Rainbow Mussel

Villosa iris

DIAGNOSTICS 8

SHELL

  • size: small to medium, maximum 85 mm, most under 60 mm.
  • thickness: thin
  • shape: elliptical/elongate to oval
  • width: compressed to moderately inflated
  • surface: smooth, matte
  • beaks: slightly inflated, posterior. sculpture: 4 to 6 double loop bars
  • color/markings: periostracum yellow to tan with regular green rays, often interrupted and usually wider and concentrated in posterior. Some specimen rayless.
  • sexual dimorphism: males with posterior end more tapered and pointed while more rounded and wider in females. Males grow larger than females.
  • pseudocardinal teeth: small and somewhat compressed
  • lateral teeth: well developed but delicate, straight.
  • nacre: white, irridescent

Soft parts: foot while. deployed female lure large, marbled, with many papillae (crayfish mimic)

Similar species/lookalikes: usually readily identifiable. live specimens with faint rays may resemble cylindrical papershell. small size, elongated shape and wide interrupted rays on yellow background are diagnostic.

DISTRIBUTION/WATERSHEDS 9

ONTARIO
Lake Huron-St-Clair dr.:

  • Saugeen R.
  • Maitland R.
  • Bayfield R.
  • Ausable R.
  • Sidenham R.
  • Thames R.
    Lake Erie dr.:

  • Grand R.
    Lake Ontario dr.:

  • Trent R.
  • Moira R. < Parks Cr.
  • Salmon R.

Sources and Credits

  1. (c) redgarter, some rights reserved (CC BY-NC-ND), uploaded by Philippe Blais, https://www.inaturalist.org/photos/49879404
  2. (c) redgarter, some rights reserved (CC BY-NC-ND), uploaded by Philippe Blais, https://www.inaturalist.org/photos/49879410
  3. (c) Matthew Ireland, some rights reserved (CC BY-NC), http://inaturalist.ca/photos/7600574
  4. (c) redgarter, some rights reserved (CC BY-NC-ND), uploaded by Philippe Blais, https://www.inaturalist.org/photos/49879412
  5. (c) Matthew Ireland, some rights reserved (CC BY-NC), http://inaturalist.ca/photos/7600734
  6. (c) redgarter, some rights reserved (CC BY-NC-ND), uploaded by Philippe Blais, https://www.inaturalist.org/photos/49879413
  7. (c) redgarter, some rights reserved (CC BY-NC-ND), uploaded by Philippe Blais, https://www.inaturalist.org/photos/12406979
  8. Adapted by Philippe Blais from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Villosa_iris
  9. (c) Philippe Blais, some rights reserved (CC BY-SA)

More Info

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