Review of the Spirobolida on Madagascar, with descriptions of twelve new genera, including three genera of ' fire millipedes' (Diplopoda)
Author
Wesener, Thomas
urn:lsid:zoobank.org:author:
Field Museum of Natural History, 1400 S. Lake Shore Drive, Chicago, IL 60605, U. S. A. & Zoologisches Forschungsmuseum Alexander Koenig, Museumsmeile Bonn, Adenauerallee 160, D- 53113 Bonn, Germany. & B 54 D 3623309
Author
Enghoff, Henrik
urn:lsid:zoobank.org:author:
Natural History Museum of Denmark, Universitetsparken 15, DK- 2100 Copenhagen, Denmark
Author
Sierwald, Petra
urn:lsid:zoobank.org:author:
Field Museum of Natural History, 1400 S. Lake Shore Drive, Chicago, IL 60605, U. S. A.
text
ZooKeys
2009
2009-09-04
19
19
1
128
journal article
10.3897/zookeys.19.221
e6ea8eea-7156-4785-8313-f4bd88dadad1
1313–2970
576503
C473F9F6-1AE7-4B3F-B17F-CA1C2709010C
Riotintobolus minutus
Wesener
,
sp. n.
urn:lsid:zoobank.org:act:
69657A54-E55E-4B78-BD6A-C14D398BC1F6
Material
examined:
1 ♂,
2 ♀
,
2 imm.
Holotype
:
1 ♂ (
22 mm
long),
FMMC
,
Province
Toliara
,
Sainte Luce, S
9, littoral forest on sand, in leaf litter (deep),
24°47’ S
,
47°10’ E
, leg.
T. Wesener
,
06.IV.2003
.
Paratypes
:
1 ♀
,
2 imm.
,
FMMC
, same data as holotype
;
1 ♀
,
FMMC
W031
B,
Sainte Luce, S
9, in leaf litter with roots,
24°46.769’ S
,
47°10.288’ E
,
12 m
, littoral forest on sand, leg.
Wesener
et al.,
01.VI.2007
.
Differential
diagnosis:
R. minutus
is the smallest known species of the genus and with a body length in mature males of only
22 mm
, one of the smallest
Spirobolida
species known from
Madagascar
. The pitch-black colour with a thick dorsal red stripe (
Fig. 27A
) helps to clearly identify this species. The gonopods of this species are in some aspects similar to those of
R. mandenensis
and
R. anomalus
sp. n.
Description
.
Measurements
: male
holotype
with 38 podous and 2 apodous rings,
22 mm
long,
2.3 mm
wide. Females with 39–41 podous and 0–2 apodous body rings,
23–26 mm
long,
2.9 mm
wide.
Coloration
pitch-black, dorsally with an extraordinary wide, red stripe (
Fig. 27A
). Openings of ozopores highlighted by a red spot (
Fig. 27B
). Posterior half of collum dorsally black (
Fig. 27E
). Head, lateral part of anal valves and subanal scale red, legs whitish brown (
Fig.40B
).
Eyes
with 12–14 partly fused ocelli arranged in three rows (
Fig. 27E
).
Antennae
protruding back to body ring 2 (
Fig. 27B
).
Legs
lacking tarsal pads. Male legs reach 0.7 times, female legs 0.5 times, body diameter (
Fig. 27D
).
Preanal process
sharp-edged, but not protruding above anal valves (
Fig. 27G
). Anal valves small, at midanterior part with a deep groove. Margin of lip towards groove sharp-edged (
Fig. 27G
).
Anterior gonopod
sternite apically elevated into a wide lobe with a triangular, wellrounded tip (
Fig. 27H
). Sternite tip almost as high as mesal coxite process, which is relatively slender but longer than sternite (
Fig. 27H
). Telopodite on posterior side apically with a large triangular, retrorse process (
Fig. 27J
), which is projecting above coxite and telopodite margins (
Fig. 27J
).
Posterior gonopods
telopodite laterally with two large, finger-shaped processes (
Fig. 27I
). Sperm canal discharging at more apical process. Apically, a large membrane present, extending into two lobes, apically twice as wide as basally (
Fig. 27K
).
Intraspecific
variation:
females with 39+2 and 41+0 body rings are known, indicating post-mature moults.
Distribution
and ecology
: this species was only collected in the isolated littoral rainforest on sand in Sainte Luce (
Fig. 25
). Only circa 200 ha of this forest will remain after a large scale mining project (
Vincelette et al. 2003
,
Bollen and Donati 2006
). Although officially protected, large scale wood removal and even slash-and-burn agriculture (
Fig. 24C
) is still ongoing in this forest (own observations in
March 2003
and
June 2007
). The surrounding pseudosteppe is regularly burned, further endangering this forest (
Fig. 24B
). However, further searches should be conducted in small remaining coastal forests north of Sainte Luce, where this species could also occur. All specimens were found deep in the soil under the wet leaf litter. Disturbed specimens often did not curl into a spiral, but remained motionless and stiff like a stick even when picked up. The giant pill-millipede species
Sphaeromimus splendidus
Wesener & Sierwald, 2005
and a still undescribed
Zoosphaerium
species are currently also only known from the littoral forest of Sainte Luce (
Wesener and Sierwald 2005
,
Wesener and Wägele 2008
).
Etymology
:
minutus
, adjective, refers to the small size of this species.