DAO 44:53-60 (2001)  -  doi:10.3354/dao044053

First report of the invasive eel pest Pseudodactylogyrus bini in North America and in wild American eels

Craig J. Hayward1,*, Makoto Iwashita1, John S. Crane2, Kazuo Ogawa1

1Department of Aquatic Bioscience, Graduate School of Agriculture, University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
2South Carolina Department of Natural Resources, 1921 Van Boklen Road, Eastover, South Carolina 29044, USA
*Present address: Laboratory of Aquatic Animal Diseases, College of Veterinary Medicine, Chungbuk National University, Chongju, Chungbuk 361-763, Korea. E-mail:

ABSTRACT: We detected 2 species of monogenean gill worms, Pseudodactylogyrus bini (Kikuchi, 1929) Gusev, 1965 and P. anguillae (Yin & Sproston, 1948) Gusev, 1965 (Monopisthocotylea: Pseudodactylogyridae), on American eel Anguilla rostrata in 2 rivers in South Carolina, USA. One of these, P. anguillae, was reported 5 yr ago from Nova Scotia; as well as in South Carolina, we also discovered it in 2 localities in Chesapeake Bay. Differences in the morphologies of specimens of either species of worm from North America and northeastern Asia were negligible. Similarly, the level of variation in sequences in the ITS2 (internal transcribed spacers) region of ribosomal RNA was minor, and not consistent with geographical origin. These data indicate that these monogeneans invaded North America only recently, possibly in parallel with the nematode Anguillicola crassus (which is known to have been introduced with commercial imports of foreign eels). We map the current global occurrence of these monogeneans, and conclude that their dispersal from northeastern Asia was largely as a result of the eel trade, and has probably been secondarily augmented by longshore migration of infected eels, and possibly also by transport in ballast waters. With present technology, all eel stocks must still be collected from the wild; unless shipments are disinfected at quarantine, these and other eel pathogens (such as A. crassus) are likely to continue to colonise other regions of the world.

KEY WORDS: Biological invasion · Anguilla · Pseudodactylogyrus · Ballast · Monogenean · Pest

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