Melchisedec thevenot, Fannes, 2010

Fannes, Wouter, 2010, On Melchisedec, a new genus of the spider family Oonopidae (Araneae, Dysderoidea), American Museum Novitates 2010 (3702), pp. 1-28 : 13-21

Melchisedec thevenot , new species

Figures 2–41 , 43–55 , 57 , 60, 61 , 68–82

TYPES: Female holotype: Cameroon, Faro Game Reserve , 8°23ʹ09.5˝N 12°49ʹ59.7˝E, Apr. 27, 2007, wooded savannah, canopy fogging , R. Jocqué, K. Loosveldt, L. Baert, and M. Alderweireldt (PBI_ OON 9209 and MRAC 228.972 ). Paratype: Cameroon, Atlantic Mountains , 8°31ʹN 12°36ʹE, Apr. 24, 2007, litter among rocks, sieving , R. Jocqué, K. Loosveldt, L. Baert, and M. Alderweireldt (PBI_ OON 9208 and MRAC 221.480 ), 1 male . Paratype: Cameroon, Faro Game Reserve , 8°24ʹN 12°49ʹE, Apr. 25, 2007, gallery forest, sieving, same collectors (PBI_ OON 9210 and MRAC 221.441 ), 1 female .

ETYMOLOGY: The specific name is a noun in apposition and refers to Melchisédec Thévenot.

DIAGNOSIS: M. thevenot can be distinguished from M. birni by its more elevated pars cephalica (fig. 55), and by its carapace microsculpture, which consists of widely spaced ridges (figs. 6, 55).

MALE: TL 1.17, CL 0.53, CW 0.43, DSL 0.63, DSW 0.41, Ti I l 0.26, Ti I l/d 5.68. Habitus as in fig. 2. Carapace yellow. Pars cephalica elevated, reaching its highest point at the level of coxal insertion I, thereafter slowly declining (fig. 2). Carapace microsculpture consisting of dark, widely spaced ridges; ridges varying from short and straight to long, meandering, and repeatedly branching (figs. 2, 6, 55). Sternum pale yellow, without hair tufts, with a single pouch situated behind labium (fig. 9); no sclerotized triangles in front of anterolateral corners. Anterior face of paturon light grey. DS light grey, covering entire dorsum. ES and PES pale yellow, fused into single ventral scutum that covers full length of abdomen (fig. 27). Lateral apodemes rather short; a faint brown band connecting anterior ends of apodemes (fig. 27). Left leg II examined with SEM; morphology as in female (see below). Sperm pore small, circular, situated anterior of brown band (fig. 27). Right and left pedipalps symmetrical, not strongly sclerotized, proximal segments yellow, cymbium and bulb white, ECC brown with black tip. Palpal trochanter without ventral projection; femur more than two times as long as trochanter, attaching to patella basally; patella much shorter than femur, not enlarged (fig. 47); tibia approximately as long as patella, with three dorsal trichobothria (structure as on legs). Cymbium approximately as long as bulb (fig. 46); fused to bulb but with clearly defined seam between them; without distal patch of setae; tarsal organ situated on distal third of cymbium, structure as on legs. Bulb distally giving rise to long ECC (figs. 46, 48); bulbal apex not conical. ECC longer than bulb, inward curved (fig. 46), consisting of two elements, a dorsal embolus and a ventral conductor (fig. 48). Dorsal surface of embolus densely grooved (fig. 49). Embolus distally splitting into two embolar flanges (figs. 48–50); one flange is distally broadened, the other is somewhat ribbon shaped (broadened flange, bf, and ribbonlike flange, rf; figs. 51–54). Ventral surface of broadened flange showing fold (fig. 53). Sperm duct opening could not be located with certainty; possibly, the opening is situated at the fold (fig. 53). Conductor distally splitting into a dorsal and ventral branch (figs. 50–52, 54); dorsal branch flat and relatively broad (fig. 51); ventral branch slender, somewhat threadlike (fig. 52), not visible from dorsal point of view. Both branches have a crenulate retrolateral edge (figs. 50–52). Tip of ECC held in sternal pouch (fig. 9).

FEMALE: TL 1.30, CL 0.56, CW 0.46, DSL 0.74, DSW 0.57, Ti I l 0.28, Ti I l/d 4.78. Carapace as in male. Clypeus rebordered. Sternum pale orange. Infracoxal grooves without pores; a slit sensillum on posterior part of each groove. Anterior face of paturon pale yellow, with sparse setae (fig. 11). Cheliceral teeth absent. Cheliceral fang without basal process (fig. 11), tip unmodified; anterior edge of fang smooth, posterior edge serrated near base (fig. 12). A short, apically pointed seta arising from inner surface of each chelicera (figs. 11, 13). Promargin flanked by double row of setae (inner and outer row, fig. 14); each row with about six setae; most setae of inner row bent and with small, triangular teeth on shaft (fig. 14). Between double row and fang base a plumose hair (anterior plumose seta, aps; fig. 14). Posterior surface of paturon with two medially directed setae and three shorter spines (fig. 15). Fang base flanked posteriorly by two hairs (fig. 15), innermost one plumose (posterior plumose seta). At least 17 setae on labium: eight on distal margin, four situated subdistally, five situated medially (fig. 16). Labrum as in figure 17. Serrula with about 24 teeth in single row. Female palp without claw; structure of trichobothria as on legs (fig. 18). Soft portions of dorsum white, without color pattern. Two groups of small, rounded tubercles above pedicel tube (fig. 22). Outer surface of pedicel tube rugose and bearing setae (fig. 23), at least some setae have swollen bases (fig. 24); inner surface of tube closely ridged (fig. 25). DS grey, covering more than 3/4 of abdomen length and entire width. ES and PES pale orange. A slit sensillum anterior to each posterior spiracle (fig. 31). Dense patch of setae anterior to spinnerets absent. Colulus weakly sclerotized, bearing two setae; anterior lateral spinnerets with one spigot (fig. 32); posterior median spinnerets with one spigot (fig. 33); posterior lateral spinnerets with two spigots (fig. 34). The specimen examined by SEM showed a single scepterlike seta on one of the legs III; other leg III and both legs IV devoid of such setae. Distalmost, toward onychium sloping part of tarsus provided with proprioreceptor hair. Onychium bearing many setae, some spatulated. Tarsi without inferior claws. Superior claws hirsute and biseriate; lateral row consisting of 4–5 large teeth; median row situated close to claw tip, consisting of up to 10 small teeth, distalmost teeth often fused (fig. 45). Trichobothria: bothrium as in figure 36; no variation in bothrium structure among legs or among positions on a given leg. Tarsal organ pear shaped, receptor lobes exposed, inner surface of walls covered by ridges (fig. 44); no variation in structure among legs. Genitalia: no external copulatory structures (figs. 26, 29, 30); internally a large receptaculum, two uterine sclerites, and broad lateral apodemes (see Internal Female Genitalia and Respiratory System, below, for details).

OTHER MATERIAL EXAMINED: Cameroon: Faro Game Reserve , 8°24ʹ21.1ʹN 12°48ʹ20.4ʹE, Apr. 22, 2007, gallery forest, canopy fogging, R. Jocqué, K. Loosveldt, L. Baert, and M. Alderweireldt (PBI_ OON 9211 and MRAC 228.973 ), 1 female. Same locality, 8°24ʹ26.9˝N 12°48ʹ44.6ʹE, Apr. 24, 2007, gallery forest, canopy fogging, same collectors (PBI_ OON 9212 and MRAC 228.974 ), 1 female (used for SEM) . Guinea-Bissau: Buba , 11°30ʹN 15°05ʹW, June 9–11, 1989, A. van Harten (PBI_ OON 9859 and MRAC 228.968 ), 1 female. Same collection data (PBI_ OON 9860 and MRAC 228.969 ), 1 female . Ivory Coast: Odienné , Saméso, Kourou Kélé, 9°45ʹN 7°45ʹW, Mar. 3, 1980, pitfalls, J. Everts (PBI_ OON 9207 and MRAC 174.130 ), 1 female . Nigeria: Wudil , 11°48ʹ38˝N 8°50ʹ42˝E, Nov. 12, 1976, litter, leg. APB Deeleman, Museum Leiden ex coll. C.L. Deeleman-Reinhold; 2000-704 (PBI_ OON 33824), 1 female . Ethiopia: Awash N.P., compound of RAS Hotel , 9°05ʹ00˝N 40°00ʹ00˝E, Apr. 24, 1986, elev. 1000 m, under stone, A. Russell-Smith (PBI_ OON 33823 and MRAC 228.970 ), 1 female. Melka Werer, IAR station, 9°33ʹ00˝N 40°24ʹ00˝E, Feb. 17, 1986, elev. 750 m, litter of Acacia nilotica forest, A. Russell-Smith (PBI_ OON 33822 and MRAC 228.971 ), 8 females .

DISTRIBUTION: Known from Guinea-Bissau, Ivory Coast, Nigeria, Cameroon, and Ethiopia (fig. 1).

NOTE: The specimens from Guinea-Bissau, Ivory Coast, and Ethiopia are tentatively assigned to M. thevenot . These specimens, all females, strongly resemble the female holotype from Cameroon. However, given the large geographical distances involved (fig. 1), it is possible that some of them do not belong to M. thevenot . The specific status of these specimens will remain uncertain until males have been collected from the same localities.

Figures

FIGS. 2–4. Melchisedec thevenot, new species. 2. Male, habitus, lateral view. 3. Female, carapace, dorsal view. 4. Same, anterior view. Scale bars: 0.10 mm.

FIG. 5. Melchisedec thevenot, new species, female. Carapace, anterior view, showing distribution of setae on clypeus, around the eyes and on top of cara- pace. Other setae not depicted. Scale bar: 0.10 mm.

FIGS. 6–10. Melchisedec thevenot, new species. 6. Female, microsculpture on carapace. 7. Female, carapacesternum boundary, ventral view. Asterisks: coxal insertions. Arrow: elevated region. 8. Female, right half of sternum, ventral view, showing radial furrows. 9. Male, mouthparts and anterior part of sternum, ventral view. Arrow: pouch. 10. Female, prosoma, posterior view. Black arrowheads: curved ridges. White arrowheads: short rows of setae. Scale bars: 3 µm (6), 20 µm (7, 8), 80 µm (9, 10).

FIGS. 11–15. Melchisedec thevenot, new species, female, chelicerae. 11. Right chelicera, anterior view. Arrowhead: pointed seta. 12. Fang, posterior view. 13. Pointed setae (arrowheads). 14. Setae on promargin, anterior view, showing anterior plumose seta (aps), outer row (light grey) and inner row (dark grey). 15. Left chelicera, posterior view, showing long, medially directed setae (arrowheads) and spines (medially on paturon). Scale bars: 3 µm (13, 14), 5 µm (12), 20 µm (11, 15).

FIGS. 16–20. Melchisedec thevenot, new species, female. 16. Labium, posterior view. 17. Labrum, anterior view. 18. Left pedipalp, tibia, dorsal view. Arrowheads: trichobothria. 19. Same, patella and tibia, prolateral view. Arrowheads: pairs of robust setae. 20. Same, tarsus, prolateral view. Scale bars: 15 µm (16–18), 25 µm (19, 20).

FIGS. 21–25. Melchisedec thevenot, new species, female. 21. Epigastric scutum, anterior view. 22. Same, detail of region above pedicel tube. Arrowheads: tubercles. 23. Pedicel tube, lateral view. 24. Same, detail of setal bases. 25. Pedicel tube, oblique anterior view. Scale bars: 2.5 µm (24), 15 µm (23, 25), 30 µm (22), 60 µm (21).

FIGS. 26–27. Melchisedec thevenot, new species. 26. Female, abdomen, ventral view. Arrowheads indicate position of epigastric furrow. 27. Male, abdomen, ventral view. Scale bar: 0.10 mm.

FIGS. 28–34. Melchisedec thevenot, new species, female. 28. Epigastric scutum (es) and postepigastric scutum (pes), ventral view. 29. Postepigastric scutum, ventral view. 30. Epigastric region, ventral view. 31. Groove extending laterally from posterior spiracle (arrowheads). Arrow: spiracle. Note slit sense organ above spiracle. 32. Anterior lateral spinneret, posterior view. 33. Posterior median spinneret, posterior view. 34. Posterior lateral spinneret, posterior view. Scale bars: 4 µm (32–34), 15 µm (31), 40 µm (29, 30), 80 µm (28).

FIGS. 35–41. Melchisedec thevenot, new species. 35. Female, leg III, lateral view. 36. Female, trichobothrial base from metatarsus II, dorsal view. 37. Female, part of tarsus II, dorsal view. Arrowhead: short, densely barbed seta. Double arrowhead: needlelike seta. 38. Female, short, densely barbed seta, lateral view. 39. Male, coxa II, dorsal view. Arrowhead: group of three smooth setae. 40. Same, smooth seta, lateral view. 41. Same, base of smooth seta, dorsal view. Scale bars: 2 µm (36, 38, 40, 41), 10 µm (37, 39), 70 µm (35).

FIGS. 42–45. Melchisedec, new genus, females. 42. M. birni, new species, metatarsus (mt) and tarsus (ta), leg II, lateral view. Arrow: scepterlike setae. 43–45. M. thevenot, new species: 43. Scepterlike setae, leg II, prolateral view. 44. Tarsal organ from leg I, dorsal view. 45. Inner surface of claw, leg III. Arrow: fused distal teeth of median row. Scale bars: 2 µm (43–45), 5 µm (42).

FIGS. 46–48. Melchisedec thevenot, new species, male. 46. Right pedipalp, dorso-prolateral view. 47. Palpal patella, prolateral view. Arrowhead: lip. 48. Embolus-conductor complex, prolateral view. Abbreviations: C, conductor; E, embolus; ef, embolar flanges. Scale bars: 10 µm (47, 48), 30 µm (46).

FIGS. 49–50. Melchisedec thevenot, new species, male, embolus-conductor complex. 49. Dorsal view. 50. Ventral view. Abbreviations: C, conductor; E, embolus. Scale bars: 15 µm.

FIGS. 51–54. Melchisedec thevenot, new species, male, distal part of embolus-conductor complex. 51. Dorsal view. 52. Ventral view. Asterisk: ventral branch of conductor. 53. Detail of broadened flange, showing fold (arrowhead). 54. Anterior view. Abbreviations: bf, broadened flange; db, dorsal branch of conductor; rf, ribbonlike flange. Scale bars: 4 µm.

FIGS. 55–56. Carapace, lateral view. 55. Melchisedec thevenot, new species, male. 56. Melchisedec birni, new species, female. Scale bars: 80 µm.

FIGS. 57–59. Pedicellar sclerites. 57. Melchisedec thevenot, new species, female, ventral and dorsal pedicel sclerites, posterior view. Arrow: crest. Asterisk: dorsal sclerite. 58. Antoonops corbulo Fannes and Jocqué, female, dorsal pedicel sclerite and slender sclerites, dorsal view. Asterisk: dorsal sclerite. 59. Undescribed oonopid, female, ventral and dorsal pedicel sclerites and slender sclerites (arrowhead), lateral view. Asterisk: dorsal pedicel sclerite. Abbreviation: VS, ventral pedicel sclerite. Scale bars: 30 µm (57, 59), 90 µm (58).

FIGS. 60–67. Ventral pedicel sclerite. 60. Melchisedec thevenot, new species, female, ventral view. 61. Same, lateral view. Arrow: crest. 62. Antoonops corbulo Fannes and Jocqué, female, ventral view. 63. Same, lateral view. 64. Opopaea species, female, ventral view. 65. Same, lateral view. Arrowhead: ridge. 66. Undescribed species, female, ventral view. 67. Same, lateral view. Arrowhead: bilobed ridge. Scale bars: 10 µm.

FIGS. 68–70. Melchisedec thevenot, new species, female. 68. Abdomen, digested, dorsal view, showing internal genitalia and respiratory system. Receptaculum at centre of image. Abbreviations: ap, lateral apodeme; tt, tracheal trunk. 69. Receptaculum, dorsal view, showing anterior (a), middle (m) and posterior (p) parts. 70. Same, close-up of folds. Scale bars: 5 µm (70), 25 µm (69), 100 µm (68).

FIGS. 71–76. Melchisedec thevenot, new species, female. 71. Receptaculum and uterine sclerites, oblique anterior view. 72. Same, close-up of globular appendix. 73. Image of a single papilla. 74. Uterine sclerites, anterior view. Asterisk: process of anterior uterine sclerite. 75. Receptaculum and uterine sclerites, epigastric scutum removed, ventral view. 76. Same, close-up of uterine sclerites. Abbreviations: Fo, fold in uterus externus wall; GAp, globular appendix; Pa, papillae; PS, posterior uterine sclerite; Ri, ridge; TA, transverse apodeme of anterior uterine sclerite; UE, uterus externus, anterior wall. Scale bars: 2 µm (73), 10 µm (72, 74, 76), 30 µm (71, 75).

FIGS. 77–82. Melchisedec thevenot, new species, female. 77. Ventral part of receptaculum wall, excised, outer surface, showing globular appendix (GAp) and posterior uterine sclerite (PS). Arrowhead: slitlike opening. 78. Same, inner surface. Arrowheads: groove. 79. Detail of figure 77, showing distal part of slitlike opening. 80. Detail of figure 78. 81. Ridge between posterior spiracles, posterior view. Arrowheads: spiracles. 82. Same, detail of spongy tissue (asterisk). Abbreviation: tt, tracheal trunk. Scale bars: 5 µm (79, 80, 82), 10 µm (77), 20 µm (78, 81).