A review of the Entocytheridae (Ostracoda) of the world: updated bibliographic and species checklists and global georeferenced database, with insights into host specificity and latitudinal patterns of species richness

Abstract

The creation of biodiversity datasets freely available for the scientific community is a valuable task to stimulate global research on biodiversity. Among others, the Global Biodiversity Information Facility (GBIF) is a remarkable resource providing free online access to biodiversity data on many diverse taxonomic groups (including Ostracoda) from both terrestrial and marine ecosystems. More specific databases for Ostracoda georeferenced data have been built (e.g., NACODe and OMEGA), some with freely available data. However, the Entocytheridae, a family of ostracods living commensal on other crustaceans, with 220 living species, representing the third non-marine ostracod family in number of species, has been remarkably under-represented in the currently available biodiversity databases. To cover this gap, we present here a free-access world database of Entocytheridae published in GBIF and review the current knowledge of the group by updating a bibliographic and species checklists of the Entocytheridae. We also analyse the host specificity of the group and the latitudinal species richness pattern in North and Central America (including 186 spp.). The current database includes 3509 georeferenced records from 220 species, in contrast to just 44 entocytherid georeferenced records previously published in GBIF. In addition, the updated species list accounts for 43 species and 2 genera that were not included in the previous compendium on Entocytheridae published by Hart & Hart in 1974, so as 40 species not included in the 2013 Checklist provided by the Catalogue of Life. We show that the specialisation in one unique host species is not the rule in Entocytheridae, and evidence an unusual latitudinal pattern of species richness in North and Central American entocytherids, most probably related to the biogeographic history of their hosts.3)

Invasion biology in non‐free‐living species: interactions between abiotic (climatic) and biotic (host availability) factors in geographical space in crayfish commensals (Ostracoda, Entocytheridae)

“…No more entocytherid species were found on the exotic crayfishes sampled in this study across Europe. In contrast, all the sampled American exotic crayfishes had been previously found with entocytherid associates in their native ranges, for example, 27 entocytherid species associated with Procambarus acutus (Girard, 1852) (Mestre and Mesquita-Joanes 2013 ). Moreover, P. clarkii and P. leniusculus have all been found to be associated with four other entocytherid species (Mestre and Mesquita-Joanes 2013 ) .…”

“…We evidenced the widely ranging presence of two exotic entocytherid species, Ankylocythere sinuosa and Uncinocythere occidentalis , in W Europe, previously observed in some locations of E Iberian Peninsula in the case of A. sinuosa (Aguilar-Alberola et al 2012 ), and in a German locality for U. occidentalis (Grabow et al 2009 ). Both species have been cited in association with more than one host species in their native range (Mestre and Mesquita-Joanes 2013 ), including those observed in Europe, P. clarkii and P. leniusculus, respectively. Notably, both entocytherid species have been observed living on crayfish species belonging to two different families, Cambaridae and Astacidae, showing a broad taxonomic range of hosts.…”

“…Recently, two American exotic entocytherid species associated with invasive crayfish were cited in Europe and Japan: Ankylocythere sinuosa (Rioja, 1942), found in some localities of the E Iberian Peninsula, associated with Procambarus clarkii (Girard, 1852) (Aguilar-Alberola et al 2012 ) and Uncinocythere occidentalis (Kozloff and Whitman, 1954), cited in a few German and Japanese localities living on Pacifastacus leniusculus (Dana, 1852) (Smith and Kamiya 2001 ; Grabow and Martens 2009 ; Grabow et al 2009 ). In their native range, both entocytherid species have been found in 47 different host species in the case of A. sinuosa and three different species of crayfish in the case of U. occidentalis (Mestre and Mesquita-Joanes 2013 ), suggesting that they are not very host specific as seems to be common in the group (Mestre et al in press ). Although both exotic crayfish species have a much longer history in Europe (more than 35 years), entocytherids had not been previously detected, probably because they are tiny (<0.5 mm in length) and apparently not harmful to their hosts.…”

Long-anticipated new records of an ectosymbiotic branchiobdellidan and an ostracod on the North American red swamp crayfish, <i>Procambarus clarkii</i> (Girard, 1852) from an urban stream in Tokyo, Japan

“…However, most entocytherid species have far fewer known hosts, with approximately 50% being known from only one or two host species (Mestre et al 2014). The low host specificity of A. sinuosa suggests a high propensity of this particular species to translocate to different host species, as demonstrated by its ability to translocate from Pr.…”

“…Branchiobdellidans have a disjunct Holarctic distribution, consisting of North and Central America, Europe and East Asia, and although the worms live mainly on astacoidean crayfish, a few species have used freshwater crabs, shrimps, and isopods as hosts (Gelder & Williams 2015). There are, in total, 200 species of entocytherids, which have been reported mainly from North and Central America, Europe, and Australia, with additional isolated records from Hawaii, Japan, Papua New Guinea, India, New Zealand, and South Africa (Mestre et al 2014). Although their primary host is crayfish, they are also found on other crustaceans such as crabs, isopods and amphipods (Hart & Hart 1974).…”