Rhitymna senckenbergi, Jäger, 2019

Jäger, Peter, 2019, Review of the huntsman spider genus Rhitymna Simon, 1897 (Araneae: Sparassidae), Zootaxa 4560 (3), pp. 441-462 : 458-460

Rhitymna senckenbergi spec. nov.

Figs 43–45 , 59–61

Type material. Holotype male ( PJ 3671 ): PHILIPPINES: Negros : Dumaguete, area of camp, lookout to about 3300 feet [ca. N 9°16'52.62", E 123° 9'43.75''], 1005 m elevation (AMNH). Paratype: 1 male ( PJ 3672 ), same data as holotype ( SMF) .

Etymology. The species is named in honour of Dr Johann Christian Senckenberg (1707 Frankfurt–1772 Frankfurt), name giving founder of the Senckenberg Research Institute, the latter still prospering after 200 years, for his visionary idea to build a museum from citizens for citizens; name in genitive case.

Diagnosis. Relatively small Sparassidae (body length of males: 8.0–9.5) with similar male copulatory organ as in R. ambae in having a similar distal embolic coil with a distally situated embolic apophysis and a simple RTA ( Figs 43–44 ), but can be distinguished by the absence of a prolateral embolic indentation (present in R. ambae), the embolic apophysis with bluntly rounded tip (slightly pointed in R. ambae) and the embolus tip retrolaterad (proximad in R. ambae).

Description. Male (holotype): PL 4.5, PW 4.6, AW 2.5, OL 5.0, OW 3.0. Eyes: AME 0.35, ALE 0.30, PME 0.25, PLE 0.31, AME–AME 0.22, AME–ALE 0.21, PME–PME 0.40, PME–PLE 0.52, AME–PME 0.29, ALE– PLE 0.24, clypeus height at AME 0.17, clypeus height at ALE 0.13. Cheliceral furrow with 3 promarginal and 4 retromarginal teeth, without denticles. Retromargin of chelicerae close to fang base with 4–5 bristles ( Fig. 45 ). Spination: Palp: 131, 002(1), 2121; legs: femur I–III 323, IV 321; patella I–III 101, IV 100; tibia I–II 2224, III–IV 2124; metatarsus I–II 2024, III 2025, IV 3 0 26. Leg formula: 2143. Measurements of palp and legs: Palp 6.9 (2.2, 0.9, 1.6, -, 2.2), I 28.8 (7.7, 2.5, 8.6, 8.0, 2.0), II 32.8 (8.9, 2.6, 9.9, 9.2, 2.2), III 18.4 (5.4, 2.0, 5.1, 4.3, 1.6), IV 24.6 (7.0, 2.0, 6.9, 6.8, 1.9). Metatarsi III–IV with ventro-distal spine within scopula (III) or field of stiff setae (IV).

Palp as in diagnosis ( Figs 43–44 ). RTA arising distally from tibia, straight and pointed. Embolus arising in a 5.30-o’clock-position from tegulum; embolic apophysis arising in 9-o’clock-position from embolus, extending up to 1-o’clock-position; distal part of embolus narrow, embolus tip situated in a 12-o’clock-position.

Colouration ( Figs 59–60 ). Yellowish- to reddish-brown. Prosoma dorsally dark yellowish-brown with fovea and striae marked. Chelicerae reddish-brown. Sternum, ventral coxae light yellowish-brown, without pattern; gnathocoxae and labium reddish-brown with distal part yellowish brown. Legs dark yellowish-brown with femora I–II sparsely dotted and metatarsi I–II proximally with dark annulation. Opisthosoma yellowish-brown, dorsally with dark dots especially in posterior half, medially with row of dark patches; ventrally without pattern.

Female. Unknown.

Variation. Male paratype (n=1) with PL 3.6, OL 4.4. Left chelicerae with distal anterior tooth replaced by two denticles. Legs I–II with tibiae dotted additionally to femora. Opisthosoma dorsally with tuning fork pattern.

Distribution. Known only from the type locality ( Fig. 61 ).

Figures

FIGURE 61. Records of Rhitymna species currently known (World Spider Catalog 2019 and works cited therein, records in this paper). Species with larger distribution ranges: stars—R. verruca, light triangles—R. plana, light squares—R. pinangensis. Inset: Sri Lanka.

FIGURES 40–45. Rhitymna spp., male copulatory organs (40–42 Rhitymna flores spec. nov., holotype from Flores, Indonesia; 43–45 Rhitymna senckenbergi spec. nov., holotype from Negros, Philippines). 40–41, 43–44 Left male palp (40, 43 ventral, 41, 44 retrolateral); 42 Embolus, distal part, ventral; 45 Left chelicerae, ventral, showing bristles close to fang base. aT—apical tooth of embolic apophysis, dA—dorsal angle of RTA, EA—embolic apophysis.

FIGURES 51–60. Rhitymna spp., habitus in ethanol. 51–52 Rhitymna deelemanae, female from Bali, Indonesia; 53–54 Rhitymna merianae spec. nov., holotype female from Bali, Indonesia; 55–58 Rhitymna flores spec. nov. from Flores, Indonesia (55–56 holotype male, 57–58 female paratype); 59–60 Rhitymna senckenbergi spec. nov., holotype male from Negros, Philippines.