Cumberlandia diver.jpg (20595 bytes) Cumberlandia monodonta (Say) is the only Margaritiferid mussel widely distributed in the Mississippi basin.  The largest remaining populations of this species may be found in the Gasconade and Meramec systems in east-central Missouri.  This species is a candidate for Federal listing.
mass of cumberlandia.jpg (39942 bytes) Cumberlandia, like other Margaritiferids, tends to assemble in dense aggregations. In Missouri, these aggregations are usually found among large rocks that lie in or near areas of strong current, and often include few or no other mussel species.  Population densities reach up to 40 individuals per 1/4 m2 in quadrat samples.
conglutinates.jpg (22423 bytes) This photo shows immature conglutinates, cohesive clumps of eggs that are molded in spaces within the marsupial gills of the female mussel.  In Cumberlandia, mature conglutinates are less cohesive and may disperse during and after release from the female.  Thus, it is not clear whether they function to attract host fish.
cumberlandia-glochidia.jpg (33542 bytes) The glochidia of Cumberlandia are among the smallest of any unionoid, averaging only 60 micrometers in length and height.  This photo shows glochidia of Cumberlandia alongside the much larger (and more typically sized) glochidia of fat mucket, Lampsilis siliquoidea.
cumberlandia-cysts.jpg (40331 bytes) Cumberlandia glochidia attach and encyst readily on the gills of many fish species, but the fish host(s) of this species remain unknown to us.  These glochidia are attached to red-eared sunfish, but this species is not a suitable host, and the glochidia will soon be sloughed from the gill.
size-series.jpg (18197 bytes) Young Cumberlandia are relatively rare.  The smallest individual in this photograph is probably in its second year of growth, and is approximately 4 mm long.

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