Endogeophilus alberti, Iorio & Bonato, 2024

Iorio, Étienne & Bonato, Lucio, 2024, A new species of the rare genus Endogeophilus from southern France, with a key to the European genera of Geophilidae s. l. (Chilopoda), ZooKeys 1213, pp. 199-224 : 199-224

Endogeophilus alberti sp. nov.

Type specimen.

Holotype (Figs 2 , 3 ): • ♀, 31. III. 2023, É. Iorio leg. In ethanol. Body in four pieces: head, maxillae, mandibles, and trunk. Original label: Cavalaire-sur-Mer (Var), Malatra, “ MALAT 3 ”, 43.1795 ° N, 6.5068 ° E ( WGS 84 ), 31. III. 2023, É. Iorio leg. Deposited in the Muséum national d’Histoire naturelle, Paris ( Chilopoda collection, number M 370 ).

Type locality.

France: Var department: Cavalaire-sur-Mer: near Malatra: 43.1795 ° N, 6.5068 ° E (WGS 84), 215 m a. s. l., north-eastern slope (Fig. 1 ).

Diagnosis.

An Endogeophilus species with claw of the second maxillae slender and hooked at its tip; forcipular trochanteroprefemur ~ 1.1 × as long as wide; forcipular tarsungulum> 2.0 × as long as wide, almost as long as the trochanteroprefemur, distinctly curved, fairly slender, and gradually narrowing. See also Table 1 , Figs 2 – 4 , and Discussion.

Description of the holotype

(Figs 2 , 3 ). General features. Body remarkably slender, 24.5 mm long, uniformly ~ 0.3 mm wide for most part of the trunk, only very slightly narrowing anteriorly along ~ 20 most anterior leg-bearing segments and backwards along approximately the five most posterior leg-bearing segments. Legs relatively short. Colour almost uniformly pale yellow, only the forcipules and the head slightly darker, both pale orange.

Cephalic capsule and antennae. Head 0.4 mm long, sub-rectangular, 1.15 × longer than wide (Fig. 3 A ); the anterior margin slightly angulated with a small medial notch. Transverse suture absent. Approximately 40 setae on the head, the majority being short except those of the lateral margins, longer, reaching up to ~ 22 μm. Clypeus uniformly areolate, without clypeal areas and without plagulae, with six setae, arranged in a longitudinal series of three pairs on the anterior median part of the clypeus. Pleurites uniformly areolate, with some setae. Labrum composed of an intermediate part narrow and almost negligible, having one tubercle (Fig. 2 A ); side pieces not clearly distinct from the intermediate part of labrum, each with four bristles. Antennae with 14 articles, 1.3 mm long, 3.2 × longer than the head (Fig. 3 B ). article I ~ 0.7 × longer than wide, articles II – VII up to 1.7 × longer than wide, article VIII ~ 1.2 × longer than wide, articles IX – XIII approximately as long as wide; setae gradually denser and shorter from basal to distal articles, both ventrally and dorsally. Article XIV 2.0 × longer than wide, with numerous setae and with club-like sensilla grouped on the distal parts of both internal and external sides (Fig. 3 C ).

Mandibles and maxillae. A single pectinate lamella on each mandible. Coxosternite of the first maxillae entire, without mid-longitudinal sulcus. Coxal projection sub-triangular, longer than wide, bearing one or two basal setae and some more distal spine-like sensilla. Telopodite comprises two articles, the basal one without setae, the distal one with three setae and five or six spine-like sensilla. No coxosternal lappets; telopodital lappets present and pointed (Fig. 2 B ). Coxosternite of the second maxillae entire, the intermediate part uniformly sclerotised as the remaining parts, its anterior margin concave; no sclerotised ridges. Telopodite of the second maxillae composed of three articles: article 1 with two or three very short external setae, article 2 with one or two very short external setae, article 3 with five or six long distal setae; a simple long apical claw, subconical but hook-shaped at its extremity, with a dorsal bulge at its mid length (Fig. 3 D ).

Forcipular segment. Tergite trapezoid, the lateral margins distinctly converging anteriorly, ~ 2.3 × wider than long, posteriorly almost as wide as the subsequent metatergite (Fig. 3 A ). Exposed part of the coxosternite ~ 1.1 × wider than long; anterior margin with a medial shallow concavity, without denticles. Coxopleural sutures complete, entirely ventral or almost, only very slightly sinuous, and strongly converging posteriorly. Chitin-lines well distinct, reaching the condyles, moderately curved and converging posteriorly (Figs 2 C , 3 E ). Trochanteroprefemur ~ 1.1 × as wide as long, the external side ~ 2.2 × longer than the internal side, without denticles and with some setae (Figs 2 C , 3 F ). Forcipular intermediate articles distinct, without denticles, each with some long setae. Tarsungulum curved, gradually narrowing, ~ 2.2 × as long as wide and with a basal sub-conic tubercle; slightly crenulated in its concavity, with 3–6 shallow projections, less pronounced on the left than on the right (Figs 2 C , 3 F ).

Leg-bearing segments. 99 LBS. No paratergites. Metatergite 1 wider than the subsequent one, lateral margins converging posteriorly, without pretergite. Metatergites with two paramedian sulci. Metasternites slightly longer than wide (length / width ratio ~ 1.1 at ~ 20 % of the LBS), uniformly areolate; setae very sparse. Metasternites of LBS 10–20 with a carpophagus pit on the anterior margin, fairly deep on LBS 14–19, ~ 0.6 × as wide as the margin of metasternite (Figs 2 D , 3 G ). Glandular pores on the metasternites from the 2 nd to the penultimate, up to 30–35 pores and loosely arranged in a sub-ovoid / sub-triangular pore-field on the posterior half of each metasternite in the anterior part of the trunk (Fig. 2 D ); the pore-fields being much less visible in the posterior half of the trunk, loosely arranged in a transverse band of pores in the ~ 5–10 penultimate LBS. Length / width ratio of leg tarsus ~ 2.3 at ~ 20 % of the LBS. Leg claws simple.

Ultimate leg-bearing segment. Setae uniformly sparse. Pleuropretergite entire, lacking sutures or sulci. Metatergite sub-trapezoid, ~ 1.5 × wider than long, lateral margins very slightly convex and distinctly converging posteriorly, posterior margin convex. Presternite not medially constricted. Metasternite trapezoid, ~ 1.3 × wider than long, anteriorly 1.4 × wider than posteriorly (Fig. 2 E ); lateral margins slightly convex, converging backwards; posterior margin straight. Coxal organs of each coxopleuron opening through five or six independent pores: two dorsal pores, one covered by the pleuropretergite and one exposed on the dorso-lateral side (Fig. 2 F ); three or four ventral pores including two or three more or less aligned under the edge of the corresponding metasternite and a single pore isolated on the postero-central part of the ventral side (Figs 2 E , 3 H ). Telopodite 0.43 mm long, 7.8 × as long as wide, ~ 1.7 × as long as the penultimate telopodite; six articles, all covered dorsally with sparse long setae, ventrally with dense shorter setae; a fairly well-developed apical claw (Fig. 3 H ).

Postpedal segments. Gonopods in the shape of a short, slightly bilobate lamina. A pair of anal pores.

Distribution and ecology.

The new species is only known from the type locality (see above; Fig. 1 ). The single specimen was collected in a shaded maquis of old Arbutus unedo L., 1753 with also some large Quercus suber L., 1753 (Fig. 5 ). It was found after sieving with a Winkler apparatus, at a depth of 10–20 cm in the soil.

Etymology.

This species is dedicated to Prince Albert II de Monaco, because the Foundation Prince Albert II de Monaco has supported the field work of this study. The epithet alberti is intended as a noun in the genitive case.

Identification key to the European genera of Geophilidae s. l.

Within Europe, the Geophilidae s. l. can be distinguished from all other Chilopoda by means of the combination of the following two characters:> 25 pairs of legs and second maxillary pretarsi in shape of either subconical, non-spatulate, pointed claw or a tubercle with only one or two tiny spines. A total of 20 genera of Geophilidae s. l. are recorded in Europe (Table 2 ).

The key should be applied by examining any specimen through a microscope. A magnification of 50 × is recommended, even 100 × for examining labrum and pore-fields. For characters defined on the leg-bearing segments, examination between the 5 th and the 20 th LBS is recommended.

In addition to the dichotomic characters included in the key, additional information is given for each genus (number of species recorded in Europe, geographical distribution within Europe, and additional morphological characters), between square brackets, to assist in the identification.

Figures

Figure 1. Distribution of all known records of Endogeophilus.

Figure 2. Endogeophilus alberti sp. nov., holotype A labrum B first maxillae C right part of the forcipular segment D LBS 18 E ultimate LBS without distal part of legs F left part of the ultimate LBS without distal part of leg. Views: ventral (A – E), dorsal (F). Scale bars: 20 µm (A); 40 µm (B); 100 µm (C – F).

Figure 3. Endogeophilus alberti sp. nov., holotype A head and forcipular segment B antennae C distal articles of left antenna D right telopodite of second maxillae E head and forcipular segment F right forcipule G LBS 15 and anterior part of 16 H ultimate LBS without right leg. Views: ventral (D – H), dorsal (A – C). Abbreviations: cls club-like sensilla, cmx claw of the second maxillae, cp coxopleural pores, cs carpophagus-structure. Scale bars: 200 µm (A – B, E, G – H); 50 µm (C – D, F).

Figure 4. Endogeophilus ichnusae, paratype PD 1373, ventral A head and forcipular segment B right forcipule and apical claw of the second maxillae. Abbreviation: cmx claw of the second maxillae. Scale bars: 100 µm.

Figure 5. Habitat of Endogeophilus alberti sp. nov., near Malatra, Cavalaire-sur-Mer, France (Fig. 1).

Figure 6. Head and forcipular segment. Species A Pachymerium ferrugineum B Gnathoribautia bonensis C Pleurogeophilus mediterraneus D Strigamia carniolensis E Henia vesuviana F Strigamia carniolensis G Dignathodon microcephalus H Henia bicarinata I Gnathoribautia bonensis. Views: dorsal (A – E), ventral (F – I). Abbreviations: cl chitin-lines, d forcipular denticle, dc denticles of the mesal side of the forcipular tarsungulum, ft forcipular tergite. Arrow: median diastema of the forcipular coxosternite. Scale bars: 400 µm (A – F, H-I); 300 µm (G).

Figure 7. A, B labrum C, D, F, G forcipular segment E distal part of the forcipular coxosternite. Species A Clinopodes vesubiensis B Geophilus studeri C Arctogeophilus inopinatus D Eurygeophilus pinguis E Clinopodes vesubiensis F Galliophilus beatensis G Geophilus gavoyi. Views: all ventral. Abbreviations: cl chitin-lines, d forcipular denticle, tp trochanteroprefemur. Arrow: denticles on the forcipular coxosternite. Scale bars: 50 µm (A, B); 300 µm (C – G).

Figure 8. Metasternite of an anterior LBS. Species A Clinopodes vesubiensis LBS 16 B Galliophilus beatensis LBS 19 C Eurygeophilus pinguis LBS 10 D Geophilus osquidatum LBS 11 E Geophilus electricus LBS 11 F Pleurogeophilus mediterraneus LBS 15 G Stenotaenia linearis LBS 20 H Tuoba poseidonis LBS 12. All ventral views. Abbreviations: cs carpophagus-structure, pf pore-field. Scale bars: 200 µm.

Figure 9. Ultimate LBS without distal part of legs. Species A Arctogeophilus inopinatus female B Galliophilus beatensis male C Geophilus flavus female D Pachymerium ferrugineum male E Pleurogeophilus mediterraneus female F Pleurogeophilus mediterraneus male G, H Stenotaenia linearis female I Tuoba poseidonis female. Views: ventral (A – G), lateral (H, I). Abbreviations: p pit or fossa (H wide fossa from dorsal to ventral side, indicated by dotted lines), um metasternite of the ultimate LBS (medial length and maximum width are indicated by dotted lines). Scale bars: 300 µm.

Figure 10. Legs of the ultimate pair A, C right leg B, D distal articles of the right leg E – G both legs H left leg. Species A Arctogeophilus inopinatus male B Arenophilus peregrinus female C Eurygeophilus pinguis female D Geophilus fucorum female E Geophilus richardi female F Pachymerium ferrugineum female G Pleurogeophilus mediterraneus male H Pleurogeophilus mediterraneus female I Acanthogeophilus spiniger female. Views: ventral (A-E, I), lateral (F) and dorsal (G-H). Abbreviations: c claw, t tubercle with spines. Scale bars: 300 µm (A, C, F); 50 µm (B); 100 µm (D, E, I); 1 mm (G – H).