Shell small, short oval or quadrangular, moderately convex. Surface irregularly striated. Pores moderately dense. Hinge plate relatively narrow. Cardinal teeth arched or bent. Ligament enclosed. Presiphonal mantle suture elongated. Inner radial mantle muscles form five to seven strong bundles. Outer demibranch small, strongly shifted posteriorly.
Euglesa Jenyns, 1832
Class Bivalvia
Infraclass Heteroconchia
Cohort Heterodonta
Megaorder Neoheterodontei
Order Sphaeriida
Superfamily Sphaerioidea
Family Sphaeriidae
Subfamily: Sphaeriinae
Genus Euglesa Jenyns, 1832
Type species: Euglesa henslowiana Jenyns, 1832 (= Pisidium personatum Malm, 1855) (also sometimes cited as Tellina pusilla Gmelin, 1791)
Original reference: Jenyns, L. (1832). A monograph on the British species of Cyclas and Pisidium. Transactions of the Cambridge Philosophical Society 4: 289–311.
Type locality: near Cambridge, England.
Synonyms: Australpera Iredale, 1943; Glacipisum Iredale, 1943 and several others - see https://www.marinespecies.org/aphia.php?p=taxdetails&id=885715
We follow the latest revision of the species of this group by Korniushin (2000) except we treat Euglesa as a genus rather than a subgenus of Pisidium following Bespalyala et al. (2024).
In rock and gravel substrate, amongst weed, and in sand and mud. Most frequent in creeks and small rivers. In South Australia and Tasmania, it also inhabits springs, peat bogs, lakes, and lagoons. Suspension and deposit feeder.
In Australia, the genus is found throughout much of south-eastern Australia, including Tasmania, as well as in Central Australia. Otherwise has a wide distribution including Europe, New Zealand, New Guinea, Indonesia, much of Europe and North America.
Korniushin treated Euglesa as a subgenus of Pisidium Pfeiffer, 1821, as we also did in earlier versions of this key. Pisidium is a distinct genus found in eastern Europe and the USA (Bespalyala et al. 2024).
Beesley, P. L., Ross, G. J. B. & Wells, A., Eds. (1998). Mollusca: The Southern Synthesis. Parts A & B. Melbourne, CSIRO Publishing.
Bespalaya, Y. V., Vinarski, M. V., Aksenova, O. V., Babushkin, E. S., Gofarov, M.Y., Kondakov, A. V., Konopleva, E. S., Kropotin, A. V., Mabrouki, Y., Ovchankova, N. B., Palatov, D. M., Sokolova, S. E., Shevchenko, O. V. T., Abdelkhaleq, F. T., Soboleva, A. A., Zubrii, N. A. & Bolotov, I. N. (2024). Phylogeny, taxonomy, and biogeography of the Sphaeriinae (Bivalvia: Sphaeriidae). Zoological Journal of the Linnean Society 201: 305-338.
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Lee, T. & Ó Foighil, D. (2003). Phylogenetic structure of the Sphaeriinae, a global clade of freshwater bivalve molluscs, inferred from nuclear (ITS-1) and mitochondrial (16S) ribosomal gene sequences. Zoological Journal of the Linnean Society 137: 245-260.
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