Anterior and Posterior

posterior
Anodonta implicataalewife floater

Anodonta implicata
alewife floater


anterior
posterior
Alasmidonta heterodondwarf wedgemussel

Alasmidonta heterodon
dwarf wedgemussel


anterior
The anterior is the shorter end of the shell as measured from beak. In species with a long, elliptical or "narrow" shape the anterior end should always be evident. Mussel Shell Shape
posterior
Alasmidonta undulatatriangle floater

Alasmidonta undulata
triangle floater


anterior
posterior
Leptodea ochraceatidewater mucket

Leptodea ochracea
tidewater mucket


anterior
In those species that are rhomboidal or "rounder" in shape, such as Leptodea ochracea, the shorter end may not be apparent at first. Typically, the end where the growth lines are farthest from the beak is the posterior (see image left).