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A new species of the harvestmen Tithaeus calyptratus sp. n. (Epedanidae, Opiliones) from Hainan Island (China) is diagnosed, described and illustrated. A key to the two Chinese species of Tithaeus is provided.
Opiliones, Laniatores, Tithaeus, new species, Hainan Island, China
The family Epedanidae Sørensen, 1886 is represented by 188 species in 73 genera worldwide (
During a 2009 faunal survey of tropical Hainan Island, a few specimens of the Laniatores were collected. Among them, one species of Tithaeus was identified as new to science and is described in this paper.
Distribution of Tithaenus drac (black circles) and Tithaenus calyptratus (black triangle) in China
Two males and one female were collected from Hainan Island in south China (Fig. 1).
All type specimens are deposited in the Museum of the Hebei University
(MHBU), Baoding, China. Specimens were preserved in 75% ethanol,
examined and drawn using a Leica M165c stereomicroscope equipped with a
drawing apparatus. The genitalia were first placed in hot lactic acid
then moved to distilled water in order to expand them for observation (
Tithaeus laevigatus Thorell, 1891, by original designation.
see
| 1. | Carapace flat between its anterior margin and ocularium | Tithaenus drac (Lian, Zhu & Kury, 2008) |
| – | Carapace with a low hump situated between its anterior margin and ocularium | Tithaenus calyptratus sp. n. |
The ♂ holotype (MHBU) from China, Hainan Province, Mt. Diaoluo [18.67° N, 109.92° E], 5 June 2009, C. Zhang leg.
Paratypes: 1♀ (MHBU), together with the holotype; 1♂ (MHBU), China, Hainan Province, Mt. Qixianling [18.77° N, 109.68° E], 9 June 2009, C. Zhang leg.
The specific name is derived from the Greek word “calyptra” meaning a cap or hat, referring to the straw-hat type stylar lobe of the penis.
The new species is similar to Tithaenus kokutnus Suzuki, 1985, recorded from northern Thailand (Suzuki, 1985: fig. 4), but can be easily distinguished from it by the following characters: (1) Cheliceral proximal segment armed with a large tooth and two smaller ones, situated medially on the ventral surface and the second segment is covered with granules on its frontal surface; (2) Both the dorsal margin of pedipalpal femur and its ventral margin between two setiferous tubercles are finely serrated; (3) Penis with a straw-hat shaped stylar lobe.
Tithaenus calyptratus sp. n. has various morphological characters that support its placement in the genus Tithaeus:
viz., scutal region with five areas, eye tubercle without a median
spine, pedipalpus relatively short and thick, tarsi III and IV without
scopulae and distitarsus I with two tarsalia. Furthermore, the genital
characters (such as, the distal margin of the penial ventral plate
with a deep cleft, glans with simple membranous lobe and each lobe of
the ovipositor with two ventral and two dorsal setae) are also in
agreement with to the generic disagnosis of Tithaeus (as per
Male (holotype) habitus as in Figs 2–3. Coloration: body rusty yellow; carapace and ocularium with yellow-brown reticulation; lateral margins and opisthosomal areas of scutum, and free tergites banded with blackish brown; all coxae and genital plate yellowish, free sternites somewhat clouded; chelicerae and pedipalpus yellowish, with brown reticulate markings above; trochanters of legs yellowish; femora to tarsi slightly darker.
Body from above as a trapezoid, wider posteriorly than anteriorly. Ocularium ovoid, only with a few granules. A low hump, lower than the ocularium, is situated between it and the anterior margin of carapace. Abdominal scutum, as well as each free tergite, with a transverse row of very small tubercles, and with a longitudinal row of granules on their lateral margins. Anal plate with scattered tubercles. Each of the free sternites with a row of obsolete granules. Coxa I with irregular hair-tipped granules, coxae II-IV smooth. Dorsal surface of coxa IV with several rather coarse granules. Coxa III with a few humps along the frontal and rear margins. Tracheal stigma clearly visible.
Chelicera (Figs 7–9). Proximal segment disto-dorsally visibly swollen, armed with a large tooth and two smaller ones, situated medially on the ventral surface. Second segment with some hair-tipped tubercles on frontal surface. Fingers relatively short but stout; inner edges toothed as shown in Fig. 8.
Pedipalpus (Figs 4–5) short and robust, trochanter with a ventral setaceous tubercle. Femur ventrally with three strong and a small setiferous tubercles; on the prolateral distal side with a setiferous tubercle. Femur dorsally with a minutely serrate margin (Fig. 6). Such a margin also between the two ventral setiferous tubercles. Patella disto-medially with a setiferous tubercle. Tibia ventro-laterally with two small and two prominent setiferous tubercles, ventro-medially with two stout and two reduced setiferous tubercles. Tarsus ventrally with three setiferous tubercles on each side.
Legs slender and relatively elongated. All segments unarmed, smooth. Femora I-IV straight. Tarsi III-IV with simple double claws, no scopulae. Tarsal formula: 5/11/5/6. Distitarsi of first and second tarsi each with two tarsalia.
Penis (11–17). Shaft slender and long, distal portion swollen. Ventral plate with a wide median cleft, setae arranged as shown in Figs 11–13. Basal sac oval, well developed, immovable and sunken into truncus. Glans with complex structures, twisted when at rest. Stylar lobe shaped somewhat like a straw hat and surrounding the stylus.
Female. Similar to male in general appearance but with a slightly larger body.
Ovipositor as illustrated (Fig. 10). Each lobe with two ventral and two dorsal setae.
Measurements: Male holotype (female paratype). Body 4.13 (4.44) long, 2.91 (3.06) wide at the widest portion, scutum 3.42 (3.52) long; eye tubercle 0.40 (0.38) long, 0.93 (0.85) wide. Pedipalpus claw 0.50 (0.63) long. Penis 1.78 long. Measurements of left pedipalpus and right legs as in Table 1.
Tithaeus calyptratus sp. n. 2 Male body, lateral view 3 Same, dorsal view 4 Left pedipalpus, male, posterior view 5 Same, anterior view 6 Minute serrate margin on the ventral side of femur, left pedipalpus, male 7 Left chelicera male, anterior view 8 Distal segment of the left chelicera, male, above view 9 Left chelicera, male, posterior view 10 Ovipositor. Scale bars: 1mm (1–2); 0.5mm (3–4, 6–8); 0.25mm (5, 9).
Tithaeus calyptratus sp. n. 11 Entire penis 12 Penis tip, ventral view 13 Ditto, lateral view 14 Ditto, dorsal view 15 Expanded penis, ventral view 16 Ditto, lateral view 17 Ditto, dorsal view. Abbreviations: BS basal sac S stylus SL stylar lobe VP ventral plate. Scale bars: 0.5 mm (10); 0.25mm (11–16).
Table 1. Pedipalpus and leg measurements of the male holotype (female paratype).
| Trochanter | Femur | Patella | Tibia | Metatarsus | Tarsus | Total | |
|---|---|---|---|---|---|---|---|
| Pedipalpus | 0.35(0.38) | 1.00(0.90) | 0.70(0.68) | 0.75(0.68) | 1.00(0.90) | 3.80(3.54) | |
| Leg I | 0.56(0.51) | 2.70(2.35) | 0.77(0.71) | 2.19(1.89) | 3.21(2.86) | 1.68(1.73) | 11.11(10.05) |
| Leg II | 0.77(0.77) | 6.32(5.30) | 1.28(0.92) | 5.97(4.74) | 7.45(6.22) | 4.28(4.34) | 26.07(22.29) |
| Leg III | 0.77(0.61) | 3.57(2.91) | 1.02(1.02) | 2.40(2.09) | 3.88(3.57) | 2.04(2.04) | 13.68(12.24) |
| Leg IV | 0.71(0.71) | 5.00(4.18) | 1.12(1.02) | 3.26(2.86) | 5.61(5.20) | 2.81(2.55) | 18.51(16.52) |
Collected under fallen logs in the humid tropical forest.
Hainan Province, China.
The opilionids genus Tithaeus was established by Thorell in 1891 (type species: Tithaenus laevigatus Thorell, 1891). Later,
We wish to express our sincere gratitude to Dr. J. MacDermott for reading of the manuscript and for valuable comments on it. Thanks are due to two anonymous referees for valuable comments. This work was supported by the Ministry of Science and Technology of the People’s Republic of China (MOST Grant No. 2006FY110500).