Authors

Discussion

Members of the cestode genus Amphilina are monozoic cestodes parasitic in the body cavity (coelom) of sturgeons. It has been suggested that they are neotenic forms of strobilate tapeworms that once developed as adults in a now extinct reptile definitive host, possibly a fish-eating dinosaur. During examination of the Dawes Collection of helminth microscope slides at the Museum of Life Sciences, King’s College London, a single specimen, (D901), of a monozoic cestode was discovered labelled “Amphilina bipunctata, Ex. White & Green Surgeon, Oregon. U.S.A.” Subsequent research revealed that this species had first been described by Riser (1948) from specimens found at the Hopkins Marine Station of Stanford University in a jar mis-labelled “Trematoda”, the label with the specimens having the following information, “Dodson, Oregon. From coelom of sturgeon. Aug 1923. Carl D. Duncan”.

Since its description A. bipunctata has been relegated to a junior synonym of Amphilina japonica Goto & Ishii,1936. Though this status is currently accepted, we venture to pose the question as to whether the situation might be re-examined, citing the following. Amphilina japonica of Goto and Ishii (1936) was described from the Sakhalin Sturgeon (Acipenser mikadoi) a species known to inhabit the Amur and Tumin Rivers in Russia, Sakhalin Island and the Sea of Japan, locations geographically distant from Oregon on the West Coast of North America (most probably the Columbia River at Dodson) where the sturgeonspecies from which A. bipunctata was described were obtained; the White Surgeon (Acipenser transmontanus) and the Green Sturgeon (Acipenser medirostris). In his description of A. bipunctata Riser (1948) mentioned several morphological features that he felt differentiated the North American species from A. japonica, these including the size and shape of the testes and ova, the extent of the testes with respect to the vitellaria, and the configuration of the Mehlis gland. In a footnote to their Table 1, Margolis & McDonald (1986) mention that Malmberg (University of Stockholm) concluded that the two species could actually be distinguished on the basis of the shape of the larval (lycophore) hooks.

It is envisaged that detailed morphological studies, perhaps using new technologies such as Micro-CT Scanning, and also the use of molecular genetic analyses might shed light on the true systematic relationship between A. bipunctata and A. japonica.

Acknowledgements

The author gratefully acknowledges Dr Gillian Sales Curator of the Museum of Life Sciences at Kings College London for access to the Dawes Collection and provision of research facilities.

References

Goto, S. and Ishii, N. (1936) On a new cestode species, Amphilina japonica. Japanese Journal of Experimental Medicine. 14, pp. 81-83.

Margolis, L. and McDonald, T.E. (1986) Parasites of the White Surgeon, Acipenser transmontanus, from the Fraser River, British Columbia. Journal of Parasitology 72 (5) pp.794-796.

Riser, N.W. (1948) Amphilina bipunctata n. sp. A North American Cestodarian. Journal of Parasitology 34 (6), pp.479-485.