Sparganophilus tamesis

# First record of the aquatic earthworm Sparganophilus tamesis Benham, 1892 (Clitellata, Sparganophilidae) in Germany

## Abstract

In sediments of the river Alster in Hamburg we found a large population of a curious earthworm which we could identify as Sparganophilus tamesis Benham, 1892, hitherto unknown from Germany. After the first description from England the species was described several times under different names from North and Central America (Smith 1895, Eisen 1896) and from France (Tétry 1934). The synonymy of these species was repeatedly reviewed (e.g. Cernosvitov 1945, Jamieson 1971). Sparganophilus langi Bouché & Qiu, 1998, from Switzerland (Lake Geneva) is probably also a junior synonym of Sparganophilus tamesis. Its description as new species is apparently due to a misleading characterization of S. tamesis in the key given by Reynolds (1980). Sparganophilus tamesis seems to have persistent populations in Europe. It is arguable whether this distribution should be explained by past geological relations between the American and European continents (Cernosvitov 1945, Omodeo 1963, Bouché & Qiu 1998) or by accidental importation (Benham 1892, Gates 1982, Sims & Gerard 1985, Reynolds 2008).

Discovery

In May 2010 the Hamburg group of Friends of the Earth Germany (BUND) organized an

awareness raising event on aquatic biodiversity. In a small open air laboratory,

macrozoobenthos samples from the nearby river Alster were presented to the public.

Among the commonly known river invertebrates some conspiciously long and slender

worms soon attracted everbody‘s attention. Clearly, they did not belong to the river fauna

expected here. Could they be terrestrial earthworms, having fallen into the stream from

the steep banks? “But they do not look like any earthworm I have ever seen before”, said

the soil biologist present at the event…

Young researcher fingeringSparganophilus tamesis

The day of the discovery in May 2010

References

Benham, W.B., 1892. A new English genus of aquatic Oligochaeta (Sparganophilus) belonging to the family Rhinodrilidae. Quart. J. micr. Sci., n.s. 34: 155-179.

Bouché, M.B., Qiu, J.-P., 1998. Un nouveau Sparganophilus, (Annelida : Oligochaeta) d’Europe, avec considérations paléogéog raphiques sur les Lumbricina. Documents pédozoolog iques et intégrol ogiques 4: 178-180.

ernosvitov, L., 1945. Oligochaeta from Wind ermere and the Lake District. Proc. Zool. Soc. London 114: 523-548.

Eisen, G., 1896. Pacific Coast Oligochaeta. II. Mem. California Acad. Sci. 2: 123-199.

Gates, G.E., 1982. Farewell to North American megadriles. Megadrilogica 4: 12-78.

Jamieson, B.G.M., 1971. Family Glossoscolecid ae. In: Brinkhurst, R.O. & Jamieson, B.G.M. (eds.), Aquatic Oligochaeta of the World. Oliver & Boyd, Edinburgh, pp. 723-837.

Omodeo, P., 1963. Distribution of the terricolous oligochaetes on the two shores of the Atlantic. In: Löve, A. & Löve, D. (eds.), North Atlantic Biota and their History. Pergamon Press, New York, pp. 127-151.

Reynolds, J.W., 1980. The earthworm family Sparganophilidae (Annelida, Oligochaeta) in North America. Megadrilogica 3: 189-204.

Reynolds, J.W., 2008. Sparganophilidae (Annelida, Oligochaeta) distribution in North America and elsewhere, revisited. Megadrilogica 12: 125-143.

Sims, R.W., Gerard, B.M., 1985. Earthworms. Keys and notes for the identification and study of the species. Synopses of the British Fauna (New Series), No. 31. Brill, Leiden, 171 pp.

Smith, F., 1895. A preliminary account of two new Oligochaeta from Illinois. Bull. Illinois St. Lab. Nat. Hist. 4: 138-147.

Tétry, A., 1934. Descr iption d‘une espèce française du genre Pelodrilus (Oligochètes). C. R. Séan c. Acad. Sci. Paris 199: 322-324.

Zicsi, A., Vaucher, C., 1987. A propos de la présence de Sparganophilus tamesis Benham dans le lac Léman à Genève (Oligochaeta: Sparganophilidae). Revue suisse Zool. 94: 861-864.

Sparganophilus tamesis Benham vs. Sparganophilus eiseni Smith

After its description from England the species was described several times under different

names from North and Central America (Smith 1895, Eisen 1896) and from France (Tétry

1934). The synonymy of these species was repeatedly reviewed (e.g. ernosvitov 1945,

Jamieson 1971). Nonetheless, Reynolds (1980, 2008) claimed to maintain the distinction

between S.tamesis occuring in Europe and S.eiseni occuring in North America using as

distinctive character the position of the lateral setae below (tamesis) or above (eiseni) the

lateral line. However, this feature was found to be in all examined specimens from Europe

as in eiseni (Table 1). Therefore, Sparganophilus eiseni Smith is considered to be a junior

synonym of Sparganophilus tamesis Benham. It appears that also Sparganophilus langi

Bouché & Qiu, 1998, from Switzerland (Lake Geneva) is a junior synonym of S.tamesis.

Accidentally introduced vs. ancient endemic presence in Europe

The monogeneric family Sparganophilidae seems to have its evolutionary centre in North

America (Reynolds 2008). The first British records being mostly associated with Botanic

Gardens, support the assumption that the species has been introduced among the roots

of Nearctic water plants (Gates 1982, Sims & Gerard 1985). The occurrence of S.tamesis

in a larger area of Europe, including England, France, Switzerland and Germany, throws

new light on the problem, how to explain this distribution. Against the land bridge theory

suggested by Omodeo (1963) it can be argued, considering the synonymy of S.tamesis

and S.eiseni, that there is no sign of divergent evolution which should have happened to

species isolated at geological time scales.

Acknowledgements

We are most grateful to our friends and colleagues Tarmo Timm from the Estonian University of Life Sciences, Tartumaa, and Ton van Haaren from Grontmij, Amsterdam, for providing us with valu able literature.