A new species of the pill millipede genus Rhopalomeris Verhoeff, 1906 (Diplopoda, Glomerida, Glomeridae) from Myanmar, and notes on Rhopalomeris carnifex (Pocock, 1889)AuthorLikhitrakarn, Natdanai0000-0002-1306-317XProgram of Agriculture, Faculty of Agricultural Production, Maejo University, Chiang Mai 50290, ThailandAuthorGolovatch, Sergei I.0000-0001-7159-5484Institute of Ecology and Evolution, Russian Academy of Sciences, Leninsky pr. 33, Moscow 119071, RussiaAuthorSrisonchai, Ruttapon0000-0002-7142-0999Department of Biology, Faculty of Science, Khon Kaen University, Khon Kaen 40002, ThailandAuthorJirapatrasilp, Parin0000-0002-5591-6724Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, ThailandAuthorSapparojpattana, Pichsineehttps://orcid.org/0009-0005-9134-4910Animal Systematics and Molecular Ecology Laboratory, Department of Biology, Faculty of Science, Mahidol University, Bangkok 10400, ThailandAuthorJeratthitikul, Ekgachai0000-0002-3477-9548Animal Systematics and Molecular Ecology Laboratory, Department of Biology, Faculty of Science, Mahidol University, Bangkok 10400, ThailandAuthorPanha, Somsak0000-0002-4431-2458Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand & Academy of Science, The Royal Society of Thailand, Bangkok 10300, ThailandAuthorSutcharit, Chirasak0000-0001-7670-9540Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, ThailandtextZooKeys20242024-10-161215235257journal article10.3897/zookeys.1215.13091963D44DED-AB0D-4762-99A9-CC64B9EB8AE4Rhopalomeris nigroflava
Likhitrakarn
sp. nov.Figs 4
,
5
,
6Material examined.Holotype
:
Myanmar
–
Kayin State
•
♂
;
Linno Gu
(
Lateral small cave
);
16°50'52.9"N
,
097°36'37.7"E
;
25 Nov. 2015
;
F. Bréhier
leg.; MY 15-13 / 01 -
CUMZ
-GLO 093
.
Paratypes
:
Myanmar
–
Kayin State
•
7 ♂♂5 ♀♀
; same locality as holotype; MY 15-13 / 01 -
CUMZ
-GLO 093
) •
2 ♂♂2 ♀♀
; same locality as holotype;
MNHN
-MY 15
-13 / 01
.
Diagnosis.
Differs from other species of
Rhopalomeris
by the yellowish body with contrasting brown to blackish markings on terga 4–9 (Fig.
4 A – F
). Additionally, characterized by the smallest body sizes (
5.1–9.7 mm
in length and
2.6–4.7 mm
in width), coupled with the telopod syncoxital lobe being slightly lower than lateral syncoxite horns. For further details, see key below.
Rhopalomeris nigroflavasp. nov.
,
A – C
♂ holotype in
A
dorsal
B
lateral and
C
ventral views
D – F
♂ paratypes
D, E
dorsal and
F
ventral views. Scale bars: 0.2 mm.
Description.
Body length of unrolled
holotype
,
7.3 mm
, width
4.1 mm
. Body length of unrolled
paratypes
,
5.6–9.3 mm
(
♂
),
5.1–9.7 mm
(
♀
), width 3.1–4.8 (
♂
),
2.6–4.7 mm
(
♀
).
Color faded after nine years of preservation in alcohol (Fig.
4 A – F
): body yellowish to brown yellowish, with contrasting brown to blackish markings on terga 4–9 (Fig.
4 A, B, D, E
); lateral sides of terga 10, 11, and anal shield sometimes with a pair of small, faint, dark paramedian spots, these reaching neither caudal nor lateral edges (Fig.
4 A, B, D, E
); head, antennae and collum brown to dark brownish, only labrum, vertex and Tömösváry’s organ light brown; venter yellow brown to light yellowish; legs pale brown to brownish, with basal part of each podomere whitish (Fig.
4 C, F
).
Labrum sparsely setose (Figs
4 C, F
,
5 A
). Gnathochilarium with 2 + 2 palps subequal in length. Eyes blackish, with 6 (7) + 1 (
♂
) ommatidia (Fig.
5 A
), 6 – (9) + 1 ommatidia (
♀
), cornea convex and translucent. Antennomere 6 rather short, ~ 1.7–1.8 × as long as its height, dorsal margin only slightly curved (Figs
4 C
,
5 A, C
). Disk of antennomere 7 beset with 22–28 small sensory cones apically (Fig.
5 A, C
), 16–26 small sensory cones apically (
♀
). Tömösváry’s organ typical, horseshoe-shaped, oblong-oval, elongate, ~ 1.6–1.7 × as long as broad (Fig.
5 A, C
).
Rhopalomeris nigroflavasp. nov.
, ♂ holotype
A
head and anterior part of body, ventral view
B
thoracic shield, lateral view
C
left antenna, frontal view
D
leg 18, anterior view. Scale bars: 1 mm (
A, B
), 0.2 mm (
C
), 0.4 mm (
D
). Abbreviations: cxl coxal lobe, e eggs, hy hyposchism field, K caudomedial tubercle, sc schism, sn syncoxite notch, sx syncoxite.
Collum as usual, with two transverse striae (Fig.
5 A
). Thoracic shield with a small hyposchism field not projecting past rear tergal margin (Fig.
5 B
). 7–9 mostly superficial striae, only lower 4 or 5 lying above schism, one level to schism, remaining 3 or 4 below schism, 6 or 7 complete, crossing the dorsum (Fig.
5 B
). Terga 3–7 rather broadly rounded laterally, with two or three striae starting above lateral edge, sometimes middle stria fading away mid-dorsally (Fig.
5 B
). Following terga in front of pygidium concave medially at caudal edge and with one or two striae starting above lateral edge. Male pygidium faintly concave medially at caudal edge (Fig.
4 A, D, E
).
♂
legs 17 (Fig.
6 A – C
) particularly strongly reduced, with a rather small to medium-sized, often irregularly rounded coxal lobe and a 4 - segmented telopodite. Tarsus with 2–4 strong apical spines.
Rhopalomeris nigroflavasp. nov.
,
A, B
♂ paratypes
C – F
♂ holotype
A – C
leg 17, anterior view
D, E
telopod, posterior and anterior views, respectively
F, G
tip of syncoxital lobes (without scaling). Scale bars: 0.2 mm. Abbreviations: cx coxa, cxl coxal lobe, fe femur, fp femoral process, ft femoral trichostele, pf prefemur, pft prefemoral trichostele of telopod, sh syncoxital horn of telopod, sl syncoxital lobe of telopod, ta tarsus, ti tibia, tp tibial process.
♂
legs 18 (Fig.
5 D
) rather strongly reduced, with a rounded ogival syncoxital notch and a 4 - segmented telopodite. Femur with a small, setose, caudomedial tubercle near apex. Tarsus with a small apical spine.
Telopods (=
♂
legs 19) (Fig.
6 D – G
) with a small subtrapeziform, narrowly and roundly emarginated syncoxital lobe, this being flanked by two setose syncoxite horns, each of the latter higher than syncoxital lobe (Fig.
6 D, E
) and crowned by a subapical setoid filament (Fig.
6 F, G
). Telopodite 4 - segmented. Prefemur (Fig.
6 E
) rectangular, with a conspicuous, elongated, robust, tuberculiform, distomesal prefemoral trichostele; in anterior view, with a rounded tip, extending to about half or distal boundary of femur (Fig.
6 E
). Femur (Fig.
6 D, E
) rectangular, with a prominent, stout, relatively short femoral trichostele in anterior view, extending apically to ~ 1 / 2–3 / 4 prefemoral trichostele, in posterior view with a rounded, subtriangular femoral process, this being curved anterolaterally and gently tapering into an acuminate rounded tip distally (Fig.
6 D, E
). Tibia stout, gently tapering distally and curved apicobasally towards femoral process, with a rather large, distolateral tibial process strongly curved mesad (Fig.
6 D, E
), with a strong anterior seta in anterior view (Fig.
6 D
) near base of tibial process. Tarsus the smallest, subcylindrical, moderately sigmoid, strongly curved, narrowly rounded apically, with a robust and small terminal seta (Fig.
6 D, E
).
Remarks.
It seems noteworthy that a female and
two male
(Fig.
5 C
) specimens were found guarding a clutch of eggs near its head, beneath the thoracic shield. This behavior deviates from the typical reproductive strategy so far known in the entire order
Glomerida
, where females deposit eggs in specialized clay chambers and leave them to develop independently (
Thomas et al. 1970
;
Janssen 2013
). This is the first instance of paternal brood care observed in
Glomerida
. Therefore, this newly discovered species presents fascinating traits worthy of a dedicated future study.
Etymology.
The specific epithet
nigroflava
is derived from the Latin
niger
meaning black and
flavus
meaning yellow, in reference to the dark bands on a yellowish dorsum, adjective in feminine gender.