Megalomma vigilans ( Claparede , 1870) [unreplaced junior secondary homonym]

Gil, Joao & Nishi, Eijiroh, 2017, Nomenclatural checklist for Acromegalomma species (Annelida, Sabellidae), a nomen novum replacement for the junior homonym Megalomma Johansson, 1926, ZooKeys 677, pp. 131-150 : 139-140

Megalomma vigilans ( Claparede, 1870) [unreplaced junior secondary homonym]

Branchiomma vigilans Claparède 1870: 501-503, plate XIV fig. 3.

Type locality.

Gulf of Naples, Mediterranean Sea (40.7°, 14.3°; estimated geolocation).

Remarks.

Branchiomma vigilans was described on the basis of three specimens from the Gulf of Naples, all of them found with their muddy tubes inserted among the dorsal chaetae of individuals of Aphrodita aculeata Linnaeus, 1758 ( Claparède 1870). Afterwards the species was recorded on only a couple of occasions in the Western Mediterranean, first by Marion (1876), in the Gulf of Marseille and from 60-65 m (no habitat details), and later by Soulier (1903), who observed about ten specimens collected off Séte (Gulf of Aigues-Mortes) among the chaetae of A. aculeata specimens. Rioja (1923) attributed an empty sandy tube found among the dorsal chaetae of an A. aculeata collected in the region of Valencia to this species, but this record is very dubious, as not only was the worm not present but also the nature of the tube differed from that described by Claparède (1870). Moreover, no type material of B. vigilans is known to exist ( Knight-Jones 1997, Giangrande and Licciano 2008, Tovar-Hernández and Carrera-Parra 2011) as Claparède normally did not deposit specimens in museums or collections ( Fauchald 1989).

The species was transferred to Megalomma by Hartman (1959: 550), creating a junior secondary homonym of the tiger beetle Megalomma vigilans (Westwood, 1842) (see above), and has since remained a poorly known but valid taxon ( Knight-Jones 1997, Tovar-Hernández and Salazar-Vallejo 2008). Giangrande and Licciano (2008) considered the species as being quite rare, probably due to its peculiar habitat, and in spite of stating that its real status needed confirmation, they also observed that it was likely a valid species. However, the species was subsequently omitted from the discussions on new Mediterranean species of Megalomma by Mikac et al. (2013) and Giangrande et al. (2015). The most recent reference to the species seems to be by Tovar-Hernández and Carrera-Parra (2011: 5), who wrote:

Megalomma vigilans ( Claparède, 1870) was originally found as an epibiont of the sea mouse Aphrodita aculeata Linnaeus, 1758, in the Mediterranean Sea, however, no new records of this association exist. [...] In the case of M. vigilans , the description is poor, the type is lost and there are no additional records.

The described habitat of Megalomma vigilans is unusual, and there are no references of similar cases in the family Sabellidae . It is possible that the habitat is an artefact resulting from the collection process, and that the presence of the species on individuals of Aphrodita aculeata was the consequence of the rough treatment and mixing suffered by the biological material collected by grabs and trawls, or even during the processing of the samples. So, the presence of M. vigilans on A. aculeata could be a post-collection phenomenon, and not the natural habitat of the worm. It is difficult or even impossible to know if the records by Marion (1876) and Soulier (1903) refer to the same species as that collected and described by Claparède (1870) without studying the material, if still existing. There is a possibility that M. vigilans is not as uncommon as it seems, but that for some reason it has not been collected or recognised. For the time being, M. vigilans is here considered as a species inquirenda.