Creatures in Crisis
Photograph of Thick shelled river mussel (Unio crassus), recorded as Endangered
Thick shelled river mussel (Unio crassus). Image via Wikimedia Commons.

Endangered

Thick shelled river mussel

Unio crassus

Thick shelled river mussel is a bivalve in the family Unionidae (order Unionida) — Unio crassus, recorded as Endangered.

Status
Endangered
Scientific name
Unio crassus
Taxonomy
Bivalvia · Unionida · Unionidae · Unio

Appearance

Thick shelled river mussel is known for its thick-walled shell. Thick shelled river mussel, the thick shelled river mussel, is a freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels.

Range and habitat

The species lives in large streams and rivers with clear water, though it is more tolerant of silt than other threatened species.

Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.

Diet

Like most Unionidae mussels, the larvae have a parasitic stage where they are required to attach and feed off a host fish.

In crisis

U. Crassus was noted to be more tolerant of silt in the water than other threatened species. The most stable populations are found in Russia and northern Europe. A project in Poland successfully used artificial breeding methods among them release of gravid females, release of glochidia-infested fish, and in vitro-raised juveniles, to double the population of the mussel in the Biała Tarnowska river.

More research is needed to identify priority populations for monitoring.

Thick shelled river mussel is Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.

Sources

Written for this catalog from the English Wikipedia article on Thick shelled river mussel, Wikidata item Q798236. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.

Photograph via Wikimedia Commons. Wikipedia · Wikidata · IUCN Red List.

Same genus

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Unio tumidiformis
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Dolphin Freshwater Mussel

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Photograph of Vaquita (Phocoena sinus), recorded as Critically EndangeredCR

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Photograph of Javan rhinoceros (Rhinoceros sondaicus), recorded as Critically EndangeredCR

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Quick answers

What is Thick shelled river mussel?
Thick shelled river mussel is a bivalve in the family Unionidae (order Unionida) — Unio crassus.
What is the conservation status of Thick shelled river mussel?
Endangered, as the IUCN category stored on Wikidata for Unio crassus. Confirm the official assessment on iucnredlist.org.
Where does Thick shelled river mussel live?
The species lives in large streams and rivers with clear water, though it is more tolerant of silt than other threatened species.
Why is Thick shelled river mussel in crisis?
U. Crassus was noted to be more tolerant of silt in the water than other threatened species.
Is this the IUCN Red List page for Unio crassus?
No. This is a researched catalog account. The Red List is the assessment.
Is Thick shelled river mussel a pet?
An animal on this catalog is in crisis in the wild. Keeping one is usually the wrong question.