Modisimus tiburon, 2010

Huber, Bernhard A., Fischer, Nadine & Astrin, Jonas J., 2010, High level of endemism in Haiti’s last remaining forests: a revision of Modisimus (Araneae: Pholcidae) on Hispaniola, using morphology and molecules, Zoological Journal of the Linnean Society 158 (2), pp. 244-299 : 277-278

MODISIMUS TIBURON HUBER & FISCHER SP. NOV.

( Figs 51, 52 , 73 , 157–160 , 199 )

Type: Male holotype from ‘Case Dent’ (18°20.2 ′ N, 72°16.4 ′ W), La Visite N. P., Dept Sud-Est, Haiti ; 1880 m a.s.l., ravine in pine forest, 27 November 2007 (B.A. Huber), in ZFMK ( Haiti 2a) .

Etymology: The species name refers to the Tiburon Peninsula that encompasses Haiti’s southern coast; it is used as a noun in apposition.

Diagnosis: Medium-sized species with distinctive epigynum shape ( Figs 51, 52 , 160 ). Similar to M. leprete sp. nov., but distinguished by pattern of modified hairs on male chelicerae ( Fig. 158 ), larger epigynum, and relatively smaller and narrower pore plates ( Fig. 159 ). Also similar to M. enriquillo sp. nov. (palps and male chelicerae), but without apophyses on female sternum, and with different epigynum shape.

Male (holotype): Total length, 3.1; carapace width, 1.5. Leg 1: 31.6 (8.3 + 0.6 + 8.3 + 11.2 + 3.2); tibia 2, 5.8; tibia 3, 4.8; tibia 4, 6.1. Tibia 1 L/d: 55. Habitus similar to M. seguin sp. nov. (cf. Figs 27–29 ), carapace pale ochre-white, with wide brown lateral margins posteriorly, thoracic furrow also dark brown, dark median spot posteriorly; ocular area and clypeus brown, clypeus with pair of lateral dark-brown bands; sternum medially brown with some light spots, laterally whitish; legs ochre to greenish brown, tips of femora and tibiae whitish, darker rings subdistally on femora and tibiae; abdomen bluish-grey, densely covered with black spots dorsally (except heart area) and laterally, with some small white spots forming disrupted lines; genital area and area in front of spinnerets light brown, bluish spot in between. Ocular area strongly elevated; thoracic furrow distinct. PME–PME, 175 Mm; PME diameter, 135 Mm; PME–ALE, 175 Mm; AME–AME, 20 Mm; AME diameter, 35 Mm. Sternum wider than long (1.1/0.9), unmodified. Chelicerae with patch of ~20 short modified hairs on each side ( Fig. 158 ). Palps as in Figure 157 , coxa with retrolateral apophysis, femur with rounded proximal and pointed distal ventral apophyses; procursus without dorsal spine-like process, bulb with large, weakly curved apophysis, and complex membranous and sclerotized subdistal projections. Legs without spines; all femora with many short vertical hairs; curved hairs on all tibiae and metatarsi; retrolateral trichobothrium of tibia 1 at 12%; prolateral trichobothrium missing on tibia 1, present on all other tibiae. Tarsus 1 with ~30 pseudosegments.

Variation: Second male from type locality with a few weak spines distally on femur 2. Tibia 1 in two other males: 7.9 and 8.4.

Female: In general similar to male, sternum with pair of low and indistinct elevations on posterior margin. Tibia 1 in eight females: 6.1–7.0 (mean 6.4). Epigynum, composed of two oval plates, with two pairs of brushes/combs of stronger hairs ( Figs 51, 52 , 160 ); dorsal view as in Figures 73 and 159 .

Distribution: Known from two localities in Massif de la Selle, south-east Haiti ( Fig. 199 ). Near La Visite, this species was found in the thick layer of pine leaves overhanging an embankment (together with M. fuscus ); near Kenscoff, it was found in little cavities of rocks and soil in a ravine.

Material examined: Haiti: Dept Sud-Est, La Visite N. P., ‘ Case Dent’: 1♂, holotype above; same data, 1♂, 7♀ and one juvenile ( ZFMK, Haiti 2); same data, 3♂, 3♀ and three juveniles, in pure ethanol ( ZFMK, Haiti 67); La Visite N. P., broadleaf forest patch (‘ Berac’ , 18°19.7 ′ N, 72°17.7 ′ W), 1580 m a.s.l., 27 November 2007 (B.A. Huber), 1♀, in pure ethanol ( ZFMK, Haiti 68). Dept Ouest, near Kenscoff, at 18°27.5 ′ N, 72°17.4 ′ W, 1220 m a.s.l., in escarpment of ravine, 10 December 2007 (B.A. Huber), 1♂ and 4♀ ( ZFMK, Haiti 25); same data, 2♂, 1♀ and four juveniles, in pure ethanol ( ZFMK, Haiti 74) .

Figures

Figure 199. Known distributions of representatives of the southern paleoisland group.

Figures 38–62. Epigyna in ventral view. 38. M. femoratus (arrow points to frontal sclerite). 39. M. jima sp. nov. 40. M. angulatus sp. nov. 41. M. kiskeya sp. nov. 42. M. toma sp. nov. 43. M. vittatus (arrow points to distinctive posterior sclerite). 44. M. makandal sp. nov. 45. M. fuscus. 46. M. epepye sp. nov. 47. M. seguin sp. nov. 48. M. roumaini sp. nov. 49, 50. M. enriquillo sp. nov. from near Polo (49) and from south of Barahona (50) (arrows point to sternum apophyses). 51, 52. M. tiburon sp. nov. 53. M. leprete sp. nov. 54. M. macaya sp. nov. 55. M. bachata sp. nov. 56. M. cuadro sp. nov. 57. M. pelejil sp. nov. 58. M. mango sp. nov. 59. M. berac sp. nov. 60. M. palvet sp. nov. 61. M. miri sp. nov. 62. M. paraiso sp. nov.

Figures 63–82. Cleared and stained epigyna in dorsal view. 63. M. femoratus. 64. M. jima sp. nov. 65. M. toma sp. nov. 66. M. vittatus. 67. M. makandal sp. nov. 68. M. fuscus. 69. M. epepye sp. nov. 70. M. seguin sp. nov. 71. M. roumaini sp. nov. 72. M. enriquillo sp. nov. 73. M. tiburon sp. nov. 74. M. leprete sp. nov. 75. M. macaya sp. nov. 76. M. mariposas sp. nov. 77. M. bachata sp. nov. 78. M. cuadro sp. nov. 79. M. pelejil sp. nov. 80. M. mango sp. nov. 81. M. berac sp. nov. 82. M. miri sp. nov.

Figures 154–160. Diagnostic characters. 154–156. Modisimus enriquillo sp. nov. 154. Left palp, retrolateral view. 155. Male chelicerae, frontal view. 156. Cleared epigynum, dorsal view. 157–160. Modisimus tiburon sp. nov. 157. Left palp, retrolateral view. 158. Male chelicerae, frontal view. 159, 160. Cleared epigynum, dorsal (159) and ventral (160) views. Scale bars: 0.3 mm.

Figures 17–37. Habitus photos of males (except 33), showing typical and distinctive characters. 17, 18. M. femoratus. 19. M. jima sp. nov. 20. M. kiskeya sp. nov. 21, 22. M. angulatus sp. nov. 23, 24. M. epepye sp. nov. 25. M. mango sp. nov. 26. M. cienaga sp. nov. 27–29. M. seguin sp. nov. (arrows point to callus-like area). 30–34. M. vittatus. 35. M. palvet sp. nov. 36. M. berac sp. nov. 37. M. paraiso sp. nov.