Round Hickorynut
Obovaria subrotunda
DIAGNOSTICS 5
SHELL
- size: small; maximum 65 mm, most specimens under 30 mm
- thickness: thick
- shape: circular to slightly oval
- width: moderately inflated
- surface: smooth
- beaks: elevated above hinge line, central
- color/markings: yellowish to greenish-brown, often noticeably lighter on posterior slope, giving a two-toned appearance to live or fresh-shell specimens.
- sexual dimorphism: subtle
- pseudocardinal teeth: well developed, triangular
- lateral teeth: strong and short
- nacre: silvery white
Soft parts: ----
Similar species/lookalikes: The near circular shape combined with a plain, smooth shell is relatively distinct. Might resemble very young specimens of Quadrula pustulosa that are still devoid of any nodularities, especially if weathered specimens are concerned. Live or fresh shells of Q. pustulosa would have a distinctive broad green ray near the beaks, compared to the plain periostracum of Obovaria subrotunda.
DISTRIBUTION/WATERSHEDS 6
ONTARIO
Lake Huron-St-Clair dr.:
- Sydenham r.
Thames R.
Lake Erie dr.:- Grand R. (possibly extirpated)
Sources and Credits
- (c) Philippe Blais, some rights reserved (CC BY-NC-ND), uploaded by Philippe Blais
- (c) Scott Gibson, some rights reserved (CC BY-NC), uploaded by Scott Gibson
- (c) Femorale, some rights reserved (CC BY-NC), http://www.femorale.com/shellphotos/detail.asp?species=Obovaria%20subrotunda%20(Rafinesque,%201820)
- U.S. Fish and Wildlife Service Southeast Region, no known copyright restrictions (public domain), http://commons.wikimedia.org/wiki/File:Round_hickorynut_mussel_(14133118825).jpg
- Adapted by Philippe Blais from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Obovaria_subrotunda
- (c) Philippe Blais, some rights reserved (CC BY-SA)
.jpg){kind=link}