Messapus Simon, 1898

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 : 16

Messapus Simon, 1898

Messapus Simon, 1898: 214 ; Reiskind, 1969: 166; Bosselaers & Jocqué, 2000a: 307

Type species: Messapus martini Simon, 1898 , by original designation.

Remarks: Messapus presently includes two species, M. martini and M. secundus . In the current study, Corinna natalis Pocock, 1898 is transferred to Messapus and M. secundus is transferred to Merenius . The generic diagnosis and description provided here take into account the morphology of Messapus martini and M. natalis comb. nov., as well as four undescribed species from southern Africa, to account for intrageneric variation.

Diagnosis: Messapus can be recognised from other Afrotropical Corinninae by the following combination of characters: 1) body colouration cryptic, resembling Lycosidae spiders; 2) carapace tegument smooth; 3) sternum without precoxal triangles; 4) male palpal cymbium without any modified setae; 4) female epigyne with large anterior sclerotised ridges including the copulatory openings; 5) copulatory openings anterior to or in the same plane as ST II (usually posterior in other genera); 6) anterior tibiae with only three pairs of ventral spines.

Description: Medium to large spiders, approximately 6.00– 16.25mm in length; carapace cream to yellowbrown, with mediolateral black markings from eye region to posterior slope of carapace ( Figs 1, 2, 4, 5 , 27–30 ); carapace surface smooth, with black feathery setae covering markings, white feathery setae between them and short straight setae laterally; several long curved setae on clypeus, eye region and along midline from PER to midpoint; carapace broad, slightly longer than wide, broadest at posterior of coxae II, eye region narrowed, posterior margin straight or very slightly concave; fovea distinct, short and broad; carapace with single pair of small round shallow granulate pits either side of midline, situated half the distance between PME and fovea. All eyes with black rings; AER procurved, AME larger than ALE; AME separated by slightly more than ½ their diameter, close to ALE; PER procurved, PLE slightly larger than PME; PME closer to PLE than to each other; MOQ width nearly equal anteriorly and posteriorly, slightly longer than wide. Chilum distinct, narrow and broad, single or bilateral; cheliceral surface finely granulate, with many long erect setae on anterior surface of paturon; cheliceral promargin with three teeth, retromargin with two to five teeth; shaggy seta absent; curved setae on cheliceral promargin finely plumose in both sexes; endites straight or slightly concave laterally, sometimes enlarged distally, with distinct serrula and dense maxillar hair tuft; labium nearly semi-circular, with round distal margin, wider than long. Pleural bars weakly sclerotised, isolated; sternum shield-shaped, as long as broad or slightly broader than long, slightly narrowed anteriorly; surface smooth, covered in long erect straight setae; precoxal triangles absent; intercoxal sclerites usually absent, when present between coxae I & II and II & III. Leg formula usually 4312, rarely 4132; legs strongly spined, all segments covered in feathery and short straight setae, feathery setae only dorsally and laterally on metatarsi and tarsi; retrocoxal window present, quite large and distinct; femora with several long erect ventral setae; all patellae with proximal and distal long fine dorsal setae, clearly shorter than patellar length; patellar indentation narrow, broad at proximal end; anterior tibiae with three pairs of ventral spines, anterior metatarsi with two pairs of ventral spines and pair of terminal spines; tibiae, metatarsi and tarsi with several dorsal trichobothria; metatarsi III much longer than metatarsi I and II; anterior metatarsi distally with weak scopula, posterior metatarsi with distal preening brush; tarsi weakly scopulate; paired tarsal claws short, situated lateral to very dense claw tufts. Abdomen oval, cream to dark grey, without markings or with mottled or chevron markings; several pairs of fine straight setae on anterior margin above pedicel; dorsal scutum usually absent; one or two pairs of weakly sclerotised dorsal sigilla sometimes present; dorsum densely covered in black and white or yellow feathery setae corresponding to markings, with scattered short straight setae; epigastric region weakly sclerotised, venter without post-epigastric sclerites and ventral sclerite, sometimes with two paired rows of indistinct tiny sclerites from epigastric furrow to spinnerets; inframamillary sclerite sometimes present, indistinct and weakly sclerotised; venter densely covered in feathery and long straight setae. Female epigyne strongly sclerotized with large epigynal ridges including copulatory openings, ridges usually in anterior half of epigyne, variable in shape ( Fig. 34 ; Haddad 2005: figs 1, 2); copulatory ducts short and broad, usually medially situated; ST II situated anterolaterally, with broad channel leading to posterior ST I; epigastric fold often heavily sclerotised. Male palp with single or multiple tibial apophyses ( Figs 37, 38 ; Haddad 2005: figs 4–6); cymbium oval, without modified setae, only with weak cymbial scopula in distal third; tegulum sometimes with a sclerotised distal conductor, variable in size and shape; embolus variable, short and sickle-shaped ( Fig. 37 ) or long and curved.

Figures

FIGURES 1 – 6. General habitus photographs of Messapus martini Simon, 1898 (1 – 3) and M. natalis (Pocock, 1898) (4 – 6) from Ndumo Game Reserve, South Africa: 1, 4. Females. 2, 5. Males. 3, 6. Retreats. Arrows indicate anchor lines of retreats.

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.