Inodesmus mesibovi, Romero-Rincon & Alvear & Martínez-Torres & Robles-Piñeros, 2025

Romero-Rincon, Juan, Alvear, Santiago, Martínez-Torres, Daniela & Robles-Piñeros, Jairo, 2025, First record of the millipede family Haplodesmidae (Diplopoda: Polydesmida) from Colombia: two new species of Inodesmus Cook, 1896 from the Northern Andes, European Journal of Taxonomy 976 (1), pp. 33-46 : 35-40

Inodesmus mesibovi sp. nov.

urn:lsid:zoobank.org:act:945A115E-0BE9-484A-9581-FF7E09C59803

Figs 1–4 , 8

Diagnosis

Males with head + 19 rings, females with head + 20 rings. This species differs from its congeners in having a coxal projection on male leg 6. Telopodite ( Fig. 2 ) with pp straight; at in transverse plane, large, somewhat fusiform, and slightly bent posteriorly; dp directed laterobasally, basal portion of the dp linguiform; meb curving strongly behind mab, bifurcated basally, with a long, acuminate axial process, and a hook-shaped process, with another, small process at midlength; mab concave medially, broad distally, curved outward, and with a small subtriangular process distally.

Etymology

The specific epithet, mesobovi (noun, genetive case), is a patronym, honoring Dr. Robert Mesibov for his valuable contributions to the knowledge of the Australian millipede fauna.

Material examined

Holotype

COLOMBIA • ♂; Cundinamarca, San Antonio del Tequendama, Parque Natural Chicaque , oak forest; [04º37.028′ N, 74°18.830′ W]; 2232–2275 m a.s.l.; 12 Jan. 2023; J. Romero-Rincon and J. Veloza leg.; under a decaying fallen log; daytime hand collection; ICN-MD-2913.

Paratypes (11 ♂♂, 15 ♀♀, 17 immatures)

COLOMBIA • 1 ♂ (fragmented), 1 ♀; same data as for holotype; MHN-UPN-MD-168 • 1 ♂ (fragmented); same data as for holotype; MHN-UPN-MD-176 • 1 ♂, 1 ♀; same data as for holotype; MHNUC-MD-276 • 1 ♀; same data as for holotype; with teratologies; MHN-UPN-MD-177 • 1 ♂, 3 ♀♀, 7 immatures; same data as for holotype; MHN-UPN-MD-178 • 2 ♂♂, 2 ♀♀; same data as for holotype; ICN-MD-3130 • 1 ♂; same locality as for holotype; 26–29 Sep. 2022; J. Romero-Rincon and L. Poveda leg.; under decaying log; daytime hand collection; MHN-UPN-MD-92 • 1 ♀, 1 immature (fragmented); same data as for preceding; MHN-UPN-94 • 1 ♀; same locality as for preceding; 29 May 2022; J. Romero-Rincon and R. De La Cruz leg.; inside a decaying fallen log; daytime hand collection; MHN-UPN-MD-96 • 1 ♀; same locality as for preceding; 29 Apr. 2022; J. Romero-Rincon leg.; under a decaying fallen log; night time hand collection; MHN-UPN-MD-99 • 1 ♂, 1 ♀, 4 immatures; same locality as for preceding; 25–26 Jun. 2022; J. Romero-Rincon and R. De La Cruz leg.; inside a decaying fallen log; night time hand collection; MHN-UPN-MD-98 • 1 ♂, 1 immature; same locality as for preceding; 25–26 Jun. 2022; J. Romero-Rincon and R. De La Cruz leg.; under a decaying fallen log; daytime hand collection; MHNUC-MD-412 • 2 ♀♀, 1 immature; same locality as for preceding; 19 Jun. 2023; J. Romero-Rincon leg.; under a decaying fallen log; night time hand collection; MHN-UPN-MD-163 • 1 ♂, 3 immatures; same locality as for preceding; 16 Aug. 2023; J. Romero-Rincon and H. Reip leg.; under a decaying fallen log; daytime hand collection; MHN-UPN- MD-169 • 1 ♀; Cundinamarca, San Antonio del Tequendama, Parque Natural Chicaque , secondary forest; [04º36.854′ N, 74°18.859′ W]; 2155 m a.s.l.; 28–29 Apr. 2022; J. Romero-Rincon leg.; under bark of fallen log; daytime hand collection; MHN-UPN-MD-97 • 1 ♂; same locality as for preceding; 30–31 Jul. 2022; J. Romero-Rincon leg.; under a decaying fallen log; night time hand collection; MHN-UPN- MD-95 .

Description

MEASUREMENTS. Male with head + 19 rings, female with head + 20 rings ( Fig. 1 ). Average measurement of adult type specimens: male/female ca 10/ 11.5 mm long; maximum width ca 0.9/ 1.2 mm.

COLORATION. Metazonites, prozonites, and collum deep reddish brown 41 to deep brown 56; head, legs (prefemur and coxa pale greenish yellow 104), and antennae light reddish brown 42.

HEAD. Wider than high; narrower than collum; facing downwards ( Fig. 3A–C ); setose clypeus ( Fig. 3A ). Vertex microvillose and microgranulate. Antennae ( Fig. 3A–C ) short, stout, clavate, densely setose, and held close to head. Antennomere relative lengths as follows: 6> 1> 5> 4= 2> 3> 7. Antennae with 4 sensory apical cones.

TRUNK. Anterior and posterior margins of collum broadly convex; corners rounded and hidden under paranota of second ring, collum with an irregular pattern of two groups of rounded tubercles. At first glance, pattern continues on remaining body rings, with a supposed transverse medial separation on each tergite ( Fig. 3B–C ). Ring 2 tergite largest, extending basally, laterally, and posteriorly; extension of paranota of ring 2 incrassate without well-defined tubercles ( Fig. 3B–C ). Posterior rings ( Fig. 3G ), up to ring 18, with a lateral row of three small tubercles, neither enlarged nor forming pseudo-paranota. Ozopores ( Fig. 3F ) very small, internal closing not evident, located just above or in middle of last lateral row of tubercles ( Fig. 3G ). Ozopores internally and externally bordered by microtubercules, with neither evident elevation nor porostele. Pore formula normal (5, 7, 9, 10, 12, 13, 15–19). Diplosternites ( Fig. 3D ) with transverse impression deeper than longitudinal impression, anterior sternites with eight acicular setae, posterior sternites on ring 5 with bumps bearing six acicular setae each. Legs ( Fig. 3B– C, G–H ) short and stout; relative lengths of podomeres: tarsus>(prefemur≥ femur)>tibia>postfemur; claw about as long as postfemur. Spiracles not evident. Telson facing downwards. Paraprocts parallel to substrate and almost flat ( Fig. 3G–H ). Epiproct ( Fig. 3H–I ) distally projected, but short, flattened dorsoventrally, with four inconspicuous setae (spinnerets), each spinneret with a single low sheath, each seta inside a circular, deep, walled depression ( Fig. 3I ). Hypoproct ( Fig. 3H ) subtrapeziform with a slightly convex anterior margin. Tegument with microsculpture, especially along posterior edge of metazonite, anterior edge of prozonite, head, collum, lateral part of metazonite of second ring, edges of ozopores, and posterior area of telson ( Fig. 3 ). Microsculpture mostly as a cellular mesh with narrow irregular folds. Integument further elevated into tubercles of different sizes and shapes on head, collum, tergites, metatergites, and telson ( Fig. 3A–C, G–H ); some tubercles with a single small and acicular seta. Cell boundaries in posterior part of metazonite not extending basally past limbus ( Fig. 3E ). Primary limbus element with a regular set of rounded lobes and tooth-like lobes on the secondary element ( Fig. 3E ). Prozonites sharply demarcated from metazonites ( Fig. 3B–C, G ). Anterior part of prozonite (a) with small irregular subcardiform units arranged in transverse “rows” placed on a smooth background. A transverse ridge (r) is marked by a row of cell-like units. Posterior part of the prozonite (b) with a smooth surface and lacking spherical knobs.

GONOPOD. Oval aperture, rim widely raised laterally. Telopodite ( Fig. 2 ) long, reaching base of leg pair 5 ( Fig. 3C ). Basal portion of telopodite with a blunt, basally directed projection arising posteromedially to junction with cx, several short setae in basal portion of telopodite, and three large setae in a row on lateral edge of apical tab ( Fig. 2 ).

Remarks

A notable case of “helicomerism” was observed in a female of I. mesibovi sp. nov. in which the segmental anomaly breaks the serial arrangement of the body rings ( Demange & Pereira 1980; Minelli & Pasqual 1986; Leśniewska et al. 2009). In this specimen (MHN-UPN-MD-177), the tergite of ring 8 is entirely divided into two sections, a smaller isolated portion on the left and one on the right side of the metazonite that is completely fused with ring 7, giving a diagonal shape to the posterior part of the segment ( Fig. 4B ). Additionally, another teratological feature is observed in the collum, in which an abnormal longitudinal transverse partition is evident ( Fig. 4A ). However, it cannot be dismissed that the damage may have been influenced by external factors beyond the scope of development.

Distribution

Only known from Parque Natural Chicaque, Cundinamarca, Colombia ( Fig. 8 ).

Figures

Fig. 1. Habitus of Inodesmus mesibovi sp. nov., male paratype (above; MHNUC-MD-276) and female paratype (below; MHNUC-MD-276). Scale bar: 1 mm.

Fig. 2. Inodesmus mesibovi sp. nov., male holotype (ICN-MD-2913). A. Ventral view of the gonopods. B. Left gonopod in ventral view. Scale bars: 0.1 mm.

Fig. 3. Inodesmus mesibovi sp. nov., male holotype (A, C–D, H–I; ICN-MD-2913) and male paratype (B, E–G; MHN-UPN-MD-168). A. Ventrolateral view of head. B. Dorsolateral view of the anterior part of the body. C. Lateral view of the anterior part of the body. D. Midbody sternite. E. Sculpture of the prozonite. F. Ozopore. G. Lateral view of the posterior part of the body. H. Ventral view of telson. I. Spinnerets. Abbreviations: a = anterior part of prozonite; b = posterior part of prozonite; L = limbus; lo = lobe; o = ozopore; r = ridge; s = spherical knobs; t = tooth-like lobe. Scale bars: A, H = 0.2 mm; B, G = 0.5 mm; C = 1 mm; D = 0.1 mm; E–F = 0.02 mm; I = 0.05 mm.

Fig. 4. Teratologies inInodesmus mesibovi sp. nov., female paratype (MHN-UPN-MD-177). A. Anterior part of body. B. Middle part of the body. The numbers 6 and 9 correspond to the body ring number. Scale bar: 0.5 mm.

Fig. 8. Distribution map of the known species of Inodesmus Cook, 1896 in Colombia.