Ceratosphys dissensionis Gilgado & Andres 2025, n. sp.
Creators: name: José, Elena Andrés
name: Gilgado, José D.
name: Ortuño, Vicente M.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Diplopoda
Chordeumatida
Opisthocheiridae
Ceratosphys
Ceratosphys dissensionis

description: Ceratosphys dissensionis Gilgado & Andrés, n. sp.
(Figs 2-9)
urn:lsid:zoobank.org:pub: 8B32 BEC 0-AA57-4C23-B2FC-7DBC5EEB3B58
TYPE MATERIAL. — Holotype. Spain • 1 ♂; Madrid, Somosierra, Arroyo de la Dehesa Valley, ‘ Abedular de Somosierra’, leaf litter, mixed forest; 41°07’30”N, 3°34’40”W; 1410 m a.s.l.; 18.X.2021; Andrés E. & Ortuño V. M. leg; MNCN 20.07 /2148.
Paratypes. Spain • 5 ♂, 5 ♀; Madrid, Somosierra, Arroyo de la Dehesa Valley, ‘ Abedular de Somosierra’, leaf litter, mixed forest; 41°07’30”N, 3°34’40”W; 1410 m a.s.l.; 18.X.2021; Andrés E. & Ortuño V. M. leg; MNCN 20.07 /2149-2158 • 5 ♂, 5 ♀; same data as for preceding; UAH 95-99.
OTHER MATERIAL STUDIED (SEE ALSO TABLE 1 FOR STADIA). — Spain • 248 juveniles; Madrid, Somosierra, Arroyo de la Dehesa Valley, ‘ Abedular de Somosierra’, leaf litter, mixed forest.; 41°07’30”N, 3°34’40”W; 1410 m a.s.l.; Andrés E. & Ortuño V. M. leg.; 18.X.2021; UAH • 471 juveniles; same data; 18. VI.2021; UAH • 1 juvenile; same data; 18.VII.2021; UAH • 56 juveniles; same data; 19.IX.2021; UAH • 34 ♂, 33 ♀, 86 juveniles; same data; 18.X.2021; UAH • 13 ♂ 15 ♀, 51 juveniles; same data; 19.XI.2021; UAH • 2 ♂, 6 ♀, 3 juveniles; same data; 19.II.2022; UAH • 2 ♂, 3 ♀, 4 juveniles; same data; 19.III.2022; UAH • 1 juvenile, same data; 18.IV.2022; UAH • 1 ♂, 4 juveniles; same locality in deadwood; 15.X.2010; Gilgado J. D. & Ortuño V. M. leg.; UAH.
ETYMOLOGY. — The authors could not agree on a name for the new species, so after long discussions we decided to ‘agree to disagree’ and dedicate the species name to our ‘disagreement’ (nominative dissensio, genitive singular dissensionis in Latin).
DIAGNOSIS. — This species can be distinguished from other Ceratosphys by the combination of the following characters of anterior gonopods: angiocoxites of anterior gonopods with a single branch and possessing three tips, but lacking brush-like structures, and lyre-like syncolpocoxite, combination not present in any other species of the genus; and posterior gonopods: combination of both a smaller curved colpocoxite (C) and a larger “hook-like”-shaped horn (h) in posterior gonopods, different from the processes in all other Ceratosphys species.
DESCRIPTION
Measurements
Adults with 30 segments (including telson). Amber colour, with metazonites darker brownish, basal part of legs light amber with darker distal parts (Fig. 2). Male body size: 8.07- 9.23 mm (average 8.71 mm) long, 0.64-0.81 mm (average 0.73 mm) maximum height, and 0.78-1.03 mm (average 0.88 mm) maximum width. Female: 9.66-10.6 mm (average 10.07 mm), 0.83-0.96 mm (average 0.88 mm) and 0.97- 1.12 mm (average 1.07 mm), respectively.
Head
No remarkable characteristics, covered with scattered setae, labrum with three teeth, and 8 + 8 setae (6+ 6 labral and 2+ 2 supralabral), but some males showing a higher number of setae (Fig. 3C), frons concave in males (Fig. 3A; F), convex in females (Fig. 8A), with 19-21 ommatidia in males and 19-22 in females, in a triangular field arranged in six vertical rows (sensu Enghoff et al. 1993); and six rows sensu Demange (1972), parallel to the ventral edge of the head capsule, rugose (cobblestone paving-like) area posterior to insertion of antennae. Antennomeres I-VII measuring: 0.06, 0.13, 0.36, 0.20, 0.29, 0.11 and 0.07 mm from base to apex in male holotype, respectively, and with numerous setae, especially on the seventh antennomere surface. Basiconic sensillae present ventrodistally in distal antennomeres (Figs 3D; 8A).
Trunk
Collum with 3+3 setae, 1+1 paramedian, 2+2 lateral (Fig. 3B). Following segments with same chaetotaxy. Paranota increasing in size up to the seventh segment, maintaining approximately the same size in the next six segments, and then decreasing in size until fading towards the last segments of the body in both sexes (Fig. 2; 3E, H; 4). Prozonites and ventrolateral parts of metazonites with a cell- or scale-like microsculpture, dorsal part of metazonites and paranota relatively smooth (Figs 3C; 4A, B). Posterior margin of last segments almost serrulate (Fig. 4A).
Legs
Leg pairs 1 and 2 smaller in both sexes, with tarsal combs; femora, postfemora and tibiae with long and robust setae ventrally (Fig. 5 A-D). Leg pairs 3-7 incrassate in males. Leg pairs 3 and 4 with dorsal, rounded bulge on prefemur, a dorsally depressed, slightly concave postfemur (Fig. 5 E-G). Leg pair 5 similar but without a rounded bulge on prefemur, while postfemur is straight rather than concave (Fig. 5H, I). Leg pair 6 similar, with a concave postfemur (Fig. 6A). Leg pair 7 with modified coxae, mesally rugose, laterodorsally with a small, rounded protrusion, lateroventrally with a conical curved protrusion with a blunt tip half as long as the prefemur. Prefemur with a central concavity where these conical protrusions presumably fit (Fig. 6B, C). Leg pair 10 slender, with coxal sacs, and prefemora showing a subtle conical ventrad protrusion (Fig. 6D). Leg pair 11 with coxal sacs, and prefemora with a mesad ‘big toe-like’ process with a blunt rounded tip (Fig.6E, F). Leg pairs 12 onward without remarkable characters (Fig. 6G, H). All legs with ventral accessory claw longer than the claw itself (Fig. 5B, D). Tarsal papillae present in all male’s legs except the last eight pairs (Figs 5 E-H; 6A, B, D, E, G, H).
Telson
Epiproct with 3+ 3 setae and 1 +1 spinnerets (Figs 3C, D). Paraprocts with scale-like microsculpture, and 3 mesal setae each (Fig. 3D). Hypoproct with 1 +1 setae.
Gonopods (Fig. 7)
Anterior gonopods relatively simple (Fig. 7 C-G). Sternum (S) reduced to joining of angiocoxites in their basal mesal part (Fig. 7G) angiocoxites (A) straight, with a distal part curved posteriad. At the middle of angiocoxite, an apparent lateral ‘folding’ showing a suture (fA). Distal part of angiocoxite with a sharp tip resembling an upper seagull beak (dA). Ventroanteriorly to distal tip, a second tip (vA), formed by a foliar triangular process. Posteriorly to the distal tip, a third tip (pA), leaving a concave space (maybe an opening) (cA) between it and the distal tip. Syncolpocoxite (SC) with “lyre-like” shape, with convex rounded lateral margins, distally ending in two triangular ventrolaterad rugose tips (tC), separated by a suture. In posterior view, 1 +1 rugose flat depressions (dC) covering a large area of syncolpocoxite, separated by a column (cC) in the middle, and proximally to this column, a smaller hole (hC) (Fig. 7C). In anterior view, with two lateral and longitudinal depressions (lC) to accommodate angiocoxites from its basis to the rugose tips.
Posterior gonopods larger than anterior gonopods, with articulations and vestigial articulations visible (Fig. 7 I-K). Gonopodal sternum (S) reduced to a membrane.Telopodites (Ct), with a long distal part and two basal processes: 1) a smaller proximal, mesal, curved and anterolaterad pointing horn, most likely a colpocoxite (C) (or also possibly an angiocoxite), coming out of the coxite (Cx); and 2) a larger lateral, ‘hook-like’ curved, flattened, mesoposteriad horn ending in a blunt finger-like tip (h). Posterior margin of this second horn widened in its basal half (w). Distal part of telopodite narrow and long and with several setae, with tip pointing laterodorsad. Distalmost part with pigment remnants (pr) and ending in a small presumably membranous process (mt) at the tip.
Vulvae (Fig. 8B, C)
Slightly longer than wide. Operculum (O) with three setae in mesal lobe and five in lateral lobe. Supra-opercular prolongation (sop) of small size. Bursa (B) with a distal concavity in each valve, six setae in mesal and six in lateral lobe. Apodematic groove surrounded by a lateral and mesal lip-like rugose structures, mesal one with small denticles basally. Postvulvar organ (pv) small, curved and with serrated margin. Sternum posterior to vulvae (S) with two depressions (dS) (Fig. 8A, B), and a central knob (kS) reaching coxae of leg pair three.
POSTEMBRYONIC DEVELOPMENT
The number of segments, legs and ommatidia increases with the growth of the individuals as shown in Table 1. Morphological differences were observed between all stadia examined (Table 1; Fig. 9) except stadium I. The length of C. dissensionis Gilgado & Andrés, n. sp. increases 10 times from approximately 1 mm (stadium II) to 10 mm (adult females). The number of segments increases by three between stadia II-III and between stadia VI-VII; by four segments at each moult between stadia III to VI; and by only two segments at the moults between stadium VII and the adult stage. The number of legs increases according to two leg pairs per segment, except for the differences observed in males due to the presence of anterior and posterior gonopods. Thus, females have 49 pairs of legs, while males have 47 pairs of legs. The number of ommatidia also increases non-linearly with each moult (Table 1).
PHENOLOGY
Both the activity of C. dissensionis Gilgado & Andrés, n. sp. and the climatic conditions (temperature and precipitation) showed monthly fluctuations during the one-year sampling period, between 18.V.2021 and 18.V.2022. The climatogram (Fig. 10) shows that the highest average temperature (21.7°C) was measured in the summer months and the lowest (4.6°C) at the end of winter. The heaviest precipitation fell between April and May 2022, while there was a minimal amount of precipitation between August and November 2021. However, a certain consistency of precipitation was observed in the study area during the sampling period. The presence of C. dissensionis Gilgado & Andrés, n. sp. in the leaf litter was recorded throughout the year, except during the sampling in August and December 2021 and in January and May 2022 (Table 1; Fig. 10). Adults of this species have been observed at two different periods of the year: most specimens (58 males and 56 females) were collected at the beginning of autumn, while a few individuals (four males and nine females) were collected during late winter sampling. No specimens of stadium I have been found in the field, and all stadium II samples (23 specimens) were found in May of the first year. The majority of the stadium III individuals were collected in May and June, with only one specimen found in October. This pattern appears to coincide with the highest proportion of adults recorded in autumn and the smallest proportion of adults in spring, indicating a developmental delay in part of the C. dissensionis Gilgado & Andrés, n. sp. population. We did not record any mating couples of this new species in the study area.
description: Published as part of José, Elena Andrés, Gilgado, José D. & Ortuño, Vicente M., 2025, A new Ceratosphys Ribaut, 1920 (Diplopoda, Chordeumatida, Opisthocheiridae) from Spain: taxonomy, phenology, and postembryonic development, pp. 89-104 in Zoosystema 47 (6) on pages 92-99, DOI: 10.5252/zoosystema2025v47a6, http://zenodo.org/record/14935626