Some are disarmingly named, like the cutesy Chinese mitten crab. Others have names more indicative of their undesirable nature, like rock snot, an algae that slimes up cool forest streams.

They are some of more than 100 invasive species that conservationists must battle in New York State, which teems with a growing number of plants, birds, fish, insects, mosses, molds and fungi that actually belong somewhere else.