Rhysida pazhuthara, Joshi & Karanth & Edgecombe, 2020

RHYSIDA PAZHUTHARA SP. NOV.

( FIG. 10)

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Rhysida longipes (CES07172, CES07180, CES07187), Rhysida cf. immarginata (CES07193 – immature individual), Joshi & Karanth, 2011.

Diagnosis: Eighteen antennal articles. Coxosternal tooth-plates with four teeth. Coxopleural process bearing two apical spines, one subapical and one lateral spine. Ultimate leg prefemoral spine formula VL3, VM2, DM3. Two tarsal spurs on legs 1–18 (16); tibial spur on legs 1–3, variably on legs 4, 5 or 7.

Type material

Holotype: CES091094 , Pandimatte , Shendurney Wildlife Sanctuary, Kollam district, Kerala, India (8.8732°N, 77.1666°E, 600 m a.s.l.), collected by Jahnavi Joshi, 24 August 2009. GoogleMaps

Paratypes: CES091080 Rockwood Estate, Shendurney Wildlife Sanctuary, Kollam district , Kerala ; CES091095 , Pandimatte, Shendurney Wildlife Sanctuary, Kollam district , Kerala ; CES07172 , Peppara Wildlife Sanctuary, Thiruvananthapuram district , Kerala . Other material: CES07180 , CES07187 , Ponmudi, Thiruvananthapuram district , Kerala ; CES091076 , Rockwood Estate, Shendurney Wildlife Sanctuary, Kollam district , Kerala ; CES091082 , Rosemla forest, Shendurney Wildlife Sanctuary, Kollam district , Kerala ; CES091092 , Pandimatte, Shendurney Wildlife Sanctuary, Kollam district , Kerala, India ; collected by Jahnavi Joshi in July 2008 –2009. Locality coordinates in the Supporting Information ( Table S1) .

Etymology: Centipedes are called ‘ pazhuthara ’ in Malayalam, the language spoken in the state of the type locality. It is a noun in apposition.

Description: Length ≤ 50 mm. Eighteen antennal articles, basal three articles glabrous dorsally and ventrally ( Fig. 10A). Cephalic plate and T1 smooth. Longitudinal median furrow on anterior 10% of cephalic plate. Cephalic plate and T1 red–brown, the following tergites brown–green, legs reddish yellow. Forcipular coxosternal tooth-plates wider than long, with four main teeth, separated into two groups, the outer two teeth and the inner two teeth; base of tooth-plates defined by oblique sutures diverging at 110° ( Fig. 10B); median suture on anterior part of forcipular coxosternum about as long as tooth-plates. Trochanteroprefemoral process bearing two apical teeth and one lateral tooth. Tergites with paramedian sutures complete from T7. Tergites fully marginate from TT8–10. Tergites mostly smooth, sometimes with lateral depressions ( Fig. 10G). Paramedian sutures 5–10% length of sternites ( Fig. 10F). Tergite of ultimate leg-bearing segment ~1.4 times wider than long, with parallel lateral margins ( Fig. 10C). Sternite of ultimate leg-bearing segment slightly shorter than wide, lateral margins mostly straight, moderately convergent posteriorly; posterior margins concave (130°) ( Fig. 10D). Coxopleuron 1.75 times the length of sternite of ultimate leg-bearing segment; coxopleural process with two apical spines, one subapical spine and one lateral spine. Pores dense, with pore-field reaching close to dorsal margin of coxopleuron; non-porose area on coxopleural process a long, narrow strip almost reaching to opposite posterior margin of sternite of ultimate leg-bearing segment ( Fig. 10D). Ultimate legs long, prefemur ≤ 5 mm, femur ≤ 4 mm, tibia ≤ 3.5 mm, tarsus 1 ≤ 2.75 mm and tarsus 2 ≤ 2 mm; prefemoral spine formula VL3, VM2, DM3 ( Figs 10C, H). Legs 1–18 usually with two tarsal spurs, in some specimens (CES091080) only legs 1–16; leg 19 with one tarsal spur, leg 20 lacking tarsal spur (except one individual, CES07187). Legs 1–3 (sometimes 4, 5 or 7) with a tibial spur. Leg 1 with femoral spur.

Distribution: This species is found in the southern parts of the Western Ghats in the Agasthyamalai and Shendurney Mountains, south of the Shencottah Gap. This overlaps with another species from the R. immarginata clade, R. aspinsosa . This region represents one of the longest contiguous patches of evergreen forests in the Western Ghats and is known for high species diversity, including other scolopendrid genera, such as Digitipes and Ethmostigmus .

Remarks: In species delimitation analyses, GMYC identifies two putative species within this taxon, which are distributed in the Agasthyamalai Hill Range and the Shendurney Wildlife Sanctuary, respectively ( Fig. 2), whereas mPTP identifies only one species. The genetic variation within COI (corrected p -distance) is 0.04, and among the two putative species it is 0.02 (Shendurney clade) and 0.04 (Agasthyamalai clade), respectively. There are no distinct morphological characters to distinguish between these two putative species, and given the contiguity of the forests in the Agasthyamalai and Shendurney hill ranges, we treat it is as one.

Morphologically, R. puzhuthara can be distinguished from the three other species in the R. longipes species complex by the presence of two tarsal spurs on legs 1–18 in most specimens, a distinctive spine formula on the ultimate leg prefemur and a relatively longer coxopleural process than, e.g. R. longipes .