Madagascarhinus madagascariensis Wesener 2023, n. sp.
Creators: name: Wesener, Thomas
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Diplopoda
Siphonophorida
Siphonorhinidae
Madagascarhinus
Madagascarhinus madagascariensis

description: Madagascarhinus madagascariensis n. sp.
Figures 1A, 2 and 3
Material examined: Holotype: ♁, MHNG Mad 89/21; Madagascar, Province Antananarivo, Ankaratra massif, station Forestière Manjakatompo, près du sommet du Anosirivo, forêt primaire, prélèvement de sol dans une vieille souche, 1980 m; 26.xi.1989, leg. B. Hauser, extraction Berlese à Genève.
Paratypes: 1 ♁, 2 ♀♀, MHNG, same data as previous; 1 ♁, ZFMK MYR12534, same data as previous, utilized for SEM.
Etymology: The new species is named after the type locality. Adjective.
Diagnosis: Long, slender, whitish-beige siphonorhinid without paranota. Up to 11 mm long with 62 tergites. Antennomere 2 as long as 3 and 4 combined, antennomere 6 only slightly longer than and as wide as antennomere 5. Sensilla basiconica on antennomere 5 and 6 located in a field. Anterior gonopod with seven podomeres, typical for the family, posterior gonopod with seven podomeres, podomere 7 apically with two bifurcated, apically thickening branches, basally with a spiniform process, typical for the genus. Differs from M. andasibensis n. sp. in the wider head (wider than long in M. madagascariensis n. sp., longer than wide in M. andasibensis n. sp.), the presence of a much larger lower branch of the claw at the anterior legs, reaching 2/3 of the length of the claw (1/3 of the claw in M. andasibensis n. sp.) at leg 1 and being even larger than the claw in leg 2, in the anterior and posterior gonopods possessing seven podomeres (six in M. andasibensis n. sp.), and the last podomere of the anterior gonopod being shorter and less strongly elongated than in M. andasibensis n. sp.
Description:
Measurements: all specimens of equal width, approximately 0.5 mm, holotype male with 49+1 tergites, ~ 8.5 mm long. Largest paratype male 61+1 tergites, ~ 11 mm long, smaller paratype male 27+1 tergites, ~ 4 mm long, females with 26+1 tergites, ~ 4 mm long and 19+1 tergites, ~ 3 mm long, respectively. Two males orange-whitish (Fig. 1A), third male and females white (bleached?).
Head: pear shaped, densely setose, slightly wider than long (Figs 2A, B). Gnathochilarium consisting of well distinguishable plates: mentum, stipes, lamellae linguales and a pair of lateral palpi origination from the stipes (Figs 2B, C). Rudimentary palps as wide as lamellae linguales, with 4–7 sensorial cones (Fig. 2C). Lamellae linguales towards one another with a sclerotized ledge, separated by a short gap (Fig. 2C). Antennae elbowed between antennomeres 2 and 3, antennomere 2 elongated, narrower than other antennomeres, as long as 3 and 4 combined (Fig. 2A). Antennomere 6 cylindrical, slightly longer but as wide as 5th. Antennomeres 5 and 6 latero-apically with rows of sensilla basiconica, 2 rows on 5th and 3 rows on 6th. Disc with four apical cones standing in a single field, a field of 5–10 sensilla basiconica as well as a semi-ring of isolated spiniform sensillae (Fig. 2D).
Body-rings: collum slightly longer than following tergites, not overlapping head. Body rings clearly separated into tergite, pleurite and two sternites (Fig. 2F). Tergites without paranota, ozopore located halfway between ventral and dorsal side, relatively close to the posterior margin, surrounded by a single dense row of setae (Fig. 2E). Prozonites covered with scales, metazonites covered by long setae as well as large, well-rounded or spiny sclerotized spines (Figs 2F, H). Pleurites separated into prozonite and metazonite, covered with scales like the prozonite of the tergite (Fig. 2F). Sternites glabrous but covered with strong scales like the pleurites (Fig. 2F), paired stigma openings covered by a plate (Fig. 2G).
Legs: first leg pair larger and slightly thickened compared to following legs (Fig. 3A). Triangular coxa fused to sternite. Second leg pair with greatly enlarged apical spine, surpassing length of claw (Fig. 3B). First two leg pairs without trochanter or coxal pores, both trochanter and coxal pores starting at leg pair 3. Apical claw getting successively shorter in more posterior legs. Midbody leg (Fig. 3C) with elongated femur, 1.5 times longer than wide, as long as postfemur and tibia combined. Each podomere at mesal margin with several long setae. Tarsus slender, apically tapering, 4 times longer than wide.
Telson: densely setose, shape of prenaal ring inconspicuous; anal valves well-developed; subanal scale small (Fig. 1A).
Male sexual characters: gonopore inconspicuous hole with slightly projecting membranous part (Fig. 3B).
Anterior gonopod sternite without any processes, inconspicuous. Anterior gonopod consisting of 7 podomeres, 1–6 being cylindrical, each carrying isolated setae (Figs 3D, E). Podomere 7 strongly enlarged, as long as basal 3 or 4 podomeres combined, apically curved, forming a protection sheath for the posterior gonopod. apico-posterior edge with 5–8 long setae.
Posterior gonopod sternite inconspicuous (Fig. 3F). Posterior gonopod consisting of 7 podomeres, 1–6 cylindrical. Podomere 7 with two long processes of equal length, being as long as podomeres 1–6 combined (Figs 3F, G). In ventral (posterior) view with a third, setae-like process at mid-length, protruding up to half the length of longer processes. Longer processes forming a wide but thin, spoon-like apex.
Habitat: The forest of Manjakatompo is one of the last three (99% have been destroyed) indigenous high plateau forests in Madagascar. The forest was planted by humans a few centuries ago, when it was still connected to now no longer existing fragments of pristine highland vegetation. Manjakatompo harbors rare and endemic genera and species of mammals, but lacks other faunal elements (such as lemurs) most likely due to the artificial origin of the forest and the lack of any fruit-bearing trees (Goodman et al. 1996).
Remarks: The same vial which contained the five Madagascarhinus madagascariensis n. sp. specimens also contained 3 Betscheuma sp. (Chordeumatida) and two indeterminable small-bodied Spirobolida (1 female and one juvenile).
description: Published as part of Wesener, Thomas, 2023, Madagascarhinus, a new genus of the family Siphonorhinidae with two new species from Madagascar (Diplopoda, Siphonophorida), pp. 163-175 in Zootaxa 5278 (1) on pages 165-169, DOI: 10.11646/zootaxa.5278.1.9, http://zenodo.org/record/7895182