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
Author
Santos, Cinthya S. G.
Author
Nonato, Edmundo F.
Author
Petersen, Mary E.
text
Zootaxa
2004
2004-03-31
478
1
1
12
https://biotaxa.org/Zootaxa/article/view/zootaxa.478.1.1
journal article
4856
10.11646/zootaxa.478.1.1
20a0a9ef-f9e3-48cc-bdde-6fc03c8f8afe
11755334
5030064
A768FE63-D817-4F3D-A23E-DFE27AE36AE6
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
.