Piranthus bakau Maddison, sp. nov.

Maddison, Wayne P., Beattie, Imara, Marathe, Kiran, Ng, Paul Y. C., Kanesharatnam, Nilani, Benjamin, Suresh P. & Kunte, Krushnamegh, 2020, A phylogenetic and taxonomic review of baviine jumping spiders (Araneae, Salticidae, Baviini), ZooKeys 1004, pp. 27-97 : 27

Piranthus bakau Maddison, sp. nov. Figs 237-254

Type material.

Holotype male (specimen SWK12-0561, also known as d424), in UBCZ, from Malaysia: Sarawak: Bako Nat. Pk., Mangroves, beach forest, 1.722°N, 110.446°E, 0 m el. 8 March 2012 Maddison/Piascik/Ang/Lee WPM#12-003.

Etymology.

Referring to the type locality and to the holotype’s habitat, mangroves (Malay, Piranthus bakau = mangrove). Other names: In Maddison (2015b) and WPM’s lab notebooks the informal code for this species was “BKOMG”. This species is shown in Koh and Bay 2019 as the male of " Bavia " sp. D Strong-armed flat jumping spider.

Diagnosis.

This and the closely similar P. kohi differ from other known Piranthus in having white transverse banding on the body and legs, and the posterior legs striped with black and translucent white. P. bakau (Figs 237-254 ) differs from P. kohi (Figs 255-269 ) in having:

Second white transverse band on the dorsum of the abdomen (i.e., the first behind the basal band) complete or broken by only a slight space;

Sides of thorax lacking the three distinct narrow vertical lines seen in P. kohi (at most only a hint of two);

Carapace lateral to the PLE with a bare patch, lacking golden scales, extending from PME back to behind PLE, and lateral to the bare patch is a stripe of denser golden scales (Figs 245, 249);

First and second tibia bicoloured (black with white tip, arrow in Fig. 248);

Second femur bicoloured (white basally, black terminally, Fig. 249);

Black dorsal band on the fourth tibia incomplete, beginning mid-segment and reaching to the end (Figs 246, 247).

Carapace slightly flatter than in P. kohi.

Embolus (Fig. 237) notably longer than in P. kohi (Fig. 255), closely resembling that of P. planolancis (Nafin et al. 2020);

Epigyne with cavernous atria framed by a curved medial ridge, and relatively long copulatory ducts leading to a posterior tangle of tubes and spermathecae.

Juveniles have markings consistent with those of adults, and thus can be distinguished by the non-genitalic features above.

Description.

Male (based on holotype, SWK12-0561). Carapace length 2.7; abdomen length 3.0. Carapace with rugose surface, black on ocular area, dark brown otherwise, covered thinly with narrow golden to white scales except bare patch lateral to PLE, and on posterior slope. Clypeus narrow, dark, with a few white setae. Chelicerae small and vertical, dark, with a few pale setae. Palp (Figs 237-239 ) black except band of white scales terminally on femur, and cymbium, which is dark basally but then fades to white distally. Embolus long, arising on prolateral basal corner of bulb, looping first dorsally, then proximally, then distally. RTA a long blade. Endite margin rounded laterally. Legs relatively larger (compared to the body) than in many baviines, with first pair especially robust. First and second legs mostly dark and with terminal white annuli on the segments. First patella and tibia with ventral fringe of black setae. Third and fourth leg segments from patella to tarsus translucent white with black bands and stripes. Fourth tibia and patella with a pattern of short black and white bands. On the tibia, a black dorsal band begins not basally but half way to the end, and extends distally to the tip; basally, it is interrupted by white (Fig. 246 ; compare with Fig. 266 ). Abdomen with three narrow transverse white bands, a basal one, a second one behind that, and a third one behind that. Posterior to the third band the abdomen is a shiny black, but anterior it is dusted with golden setae.

Female (based on specimen AS19.2895). Carapace length 3.0; abdomen length 4.1. The specimen was collected and photographed as a small juvenile (Figs 251-254 ); as an adult its basic appearance is similar (Figs 249 , 250 ). Structure and markings of carapace and legs as in male. Abdomen with second transverse band oblique. Epigyne (Fig. 240 ) with medial septum dividing deep broad atria. What serves as the ECP is not obvious; there may be two, folds posterior to the atrium on each side, midway between the epigastric furrow and the posteriormost part of the medial septum. If so, it may be intermediate between P. decorus , with a medial ECP ( Caleb and Sanap 2017), and P. planolancis ( Malamel et al. 2019; Nafin et al. 2020), with a pair of distantly separated lateral ECPs (Nafin et al. 2020: fig. 17).

Male-female matching.

P. bakau and P. kohi are similar in general appearance, have overlapping geographical ranges, and have been collected to date with only adult males or adult females at a locality, not both. This leads to a question of which male matches which female. Unless there are additional closely similar species in the same areas, the inferred matching is well supported by the differences in markings, carapace shape, and lengths of embolus/copulatory ducts. The male of P. bakau and the female from Tengkorak inferred to match it share the diagnostic traits mentioned above. Doubt might arise because of one difference in their markings: the female has the second transverse abdominal band more oblique, with its two sides meeting at a central peak, while in the holotype the band is straight across. However, the second male, from Brunei, shows a peak (Fig. 242 ). A juvenile co-collected with the male holotype has the band peaked, and looks very much like the female when immature. The female is not designated as a paratype, however, because of the possibility it is a different but very closely related species, given the geographical distance between it and the holotype and their different habitats.

Natural history.

Holotype male collected from mangroves; female from Tengkorak collected by shaking vines and understory trees near waterfall.

Additional material examined.

Two juveniles with same data as holotype. Also, one male (specimen JK.11.04.17.0040), in LKCNHM, from Brunei: Tutong, Tasek Merimbun, Zone C2, Palau Luba, Sungai Melunchur, 4.5817°N, 114.6872°E, J. K. H. Koh 17 Apr. 2011. One female (specimen AS19.2895), in UBCZ, from Malaysia: Johor: Gunung Belemut Forest, Lata Tengkorak, 2.055°N, 103.543°E, 250 m elev. 16 June 2019 Maddison/Morehouse/et al. WPM#19-057.

Figures

Figures 237 - 254. Piranthus bakau sp. nov. 237 male left palp, prolateral view (holotype SWK 12 - 0561) 238 same, ventral view 239 same, retrolateral view 240 epigyne, ventral (specimen AS 19.2895) 241 vulva, dorsal 242 male JK. 11.04.17.0040 (photograph Joseph K. H. Koh) 243 - 245 male holotype (SWK 12 - 0561) 246 male holotype left fourth patella and tibia, dorsal view (right leg digitally flipped to appear as left) 247 - 254 female specimen AS 19.2895 247 left fourth patella and tibia, dorsal view 248 left first leg, prolateral view 249 adult female prosoma 250 adult female abdomen 251 - 254 same specimen while immature. Scale bars on genitalia 0.1 mm; on bodies and legs 1.0 mm.

Figures 255 - 269. Piranthus kohi sp. nov. 255 male left palp, prolateral view (holotype AS 19.1813) 256 same, ventral view 257 same, retrolateral view 258 epigyne, ventral (specimen JK. 12.04.11.0032) 259 Vulva, dorsal 260 - 265 holotype 266 male holotype left fourth patella and tibia, dorsal view 267 female left fourth patella and tibia, dorsal view (specimen JK. 19.07.19.0001) 268 female JK. 19.07.19.0001 269 Female JK. 12.04.11.0032 (photograph Joseph K. H. Koh). Scale bars: on genitalia 0.1 mm; on bodies and legs 1.0 mm.