PHYLLODOCIDA Dales, 1962

Salazar-Vallejo, Sergio I. & Harris, Leslie H., 2006, Revision of Pilargis de Saint-Joseph, 1899 (Annelida, Polychaeta, Pilargidae), Journal of Natural History 40 (3 - 4), pp. 119-159 : 124-126

Order PHYLLODOCIDA Dales, 1962

Suborder NEREIDIFORMIA Glasby, 1993

Superfamily NEREIDOIDEA Johnston, 1845

Family PILARGIDAE de Saint-Joseph, 1899

Subfamily PILARGINAE de Saint-Joseph, 1899

Pilargis de Saint-Joseph, 1899

Pilargis de Saint-Joseph 1899a, p 42, 1899b , p 175; Fauvel 1920, p 212; Horst 1921, p 74; Hartman 1947, p 490–491; Uschakov 1965, p 179; Pettibone 1966, p 160–161 (syn.); Blake 1994, p 279–280.

Phronia Webster 1879, p 268 .

Type species. Pilargis υerrucosa de Saint-Joseph, 1899, by original designation.

Emended diagnosis

Pilarginae with large biarticulated palps, palpostyles minute, without ventral papilla. Paired lateral antenna present, no median antenna. Two pairs of tentacular cirri. Parapodia well-developed, notocirri enlarged, separated in cirrophore and cirrostyles (potential autopomorphy in the subfamily), sometimes reduced. Notosetae completely absent (autoapomorphy in the subfamily). Neurosetae capillaries smooth or slightly limbate, blade slightly spinulose or smooth, tips straight or curved (‘‘bifid’’). Pygidium with or without anal cirri. Pharynx globose, smooth. Intestine with lateral diverticula.

Phronia Webster, 1879 , is a junior homonym of a dipteran genus (de Saint-Joseph 1899, p 179). These are the taxa currently included in Pilargis and their original region: P. berkeleyae Monro, 1933 , from the Northeastern Pacific Ocean, P. maculata Hartman, 1947 , from the Northeastern Pacific Ocean, P. modesta Intes and le Loeuff, 1975 , from Western Africa, P. mohri Gallardo, 1968 , from the Western Pacific Ocean, P. papillata Rasmussen, 1973 , from the Northeastern Atlantic Ocean, P. tardigrada ( Webster, 1879) , from the Northwestern Atlantic Ocean, P. υerrucosa de Saint-Joseph, 1899, from the Northeastern Atlantic Ocean (including P. perezi Charrier, 1924 ), P. υerrucosa pacifica Uschakov, 1955 , from the Northwestern Pacific Ocean, and P. sp. A Wolf, 1984, from the Western Atlantic Ocean.

Pilargis hamatus Hartman, 1960 and P. matsunagaensis Kitamori, 1960 were transferred to Ancistroyllis McIntosh, 1879 by Pettibone (1966); P. mirasetis Fauchald, 1972 has been transferred to a different genus ( Santelma Blake, 1993 ) and family ( Nautiliniellidae ) by Blake (1993). Some records have not been included in the key below because there was no material available: Blake’s (1994, p 280) record of P. berkeleyae does not belong in that species, but its affinities are not settled; the records of P. berkeleyae by Britayev (1993), Buzhinskaja (1980), Buzhinskaja and Britayev (1994), and Imajima (1987), may belong to P. pacifica Uschakov, 1955 (see below).

The proposal of the subfamilies Synelminae and Sigambrinae was made by comparative morphology methods ( Salazar-Vallejo 1987). However, it failed to follow the Principle of Coordination (International Commission on Zoological Nomenclature (ICZN) 1999, Art. 36), thus it was consequently modified by using Pilarginae instead of Sigambrinae by Salazar-Vallejo and Orensanz (1991). After the subfamilies proposal by Salazar-Vallejo (1987), there have been two independent evaluations of the intergeneric cladistic affinities in the Pilargidae . The first was by Fitzhugh and Wolf (1990), and the second by Licher and Westheide (1994), and despite their conclusions, the subfamilies are apparently well delineated in their cladograms.

Fitzhugh and Wolf (1990, p 16, Appendix 2) regarded three genera as lacking notopodial spines: Loandalia Monro, 1936 , Parandalia Emerson and Fauchald, 1971 , and Pilargis . However, as has been shown in several publications ( Salazar-Vallejo 1987; Salazar-Vallejo and Orensanz 1991; Blake 1994), the former two do have notopodial spines, some species even have a few thin capillary setae along with them. Further, these two genera have been shown to be synonyms ( Salazar-Vallejo 1998), so among the genera included by Fitzhugh and Wolf (1990), only Pilargis completely lacks notospines or notohooks. Further, Synelmis (5 Glyphohesione ) klatti was regarded as a member of the family (but it belongs elsewhere), and if we understand the proposed subfamilies as represented by genera 1–6 for Pilarginae against 7–12 for Synelminae , they were grouped in two out of three trees ( Fitzhugh and Wolf 1990, Figures 4 , 5 ).

Licher and Westheide (1994, p 228, Table 1, p 232, Figure 4 ) indicated that two genera lack notopodia (although they probably meant notosetae): Pilargis and Otopsis Ditlevsen, 1917 , and they differ especially because Otopsis has a smooth integument, median antenna, and its palps are regarded as simple, while in Pilargis integument is verrucose, median antenna is missing, and palps are biarticulated. Further, in their single cladogram, they found that Glyphohesione was basal and the two subfamilies are better delineated, since they found a single tree, with the sole exception of Otopsis , which was wrongly coded (see Licher and Westheide (1994, Figure 4 , 19d) because they indicated lack of notopodia, but Otopsis only lacks notosetae, and has large dorsal cirri. These features bring it in close proximity to, and may eventually fall within Pilargis . Anyway, after Jenner (2002, 2004), there is a widespread problem in character definition and character coding, so we are still far from a robust conclusion or rejection of the subfamily groupings.

Regarding the differences between Pilargis and Otopsis , as will be shown below, there is a marked variation in the verrucal density or relative size, and in some species they are markedly reduced in size or body coverage (see below). The number of antennae has been rejected as a generic diagnostic feature by Pettibone (1966, p 164) for separating Ancistargis Jones, 1961 from Ancistrosyllis McIntosh, 1879 (a contrasting view was briefly exposed by Emerson and Fauchald 1971, and by Licher and Westheide 1994, p 233) for Litocorsa Pearson, 1970 . However, the median antenna in Otopsis is very large, at least in the type species ( O. longipes Ditlevsen, 1917 ). Further, palpostyles may be very small and difficult to find, or they can be eroded, making any distinction of simple against biarticulate rather difficult to make. However, another species ( O. kurilensis Uschakov, 1971 ) has a tiny median antenna and biarticulated palps, which indicates a much closer similarity with Pilargis . If we follow the same approach of disregarding the number of antennae as a distinguishing feature, then Otopsis might have to be included in Pilargis since no other feature separates them, as was indicated by Hartman (1947, p 483, footnote 1). This is an interesting question that will be addressed in a forthcoming contribution.

Figures

Figure 4. (A–D) Pilargis angeli n. sp. UANL-1474: (A) anterior end in dorsal view (verrucae are mostly restricted to parapodia); (B) right setiger 10 in anterior view; (C) median setiger in anterior view; (D) right setiger 60 in anterior view. (E) Pilargis sp. juvenile BLM 85401 BF1, complete organism in dorsal view, slightly distorted by cover slip. Scale bars: 225 mm (A); 120 mm (B–D); 500 mm (E).

Figure 5. Pilargis berkeleyae Monro, holotype BMNH-1933.1.14.1. (A) Anterior end in dorsal view (body laterally distorted); (B) same, close-up; (C) right setiger 22 in posterior view; (D) right setiger 46 in posterior view; (E) dorsal view of setigers 41–44. Scale bars: 380 mm (A); 200 mm (B); 270 mm (C, D); 700 mm (E).