Dalodesmus tectus Cook, 1896

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), ZooKeys 1223, pp. 185-220 : 185-220

Dalodesmus tectus Cook, 1896

Figs 11 , 12

Dalodesmus tectus Cook, 1896: 26 (D); Attems 1940: 489 (L); Jeekel 1965: 238, figs 1, 2 (D); Hoffman 1974: 230 (D); Golovatch and Hoffman 1989: 161 (L); Enghoff 2003: 623 (L); Wesener and Enghoff 2022: 926 (L).

Polydesmus hova de Saussure & Zehntner, 1897 : plate 5, figs 23–23 c (D), syn. nov.

Pterodesmus hova – de Saussure and Zehntner 1901: 436 (D).

Polydesmus (Tubercularium) hova – de Saussure and Zehntner 1902: 91 (D).

Tubercularium hova – Attems 1940: 434, figs 619, 620 (D, K).

Dalodesmus hova – Jeekel 1965: 238 (L); Hoffman 1974: 230, figs 10, 11 (D); Golovatch and Hoffman 1989: 162, figs 7–9 (D); Enghoff 2003: 623 (L); Hollier and Wesener 2017: 58 (L, N); Wesener and Enghoff 2022: 926 (L).

Note.

This species was described from a ♂ holotype coming from an unspecified locality in central Madagascar ( Cook 1896), in the ZMB collection, revised. The type series, ZMB MYR 2110, actually contains two ♂ syntypes, one with dissected and missing gonopods, apparently the one depicted by Jeekel (1965), the second ♂ with still intact gonopods (Fig. 11 A – F ). Originally, D. hova was verbally described from an uncertain number of syntypes of both sexes ( de Saussure and Zehntner 1901, 1902), with males from ‘ Madagascar’ (coll. Sikora), as well as females and juveniles from Nosy Be Isle. Franz Sikora collected in Madagascar around the capital city Antananarivo and briefly in the southeast around Fort Dauphin. Hoffman (1974) recorded and illustrated the gonopods of D. hova from a ♂ taken as far away from part of the type locality (Nosy Be) as the Andasibe National Park (= Périnet) in eastern Madagascar, questioning such a vast and disjunct distribution. An incomplete ♂ syntype (with missing gonopods) from Nosy Be and 2 ♀ non-types from Nosy Sakatia Isle, all in the SMF collection, were later revised and partly depicted ( Golovatch and Hoffman 1989). An additional six syntypes, collected by Franz Sikora, including the male on which the illustration of the gonopod was based in the original description, are in the MHNG collection ( Hollier and Wesener 2017), as well as a non-type tube labeled “ Tubercularium hova ”, “ Madag. Fort Dauphin, S 2 Remy 49; leg. Remy, det. Attems 1951 ”, in the NHMW collection.

Hoffman (1974) listed the type locality as Nosy Be, overlooking that the only male specimens used for the first description by de Saussure and Zehntner had come in fact from Franz Sikora (so either central Madagascar or Fort Dauphin in the southeast). We discovered another Malagasy Dalodesmidae species (see Phymatodesmus sakalava above) collected by Franz Sikora that had actually come from Andasibe, exactly the same locality whence Hoffman briefly redescribed the species and finely illustrated its gonopodal structure. Thus, based on the female-based records of “ D. hova ”, D. tectus could be a congener particularly widely distributed across Madagascar, ranging from the isles of Nosy Be and Nosy Sakatia in the very north to Fort Dauphin (Tolagnaro) in the very southeast. If true, this seems to be the most widespread native millipede in Madagascar. The populations from Nosy Be and Fort Dauphin, from which the gonopods are currently unknown, should be carefully checked in the future to clarify their taxonomic status. Nosy Be is the type locality of another two Dalodesmidae , D. odontopezus and Eutubercularium voeltzkowi .

Brief description.

(After Cook 1896 and Jeekel 1965.) Body of ♂ syntypes ~ 21 mm long and 2.8 mm wide. Colouration uniformly dark brown. Paraterga largely subhorizontal, lying below dorsum; tips sharpened caudally, but not projecting past posterior margin; dorsal surface between paraterga mostly tuberculate, tuberculations being rounded to subconical (Fig. 11 A ).

Gonopods (Fig. 11 C, D, G, H ) showing nearly bare femorites (fe), both only basally with 2 + 2 lateral setae, coupled with rather simple acropodite: an untraceable, apparently rudimentary solenomere lying between both branches of a distinct solenophore: the highest, suberect, at midlength unequally bifid mesal branch (mb) and a much shorter, strongly folded and lamelliform lateral branch (lb).

Based on a restudy of the gonopods of the type series of D. tectus , no meaningful differences to the gonopodal structure of D. hova as illustrated by de Saussure and Zehntner (1897) and redescribed by Hoffman (1974) could be found (Fig. 12 A – H ). The potential type locality of D. tectus (central Madagascar) fits very well to the type locality of D. hova (Andasibe) .

Figures

Figure 11. Dalodesmus tectus Cook, 1896, ♂ syntypes (ZMB MYR 2110). Multi-layer photographs (A – F), drawings (after Hoffman 1974) (G, H). A Anterior body, dorsal view B both syntypes, fragmented mix C ventral view with gonopod D anterior body, lateral view with gonopod E telson, ventral view F telson, lateral view G gonopod, posterior view; gonopod, mesal view of acropodite. Abbreviations: fe = femorite; lb = lateral branch; mb = mesal branch. Not to scale.

Figure 12. Dalodesmus tectus Cook, 1896, syntypes of D. hova (de Saussure & Zehntner, 1897) syn. nov., ♀ syntype (A) and ♂ syntype (E, F) (after de Saussure and Zehntner 1902), ♂ syntype (B – D) (after Golovatch and Hoffman 1989), all from Nosy Be, and ♂ from Andasibe National Park (E – H) (after Hoffman 1974). A Anterior part of body, dorsal view B right half of metazonum 10, dorsal view C posterior end of body, dorsal view D body ring 9, oral view E right gonopod, ventral view F left gonopod, lateral view G, H left gonopod, ventral and lateral views, respectively. Abbreviations: cx = coxite, fe = femorite, lb = lateral branch, mb = mesal branch, sl = solenomere. Scale bar: 1000 µm (B – D).