The Asian tapeworm
is pathogenic to fresh-water fishes, especially young carp fry, and may cause great economic loss in hatcheries and fish farms.
Some, such as green algae, the Asian tapeworm
, and the suckermouth minnow, have had little or no impact so far.
The Asian fish tapeworm (hereafter, Asian tapeworm) has a simple life cycle that requires only two hosts: a definitive host, a fish in which larval stages develop into adult worm producing eggs, and an intermediate host, a cyclopoid copepod, which is a transmitter of the early larval stage (Liao and Shin 1956).
Due to low specificity for both intermediate and definitive hosts, and by colonizing other cyprinid as well as poeciliid hosts, the Asian tapeworm easily became established within native fish populations in new regions and continents, eventually resulting in its current global distribution (Hoffman 1999, Font 2003, Choudhury and Cole 2012).
Surveys conducted in 1999-2001 revealed seven additional fish species (six cyprinid, one poecillid) in southern California infected by the Asian tapeworm (Kuperman et al.
Asian tapeworm (Bothriocephalus acheilognathi) was positively identified in one specimen.
Asian tapeworm was reported in humpback chub from the Little Colorado River in Grand Canyon (Clarkson et al., 1997), but ours represents the first record of Asian tapeworm in bonytail from natural habitat on the lower Colorado River (see Choudhury et al., 2006) and may signal future occurrences of this parasite in other species and in other places.
Update on the distribution of invasive Asian tapeworm, Bothriocephalus acheilognathi, in the U.S.