Shark fin mussel  (hyriopsis bialatus) 
 The sharkfin mussel is a large mussel reaching 6 inches in length, native to freshwater rivers and streams  of  southeast asia its similar to the swan mussel in habitat and ecology ,burying into soft sediment and filtering algae ,bacteria and  small particles from the water colum they can also be artificially fed with a with concentrated algae / zooplankton ,finely crushed fish fellets or liquifry with the use of a long pipette ,this species is also used in aqua culture to produce freshwater pearls ,being native to southeast asia its unlikely this species would survive a uk winter and therefore better suited to indoor aquaria than outdoor ponds.