Lobochesis, Hutchings & Murray, 1984

Santos, Cinthya S. G., Nonato, Edmundo F. & Petersen, Mary E., 2004, Two new species of Opheliidae (Annelida: Polychaeta): Euzonus papillatus sp. n. from a northeastern Brazilian sandy beach and Euzonus mammillatus sp. n. from the continental shelf of southeastern Brazil, Zootaxa 478 (1), pp. 1-12 : 10-11

Status of Lobochesis

We have not seen any material of Lobochesis , but the original illustrations are very carefully done. However, we can not see that the taxon is different enough from Euzonus to warrant separate generic status. A comparison of features believed to be unique to Lobochesis with the same or very similar ones in Euzonus suggests that the genus was erected on the basis of incomplete information about Euzonus . The expanded anterior lateral lobes on chaetiger 10 that are considered unique for Lobochesis are almost certainly the glandular ridges or corresponding lateral modifications on chaetiger 10 in Euzonus species. Except for the (now four) species with papillae on chaetiger 10, all species of Euzonus have such ridges, and it is not unexpected that the degree of development should vary.

As far as we can see, the lateral ridges are not modifications of the notopodia of chaetiger 10, suggested by Hutchings & Murray (1984) to be the case in Euzonus , but of the body wall itself. This supposed difference between the two genera is therefore nonexistent. Similarly, that bifid branchiae should be rare and occur on posterior rather than middle segments in Euzonus is incorrect. Seven species described in or referred to Euzonus have only bifid branchiae, and two species have a mixture of simple, bifid and trifid. As can be seen from the body formulas in Table 1 , branchiae occur on “middle” segments in all species. The conspicuously long chaetae of anterior and/or posterior segments believed to be typical of Lobochesis are also present on several species of Euzonus ( Table 1 ).

We therefore suggest that the genus Lobochesis is unnecessary and that it be treated as a junior synonym of Euzonus .