Guipuzcosoma reipi, Antić & Mauriès, 2022

Antić, Dragan & Mauriès, Jean-Paul, 2022, Two new species of the previously monospecific genus Guipuzcosoma Vicente & Mauriès, 1980 from Spain, with establishment of Guipuzcosomatidae fam. nov. (Diplopoda: Chordeumatida), Zootaxa 5093 (2), pp. 142-168 : 156-163

Guipuzcosoma reipi sp. nov.

Figs 7–12

Diagnosis. Differs from both congeners in the structure of angiocoxites 1, whose distal processes are sigmoid vs. distal processes reduced, with lateral bumps in G. comasi , or almost the same width in its entire length, with an acuminate distal part bent laterad in G. karinae sp. nov. The anterior part of the medial bursal structure of the vulvae in G. reipi sp. nov. is quadrangular with straight lateral margins, vs. heart-shaped in G. comasi or subquadrangular with convex lateral margins in G. karinae sp. nov. Additionally, G. reipi sp. nov. differs from G. comasi by subtriangular vs. rounded lateral parts of colpocoxites in posterior view, or by more differentiated coxal processes on leg-pairs 7 and 11 compared to G. karinae sp. nov. Significant differences also exist in the shape of the posterior part of the medial bursal structure of the vulvae in all three species.

Name. The new species is named in honour of colleague and friend, myriapodologist Hans Reip (SMNG), one of the collectors. A noun in the genitive case.

Material examined (7 ♂♂, 4 ♀♀, 2 juveniles).

Holotype: SPAIN ● ♂; Alava province , Montes de Altzania , Sierra de Urquilla , south of mountain chain Aikorriko Mendikatea , south west of Mountain Aitzgorri , north of end of road from Salvatierra-Ordonana-ZalduondoZumarraundi, north of Zumarraundi, deep gryke with stream discharge (cave), in the lower third, 42.9241, -2.3224, 980 m a.s.l., Fagus forest, thick leaf layer, in leaf litter; 24. April 2009; K. Voigtländer leg.; SMNG.

Paratypes: SPAIN ● 1 ♂; same data as for holotype; SMNG ● 1 ♀; same data as for holotype but near the entrance of cave, Fagus leaves; SMNG ● 1 ♂, 1 ♀, 2 juveniles; Gipuzkoa province , Sierra de Aralar , Beasain , road from Lazkao to Etxarri-Aranaz, western Pass, 42.9572, -2.1122, 550 m a.s.l., Fagus forest, in leaf litter; 21 April 2009; H. Reip, K. Voigtländer leg.; SMNG ● 1 ♂, 1 ♀ (used for SEM); same data as previous; NHMW MY10255 (♂) , MY10254 (♀) ● 1 ♂, 1 ♀; same data as previous; IZB ● 1 ♂; Gipuzkoa province , Montes de Altzania , Sierra de Urquilla , south of mountain chain Aikorriko Mendikatea , south west of Mountain Aitzgorri, north of end of road from Salvatierra-Ordonana-Zalduondo-Zumarraundi, southern lower edge of slope to valley plain Aldasbarreneta, 42.9427, -2.3346, 1120 m a.s.l., lower edge of doline, ca. 1 m above ground of doline, Fagus forest, under stones in deep humus and leaf layer; 24 April 2009; H. Reip leg.; SMNG ● 1 ♂; Gipuzkoa province , Sierra de Aralar , Tolosa , south of Bedaio / Goikoa, 43.0494, -2.0400, 420 m a.s.l., farm buildings and stone wall, logs, wood, stones and rubble, under stones and logs; 21 April 2009; H. Read leg.; NHM .

Description. SIZE AND NUMBER OF BODY RINGS. Body in adults with 30 rings (including telson). Holotype male 10 mm long, vertical diameter of the largest ring 0.8 mm. Paratype males 7.8–9.7 mm long, vertical diameter of the largest ring 0.65–0.7 mm. Paratype females 8.5–10 mm long, vertical diameter of the largest ring 0.75–0.8 mm.

COLORATION ( Fig. 7 ). Variable. From yellowish-brown to darker brown, with greyish patterns. Ventral halves lighter. Ommatidia blackish.

HEAD ( Figs 7B, C , 8A–C ). Setose, frontal side slightly concave in males, convex in females. Labrum with three medial teeth and 5+5 labral and 2+2 supralabral setae ( Fig. 8A ). Promentum subtriangular, without setae. Lingual plates with 4–6 setae arranged in one or two rows. Stipites with ca. 20 setae each.Antennae 1.4 mm long in holotype male. Length of antennomeres (in mm): I (0.07), II (0.17), III (0.37), IV (0.18), V (0.34), VI (0.13), VII (0.12) and VIII (0.04). Length/breadth ratios of antennomeres I–VII: I (1), II (2), III (4), IV (2), V (3.5), VI (1) and VII (1.3). Antennomeres II, IV, V, VI and VII with one, three, one, four and one sensillum trichoideum, respectively ( Fig. 8C ). Lateral to antennal sockets a group of papillae-like outgrowths present ( Fig. 8A, B ). Number of ommatidia: 13 in 4 rows in both sexes, arranged in irregular subtriangle ( Fig. 8B ).

COLLUM. Narrower than head, with six macrochaetae, as all body rings. Anterior edge semi-circular, posterior margin gently concave.

BODY RINGS ( Figs 7 , 8D–F ). With lateral humps. Macrochaetae long and trichoid ( Fig. 8D–F ). CIX (ring 15) = 1; MIX (ring 15) ~ 2; PIX (ring 15) = 0.8; MA (ring 15) ~ 110˚. Prozonites with hexagonal tiles. Metazonites dorsally with scale-like structures, lateroventrally striated. Lateral parts of humps smooth.

TELSON. Epiproct with a pair of spinnerets and 3+3 setae (1+1 paramedian, 2+2 marginal). Hypoproct with 1+1 distal setae. Paraprocts with 3+3 marginal setae in distal part.

LEG- PAIRS 1 AND 2. In both sexes with tarsal combs; femora with several long and robust setae; postfemora and tibiae each with several long and robust setae arranged in a group.

MALE SEXUAL CHARACTERS ( Fig. 9B–C ). Leg-pair 2 with genital openings on coxae. Leg-pairs 3–7 enlarged compared to leg-pairs 1 and 2. Coxa 7 with mesal bump directed posterolaterad ( Fig. 9B ). No other peculiarities on pregonopodal legs. Leg-pair 10 with coxal sacks and with short triangular trochanteral bumps ( Fig. 9C ). Leg-pair 11 with coxal sacks and with short nippled slender coxal process ( Fig. 9D ).

ANTERIOR GONOPODS ( Figs 9E , 10A–F , 11A–D ). Gonopodal sternum (S) poorly developed, mainly membranous, distomedial parts forming subtriangular structures around round aperture and merging with gonopods. Coxites (Cx) more or less spoon-shaped, wide in lateral view, supporting two pairs of angiocoxites. Anteromedial pair (= angiocoxite 1) (A1) widest in mid-height, its mesoproximal sides accommodate shape of sternal triangle; distal process (dA1) sigmoid with distal parts curved laterad; posterior process (pA1) strongly developed, somewhat claw-like in lateral view with small denticles on posterior margin, skintight to lateral sides of distal extension of colpocoxite (deC). Angiocoxites 2 (A2) divided into two branches, anterior branch (aA2) consisting of several flagelloid processes with denticulated posterior margins distally; posterior branch (pA2) long, acuminate, with longitudinal striations, leans on flagelloid processes closing a canal between; both pA1 and pA2 are directed mesad, and slightly posteriad with overlapping distal parts; A2 outgrows all other parts of anterior gonopods. Colpocoxites (C) massive, strongly developed, chitinized; consist of smaller basal protrusions (bc) roundish in lateral view and merged with main massive structures whose distal extensions (deC) are in form of elongated horns strongly bent anteriad and skintight to mesal sides of pA1; posterior mesal protrusions (pC) rounded and laterally flattened with circular membranous remnants (ms) on lateral sides. Between A2 and C, laterally, well-developed structure with large number of long, branched hair-like outgrowths (ho) presents.

POSTERIOR GONOPODS ( Figs 9F , 10G , 11E, F ). Gonopodal sternum (S) poorly developed, membranous, leaving both gonopods almost free; only chitinized part is pair of anterior concave bulges (cb) for accommodation of proximal (basal) parts of posterior gonopods. Coxotelopodites (Ct) massive, without articulation, distally with long setae, while mesally, in upper half, with two striking acuminate horns (h); basomesally with partially chitinized colpocoxites (C) both mainly with one long distal seta and slightly serrated mesal margins. Coxotelopodites subdistally with brownish or blackish pigment remnants (pr). Distal half of Ct slightly curved posteromesad.

LEG- PAIR 3 IN FEMALE ( Fig. 9A ). With lateral sternal lobes.

VULVAE ( Figs 10H , 11G ). With a strongly-developed, massive, wrinkled postgenital membranous structure (Pgm) covering posterior and partially lateral parts of bursae (B). Lateral valves of B rounded posteriorly, without denticles and spicule-like outgrowths in distoposterior ⅔; distoanterior ⅓ wrinkled with long setae. Mesal valves of B completely merged, only with anterior fissure as evidence of former separation; anterior ⅔ wrinkled distally with long setae and straight lateral margins with sharp posterior corners; posterior ⅓ separated from rest by deep depression and represents striking unpaired medial structure (mbs) in the form of mushroom. Operculum (O) bilobed.

Remarks. Interestingly, on the SEM micrograph of the vulvae ( Fig. 10H ) in the fissure between the lateral valves and the medial structures (mesal valve), as well as on the surface of the left lateral valve (highlighted square), structures that we consider to be spermatozoa can be seen. These structures ( Fig. 10I, J ) are about 12 µm in diameter, and are characterized by a narrow medial protuberance, which rises from the coin-like structure. The medial protuberance could be an acrosome-containing structure, while the basal structure would contain a nucleus. If we are right, these could be the first photographs of spermatozoa in the entire order Chordeumatida . These spermatozoa nicely fit the general appearance of spermatozoa in other Diplopoda, whose hypothetical evolution is presented in Bacceti et al. (1979: 102, fig. 14). It is clear that only cytological methods will show whether the spermatozoa of Chordeumatida belong to the so-called monolayered or bilayered acrosome clade.

Distribution. So far, known only from a few localities on the borders between Alava and Gipuzkoa, and Gipuzkoa and Navarre provinces ( Fig. 12 , blue circles).

Figures

FIGURE 7. Guipuzcosoma reipi sp. nov., habitus. A–D. ♂ holotype (SMNG). A. Lateral view. B. Anterior part of body, showing head and collum in dorsal view. C. Anterior part of body, lateral view. D. Midbody rings, dorsal view. E. ♂ paratype, lateral view (IZB). Scale bars: 1 mm.

FIGURE 8. Guipuzcosoma reipi sp. nov., ♂ paratype, habitus (NHMW MY10255). A. Head, anterior view. B. Head and collum, dorso-lateral view. C. Right antenna, anterior view. D. Macrochaeta of ring 17. E. Half of ring 17, dorsal view. F. Ring 17, lateral view. Scale bars: 0.1 mm.

FIGURE 9. Guipuzcosoma reipi sp. nov., legs and gonopods. A. ♀ paratype (NHMW MY10254), leg-pair 3, anterior view, arrow indicates lateral sternal lobe. B–D. ♂ paratype (SMNG). B. Leg-pair 7, posterior view, arrow indicates coxal mesal bump. C. Right leg 10, anterior view, arrow indicates trochanteral bump. D. Leg-pair 11, posterior view, arrow indicates coxal process. E. ♂ paratype (NHMW MY10255), anterior gonopods, anterior view. F. ♂ paratype (NHMW MY10255), posterior gonopods, posterior view. Abbreviations: A1: angiocoxite 1; A2: angiocoxite 2; C: colpocoxite; Ct: coxotelopodite; Cx: coxite; h: mesal horns; pr: pigment remnants; S: gonopodal sternum. Scale bars: 0.2 mm.

FIGURE 10. Guipuzcosoma reipi sp. nov., ♂ paratype (NHMW MY10255) and ♀ paratype (NHMW MY10254). A–F. ♂ paratype, anterior gonopods, anterior, antero-latero-distal, lateral, posterior, postero-latero-distal and distal views, respectively. G. ♂ paratype, posterior gonopod deteriorated during SEM. H. ♀ paratype, vulvae, distal view, light square indicates single sperm. I, J. Spermatozoa. Abbreviations: A1: angiocoxite 1; A2: angiocoxite 2; aA2: anterior branch of angiocoxite 2; B: bursa; bc: basal protrusion of colpocoxite; C: colpocoxite; cb: concave bulge; Ct: coxotelopodite; Cx: coxite; dA1: distal process of angiocoxite 1; deC: distal extension of colpocoxite; h: mesal horns; ho: hair-like outgrowths; mbs: medial bursal structure; ms: membranous structure of colpocoxite; O: operculum; pA1: posterior process of angiocoxite 1; pA2: posterior branch of angiocoxite 2; pC: posterior mesal protrusion of colpocoxite; Pgm: postgenital membranous structure; S: gonopodal sternum. Scale bars: 0.1 mm (A–H), 0.005 mm (I, J).

FIGURE 11. Guipuzcosoma reipi sp. nov., ♂♂ paratypes and ♀ paratype. A. ♂ paratype, anterior gonopods, anterior view (NHMW MY10255). B. ♂ paratype, anterior gonopods, lateral view (SMNG). C. ♂ paratype, anterior gonopods, posterior view (NHMW MY10255). D. ♂ paratype, anterior gonopods, postero-distal view (SMNG). E, F. ♂ paratype, posterior gonopods, anterior and lateral views, respectively (SMNG). G. ♀ paratype, vulvae, distal view (NHMW MY10254). Abbreviations: A1: angiocoxite 1; A2: angiocoxite 2; aA2: anterior branch of angiocoxite 2; B: bursa; bc: basal protrusion of colpocoxite; C: colpocoxite; cb: concave bulge; Ct: coxotelopodite; Cx: coxite; dA1: distal process of angiocoxite 1; deC: distal extension of colpocoxite; h: mesal horns; ho: hair-like outgrowths; mbs: medial bursal structure; ms: membranous structure of colpocoxite; O: operculum; pA1: posterior process of angiocoxite 1; pA2: posterior branch of angiocoxite 2; pC: posterior mesal protrusion of colpocoxite; Pgm: postgenital membranous structure; pr: pigment remnants; S: gonopodal sternum. Scale bars: 0.2 mm.

FIGURE 12. Distribution of the genus Guipuzcosoma Vicente & Mauriès (1980).