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Genus Leptodea

Family Unionidae



Until the early 1990's, L. ochracea, the only member of Leptodea that occurs in the metro area, was a common to abundant species in the tidal Hudson River above the salt plume, and a characteristic resident of coastal tidal waters along the eastern seaboard. It now appears to be in serious decline, possibly due to the proliferation of Dreissena polymorpha, the zebra mussel. Today considered rare in our area by some workers, it has been assigned Threatened status in Connecticut, and was described as a species of Special Concern in (Williams, et al) 1993.

Species Summaries

Species Summary

Leptodea orchracea (Say, 1817)
tidewater mucket



size: 75mm
beak: weakly double-looped sculpture rising above the hinge line; moderately swollen with deep beak cavity
color pattern: many fine dark rays on pale greenish yellow; periostracum satiny, yellow to golden brown; nacre may be pink to salmon-colored
shape: sub-ovate; sexes are dimorphic
shell features:
teeth: delicate but well-developed hinge, pseudocardinals compressed and curved, two in each valve


abundance: rare
status: US, NY: not legally protected; NJ, CT: threatened
conservation challenges: Control of zebra mussel populations is probably key to the viability of L. ochracea in the metro area and throughout NY. Any populations of L. ochracea species should be reported immediately. Although the disappearance of L. ochracea is documented in NY, there is need for more information on its status in NJ and CT.


N.A. distribution: Nova Scotia (Canada) to Georgia
present metro distribution: NY: freshwater tidal Hudson River
other regional localities: NY: Grass River (northern St. Lawrence River watershed); NJ: mid, lower and upper Delaware River watershed; CT: lower Connecticut River watershed
historical localities: NJ: Passaic River (lower Hudson River watershed); CT: Housatonic River watershed


Life History:

habitat: freshwater tidal rivers, standing coastal ponds including oxbows and sloughs, quiet tidal water; substrate: silt, mud Habitat Photo
hosts: Morone americana (Gmelin, 1789) white perch


L. ochracea

Left view

left view

Right view

right view

Dorsal view

dorsal view

Profile view

profile view


nacre whitish; may be pink or salmon

Beak sculpture

beak sculpture double-looped


pseudocardinals compressed

Hinge teeth

hinge teeth delicate

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