CR

Tubercled Blossom

Epioblasma torulosa

Declining

Overview

A detailed profile for this species is sourced from the IUCN Red List of Threatened Species as assessments become available.

The tubercled blossom pearly mussel faces severe threats from dam construction and river channelization that have fragmented and altered its riverine habitat throughout the Ohio River basin. Water pollution from agricultural runoff, industrial discharge, and urban development has degraded water quality in remaining populations. The species' complex reproductive cycle, which requires specific fish hosts for larval development, makes it particularly vulnerable to disruptions in aquatic ecosystems and declining fish populations.

Threat summary

Habitat

This freshwater mussel inhabits clean, flowing waters of medium to large rivers with stable gravel and sand substrates. It was historically found in the Ohio River system and tributaries, preferring areas with moderate current and good water quality.

FRESHWATER· major

Conservation measures underway

Species managementSpecies recovery

Other threatened species in UNIONIDAE

VU

Brazzaea anceyi

Unknown
Lampsilis higginsiiEN

Lampsilis higginsii

Unknown
CR

Recovery Pearly Mussel

Elliptio nigella

Declining
EN

Triangle Pigtoe

Fusconaia lananensis

Declining

Threatened in Canada

VU

Lepiota echinella

Unknown
EN

Nymphaea loriana

Declining
EN

Lake Lamprey

Entosphenus macrostoma

Unknown
VU

Paddlefish

Polyodon spathula

Unknown

Frequently asked questions

Why is Tubercled Blossom classified as Critically Endangered?
Tubercled Blossom is classified as Critically Endangered — facing an extremely high risk of extinction in the wild — because population sizes are very small, declining sharply, or restricted to a tiny range. The tubercled blossom pearly mussel faces severe threats from dam construction and river channelization that have fragmented and altered its riverine habitat throughout the Ohio River basin. Water pollution from agricultural runoff, industrial discharge, and urban development has degraded water quality in remaining populations. The species' complex reproductive cycle, which requires specific fish hosts for larval development, makes it particularly vulnerable to disruptions in aquatic ecosystems and declining fish populations.
Where does Tubercled Blossom live?
Tubercled Blossom occurs in Canada, Thailand, and United States. Country-level distribution data is sourced from the IUCN Red List and cross-referenced with GBIF occurrences.
What are the main threats to Tubercled Blossom?
The main threats to Tubercled Blossom are 1.1, 1.2, 11.2, and 11.4. The full IUCN-classified threat record for this species is detailed on the species page.

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