The Population of the Non-indigenous Bivalve Arcuatula senhousia of the Varano Lagoon (Adriatic Sea, Italy)

A population of the invasive mussel Arcuatula senhousia (Benson in Cantor, 1842) was monitored seasonally (May, July and October 2015) in the Varano lagoon, the largest brackish basin of Southern Italy, within the Gargano National Park, Central Adriatic Sea, in order to give information on the abundance, wet weight and frequency classes. The data were collected during a survey carried within the framework of the Regional Project FEP Apulia 2007/2013 “Identificazione di misure per una migliore gestione e conservazione della risorsa vongola nel lago di Varano (FG)”. Summer anoxia may have reduced the mussel population, resulting in less abundance, wet weight and average size in October than in July and May. In particular, about length data, two cohorts were observed in May and October 2015, while a modal distribution in July 2015.