Freshwater mussels

Code KP01999I

Class Bivalvia: Order Eulamellibranchia: Family Hyriidae (Freshwater Mussels).

This is the parasitic larval stage of the freshwater mussel, family Hyriidae. These larvae are bivalved like the adult, but much smaller. The outer shell margin carries hooks or spines with which the larvae attaches to its host organism, usually a fish. Common attachment sites are on the fins or gills, and after attachment the larva may come to be surrounded by outgrowth of the host tissue. This larval stage lasts for a few weeks to a few months, after which the young mussel drops off and buries itself in the substrate. Apart from the small bivalved shell with hooks, hyriid glochidia are characterised by limited development of the visceral mass and the possession of a tubular sucking mouth.

Reference:

Smith, B.J. (1996) Identification keys to the Families and Genera of Bivalve and Gastropod Molluscs found in Australian Inland Waters . Cooperative Research Centre for Freshwater Ecology Identification Guide No. 6., Albury, NSW.