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Sphaeriidae

Sphaeriidae is a family of small to minute freshwater bivalve molluscs in the order Sphaeriida. In the US, they are commonly known as pea clams or fingernail clams.

Last revised
Jun 7, 2026
Read time
≈ 1 min
Length
243 w
Citations
7
Source
Wikipedia ↗
Sphaeriidae
Four shells of Sphaerium corneum. Scale bar is in mm.
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia
Order: Sphaeriida
Superfamily: Sphaerioidea
Family: Sphaeriidae
Deshayes, 1855 (1820)
Genera

See text

Synonyms

Cycladidae, Rafinesque 182012

Sphaeriidae is a family of small to minute freshwater bivalve molluscs in the order Sphaeriida. In the US, they are commonly known as pea clams or fingernail clams.34

Genera

Genera:5

  • Euperinae
    • Byssanodonta d'Orbigny, 1846
    • Eupera Bourguignat, 1854
  • Sphaeriinae
  • fossils
    • †Megasphaerioides Komatsu, J.-H. Chen & Q.-F. Wang, 2003
    • †Protosphaerium Hocknull, 2000
    • †Sphaericoncha Kolesnikov, 1980

Biology and ecology

Sphaeriidae are hermaphrodites with internal fertilization. Developing young are incubated within their mother (ovoviviparity), and newborn clams look like miniature copies of the adults.4

Parasites and/or predators include the Sciomyzidae.6

References

References

  1. Bowden, John & Heppell, David (1968). "Revised list of British Mollusca. 2. Unionacea-Cardiacea" (PDF). Journal of Conchology. 26 (4): 237–272, note 55, pages 253–254. Archived from the original (PDF) on 28 December 2014.
  2. Baker, Horace Burrington (1964). "Notes on Sphaeriid Names". The Nautilus. 78 (2): 45–47.
  3. Heard, William H. 1965. Comparative life histories of North American pill clams (Sphaeriidae: Pisidium). Malacologia, 2: 381-411.
  4. Heard, William H. 1977. Reproduction of fingernail clams (Sphaeriidae: Sphaerium and Musculium). Malacologia, 16: 421-455.
  5. "WoRMS - World Register of Marine Species - Sphaeriidae Deshayes, 1855 (1820)". www.marinespecies.org. Retrieved 26 October 2021.
  6. Biology of Snail-Killing Sciomyzidae Flies at Google Books