Dichromatobolus elephantulus gen. et sp. nov.

urn:lsid:zoobank.org:act: A768C2C3-047C-43A9-8F6B-47EDD40371B4

Figs 1–6

Diagnosis

Body 60–80 mm long, massive, bulky spirobolidan. Epiproct not projecting. Males red, females grey, ozopore openings in both sexes marked by a black circle. Males with tarsal pads, coxa projections absent. Legs and antennae short. Anterior gonopods, telopodite process well-developed and at apex curved laterally. Posterior gonopod slender and elongated, telopodite simple, rectangular, apically with opening of efferent dUct.

Etymology

Elephantulus, diminutive noun in apposition, after the resemblance to an elephant in the female grey color, as well as a hint referring to the width of the species.

Type material

Holotype

MADAGASCAR • ♂; 65 km E of Itampolo; 24°39.02′ S, 43°57.79′ E; 130 m a.s.l.; 10–17 Jan. 2011; M. Irwin, R. Harin Hala leg.; Malaise trap; path in dry forest; CAS MG-54C-78 (CASENT 9068311).

Other material examined

MADAGASCAR • 2 ♂♂; Province Toliara, Mahafaly PlateaU, 6.2 km 74°ENE of Itampolo; 24°39′13″ S, 43°59′48″ E; 80 m a.s.l.; 21–25 Feb. 2002; Fisher, Griswold et al. leg.; spiny forest thicket; hand collecting; CAS BLF 5762 (GCKMP-FM-060) • 2 ♀♀; Toliara, Atsimo-Andrefena, 13.5 km SSE of Efoetse, 2 km E of Soarano village; 24°11.3′ S, 43°46.7′ E; 50 m a.s.l.; 19 Apr. 2005; Voahangy Soarimalala leg.; spiny bUsh, pitfalls; FMNH-INS 3196507 • 7 ♂♂; Odenwald Exoten import to Germany 2007; FMNH-INS 55888 • 17 ♀♀; same data as for previoUs; FMNH-INS 55887 • 3 ♀♀; same data as for previoUs; ZFMK MYR9897, MYR9898, MYR9899 • 2 ♂♂; same data as for previoUs; ZFMK MYR9896 • 2 imm. ♂♂; pet trade, ebugz.eu; import to France 2019; ZFMK MYR8708, MYR8745 .

Description

MEASUREMENTS. Male holotype: 47 +0 body rings, 62 mm long, 7.7 mm wide. Widest male (CAS BLF 5762), broken, 8.2 mm wide. Female (ZFMK MYR9899): 48 +0 body rings, 76 mm long, 9.0 mm wide.

COLORATION. Sexually dimorphic (Fig. 1A). Male: head and body reddish (Fig. 1 A–E), telson bright red (Fig. 1F), ozopores marked by black spot. Legs and antennae black (Fig. 1 B–F). Female: Head and body including telson grey (Fig. 1A), ozopores marked by black spot. Posterior margin of body rings darker. Legs and antennae black.

HEAD. In male, each eye with 45–50 ommatidia arranged in 10 vertical rows with: 4, 5, 6, 7, 7, 6, 5, 4, 3, 2 ommatidia, respectively (Fig. 1B, D). Incisura lateralis open (Fig. 1D). Labrum with standard three irregular teeth and single row of 10–12 stout marginal setae (Fig. 1E). Clypeus with two setiferous foveolae on each side. Antennae short, protruding back to ring 3 in males (Fig. 1B). Relative lengths of antennomeres: 1<< 2>> 3=4>5= 6, second antennomere twice as long as others (Fig. 2A). Terminal antennomere with four large sensory cones located together inside a membranous area (Fig. 2B). Antennomere 5 and 6 latero-apically with sensilla basiconica (Fig. 2C).

GNATHOCHILARIUM. Lamellae linguales each with two standard setae located one behind the other. Stipites each with three apical setae. Basal part of mentum not divided, but with several ridges (Fig. 4A). Endochilarium and central pads shaped like in other Spirobolida species (Fig. 2D).

MANDIBLE. In male, stipes with projecting sharp edge (Fig. 1D). Gnathal lobe, external tooth simple, rounded; inner tooth with four cusps (Fig. 2E). Six pectinate lamellae. Mesal margin of pectinate area (intermediate area) with circa four rows of small, slender spines. Molar plate with numerous (8 or 9) transverse furrows (Fig. 2E). Female not investigated.

COLLUM. Smooth, laterally not protruding as far as ring 2 (Fig. 1B, D).

BODY RINGS. Ozopores marked by black color, starting at ring 6, located a half diameter before suture between mesozona and metazona. Rings with smooth, but irregular coriaceous surface, ventrally on metazona with transverse ridges. Limbus simple, with cuticular scales and wavy margin (Fig. 3A).

TELSON. Paraprocts with weak lips, little micropunctation towards edges (Fig. 1F). Epiproct wellrounded, not protruding above paraproct (Fig.1F). Hypoproct inconspicuous (Fig. 1F).

LEGS. Leg 1 with a large cylindrical coxa, twice as long as other podomeres (Fig. 4C). Tarsus with three pairs of ventral spines, without an apical spine beyond claw. Leg 2 with a strongly elongated coxa, fused to sternite. Tarsus with four pairs of ventral spines and a short apical spine (Fig. 4B). Midbody legs with a rectangular coxa, as long as other podomeres. Each podomere ventrally with a single or a pair of apical setae, tarsus in males with a ventral pad, 6 pairs of ventral and 5 pairs of lateral spines (Fig. 4D). Length of midbody legs circa 0.7 times body diameter in males (Fig. 1E).

Female sexual characters

Body color grey (Fig. 1A). Female vulva simple, resembling a bivalve shell.

Male sexual characters

Tarsal pads present (Fig. 4D). Coxae 3–7 without coxal processes (Fig. 1E).

Anterior gonopod sternite massive (Fig. 4E), elongated into wide, well-rounded lobe (Fig. 4E), lobe lower than coxite. Sternite in posterior view well-visible, without discernable apodemes. Coxite mesally in anterior view with wide, well-rounded process, apical part of process recessed (Fig. 4E, F). Telopodite with slender process arising mesally (Fig. 4F), process conspicuously curved laterad (Fig. 4E), with well-rounded tip, not reaching lateral margin of telopodite (Fig. 4F).

Posterior gonopods each consisting of two parts, separated by sutures (Fig. 5 A–C): (1) basally large, bulky coxite with slender, elongated process of coxite, and (2) apically almost rectangular telopodite with slight membranoUs folds extending meso-apicad and apicad, efferent dUct discharging apically (Fig. 5 A–C). Coxal process and telopodite placed in same axis (Fig. 5 A–B). Pair of posterior gonopods located parallel to each other, connected by small, sclerotized and visible sternite. Basal part of coxite wide, mesally with small sclerite located on lower level than remaining part (Fig. 5B). Coxite elongated into long coxal process (Fig. 5A). Efferent dUct rUnning at mesal margin of coxite (Fig. 5B). Telopodite straight, as wide as coxite process, discharge opening of efferent dUct apically. Telopodite shorter than coxite process (Fig. 5A), meso-apically with well-rounded, triangular, membranous process (Fig. 5 B– C), apically with slightly projecting opening of efferent dUct (Fig. 5 A–C).

Distribution

Spiny forests around Toliara in Southwest Madagascar (Fig. 6).

Intraspecific variation

The three known populations from southwestern Madagascar, as well as the specimens from the pet trade, coming from at least two different imports 2007 and 2019 look very similar to one another, showing only a slight variation in body ring counts, varying between 47 and 48.

Remarks

Some element associated with the species, or the surroundings they live in, reacts to ethanol. White crystallizations appear around the specimens and appendages when conserved in ethanol for a longer time.