Vesicomyidae (Bivalvia): Current Taxonomy and Distribution

Abstract

Vesicomyid bivalves are a consistent component of communities of sulphide-rich reducing environments distributed worldwide from 77° N to 70°S at depths from 100 to 9050 m. Up-to-now the taxonomy of the family has been uncertain. In this paper, the current state of vesicomyid taxonomy and distribution at the generic rank are considered. This survey is founded on a database including information both from literature sources and also unpublished data of the authors on all recent species of vesicomyids. We suggest that the Vesicomyidae is not a synonym of Kelliellidae, and is therefore a valid family name. We propose to divide the family Vesicomyidae into two subfamilies: Vesicomyinae and Pliocardiinae. The Vesicomyinae includes one genus, Vesicomya, which comprises small-sized bivalves characterized by non-reduced gut and the absence of subfilamental tissue in gills. Symbiosis with chemoautotrophic bacteria has, so far, not been proved for Vesicomya and the genus is not restricted to sulphide-rich reducing habitats. The subfamily Pliocardiinae currently contains about 15 genera with mostly medium or large body size, characterized by the presence of subfilamental tissue in the gills. The Pliocardiinae are highly specialized for sulphide-rich reducing environments, harbouring chemoautrophic bacteria in their gills. This is the first summary of the generic structure of the family Vesicomyidae that allow us to analyze the distribution of vesicomyids at the generic level. We recognize here five different distribution patterns that are related to the specific environmental demands. The general trends in the distribution patterns of the vesicomyids are an occurrence of the majority of genera in broad geographical ranges and the prevalence of near continental type of distribution.

Comparative mitochondrial genomic analyses of three chemosynthetic vesicomyid clams from deep‐sea habitats

“…Vesicomyid bivalves occur globally, mostly in sulfide‐rich marine substrates found at deep‐sea hydrothermal vents, hydrocarbon seeps, and sites of organic enrichment such as whale carcasses (Johnson, Krylova, Audzijonyte, Sahling, & Vrijenhoek, 2017; Krylova & Sahling, 2010; Peek, Gustafson, Lutz, & Vrijenhoek, 1997; Peek et al., 2000). Most members of this family housing intracellular autotrophic sulfide‐oxidizing endosymbionts that provide essentially all of their nutrients and energy supply, making them primary subjects for studying adaptive strategies for chemosynthesis‐based nutrition (Krylova & Sahling, 2010), and host/symbiont coevolution (Ozawa, Shimamura, Takaki, Takishita et al., 2017; Shimamura et al., 2017).…”

“…Most members of this family housing intracellular autotrophic sulfide‐oxidizing endosymbionts that provide essentially all of their nutrients and energy supply, making them primary subjects for studying adaptive strategies for chemosynthesis‐based nutrition (Krylova & Sahling, 2010), and host/symbiont coevolution (Ozawa, Shimamura, Takaki, Takishita et al., 2017; Shimamura et al., 2017). The Vesicomyidae are divided into two subfamilies: Vesicomyinae and Pliocardiinae partially according to their gut and gill structure (Krylova & Sahling, 2010). Vesicomyinae including small‐sized bivalves are characterized by nonreduced gut and the absence of subfilamental tissue in gills, whereas all Pliocardiinae studied to date have reduced gut systems.…”

The smaller vesicomyid bivalves in the genus Isorropodon (Bivalvia, Vesicomyidae, Pliocardiinae) also harbour chemoautotrophic symbionts

“…hydrothermal vents, cold seeps, whale carcasses) and occur worldwide from 77°N to 70°S at depths from 100 to 9,050 m (Krylova and Sahling 2010). Genera within the subfamily Pliocardiinae (considered large-sized vesicomyids, with shell lengths in the range of 1 to 30 cm) display distinctive shared features including reduced gut and feeding groove, indicating a large dependence upon (intracellular) chemoautotrophic bacteria for their nutrition (Krylova and Sahling 2010).…”

Chemosymbiotic bivalves from Miocene methane-seep carbonates in Italy

“…The taxonomy of the Vesicomyidae is still in flux, partially due to the frequent convergence among their few shell characters (Krylova and Sahling, 2010). Amano and Kiel (2010) recently questioned Paleogene records of Archivesica, and Amano et al (2014) identified the early Miocene Japanese A. sakoi Amano et al, 2014 as earliest member of Archivesica sensu strictu.…”

“…Because the species described below are morphologically most similar to several members of this clade-Archivesica soyoae (Okutani, 1957) A. kilmeri (Bernard, 1974), A. okutanii (Kojima and Ohta, 1997), and A. kawamurai (Kuroda, 1943)-we assign them to Archivesica. Other authors (Krylova and Janssen, 2006;Krylova and Sahling, 2010) have separated these species into the genera Archivesica, Phreagena, and Akebiconcha, but they have not consistently emerged as monophyletic groups in molecular phylogenetic studies (Audzijonyte et al, 2012;Valdés et al, 2013). The first claim of the occurrence of large deep-water vesicomyids in the Mediterranean Miocene was based on the discovery in 1992 (Taviani et al, 1992;Taviani, 1996) of a bed containing 'Calyptogena' (= Archivesica) associated with turbidites in the Romagna Apennines (for details see Berti et al, 1994;Taviani, 2014).…”