Cylindroiulus mitta, Akkari, Nesrine & Enghoff, Henrik, 2008

Akkari, Nesrine & Enghoff, Henrik, 2008, Cylindroiulus mitta n. sp., a new Tunisian millipede (Diplopoda, Julida: Julidae) and notes on the Cylindroiulus distinctus group, Zootaxa 1768, pp. 61-68 : 62-64

Cylindroiulus mitta n. sp.

Figs 1–15

Material examined. Holotype: adult male; Tunisia (Cap Bon); Nabeul governorate, Jebel Abderrahman, Quercus forest, 12.xi.2006, N. Akkari leg. (Natural History Museum of Denmark—ZMUC) Paratypes: 2 males, 11 females, data as holotype ( ZMUC); 1 male, 3 females and 12 juveniles; Tunisia (Cap Bon); Nabeul governorate, Oued El Abid, N: 36° 40’, E: 10°18’, 200–300m altitude, Quercus forest, 9.iii.2005, N. Akkari leg. ( ZMUC)—Additional material (not paratypes): 15 females /juveniles; Tunisia; Zaghouan governorate, Oued Ezzit, N: 36° 30’.933; E: 10°18’ 831, 180 m, Quercus forest, 27.iii.2005, N. Akkari leg. ( ZMUC).

Etymology. The specific epithet is a Medieval Latin noun in apposition, meaning “mitten” and referring to the shape of the brachite.

Diagnosis. A species of the Cylindroiulus distinctus group sensu Read (2005). Differing from other species in the group by smaller body size, simpler gonopods and, especially, by the simple, mitten-shaped brachite.

Description (all measurements in mm, see also Table 1). Body yellowish brown, antennae and telson darker, prozonites glossy, light brownish. Ventral side and legs yellowish. Metazonites glabrous with darker pigmentation. Defense glands showing as prominent dark spots. Body length measured along the line of ozopores: 11.3–12.8 (males) and 13.3–16.7 (females); vertical diameter at the 15th body ring: 0.90–1.02 (males) and 1.05–1.33 (females); Ratio length/height: 12–13, adult males shorter and slenderer than females. Eyes composed of 19–31 ocelli in 7–9 vertical rows. Length of antennae 1.2 X body height (adult male). Ozopores opening on the suture. Length of legs: 0.9 X body height (adult male). Telson with no caudal projection, preanal ring and anal scale each with 2 setae, each anal valve with one row of 4–5 setae.

Characters males Females Body length (mm) 11.3–12.8 13.3–16.7 Body vertical diameter 0.9–1.02 1.05–1.33 Ocelli Vertical rows 7–8 7–9

Number 19–28 26–31 Body ring number Podous rings 36–45 44–50

Apodous rings 2–4 1–3

Telson setae Preanal ring 2 2

Anal valve 4-5 4-5

Subanal scale 2 2 Gonopods ( Figs. 1–4 ). Promerite ( Figs. 1–4 , p) in anterior view rather broad and squat; in posterior view showing a shallow concavity; in lateral view quite narrow with a triangular apex and scaly margin; in mesal view, concave in distal 2/3 with a shallow incision on the subapical interior margin. Mesomerite ( Figs. 1, 3, 4 , m) in mesal and lateral view considerably shorter than promerite, closely fitting into posterior concavity of the latter. Flagellum ( Fig. 4 , f) rather long.

Paracoxal rim ( Figs. 3–4 , pcr) prominent, with a semicircular profile, in lateral view covering ca. 2/3 of opisthomerite. Paracoxal process absent. Solenomerite ( Fig. 2–4 , s) simple, without a projection, slightly bent mesad, apically narrower, apical external margin folded over; in mesal and lateral view showing apical serrations. Brachite ( Fig. 2–4 , b) in mesal and lateral view broad, rounded, without a projection, apical part bent laterad, giving it the appearance of a mitten (cf. name). Brachite and solenomerite connected by hyaline membrane ( Fig. 3 , hm), margin of membrane serrated.

Vulvae ( Figs. 5–6 ). Operculum ( Fig. 5 ) longer than bursa, in posterolateral view broad, strongly narrowed towards conical tip. A row of 3–4 setae along each border and a few additional setae scattered over the oral surface. Bursa ( Fig. 6 ): Valves with prominent triangular, pointed lamellar tips ( Fig. 6 , l). Each valve with two parallel irregular rows of setae, the external rows with ca. 5 aligned setae and the internal ones with 3–5 setae. Receptaculum seminis ( Fig. 6 , rs) originating in a longitudinal depression between valves, consisting of a long, almost straight apodematic branch ( Fig. 6 , ab), bifurcating distally into a spherical ampulla ( Fig. 6 , am) bearing an appendix ( Fig. 6 , ap), and a long and straight blind tube ( Fig. 6 , t).

Figures

FIGURES 1 – 4. Cylindroiulus mitta n. sp., male paratype: Gonopod structures, Fig. 1: anterior view, Fig. 2: posterior view, Fig. 3: lateral view, Fig. 4: mesal view. Abbreviations see text.

FIGURES 5 – 6. Cylindroiulus mitta n. sp., female paratype: Vulval structures, Fig. 5: Operculum, Fig. 6: Bursa. Abbreviations see text.

FIGURES 7 – 9. Cylindroiulus spp. Operculum: Fig. 7: C. algerinus, Fig. 8: C. attemsi, Fig. 9: C. distinctus.

FIGURES 10 – 12. Cylindroiulus spp. Bursa: Fig. 10: C. algerinus, Fig. 11: C. attemsi, Fig. 12: C. distinctus, Abbreviations see text.

FIGURES 13 – 15. Other Cylindroiulus species from Tunisia: C. truncorum and C. tunetanus: Fig. 13: Bursa structure in C. tunetanus Fig. 14: gonopod structures of C. truncorum, mesal view, Fig. 15: gonopod structures of C. tunetanus, mesal view. Abbreviations see text.