Conventus conventus

Conventus conventus
Conservation status
	; Least Concern (IUCN 3.1)
	; Secure (NatureServe)
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Bivalvia
Order:	Sphaeriida
Family:	Sphaeriidae
Genus:	Conventus
Species:	C. conventus
Binomial name
	Conventus conventus; (Clessin, 1877)
Synonyms
	List Conventus (Conventus) conventus (Clessin, 1877) ; Conventus (Conventus) urinator (Clessin, 1877) ; Conventus (Kurilipisidium) iturupensis Prozorova, 1997 ; Conventus (Kurilipisidium) occultus Prozorova, 1997 ; Conventus (Kurilipisidium) subtilis Prozorova, 1997 ; Cyclas errans Prime, 1869 ; Euglesa (Conventus) akkesiensis (Mori, 1938) ; Euglesa (Conventus) conventa (Clessin, 1877) ; Euglesa (Conventus) iturupensis (Prozorova, 1997) ; Euglesa (Conventus) occulta (Prozorova, 1997) ; Euglesa (Conventus) subtilis (Prozorova, 1997) ; Euglesa (Conventus) urinator (Clessin, 1877) ; Euglesa conventus (Clessin, 1887) ; Euglesa urinator (Clessin, 1877) ; Pisidium (Neopisidium) conventus Clessin, 1877 ; Pisidium abditum var. abyssorum Stimpson, 1874 ; Pisidium abortivum Sterki, 1916 ; Pisidium abortivum exiguum Sterki, 1916 ; Pisidium abortivum var. exiguum Sterki, 1916 ; Pisidium abyssorum Stimpson, 1898 ; Pisidium clessini Surbeck, 1899 ; Pisidium conventus Clessin, 1877 ; Pisidium conventus akkesiense Mori, 1938 ; Pisidium hendersoni Sterki, 1923 ; Pisidium imbecille Sterki, 1900 ; Pisidium notophthalmi Sterki, 1922 ; Pisidium tornense Odhner, 1908 ; Pisidium urinator Clessin, 1877 ; Pisidium urinator Clessin, 1876;

Conventus conventus, the arctic-alpine pea clam, is a species of freshwater bivalve from the family Sphaeriidae.

Description

The small (2.2–2.8 mm.) shell is oval in shape and thin and fragile. It is broad and flattened (laterally compressed) with flattened umbos near the midpoint. The colour is yellowish-white and the periostracum (surface) is silky with fine, concentric striation.

Ecology

C. conventus is a relict of colder climatic periods found only in deep, cold, upland lakes.

Distribution and conservation status

Germany – endangered (gefährdet)^[4]
Poland – vulnerable (VU)^[5]
Nordic countries: Faroes, Finland, Norway and Sweden (not in Denmark, Iceland)^[6]
Great Britain and Ireland^[7]

References

^ Van Damme, D.; Killeen, I.; Mackie, G.; Seddon, M.B. (2017). "Euglesa conventus". IUCN Red List of Threatened Species. 2017 e.T155516A58615885. doi:10.2305/IUCN.UK.2017-3.RLTS.T155516A58615885.en. Retrieved 27 January 2026.
^ NatureServe. "Pisidium conventus". NatureServe Explorer. Arlington, Virginia. Retrieved 27 January 2026.
^ Bieler R, Bouchet P, Gofas S, Marshall B, Rosenberg G, La Perna R, Neubauer TA, Sartori AF, Schneider S, Vos C, ter Poorten JJ, Taylor J, Dijkstra H, Finn J, Bank R, Neubert E, Moretzsohn F, Faber M, Houart R, Picton B, Garcia-Alvarez O (eds.). "Conventus conventus (Clessin, 1877)". MolluscaBase. World Register of Marine Species.
^ Glöer P. & Meier-Brook C. (2003) Süsswassermollusken. DJN, pp. 134, page 109, ISBN 3-923376-02-2
^ Pisidium conventus - Polish Red Data Book of Animals
^ Kuiper, J. G. J.; Økland, K. A.; Knudsen, J.; Koli, L.; von Proschwitz, T.; Valovirta, I. (1989), "Geographical distribution of the small mussels (Sphaeriidae) in North Europe (Denmark, Faroes, Finland, Iceland, Norway and Sweden)" (PDF), Annales Zoologici Fennici, 26 (2): 73–101
^ Roy Anderson, 2005 An annotated list of the non-marine molluscs of Britain and Ireland Journal of Conchology, 38 (6): 607–637, (published 2005) [1].

External links

Pisidium conventus at Animalbase taxonomy, short description, biology, status (threats)
Polish Red Data Book

[IUCN-1] Van Damme, D.; Killeen, I.; Mackie, G.; Seddon, M.B. (2017). "Euglesa conventus". IUCN Red List of Threatened Species. 2017 e.T155516A58615885. doi:10.2305/IUCN.UK.2017-3.RLTS.T155516A58615885.en. Retrieved 27 January 2026.

[NS-2] NatureServe. "Pisidium conventus". NatureServe Explorer. Arlington, Virginia. Retrieved 27 January 2026.

[WoRMS-3] Bieler R, Bouchet P, Gofas S, Marshall B, Rosenberg G, La Perna R, Neubauer TA, Sartori AF, Schneider S, Vos C, ter Poorten JJ, Taylor J, Dijkstra H, Finn J, Bank R, Neubert E, Moretzsohn F, Faber M, Houart R, Picton B, Garcia-Alvarez O (eds.). "Conventus conventus (Clessin, 1877)". MolluscaBase. World Register of Marine Species.

[4] Glöer P. & Meier-Brook C. (2003) Süsswassermollusken. DJN, pp. 134, page 109, ISBN 3-923376-02-2

[5] Pisidium conventus - Polish Red Data Book of Animals

[kuiper1989-6] Kuiper, J. G. J.; Økland, K. A.; Knudsen, J.; Koli, L.; von Proschwitz, T.; Valovirta, I. (1989), "Geographical distribution of the small mussels (Sphaeriidae) in North Europe (Denmark, Faroes, Finland, Iceland, Norway and Sweden)" (PDF), Annales Zoologici Fennici, 26 (2): 73–101

[7] Roy Anderson, 2005 An annotated list of the non-marine molluscs of Britain and Ireland Journal of Conchology, 38 (6): 607–637, (published 2005) [1].

[1]

[2]

[3]

[4]

[5]

[6]

[7]