Rharodesmus Schubart, 1960 — a tropical element in the North African fauna: a new species from Tunisia and notes on the family Pyrgodesmidae (Diplopoda: Polydesmida)
Author
Akkari, Nesrine
Author
Enghoff, Henrik
text
Zootaxa
2011
2985
55
63
journal article
10.5281/zenodo.202201
c910f090-5e2a-45f9-830d-354e9774a433
1175-5326
202201
Rharodesmus tabarkensis
n. sp.
Figs 1–17
Material examined.
13 3, 8 ƤƤ,
14 juveniles
,
TUNISIA
, Jendouba Governorate, Tabarka, N36°57.8, E8°44.6, alt. <
40 m
, coastal slope below the Genoese fort, under stones,
9.iii.2009
, N. Akkari & H. Enghoff leg. (
ZMUC
).
Etymology.
Named after the
type
locality, Tabarka (northwestern
Tunisia
).
Description
(all measurements in mm). Whitish to light brownish, 20 body rings in both sexes; length: 7–7.9 (males) and 7–8.2 (females); width of prozona 0.40–0.47 (males) and 0.37–0.52 (females); width of metazona: 0.88–0.95 (males) and 0.80–0.95 (females).
FIGURES 1–6.
Rharodesmus tabarkensis
n. sp.
, adult, morphological details: Fig. 1 Head and first two body rings, adult male, anterior view; Fig. 2 Collum and three subsequent tergites, adult female; Fig. 3 Prozona detail: cellular scaly structure (left), transverse ridge of tooth-shaped cuticular ‘cells’ and knobby area next to metazona (right), adult female; Fig. 4 Body rings 3 and 4, showing microsculpture of prozona and tubercles of metazona, adult female; Fig.5 Tubercles on metazona 7 and 8, adult female; Fig 6 Limbus, adult male. Abbreviations:
lb
: posterior lobe;
o
: ozopore;
p
: porostele;
t
: caudolateral tubercle.
Head transverse; dorsal surface microgranulate, epistome with short scattered setae, labral and supra-labral surface with longer ones (
Fig. 1
). Antennae claviform and stout (
Fig. 1
), length of antennomeres: 5=6>3>2=4>7>1. Collum (
Fig. 2
): anterior margin with 10 distinct lobes; dorsal surface domed with numerous small tubercles and 4 bigger ones on the posterior margin.
Body rings: Prozona with fine longitudinal stripes on the anterior margin, followed by a scaly cellular structure covering most of the surface (
Figs 3, 4
). Posterior limit of the latter area marked by a row of tooth- shaped (dorsal side) or rectangular (ventral side) cuticular ‘cells’ forming a distinct transverse ridge. Prozona behind ridge (ca. ¼ of the length of prozona) with a regular covering of subhemisphaerical knobs.
Metaterga (following the terminology of
Hoffman 1976
) with 4 longitudinal–two paramedian and two dorso-lateral—rows of big tubercles (
Fig. 4
) and additionally smaller ones irregularly scattered over the lateral surfaces. Paraterga surmounted of a pair of big caudolateral tubercles (
Figs 4, 5
, 7,
t
). The three first body rings following the collum with 2 (sometimes 3) transversal tergal rows (
Fig. 4
), subsequent body rings with 3 rows (
Fig. 5
). Tubercles of the posteriormost body rings generally much bigger and strongly protruding caudad. Limbus narrow with regularly denticulate margin (
Fig. 6
). Paraterga well expanded with 3 lateral lobes on body ring 2 (
Fig. 2
) then becoming bilobed (
Figs 2, 4
), except on the poriferous rings. In latter rings, the posterior lobe bifurcating into a big lobe forming the porostele and a smaller posterior one (
Figs 5
, 7, p). Ozopores opening on porosteles, present on body rings 5, 7, 9, 10, 12, 13, 15 and 16 (
Figs 5
, 7,
o
). Legs almost invisible from above, length of podomeres: tarsus>femur>prefemur>postfemur= tibia>claw. Telson (Fig. 8): epiproct short and subtruncate, ventrally with scattered marginal setae and 4 spinnerets (Fig. 8,
s
) (cf.
Shear 2008
); paraprocts each with 2 setae, both located well away from mesal margin; hypoproct subtriangular with 2 strong setae on caudal edge.
FIGURES 7–8.
Rharodesmus tabarkensis
n. sp.
, close-up of ozopore and Telson: Fig. 7 Ozopore on the 16th tergite, adult male; Fig. 8 Telson, adult female. Abbreviations: lb: posterior lobe; o: ozopore, s: spinneret-like setae; t: caudolateral tubercle.
Male sexual characters.
Tarsus of 1st and 2nd pairs of legs with ca 17 stout, spatulate setae; tibia of these legpairs with a few similar setae (Fig. 9). Coxal gonapophyses on 2nd pair of legs flattened (Fig. 10). Prefemur modified on the 7th and 8th pairs of male legs (Fig. 11): apically protruding into a pointed knob surmounted by a stout and contorted seta emerging from a densely poriferous basal area (Fig. 12).
FIGURES 9–12.
Rharodesmus tabarkensis
n. sp.
, secondary sexual characters in male: Fig. 9 Spatulate setae on right second leg; Fig. 10 Flattened coxal gonapophyses on second leg pair; Fig. 11 Modified prefemora on the 7th and 8th pairs of legs; Fig. 12 close up of prefemoral process and seta on the 7th left leg.
Gonopods: in situ with crossing telopodites (Figs 11, 13); coxa voluminous, covering most of the lateral side of the telopodite (Figs 11, 13,
c
), hemispherical with a granulate surface and a rounded-triangular smooth distal process (
Fig. 14, 15
,
sp
) surmounting a small setose hump (
Fig. 14, 15
,
h
), median margin with scattered short setae. Basal part of telopodite consisting of a big subrectangular, transverse, strongly granulated and setose ‘prefemoral’ part (
Fig. 14
,
p
) linked to the coxa by a small cannula (
Fig. 14
,
ca
); median margin of ‘prefemoral’ part with stout setae, becoming longer anteriad (
Fig. 14
). ‘Post-prefemoral’ part of telopodite elongated and distally divided in a short membranous rounded cylindrical branch (
Figs 14, 16
,
r
) and 2 processes of the same length: process A subrectangular (
Figs 14, 16
,
A
), folded interolaterad and distally serrated, especially on the margin; process B abruptly expanded distad (
Fig. 16
,
B
) and bifurcating into an elongated smooth conical process (
Figs 14, 16
, cp) and a shorter truncated one (
Fig. 16
,
so
) forming the solenomere; seminal groove arising from the bases of processes (A) and (B) and running into a lateral furrow up to the tip of the solenomere.