo Agostinho, Pernambuco, Brazil, Pernambuco, Brazil.
² Departamento de Oceanografia, Universidade Federal de Pernambuco, Recife, Pernambuco, Brasil, Pernambuco, Brazil.

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).

Keywords: Anomalocardia brasiliana; Estuarine ecology; Population dynamics; Size classes; Traditional fisheries.

Grants and funding

Jacqueline Santos Silva-Cavalcanti was supported by CAPES-Brasil for a PhD scholarship from 2007–2008 and CNPq for the pos-doctoral grant Proc. No. 157563/2015-4. Monica Ferreira da Costa is a CNPq Fellow. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.