The Goblin Spider Genus Khamisia and Its Relatives (Araneae, Oonopidae)

ABSTRACT The goblin spider genus Khamisia Saaristo and van Harten was based on a single female from Yemen characterized by large lateral extensions of the sternum that widely separate coxae II and III. Three new species, including the first known males of the genus, are described: K. hayer from the United Arab Emirates, K. atlit from Israel, and K. holmi from Kenya. All these species are united by having only two trichobothria on the palpal tibia; K. hayer has apparently been introduced into Cape Verde. Other specimens with a similarly modified sternum have been found in Africa, Madagascar, and the Virgin Islands, but differ in having the normal set of three trichobothria on the palpal tibia. The new genus Khamisina is established for three new species that also differ in having an abdominal color pattern, a punctate sternum, and uniquely shaped cheliceral setae: K. kivu from DR Congo, K. kilifi from Kenya, and K. ibadan from Nigeria. A second new genus, Khamiscar, is established for six new species from Madagascar in which the sternum is widened posteriorly and bears marginal radiating ridges, and the tarsal organs have only a single raised receptor: K. anta, K. maro, K. tola, K. kiri, K. baly, and K. ambi. A third new genus, Khamisoides, is established for three bizarre new species from the Virgin Islands (K. muchmorei from St. Croix; K. edwardsi and K. calabash from St. John) that differ in having only two eyes, fused posterior median spinnerets, and female genitalia with a pair of lateral receptacula and anteriorly directed apodemes.


INTRODUCTION
The goblin spider genus Khamisia was described by Saaristo and van Harten (2006: 135) for K. banisad, a species based on a single female specimen from Yemen notable for "the wide lateral outgrowths of the sternum between the second and third coxae" (see figs. 7, 50, 55, 63, 99, 101, 116-118, 125, 142). Since that time, specimens with a similarly modified sternum have been detected from other localities in the Middle East, Africa, Madagascar, and the Virgin Islands. Although relatively few specimens are available, detailed study of them suggests that there are four different genera that share this type of sternal modification, and that they may not constitute a single monophyletic group. As delimited below, Khamisia is known only from the Middle East and Kenya, whereas new genera are described for other species from tropical Africa (Khamisina), Madagascar (Khamiscar), and the Virgin Islands (Khamisoides).
All four genera belong to the subfamily Oonopinae, as the males have lost the heavily sclerotized sperm duct in their palps that are found in all spiders other than oonopines. Oonopines are also usually easy to recognize by their rather stereotyped tarsal organ morphology (Platnick et al., 2012a); their tarsal organs are serially dimorphic, with three raised receptors on the anterior legs but only two raised receptors on the posterior legs and pedipalps. Perhaps the most obvious modifications of this general pattern occur within the complex of genera including Stenoonops Simon, Longoonops Platnick and Dupérré, Australoonops Hewitt, Scaphioides Bryant, Hortoonops Platnick and Dupérré, and Reductoonops Platnick and Berniker. Members of those genera typically have the distalmost raised receptor on their tarsal organs bifid, with two lobes originating from a single base (e.g., Platnick andDupérré, 2010b: figs. 66-70, 2012: figs. 20-24;Platnick and Berniker, 2014a: figs. 25-29).
Members of Khamisia and the new genera described below resemble those of the Stenoonops complex in their general level of sclerotization (i.e., the carapace is lightly sclerotized, but the abdomen is not, save for small, weakly sclerotized epigastric and postepigastric scuta). However, their tarsal organ morphology is far from stereotyped.
In a female of the new species Khamisia hayer, for example, a tarsal organ from leg I shows only two raised receptors ( fig. 92), accompanied by what appears to be a pore receptor of the type found in the dysderoid families Dysderidae and Segestriidae, but not previously reported in an oonopid (see Platnick et al., 2012a: 12). The pore receptor also occurs on leg II, where there is also a tiny protrusion that might represent a remnant of the third raised receptor (fig. 93). In this specimen, the tarsal organs on the posterior legs and the pedipalps are narrowed, but appear to have the normal complement of two raised receptors (figs. 94-96).
Males of K. hayer, however, seem to have highly variable tarsal organs, sometimes even showing differences between the right and left legs of a single specimen. On leg I, there can be either three or four raised receptors, one of which may be unusually narrow and elongated (figs. 39-41), and there may also be a pore receptor ( fig. 41). On leg II, there can be either two or three raised receptors (figs. 42, 43). The tarsal organ on leg III is slightly narrowed, and can have either just the normal two raised receptors or a tiny third raised receptor as well (figs. 44, 45). On leg IV, the tarsal organ is narrower, but seems to have just the normal two raised receptors (figs. 46, 47). On the pedipalp, the tarsal organ is not narrowed, but again can have either two or three raised receptors (figs. 48, 49).
A female of the new African species Khamisina kivu has only two raised receptors on each of the legs and on the palps; those raised receptors are both elongated, and the distal one is bifid (figs. 229-233). On legs I and II, there does appear to be a pore receptor just proximal to If Khamisoides is more closely related to Reductoonops than to Khamiscar, the sternal extensions, loss of tarsal organ serial dimorphism, and reduction in raised tarsal organ receptor number must have occurred in parallel. On the other hand, if Khamisoides is more closely related to Khamiscar than to Reductoonops, the forklike endite setae, loss of the posterior eyes, and reduction in spinneret number are homoplasious. That would scarcely be surprising for the latter two characters, as there is certainly homoplasy in eye loss (because some members of Reductoonops retain six eyes), and fusion of the posterior median spinnerets need not be a necessary step in their loss.
If the first hypothesis is true, we would expect that Khamiscar species would lack the subdistal femoral constrictions, accompanied by a straight row of setae, that occur in Reductoonops (see Platnick and Berniker, 2014a: figs. 89, 90) as well as Stenoonops (see Platnick and Dupérré, 2010b: figs. 63, 375) and Scaphioides (see Platnick and Dupérré, 2012: figs. 289, 290), and that Khamisoides species would have those femoral features. Although there is sometimes a straight, subdistal setal row in Khamiscar ( fig. 466), it does not seem to be followed by a distinct constriction (figs. 463-469). However, the Virgin Islands Khamisoides species also lack those femoral features (figs. 470-477).
Interestingly, though, the femora of Khamisoides species do have dorsal rows of pore plates (figs. 470-477). Members of the three Old World genera with sternal extensions lack femoral pore plates, but such plates do occur in Reductoonops (see Platnick and Berniker, 2014a: figs. 39, 89, 90) as well as Longoonops (see Platnick and Dupérré, 2010b: figs. 592, 593). Khamisoides species also have platelets on the carapace (figs. 493, 537), a feature shared (among these genera) only with Reductoonops, but such platelets are common in fully soft-bodied oonopids, and may well be plesiomorphic for the family.
One of the reviewers of our manuscript, Darrell Ubick, noted that in all four genera treated here, the tarsal claws are accompanied by setae with greatly elongated bases, especially on the anterior legs (see figs. 35, 88, 176, 322, 355, 517). This is not a character that has been well studied in any oonopid groups, but setae with similarly elongated bases are found near the claws in at least some species of Stenoonops (see Platnick and Dupérré, 2010b: fig. 376) and Hortoonops (see Platnick and Dupérré, 2012: fig. 341).
The bizarre genitalia found in female Khamisoides (figs. 536, 580, 600) present some similarities to those of Khamisia (cf. figs. 59, 100) but could just as easily be derived from genitalic structures like those found in some Stenoonops species (cf. Platnick et al., 2012b: figs. 3I-K). Hence we do not regard the available evidence as decisive. The sternal extensions may or may not be a synapomorphy uniting all the taxa treated below; the Virgin Islands Khamisoides may actually be more closely related to the widespread Neotropical genus Reductoonops than to the Old World genera Khamisia, Khamisina, and/or Khamiscar, despite their similarly modified sterna. However, to date Khamisoides and Khamiscar are the only oonopine genera in which both the typical tarsal organ serial dimorphism and the typical tarsal organ raised receptor numbers appear to have been reduced, and that may signify a true trans-Atlantic relationship.
Our methods follow those of Platnick and Dupérré (2009a); only differences from the males (beyond the obvious lack of male endite modifications) are mentioned in the descriptions of females. Scans were taken from uncoated right male palps, and the images were flipped for consistency. All measurements are in mm; high-resolution versions of the presented images as well as many additional images, a sortable version of the geocoded locality data, and a distribution map for each species (with dots linked to the specimen data) will be available on the goblin spider Planetary Biodiversity Inventory (PBI) project's website (http://research.amnh.org/oonopidae). Users should note that the relatively small published images are merely avatars for the actual image files on the website, which can each be enlarged several times before pixelating. Diagnosis: The combined presence of large lateral extensions of the sternum that widely separate coxae II and III (figs. 7,50,55) and only two trichobothria on the palpal tibia (figs. 13, 71) separates members of this genus from all other known oonopids. Males have a distinctively short, wide embolus with deep basal ridges and a tiny, prolaterally directed prong (figs. 20, 111, 135); females have tripartite anterior genitalia, with one median and two lateral projections (figs. 59, 100, 123).
Description: Total length of males 1.1-1.3, of females 1.2-1.4. Cephalothorax and appendages yellow, without pattern, abdomen white except for pale yellow ventral scuta, with pattern ( fig. 191). Cephalothorax: Carapace elongated hexagonal in dorsal view (figs. 144, 201), pars cephalica flat in lateral view, anteriorly narrowed to 0.49 times its maximum width or less, anterolateral corners with slightly sclerotized triangular projections, pars thoracica with rounded posterolateral corners, without depressions or radiating rows of pits, posterolateral edge without pits, posterior margin not bulging below posterior rim, posterolateral surface without spikes, surface of elevated portion of pars cephalica punctate, sides punctate (figs. 146, 203), fovea absent, lateral margin straight, rebordered, without denticles; plumose setae near posterior margin of pars thoracica absent; marginal, nonmarginal pars cephalica, pars thoracica setae dark, needlelike, scattered. Clypeus margin slightly rebordered (figs. 145, 202), straight in front view, sloping forward in lateral view, high, ALE separated from edge of carapace by more than their radius, slight median projection present; setae dark, needlelike. Chilum undivided. Eyes six, well developed, ALE largest, oval, PME relatively long, narrow ( fig. 189), PLE oval; posterior eye row recurved from above, procurved from front; ALE separated by less than their radius, ALE-PLE separated by less than ALE radius, PME touching throughout most of their length, PLE-PME separated by less than PME radius. Sternum longer than wide, not fused to carapace, median concavity absent, with radial furrows between coxae I-II, II-III, III-IV, furrows smooth, radial furrow opposite coxae III absent, surface finely punctate (figs. 149, 206), without pits, microsculpture everywhere but middle, sickle-shaped structures absent, anterior margin with continuous transverse groove, posterior margin not extending posteriorly of coxae IV, anterior corner unmodified, lateral margin without infracoxal grooves, distance between coxae II and III greater than distance between coxae I and II or coxae III and IV (figs. 190,196), extensions of precoxal triangles absent, lateral margins with rounded extensions between coxae, without posterior hump; setae sparse, dark, needlelike, evenly scattered, originating from surface; hair tufts absent. Chelicerae straight, anterior face unmodified; without teeth on promargin or retromargin; fangs without toothlike projections, directed medially, elongated, without prominent basal process, tip with elongated venom gland opening (  Etymology: The specific name is a noun in apposition taken from the type locality. Diagnosis: Males can easily be recognized by the lateral horns on the endites (figs. 150-153), females by the narrow posterior margins of the internal genitalic sclerites (figs. 199, 200).
Description: Total length of males 0.8-1.0, of females 0.9-1.4. Cephalothorax and appendages yellow, without pattern, abdomen white except for pale yellow ventral scuta, without pattern. Cephalothorax: Carapace elongated hexagonal in dorsal view (figs. 290, 335), pars cephalica flat in lateral view, anteriorly narrowed to 0.49 times its maximum width or less, anterolateral corners with slightly sclerotized triangular projections, pars thoracica with rounded posterolateral corners, without depressions or radiating rows of pits, posterolateral edge without pits, posterior margin not bulging below posterior rim, posterolateral surface without spikes, surface of elevated portion of pars cephalica striated, sides finely reticulate (figs. 292, 337), fovea absent, lateral margin straight, rebordered, without denticles; plumose setae near posterior margin of pars thoracica absent; marginal setae absent, nonmarginal pars cephalica, pars thoracica setae dark, needlelike, scattered. Clypeus margin unmodified (figs. 291, 336), clypeus curved downward in front view, vertical in lateral view, low, ALE separated from edge of carapace by less than their radius, median projection absent; setae dark, needlelike. Chilum absent. Eyes six, well developed, ALE largest, oval, PME squared, PLE oval; posterior eye row recurved from above, procurved from front (figs. 293, 338); ALE separated by more than their diameter, ALE-PLE separated by less than ALE radius, PME touching throughout most of their length, PLE-PME separated by less than PME radius. Sternum longer than wide, not fused to carapace, median concavity absent, with radial furrows between coxae I-II, II-III, III-IV, furrows wrinkled, radial furrow opposite coxae III absent, surface with marginal ridges radiating, anastomosing, from opposite coxal bases (figs. 296, 341), without pits, microsculpture only at sides, sickle-shaped structures absent, anterior margin with continuous transverse groove, posterior margin not extending posteriorly of coxae IV, anterior corner unmodified, lateral margin without infracoxal grooves, distance between coxae II and III much greater than distance between coxae I and II or coxae III and IV (figs. 331, 368), extensions of precoxal triangles absent, lateral margins with rounded extensions between coxae, without posterior hump; setae sparse, dark, needlelike, densest laterally, originating from surface; hair tufts absent. Chelicerae straight, anterior face unmodified (figs. 294, 339); without teeth on  . 386)  Etymology: The specific name is a noun in apposition shortened from the type locality. Diagnosis: Males are most easily recognized by the shape of the palpal conductor in ventral view ( fig. 309): the tip is deeply bifid, with a V-shaped incision between the arms. Females have a long anterior receptaculum, with an expanded tip (figs. 348, 349, 371).
Etymology: The specific name is a noun in apposition shortened from the type locality. Diagnosis: Males are most easily recognized by the shape of the palpal conductor in ventral view ( fig. 386): the tip resembles that of K. anta in being deeply bifid, but the dorsal prong of the conductor tip is much longer and straighter. Females have a short, flat-tipped anterior receptaculum ( fig. 375). Distribution: Southern Madagascar.
Etymology: The specific name is a noun in apposition shortened from the type locality. Diagnosis: Males are most easily recognized by the shape of the palpal conductor in ventral view ( fig. 404): the base is long and narrow, and the tip is widely expanded, with a U-shaped terminal excavation between the prongs. Females have a long anterior receptaculum that is narrowed at about two-thirds its length ( fig. 417) Distribution: Southeastern Madagascar; despite the distance between the localities in Fianarantsoa and Toliara, no significant differences were detected (cf. figs. 406-412).
Etymology: The specific name is a noun in apposition shortened from the type locality. Diagnosis: Males are most easily recognized by the shape of the palpal conductor in ventral view ( fig. 428): the base is very long and narrow, and the tip is only slightly expanded and scooped.
Other Material Examined: None.
Distribution: West-central Madagascar. Khamisoides, new genus Type Species: Khamisoides edwardsi, new species. Etymology: The generic name refers to the similarities to Khamisia, and is masculine in gender.

Khamiscar baly, new species
Diagnosis: The combined presence of sternal extensions widely separating coxae II and III (figs. 478, 499) plus only two eyes (figs. 496, 538) easily separates members of this genus from all other oonopids. These species all seem to have only five spinnerets, with the posterior median pair fused into a single structure (figs. 513, 515); similarly fused spinnerets are known only in a few species of the distantly related genus Escaphiella Platnick and Dupérré (2009b). The female genitalia have unique, anteriorly directed apodemes that extend almost to the pedicel (figs. 531, 578, 598). The male palps have a distinctive prolateral lobe originating subdistally on the embolus (figs. 487, 552, 589); the lobes are not heavily sclerotized, and can vary in appearance even among specimens collected at the same time. Depending on the conditions under which the palps are prepared for imaging, the lobes can be collapsed against the base of the embolus, erect and flaglike, or even erect and somewhat inflated. Similarly, the embolus tips, which are somewhat more heavily sclerotized, can twist or curl during critical point drying, making comparing images difficult. Luckily, as in some other oonopid genera, such as Hexapopha Platnick and Berniker (2014b), the male endites are fully as species specific as are the palps.
Diagnosis: Males resemble those of K. calabash in having relatively short endite extensions, but have a narrower embolus base (figs. 584-591); females have large lateral receptacula forming a heart-shaped structure with a median anterior process (figs. 599, 600).