Parvidrilus gineti, (JUGET, 1959), 2012

Martínez-Ansemil, Enrique, Châtelliers, Michel Creuzé Des, Martin, Patrick & Sambugar, Beatrice, 2012, The Parvidrilidae - a diversified groundwater family: description of six new species from southern Europe, and clues for its phylogenetic position within Clitellata (Annelida), Zoological Journal of the Linnean Society 166 (3), pp. 530-558 : 547-548

PARVIDRILUS GINETI ( JUGET, 1959) COMB. NOV.

Aelosoma Gineti Juget, 1959: 397–399 , figure 3a.

Aelosoma gineti Juget (1959) – Ginet, 1961: 310.

Aeolosoma gineti Juget, 1959 – Brinkhurst, 1967: 112; Bunke, 1967: 266; Brinkhurst & Jamieson, 1971: 695; Seyed-Reihani, 1980: 57, table VI; Dole, 1983a: 227; Dole, 1983b: 82, 110, 113, ann. 8; Juget & Dumnicka, 1986: 234, 239; Dole-Olivier et al., 1993: 457, Table 2; Dole-Olivier et al., 1994: 321; Ferreira et al., 2003: 17; Artheau & Giani, 2006: 230; Ferreira et al., 2007: 585; Timm, 2009: 18, 132.

Types: Lectotype. MHNL 44003362 , ‘ Aeolosoma gineti, Lac souterrain La Balme, février 1959 ’, fragment (first 11 segments), whole-mounted in an unspecified, slightly yellow liquid medium (Amman’s lactophenol?), sealed with red lute. La Balme Cave (45°51′10′′N, 5°20′21′′E, 220 m asl), Isère (38), France.

Paralectotype. MHNL 44003363 , ‘ Aeolosoma gineti, Lac souterrain La Balme, février 1959 ’, wholemounted in an unspecified, slightly yellow liquid medium, sealed with red lute .

Other material examined: UCBLZ 1.011.1-1.011.3, ‘ Aeolosoma cf. gineti ; Ph 7 1, 20/10/76’, alluvial plain of the Haut Rhône, phreatic and hyporheic waters (45°48′50′′N, 05°04′48′′E, 179 m asl; see Artheau & Giani, 2006), Rhône (69), France; three specimens whole-mounted in Canada balsam .

Emended description: Lectotype: length 435 Mm, 11 segments (fragment); paralectotype: length 1450 Mm, 21 segments (uncertain as specimen badly damaged as a result of stretching into two parts). Breadth 115 Mm at widest (IV- IX). Prostomium rounded to conical, 40 Mm long, 45–55 Mm wide at base; ciliation absent. Dorsal and ventral setae present from III, posteriorly situated in each segment, absent in II. Dorsal bundles with one or two straight, singlepointed needles (15–30 Mm), and one hair seta (length 150–237 Mm). Ventral bundles with one (lectotype) to two–three (paralectotype) sigmoid, bifid crotchets (15–18 Mm) with upper tooth slightly thinner and shorter than lower tooth, accompanied by one smooth hair seta (length 95–133 Mm); ventral hair setae absent from XI. Internal organs mostly destroyed in the mounting medium used. Progressive intestinal dilation from VII partially visible.

Remarks: According to the original description by Juget (1959), it seems likely that a few specimens were observed alive, which would explain the mention of chains of zooids of two to five specimens, although they were absent in the material available to us for observation. In all probabilities, the specimen shown in the original illustration ( Juget, 1959: 398, fig. 3a) corresponds to the lectotype. It is similar in external appearance, and in the number and arrangement of setal bundles, except that the first setigeral segment is not shown on the figure – suggesting that there are eight setigeral segments instead of nine. In this specimen, the so-called ‘zooid’ does not show any clear zone of scission and cannot be considered as such.

The combination of setal features (e.g. shape, number, and location of setae) is typical of Parvidrilus , supporting its placement within the family Parvidrilidae . In fact, Bunke (1967: 266) early considered ‘ Aeolosoma gineti ’ as a species dubia and suggested that the species should be excluded from the polychaete genus Aeolosoma because of setal features, the absence of coloured glands in the tegument, the small and unciliated prostomium, and the organization of intestinal tract. A possible alignment with the oligochaete family, Naididae , was also suggested by Bunke, an opinion that was later restated by others ( Brinkhurst & Jamieson, 1971; Artheau & Giani, 2006). More recently, Timm & Veldhuijzen van Zanten (2002) and Timm (2009) suggested that the species might well be a parvidrilid although no paratomy was yet recorded in this group.

The external morphology of P. gineti is similar to other Parvidrilus species. However, in the absence of properly preserved internal organs – and in particular, the genitalia – no unambiguous description of the species can be provided. Even if new material from the type locality could be collected and properly preserved, there would be no guarantee of having sampled this same taxon; thus we must consider P. gineti to be a species inquirenda.

Distribution and habitat: ‘La Balme’ cave, Isère (38), France, in a subterranean lake, heterogeneous sediment (rough sand and fine clay, with organic remains, mostly of plant origin); alluvial plain of the Haut Rhône, France, phreatic and hyporheic waters (Miribel canal and ‘Lône du Grand Gravier’; Artheau & Giani, 2006).