Summary ³

Rotundaria tuberculata, commonly called the purple wartyback, is a freshwater mussel, an aquatic bivalve mollusk.

Distribution ⁴

Global Range: (200,000-2,500,000 square km (about 80,000-1,000,000 square miles)) This species occurs in the Upper Mississippi River drainage generally; Lake St. Clair drainage, and from Pennsylvania northwest to southern Michigan and northwestern Wisconsin, south to Iowa, Missouri, and Arkansas (Parmalee and Bogan, 1998). In Canada it is found only in Ontario where it occurs in the Grand and Thames Rivers (Metcalfe-Smith and Cudmore-Vokey, 2004).

Habitat ⁵

Cyclonaias_tuberculata is mainly found in rivers where definite riverine conditions with a stronger current exist. In Michigan and Ohio it may be found in smaller rivers. In the St. Joseph River, it was found in slower moving waters that were fairly clear. In general the purple wartyback is found in better quality streams.

Habitat Regions: freshwater

Aquatic Biomes: rivers and streams

Iucn red list assessment ⁶

• Needs updating

Assessor/s

Morphology ⁷

The purple wartyback is up to 12.7 cm (5 inches) long, and is round. The shell is fairly thick, heavy and compressed. The   anterior end is rounded, the posterior end somewhat angled. The dorsal margin is straight to slightly rounded and the ventral margin is broadly rounded.

Umbos are low and only slightly raised above the hinge line. The beak sculpture has several wavy ridges.

The periostracum (outer shell layer) has several pustules, and ridges on the dorsal wing. Younger specimens are yellowish to greenish brown, while older specimens tend to be more uniformly brown.

On the inner shell, the   left valve has two widely divergent, serrated, thin and low   pseudocardinal teeth. The two lateral teeth are striated, and straight to slightly curved. The right valve has one heavy, triangular serrated pseudocardinal tooth with a small tooth on either side. The right, single lateral tooth is slightly curved and striated.

The beak cavity is very deep. The nacre is almost always purple, and rarely white.

In Michigan, this species can be confused with the pimpleback. The pimpleback usually has a prominent green ray, lacks a dorsal wing and purple nacre.

Range length: 12.7 (high) cm.

Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry

Sexual Dimorphism: sexes alike

Nature serve conservation status ⁸

Rounded Global Status Rank: G5 - Secure

Reasons: This is a wide-ranging species occurring in southern Ontario and throughout the upper Mississippi River drainage, south to Arkansas and Missouri and has experienced some declines in certain parts of the northern and outer limits of its range but is still common in others, particularly the southern parts of the range.

Physical description ⁹

The purple wartyback is up to 12.7 cm (5 inches) long, and is round. The shell is fairly thick, heavy and compressed. The   Quadrula pustulosa. One way to tell them apart is that the pimpleback usually has a prominent green ray. Also, the pimpleback does not have a dorsal wing or purple nacre.

Range length: 12.7 (high) cm.

Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry

Sexual Dimorphism: sexes alike

Sources and Credits

1. (c) William Van Hemessen, some rights reserved (CC BY-NC), uploaded by William Van Hemessen
2. (c) Femorale, some rights reserved (CC BY-NC), http://www.femorale.com/shellphotos/detail.asp?species=Cyclonaias%20tuberculata%20(Rafinesque,%201820)
3. Adapted by rkkessler from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Cyclonaias_tuberculata
4. (c) NatureServe, some rights reserved (CC BY-NC), http://eol.org/data_objects/28949976
5. (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/25064412
6. (c) International Union for Conservation of Nature and Natural Resources, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/34410677
7. (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31389181
8. (c) NatureServe, some rights reserved (CC BY-NC), http://eol.org/data_objects/28949970
9. (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/25064413

More Info

• iNat taxon page
• Animal Diversity Web
• Biodiversity Heritage Library
• BOLD Systems BIN search
• Global Biodiversity Information Facility (GBIF)
• NatureServe Explorer 2.0
• SeaLifeBase
• World Register of Marine Species

Range Map

(c) NatureServe, some rights reserved (CC-BY-NC)

iNat Map