Alewife Floater
Utterbackiana implicata
DIAGNOSTICS 5
SHELL
- size: mid-sized to large; maximum 150 mm, most under 100 mm
- thickness: thin in posterior, noticeably thicker in anterior, transitioning clearly around mid-shell
- shape: evenly oval to elliptical
- width: moderately to very inflated
- surface: smooth and often a shiny/lackered appearance. Premature and severe umbonal dissolution is very common
- beak sculptures: rarely present (see above)
- color/markings: dark green or dark brown to black in older adults; faint green rays on some young specimens
- sexual dimorphism: none
- pseudocardinal teeth: none; hinge central and thickened well back of beaks; thinning around and in front of beaks
- lateral teeth: none
- nacre: iridescent white or pale blue in posterior on thin part of shell, pinkish or white on thicker part of shell in anterior; cavity pink or white and often harboring Tulberg layers.
Soft parts: white
Similar species/lookalikes: Live specimens can be confused with Pyganodon sp. but combination of thickened front shell and edentulous hinge is diagnostic when internal shell characters are available. Shiny, dark periostracum is rarely present in Canadian Pyganodon species.
DISTRIBUTION/WATERSHEDS 5
QUEBEC
- Ottawa R. < R. du Nord
- Saint-Lawrence R.
- Richelieu R.
NEW BRUNSWICK
-
-
NOVA SCOTIA
-
-
Sources and Credits
- (c) Philippe Blais, some rights reserved (CC BY-NC-ND), uploaded by Philippe Blais
- (c) scott_makepeace, some rights reserved (CC BY-NC)
- (c) emmastream, some rights reserved (CC BY-NC)
- (c) Philippe Blais, all rights reserved, uploaded by Philippe Blais
- (c) Philippe Blais, some rights reserved (CC BY-SA)
