Dalodesmus speophilus Wesener, Akkari & Golovatch, 2025, sp. nov.
Creators: name: Wesener, Thomas
name: Akkari, Nesrine
name: Golovatch, Sergei I.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Diplopoda
Polydesmida
Dalodesmidae
Dalodesmus
Dalodesmus speophilus

description: Dalodesmus speophilus sp. nov.
Figs 15, 16, 17, 18
Type material.
Holotype • ♂ (MZUF), Madagascar, Grotta di Anjohibe, 15°32'33.08"S, 46°53'5.99"E, 12. ix. 1989, L. Bartolozzi & S. Taiti leg.; Paratypes: 6 ♂, 12 ♀, 12 juv. (MZUF); 1 M, 1 F (ZFMK), same data as holotype.
Diagnosis.
Length <20 mm in both sexes, the smallest species of the genus (all other species with males> 21 mm). Tips of paraterga not projecting past posterior tergal margin, like in D. hova, D. tectus, D. kompantsevi sp. nov., vs sharper and projecting beyond margin in D. hamatus, D. odontopezus and D. orator. Differs from D. hova, D. tectus, and D. kompantsevi sp. nov. in the contrasting yellow paratergal tips (uniformly brown in the other species). Gonopods unique for the genus Dalodesmus in the main branch being subdivided into an apical and a subapical branch. See also Key below.
Etymology.
From speophilus, a noun in apposition, after the type locality, a gigantic cave.
Description.
Length in male ~ 16.5–17.5 mm (n = 3), width of midbody pro- and metazona 1.5 and 2.8–2.9 mm (n = 3), respectively, female length 16.5–19 mm (n = 4), width of prozona 1.6 mm (n = 1), of metazona 3.7–4.1 mm (n = 4).
Colouration in alcohol light brown to beige, paraterga light, head brown, epicranium grey, legs light, except for a few tarsi pale grey; antennae dark brown (Fig. 15 A – F). A live photograph of a potential D. speophilus sp. nov., 70 km away from the type locality, shows dull, dark brown to blackish tergites with pale white to almost yellow paratergal tips, legs white to pale grey (Fig. 16 D).
Body with 20 rings. Tegument mainly dull, microgranulate to microtuberculate throughout, even surfaces of prozona and of metazona below paraterga finely microgranulate, sterna granulate. Head also densely microtuberculate or granulate throughout, micropilose up to level of antennae; epicranial suture thin, but distinct; genae squarish, set off ventrally from gnathochilarial stipes by a small, but evident ridge (Figs 15 D, 16 A). Interantennal isthmus ~ 2 × diameter of antennal socket (Fig. 15 D). Antennae short and rather clavate, in situ reaching in both sexes back past ring 3 when stretched dorsally, very densely setose and microgranulate. In length, antennomere 6> 2> 5> 4> 2> 1 = 7; antennomere 6 the largest and the highest, antennomeres 5 and 6 each with a small, round, distodorsal knob, most likely beset with sensory cones. In width, collum ≤ head <ring 3 <2 <4–16; thereafter body gradually tapering towards telson (Fig. 15 A). Collum transversely suboval, regularly and broadly rounded laterally, densely tuberculate, most tuberculations being slightly oblong-oval, evident, equipped with very short, mostly subclavate setae and arranged in 20–22 lateral, 7–8 transverse, rather irregular, arcuated rows. Metaterga 2 and 3 narrow, each with four similar, transverse, arcuated rows of setigerous tubercles (Fig. 17 C), following metaterga each largely with 5–6 such rows (Fig. 15 A). Paraterga well-developed, set high (mostly at upper ¼ body), largely slightly upturned to subhorizontal, thus leaving the dorsum only faintly convex (Fig. 15 A – C); anterior and posterior margins of paraterga 2 and 3 clearly drawn both forward and caudad, following paraterga drawn increasingly only caudad, but caudal corners produced past rear tergal margin only on rings 15–19; posterior margins clearly bisinuate, well concave behind paraterga (Fig. 15 E). Lateral and caudal margins of paraterga beset with numerous, similarly oblong and usually subequal, setigerous tubercles / lobulations, caudolateral lobulation being nearly sharp (Fig. 17 A, B). Ozopores inconspicuous (Fig. 17 E, F), opening dorsally near penultimate lateral lobulation on pore-baring rings 5, 7, 9, 10, 12, 13, 15–19. Strictures between pro- and metazona narrow and rather deep, nearly smooth (Fig. 17 A).
Telson: Epiproct small, conical and subtruncate at tip. Hypoproct trapeziform, with 1 + 1 setae borne on distinct oblong knobs at caudal margin. Paraprocts with 2 + 2 setae on triangular, projecting knobs (Figs 15 E, F, 16 E).
Limbus very thin, small, and entire. Neither an axial line nor pleurosternal carinae (Fig. 15 A – C). Endotergum inconspicuous, posterior margin of metazona projecting into dense, long sharp, apically microdenticulate, triangular projections (Fig. 15 D, I).
Gonopodal aperture roundly pentagonal, relatively small, taking up ~ 1 / 2 width of metazonum 7, clearly open and drawn into metazonum 6 (Fig. 16 A).
First ♂ leg-pair shorter and wider than other legs, with long coxae, large; size of its podomeres: tarsus> coxa> prefemur = femur> postfemur = tibia (Fig. 17 J), tarsus with sharp claw, ventral spines, and numerous long setae (Fig. 17 K). Midbody legs incrassate, rather long. 1.4–1.5 × as long as body height (Fig. 17 L), with small, stout, abundant, and usually curved setae with admixture of sphaerotrichomes ventrally on all podomeres (♂); gonopores on ♂ coxae 2 inconspicuous, each borne on a very small swelling (♂); prefemora not bulged laterally; claws very small; in length, tarsus> femur> prefemur> tibia> postfemur> coxa.
♀ vulva setose, symmetrical, lateral and inner plates of same width. Operculum large, each side with three or four very long setae, longest reaching the apical margin of vulva (Fig. 17 H).
Gonopods (Figs 16 B, C, 17 G, 18 A – L) very slender and long, tips in situ reaching anteriorly until coxae 5 (Fig. 16 A, B). Both coxites and prefemoral (= densely setose parts) of telopodites equally very short and stout, fused medially, the former fully and the latter mostly hidden inside gonopodal aperture. Femorites (fe) contiguous medially in basal 1 / 3, sparsely setose almost all along, both slightly flattened dorsoventrally and diverging distad towards acropodites. Apical portions of telopodite (= acropodites) clearly diverging, rather complex and compact, curved ventrad and clearly divided into four unequal branches: a short, submesal, tubiform, simple and non-sigmoid solenomere (sl) flanked by a rather elaborate, tri-branched solenophore, this latter being represented by an immediately adjacent, short, lobe-shaped, lateral branch (lb), a large, subacuminate, slender, twisted, and membranous medial branch (mb) with a denticle near base, and an apical (ab) and a subapical branch (sb), both latter membranous, curved / bent ventrad and ragged / irregular in shape.
description: Published as part of Wesener, Thomas, Akkari, Nesrine & Golovatch, Sergei I., 2025, Revision of the millipede family Dalodesmidae in Madagascar, with descriptions of two new Malagasy species of Dalodesmus Cook, 1896 (Diplopoda, Polydesmida), pp. 185-220 in ZooKeys 1223 on pages 185-220, DOI: 10.3897/zookeys.1223.139346