Merenius secundus ( Strand, 1907 ) Strand, 1907

Haddad, Charles R., 2013, Taxonomic notes on the spider genus Messapus Simon, 1898 (Araneae, Corinnidae), with the description of the new genera Copuetta and Wasaka and the first cladistic analysis of Afrotropical Castianeirinae, Zootaxa 3688 (1), pp. 1-79 : 21-22

Merenius secundus ( Strand, 1907) comb. n.

Figs 31–33 , 39

Messapus secundus Strand, 1907: 543 (Ƥ Holotype: TANZANIA: Tanga Region: East Usambara, Amani [05°06'S, 38°38'E], leg. Vosseler, ZMB 28240 – examined).

Remarks: This species was the second to be described in the genus Messapus . According to Strand’s (1907) description, this species is very similar in somatic morphology to M. martini . Examination of the holotype female suggests strongly otherwise, and it is possible that Strand never saw the syntypes of M. martini . The holotype female of Messapus secundus is clearly a castianeirine spider and shares with spiders of the genus Merenius (e.g. M. alberti – Haddad & Louw 2012): 1) an elongate body, particularly the carapace and legs ( Fig. 31 ); 2) small eyes, with a very slightly recurved PER ( Fig. 32 ); 3) median eyes of both rows slightly larger than laterals; 4) a dorsal abdominal scutum extending to the middle of the abdomen; 5) distinctive castianeirine genitalia, with quite narrow ST 1 ( Figs 33 , 39 ), as for most other Merenius species. Based on this evidence and the redescription below, I here propose the transfer of the species to Merenius .

The holotype is considerably faded and the redescription pertains to the colouration of the specimen in its current form, as no freshly collected specimens were available for study. Live specimens most likely have dark brown to black colouration with cream or white markings on the body, as in other Merenius species.

Female (holotype, Amani, ZMB 28240). Measurements: CL 3.00, CW 1.98, AL 3.05, AW 2.00, TL 5.82, FL 0.23, SL 1.18, SW 1.10, AME–AME 0.10, AME–ALE 0.02, ALE–ALE 0.38, PME–PME 0.16, PME–PLE 0.10, PLE–PLE 0.62, PERW 0.83, MOQAW 0.38, MOQPW 0.41, MOQL 0.41.

Length of leg segments: I 1.83 + 0.70 + 1.65 + 1.48 + 1.08 = 6.74; II 1.73 + 0.69 + 1.40 + 1.34 + 0.96 = 6.12; III 1.60 + 0.70 + 1.25 + 1.40 + 0.80 = 5.75; IV 2.33 + 0.82 + 1.97 + 2.32 + 0.90 = 8.34.

General appearance as in Fig. 31 . Carapace orange-brown, MOQ slightly darker, with faint black striae radiating from fovea; surface finely granulate, with short white straight and feathery setae laterally and in eye region, considerably less dense along midline; several long curved setae on clypeus; carapace oval, broadest at coxae II, highest at ½ carapace, eye region narrow; fovea distinct, short and narrow; posterior margin very slightly concave. All eyes with black rings ( Fig. 32 ); AER procurved, medians slightly larger than laterals; AME separated by distance approximately ½ their diameter; AME separated from ALE by distance approximately ½ AME diameter; clypeus height slightly less than 1 1⁄5 AME diameter; PER slightly recurved, medians slightly larger than laterals; PME separated by distance slightly larger than their diameter; PME separated from PLE by distance equal to ½ PME diameter; CW: PERW = 2.39:1. Chelicerae orange-brown, with long, erect straight setae on anterior margin of paturon and pectinate curved setae on fang promargin; three teeth on promargin, distal tooth smallest, median tooth largest; median and distal teeth adjacent; retromargin with two teeth, distal tooth slightly smaller than proximal tooth. Endites yellow, cream in distal half, straight laterally, with distinct serrula and maxillar hair tuft; labium yellow, cream distally, trapezoidal with slightly concave distal margin; sternum shield-shaped, rebordered, yellow, with scattered long erect and short straight setae; intercoxal sclerites present between coxae I and II, II and III, absent between III and IV; precoxal triangles present; pleural bars isolated. Leg formula 4123; legs covered in black feathery and short straight setae, feathery setae sparse on metatarsi and tarsi; coxae pale yellow-brown; femora yellow-brown with black mottling, cream distally; patellae I and II cream, III and IV pale yellow-brown, all with black mottling; tibiae, metatarsi and tarsi I and II creamy-yellow with black mottling; tibiae and metatarsi III yellow with black mottling; tibiae and metatarsi IV pale yellow-brown with black mottling, cream distally; tarsi III and IV cream. Leg spination: femora: I pl 1 do 3, II pl 1 do 3, III pl 2 do 3 rl 1, IV pl 2 do 3 rl 1; patellae: all with single long fine distal seta; tibiae: I plv 3 rlv 2, II plv 3 rlv 2, III pl 2 do 1 rl 2-3 plv 2 rlv 1-2 vt 2, IV pl 2 do 1 rl 2 plv 2 rlv 1 vt 2; metatarsi: I plv 2 rlv 2, II plv 2 rlv 2, III pl 3 rl 3 plv 2 rlv 2 vt 3, IV pl 3 rl 3 plv 2 rlv 2 vt 3. Palpal spination: femora: pl 1 do 2; patellae: pl 2; tibiae: pl 1 plv 1; tarsi: pl 1 plv 2 rlv 1. Abdomen oval, with orangebrown dorsal scutum extending 3⁄5 abdomen length; two pairs of distinct sigilla present, first at ½ and second at ½ abdomen length; dorsum pale grey, with two white transverse markings, first anteriorly, extending laterally to behind epigastric furrow, second median marking broader, extending laterally and ventrally to middle of venter; dorsum covered in short straight and feathery setae, white feathery setae predominantly on markings; venter pale grey, cream at markings, covered in short straight setae; post-epigastric and ventral sclerites absent, inframamillary sclerite weakly sclerotised and indistinct. Epigyne large, copulatory openings small, surrounded by somewhat heart-shaped ridges; anterior ST II red-brown, round, narrowly connected to smaller yellow kidney-shaped posterior ST I; ST I clearly narrower than ST II ( Figs 33 , 39 ).

Male: Unknown.

Additional material examined: None.

Distribution: Known only from the type locality ( Fig. 40 ).

Biology: Unknown, but likely a leaf-litter dwelling spider, as in the case of other Merenius .

Figures

FIGURE 40. Distribution of Messapus martini Simon, 1898 (black circles), M. natalis (Pocock, 1898) (white circles) and Merenius secundus (Strand, 1907) (black star) in the Afrotropical Region.

FIGURES 27 – 33. Digital microscope photographs of Messapus martini Simon, 1898 from South Africa (27, 28), M. natalis (Pocock, 1898) from South Africa (29, 30) and Merenius secundus (Strand, 1907) from Tanzania (31 – 33): 27, 29, 31. Female, dorsal habitus. 28, 30. Male, dorsal habitus. 32. Cephalic region of female in dorsal view. 33. Female epigyne in ventral view. Scale bars: 27 – 31 = 2.0 mm, 32 = 0.1 mm, 33 = 0.25 mm.

FIGURES 34 – 39. Genitalic morphology of Messapus martini Simon, 1898 (34 – 38) and Merenius secundus (Strand, 1907) (39): 34, 39. Female epigyne, ventral view. 35. Same, dorsal view. 36. Male palp, prolateral view. 37. Same, ventral view. 38. Same, retrolateral view. Scale bars: 34 – 38 = 0.50 mm; 39 = 0.25 mm.