Stylocellus lornei, Clouse, Ronald M., 2012

Clouse, Ronald M., 2012, The lineages of Stylocellidae (Arachnida: Opiliones: Cyphophthalmi), Zootaxa 3595 (1), pp. 1-34 : 10-16

Stylocellus lornei , sp. nov.

( Figs. 6–17 ; Table 2 )

“Peninsula sp. 16” in: Clouse & Giribet 2010, Clouse et al. 2009.

“ Meghalaya sp. 103251” in: Giribet et al. 2012.

Material examined: Holotype, Male ( MHNG sample TH-07/02, MCZ DNA103251, MCZ Cyphophthalmi database SPM006161 ), southern Thailand, Ramong Province, Ko (= Island) Phayam (9°46’00”N, 98°24’54”E), 80–130 m alt., northern tip of island, in remnant of semi-evergreen rainforest, leg. P. Schwendinger. Paratypes, 7 males ( MHNG sample TH-07/02, MCZ DNA103251, SPM006159 [SEM], 006160–3, 0 0 6164 [dissected for genitalia], 006165–6) and 13 females ( MHNG sample TH-07/02, MCZ DNA103251, SPM006167–78, 6179 [dissected for genitalia]) from same collection as holotype . All types are deposited in MHNG except the one used for SEM ( SPM 006159), which is deposited in the MCZ Cyphophthalmi SEM collection.

Description: Holotype male. Body Size ( Fig. 7 , 8; Table 2 ): Body length (5.90 mm) about twice as long as the widest point (3.10 mm), between the second and third opisthosomal segments, and 2.33 times as wide at the width across the ozophores (2.65 mm).

Eyes, ozophores, and sculpturing ( Fig. 9 ): Eyes present directly anterior to ozophores, large, without cornea; cuticle over eye slightly raised, yellowish area visible underneath, surface texture like surrounding area. Ozophores lateral, raised above carapace edge (“ type 2” for Cyphophthalmi ); pointing anteriorly, not noticeably tapering, with an infolded opening. Body with microgranules over entire surface and tuberculate-granules and granules mostly on ventral prosomal complex, medial ventral opisthosoma, anal region, appendages, ozophores, medial dorsal soma, and tergites VIII and IX; granules missing on parts of chelicerae, male anal plate groove, and certain sulci; microgranulations missing on Rambla’s organ. Microtubules with pores present, especially on tarsi, sparser than tuberculate-granules. Granule shape more frequently round on soma, more oblong and even pointed distally on legs. Larger tuberculate-granules distributed unevenly on dorsal surface of first cheliceral article, trochanters, and femurs III and IV.

Dorsal scutum ( Figs. 7 , 8): Transverse prosomal-opisthosomal sulcus and opisthosomal sulci distinct, deep, lacking sculpturing; mid-dorsal, longitudinal opisthosomal sulcus absent; dorsal midline with granules on either side on the prosoma, lacking microgranules narrowly down the opisthosoma. Dorsal prosoma meeting cheliceral ridge with pronounced lip, then rising steeply; in lateral view prosoma angling gradually to highest point at first opisthosomal tergite, rounding evenly to the posterior. Widest point at sulcus between tergites II and IIII.

Ventral opisthosoma ( Figs. 7 , 8): Transverse sulci complete after sternite 3, deep and lacking sculpturing; first three sulci after tergite 3 sinusoidal, with medial region bending forward to same point as lateral ends. Sutures between tergites 6 and 7 and 7 and 8 gently curved back laterally. Spiracles large and C-shaped, their anterior edges slightly under swollen posterior edge of fourth coxae.

Ventral prosomal complex ( Fig. 10 ): Granules distinct and completely covering coxae I, lacking on distal ends of coxae II, distal fourth of coxae III, and distal half of coxae IV. Coxae IV meet along midline for distance slightly longer than gonostome opening; coxae III not meeting, distinct sternum in between proximal ends; coxae II meeting for about the same length as coxae IV, with distinct endites. Gonostome wider than long, somewhat rectangular; first opisthosomal sternite rounded, forming concave posterior edge to gonostome; lateral walls of gonostome formed by distinct, elevated posteroproximal processes of fourth coxae.

Anal region ( Fig. 10 ): Sternites 8 and 9 and tergite IX free; tergite IX wider than sternite 9. Tergite VIII with large pore along suture with tergite IX; tergite IX with smooth area medially alongside tergite VIII pore; anal plate with distinct medial longitudinal area lacking granulations, containing fine medial longitudinal groove. Anal plate groove with slightly irregular or wrinkled appearance, ending anteriorally in short array of smaller grooves, like a river delta. Anal plate and surrounding sternites and tergites otherwise with pronounced, large granulations.

Chelicerae ( Figs. 7 , 10 B, 11): Third article slightly less than one-third the length of second article, second article widest just proximal of mid-length ( Fig. 8). First article with distinct dorsal crest, ridge continuing laterally to pronounced, moderately sized, second ventral process. First ventral cheliceral process highly reduced to broad angle ( Fig. 11 ). Ventro-lateral edge of first article with distinct ridge running from second ventral process to distal end ( Fig. 12 , A–B). Second article with tightly packed, mostly dorsal, large granulations that stop abruptly before joint, remainder of the second article and third article smooth. Smooth area around granulations on laterodistal end of second article with slightly raised region, creating low ridge ( Fig. 11 , B; Fig. 12 , B–C).

Palps, legs, and tarsi ( Figs. 7 , 10 , 12—14 ; Table 2 ): Palps completely granulated, without process on trochanter ( Fig. 11 A). Legs I–IV completely granulated on all articles, except large granules missing in patches on dorsal and ventral trochanters and femurs I and IV ( Fig. 13 ). Tarsus I with fairly distinct solae that extends more than half tarsus length, distinguished by distinct angle in ventral edge of tarsus I and dense area of short hairs distally ( Fig. 14 ). Median dorsal surface of tarsi I and II with row of evenly spaced, curved hairs, more distal on tarsus I. Tarsus IV wider distal of adenostyle; adenostyle pointing vertically and located 55% of tarsus length from joint. Retrolateral surface with faintly visible Rambla’s organ about halfway between adenostyle and claw, covering oval region with width about half this distance ( Fig. 14 , D; Fig. 15 ). Surface of Rambla’s organ not noticeably raised or depressed, lacking microgranulations, with wrinkled cuticle and microtubules with pores and micropores; edge of Rambla’s organ indistinct, marked by the patchy loss of microgranulations ( Fig. 15 , A–D).

Spermatopositor ( Figs. 15–16 ): Microtrichial formula: 4, 10, 11+10 ( Fig. 16 ); dorsal microtrichia attached along angle, medial three on each side attached distinctly proximal to the lateral dorsal microtrichia; ventral microtrichia in close proximity and fairly level, medial two slightly more distal; apical microtrichia with two groups of four separated by a medial invagination, lateral two distinctly smaller and positioned along sides at widest point; all microtrichia with denticles on shafts, ventral surface with denticles. Gonopore complex ( Fig. 17 ) with broad lobus medialis, with small lobuli laterales; lacinia dorsalis extending distally to as far as lobus medialis and flanked by digiti that extend further.

Ovipositor ( Fig. 18 ): With 49 circular articles, ending in two apical lobes, each with several setae over whole surface, ending in an apical seta, and just subapical a sensitive process containing a dense set of slightly curved setae of moderate length (shorter than apical seta but longer than setae on the lobe); with distinct pigmented body on posterior half of the insides of each lobe.

Variation ( Fig. 8): Females slightly larger than males but with same body proportions; length of males measured 5.57–6.20 mm (n=5); measured females 6.30–6.50 mm (n=2). Smaller males have smaller appendages, females have larger appendages, thus all specimens, whether male or female, have the same general appearance and body proportions. Sculpturing, ventral opisthosomal sulci, and ozophore shape similar on males and females. Females lack anal gland pore but do retain bilobed tergite IX and lack of granules on the dorsomedial anal plate (as in Fangensis and Giribetia ). Some specimens have more pronounced eyes than the male holotype, with a more distinct cornea.

Distribution: Known only from the type locality, which is the northern end of Phayam Island, off the western coast of Peninsular Thailand.

Natural history: Stylocellus lornei sp. nov. lives in humid leaf litter, but its behavior and ecology are otherwise unknown.

Etymology: This species is named in honor of Lorne Michaels, a loyal and generous supporter of the American Museum of Natural History and a member of its Board of Trustees since 2003.

Figures

FIGURE 6. Lateral views of Stylocellidae genera: A, Fangensis spelaeus Schwendinger & Giribet, 2005; B, Giribetia insulana (Schwendinger & Giribet, 2005); C, Stylocellus lornei, sp. nov.; D, Meghalaya annandalei Giribet, Sharma & Bastawade, 2007; E, Miopsalis silhavyi (Rambla, 1991); F, Leptopsalis cf. beccarii (“ Sumatra sp. 4 d ” in previous analyses, MCZ DNA 101478, collected by P. Schwendinger). All images were scaled to the same total body length and aligned along the ozophore ends.

FIGURE 7. Stylocellus lornei, sp. nov., male paratype (SPM 006159): A, dorsal; B, ventral, C, lateral. Scale bar = 1.00 mm for all views.

FIGURE 9. Detailed views of Stylocellus lornei, sp. nov.: A, ventral prosoma; B, anterior lateral prosoma; C, spiracle and surrounding region; D, dorsal anterior. Scale bars = 0.50 mm for all panels.

FIGURE 10. Stylocellus lornei, sp. nov., male paratype (SPM 006159) anal region (A) and gonostome (B). Scale bar = 0.50 mm for both panels.

FIGURE 11. Stylocellus lornei, sp. nov., male paratype (SPM 006159) palp (A) and chelicer (B). Scale bar = 1.00 mm for both.

FIGURE 12. Stylocellus lornei, sp. nov., male paratype (SPM 006159) cheliceral details: A, ventral ridge on article I; B, lateral ridge on article II (upper arrow) and ventral ridge on article I (lower arrow); C, lateral ridge on article II.

FIGURE 13. Stylocellus lornei, sp. nov., male paratype (SPM 006159) legs: A, leg I; B, leg II; C, leg III; D, leg IV. Scale bar = 1.00 mm for all legs.

FIGURE 14. Stylocellus lornei, sp. nov., male paratype (SPM 006159) tarsi: A, tarsus I; B, tarsus II; C, tarsus III; D, tarsus IV. Scale bar = 1.00 mm for all tarsi.

FIGURE 15. Stylocellus lornei, sp. nov., male paratype (SPM 006159) detailed views of inner tarsus IV: A, region of interest is shiny patch on tarsus between claw and adenostyle; B, SEM image of region; C, detailed image of cuticle at border of region showing sculpturing change; D, highly magnified image of border region.

FIGURE 16. Spermatopositor of Stylocellus lornei, sp. nov., paratype SPM 006164: A, dorsal; B, lateral; C, ventral. Scale bar = 0.10 mm for left view only.

FIGURE 17. Spermatopositor of Stylocellus lornei, sp. nov., paratype SPM 006164 with dorsal microtrichia removed, showing gonopore complex: A, dorsal; B, lateral and slightly anterior view. LM = lobus medialis; LD = lacinia dorsalis; LL = lobulus lateralis; D = digitus; Scale bar = 0.10 mm for left view only.

FIGURE 18. Ovipositor of Stylocellus lornei, sp. nov., paratype SPM 006179. Scale bar = 0.10 mm for left panel only.

Tables

TABLE 2. Body and appendage measurements for Stylocellus lornei, sp. nov. Article abbreviations are as follows: Tr = trochanter, Fe = femur, Pa = patella, Ti = tibia, Mt = metatarsus, and Ta = tarsus. All measurements are expressed in mm.

holotype male [ratio] ( SPM 006161)
	length	Width (widest)	Width (ozophore)
body	5.90	3.10 [1.90]	2.65 [2.23]
	Tr	Fe	Pa	Ti	Mt	Ta
leg I	0.45 [1.00]	1.93 [4.81]	0.93 [2.31]	1.33 [3.79]	0.48 [1.58]	1.18 [3.13]
leg II	0.40 [1.00]	1.83 [4.29]	0.80 [1.78]	1.08 [3.31]	0.53 [1.75]	1.50 [5.00]
leg III	0.40 [1.00]	1.17 [2.65]	0.80 [1.67]	1.13 [2.96]	0.53 [1.54]	1.35 [2.70]
leg IV	0.58 [1.35]	2.22 [5.54]	0.98 [2.60]	1.38 [3.54]	0.55 [1.83]	1.73 [4.60]
	I (crest)	I (whole)	II	III
chelicer	1.16	–	2.15 [7.17]	0.65 [5.70]
	Tr	II	III	IV	Ta
palp	0.50	1.17 [4.67]	0.77 [3.53]	0.78 [4.28]	0.75 [4.75]
average male [ratio] (n = 5)
	length	Width (widest)	Width (ozophore)
body	5.99	3.07 [1.95]	2.65 [2.26]
	Tr	Fe	Pa	Ti	Mt	Ta
leg I	0.46 [1.10]	1.94 [4.77]	0.90 [1.95]	1.36 [3.83]	0.50 [1.66]	1.59 [4.18]
leg II	0.42 [0.98]	1.82 [4.50]	0.88 [1.69]	1.12 [3.13]	0.51 [1.74]	1.50 [5.06]
leg III	0.39 [1.03]	1.49 [3.62]	0.76 [1.70]	1.06 [2.78]	0.49 [1.61]	1.34 [3.88]
leg IV	0.55 [1.24]	2.11 [5.00]	0.91 [1.90]	1.36 [3.32]	0.49 [1.58]	1.69 [4.12]
	I (crest)	I (whole)	II	III
chelicer	1.13 [2.37]	1.71 [3.22]	2.16 [6.95]	0.69 [5.95]
	Tr	II	III	IV	Ta
palp	0.58 [2.58]	1.25 [4.58]	0.78 [3.02]	0.81 [4.23]	0.76 [3.87]
average female [ratio] (n = 2)
	length	Width (widest)	Width (ozophore)
body	6.40	3.23 [1.98]	2.70 [2.37]
	Tr	Fe	Pa	Ti	Mt	Ta
leg I	0.50 [1.04]	2.08 [4.96]	0.98 [2.34]	1.54 [4.06]	0.60 [1.69]	1.78 [4.69]
leg II	0.44 [1.00]	1.92 [4.57]	0.84 [1.91]	1.24 [3.28]	0.56 [1.70]	1.58 [4.99]
leg III	0.46 [1.00]	1.68 [3.66]	0.80 [1.74]	1.14 [2.89]	0.52 [1.44]	1.48 [3.74]
leg IV	0.56 [1.27]	2.28 [5.18]	0.96 [2.19]	1.38 [3.27]	0.52 [1.44]	1.86 [4.91]
	I (crest)	I (whole)	II	III
chelicer	1.17 [2.14]	–	2.27 [5.46]	0.7 [2.23]
palp	Tr	II	III	IV	Ta
	0.47 [1.99]	1.02 [4.30]	0.78 [4.08]	1.05 [7.50]	0.75 [5.21]