Rainbow trout in Virginia are facing a new threat… gill lice. According to the Virginia Department of Wildlife Resources, gill lice are tiny parasites that attach to the mouths, fins, and gills of fish. The species of lice discovered here however, only infects rainbow trout and Pacific salmon species. Because of that, they say it does not appear that they pose much if any threat to Virginia’s native brook trout species. Fisheries biologists still don’t know how lice made it to Virginia. Gill lice appear as small brown and white growths on fish gills and mouths. If you spot them in trout you catch, the DWR wants you to let them know. Email them at fisheries@dwr.virginia.gov.