Research Article |
Corresponding author: Shuqiang Li ( lisq@ioz.ac.cn ) Academic editor: Galina N. Azarkina
© 2020 Ambata D. Oketch, Sergei Zonstein, Esther N. Kioko, Shuqiang Li.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Oketch AD, Zonstein S, Kioko EN, Li S (2020) Description of a new genus and three new species of the family Palpimanidae (Arachnida, Araneae) from Kenya. African Invertebrates 61(2): 93-106. https://doi.org/10.3897/afrinvertebr.61.54004
|
A new genus and three new species of the spider family Palpimanidae Thorell, 1870 from Kenya are described. Sceliscelis Oketch & Li, gen. nov. is close to Sarascelis Simon, 1887 and Scelidocteus Simon, 1907 but differs in the structure of the male palp. The new species reported are Sceliscelis marshi Oketch & Li, sp. nov., Scelidocteus taitave Oketch & Li, sp. nov., and Hybosida machondogo Oketch & Li, sp. nov. Sceliscelis marshi sp. nov. is described from males and females collected from Tsavo in south Kenya. Scelidocteus taitave sp. nov. can be distinguished from other congeners, as well as from the morphologically similar Scelidomachus socotranus Pocock, 1899, by the shape of the palpal “conductor”. Hybosida machondogo sp. nov. differs from other six-eyed Hybosida spp. by possessing rudimentary posterior median eyes.
Afrotropical, Chediminae, genus, species, taxonomy
Palpimanidae Thorell, 1870 is a small family of araneophagous spiders recognized by the coriaceous carapace, haplogyne genitalia, two spinnerets and especially by the first pair of legs with dorsally enlarged femora and well-developed prolateral scopula on the tibia, metatarsus and tarsus. A total of 152 species in 18 genera are distributed in tropical and subtropical zones worldwide, absent only in the Nearctic and Australia (
More than 800 spider species and subspecies belonging to 55 families are known from Kenya (
All spiders were preserved in 95% alcohol. Specimens were examined and measured using a LEICA M205C stereomicroscope. Images were captured using an Olympus C7070 wide zoom digital camera mounted on an Olympus SZX12 dissecting microscope or on an Olympus BX51 compound microscope. Male and female copulatory organs were dissected, and the specimens were then photographed on glass slides fitted with cotton wool to ensure a white, uniform background. Digital images were prepared using Helicon Focus version 6.0 image stacking software and then edited using Adobe Photoshop CS4 version 11.0.0.
Leg lengths and palp segments are given in the following sequence: total (femur, patella, tibia, metatarsus, tarsus). Internal structures of the genitalia were illustrated after being cleared in lactic acid, then placed in alcohol for a few minutes. Measurements are given in millimeters. Holotypes and paratypes are deposited in the National Museums of Kenya (
Abbreviations. AER – anterior eye row, ALE – anterior lateral eyes, am – accompanying membrane, AME – anterior median eyes, co – “conductor”, ch – receptive chamber, cy – cymbium, ds – dorsal portion of scutum, em – embolus, Ft – fine threads, Gr – grape-shaped glands, hle – hook-like extension, MOQ – median ocular quadrangle, pe – palm-like embolic extension, PER – posterior eye row, PLE – posterior lateral eyes, PME – posterior median eyes, Re – rigid extensions of posterior wall of epigastric fold, rt – retrolateral thorn, sco – scopula, Sr – sac-like receptacle.
Subfamily Chediminae Simon, 1893
Sceliscelis marshi sp. nov.
This genus possesses some characteristics that are also found in Sarascelis Simon, 1887 and Scelidocteus Simon, 1887, such as the dentate segments of leg I (which include at least the dorsal surface of the coxa and basal part of the femur) and the spiral embolus. The name is a combination of “Sceli” from Scelidocteus and “Scelis” from Sarascelis. The gender is feminine.
The new genus closely resembles Sarascelis in general appearance by having much larger AMEs (Fig.
Medium-sized. Carapace dome shaped, coarsely granulated and hairless, medially elevated, fovea longitudinal, open posteriorly (elongated Ω-shape). Eight eyes, MOQ trapezoidal; AME largest, about 3 times as large as PME; ALE, PLE and PME subequal to each other. AER straight. Labium triangular, notched, longer than wide but broader at base. Chelicerae directed ventrally, 2 times longer than clypeus, granulate. Endites trapezoidal, about 1.5 times longer than wide. Abdomen clay yellow, oval and covered with short, gray setae in both sexes. Femur of male palp slender, longer than wide, patella shorter than “conductor”. Cymbium with setae, pointed at tip and indented (prolateral view). Embolus spiral, with accompanying membrane and a silvery, palm-like embolic extension. “Conductor” sword-shaped, longer than wide, slightly longer than embolus. Endogyne wavy anteriorly, forming a rigid epigastric wall.
This genus currently includes only the type species.
Holotype ♂, Kenya, Taita Taveta County, near Mtito Andei, Tsavo West National Park, Rhino Sanctuary, 38°19.96'E, 03°1.230'S, 730 m, 28.VII.2016, sifting leaf litter, Grace Kioko leg. Paratype 1♀, same data as holotype.
This species is named after Mr. Brian Marsh OBE, the founder of the Marsh Christian Trust Awards for Ecologists in Africa, which the third author was awarded in 2019; noun (name) in genitive case.
See diagnosis of the genus.
Male. Habitus as in Fig.
Sceliscelis marshi sp. nov., male holotype A–C habitus in dorsal, ventral and lateral aspects D–F palp: D prolateral E ventral and F retrolateral aspects. Abbreviations: am–accompanying membrane, co – “conductor,” cy – cymbium, ds – dorsal portion of scutum, em – embolus, hle – hook-like extension, pe – palm-like embolic extension. Scale bars: 1 mm (A–C), 0.1 mm (D–F).
Female. Cephalothorax in dorsal and ventral aspects as in Fig.
Femur | Patella | Tibia | Metatarsus | Tarsus | Total | |
---|---|---|---|---|---|---|
Palp | 0.91 (0.85) | 0.15 (0.13) | 0.35 (0.37) | – | 0.50 (0.42) | 1.91 (1.77) |
I | 0.85 (0.94) | 0.94 (0.80) | 0.70 (0.75) | 0.30 (0.25) | 0.31 (0.22) | 3.10 (2.96) |
II | 1.00 (0.69) | 0.50 (0.50) | 0.65 (0.63) | 0.50 (0.38) | 0.32 (0.31) | 2.97 (2.51) |
III | 0.63 (0.52) | 0.50 (0.41) | 0.50 (0.50) | 0.35 (0.47) | 0.24 (0.22) | 2.22 (2.51) |
IV | 1.25 (0.78) | 0.30 (0.50) | 0.88 (0.81) | 0.75 (0.56) | 0.25 (0.25) | 3.31 (2.90) |
Sceliscelis marshi sp. nov., female paratype. Cephalothorax A dorsal and B ventral aspects C, D endogyne, ventral and dorsal aspects, respectively. Abbreviations: Bl – book lung operculum, ch – receptive chamber, ds – dorsal portion of scutum, Gr – grape-shaped glands, Ls – lateral sclerite, Re – rigid extension of posterior wall of epigastric fold, sco – scopula, Sr – sac like receptacle. Scale bars: 1 mm (A, B), 0.2 mm (C, D).
This species is currently known only from the type locality.
Scelidocteus pachypus Simon, 1907, by subsequent designation.
All seven described species of this genus are endemic to Africa, the majority of them in West and Central African countries. Scelidocteus taitave sp. nov. is the first species to be recorded from Kenya and East Africa (
Holotype ♂, Kenya, Taita Taveta County, Taita Hills, Mbololo Forest, 30°26.85'E, 03°20.36'S, 1631 m, 2.VIII.2018, Ambata Oketch leg. Paratypes 1 ♂, 2 ♀, same data as holotype.
The specific name is a combination of Taita and Taveta, the county from which the specimens were collected; noun in apposition.
Males of this species differ from those of other members of Scelidocteus by the uniquely spiral-shaped embolus (Fig.
Scelidocteus taitave sp. nov., male holotype A, B dorsal and ventral habitus respectively C–E palp: C prolateral D ventral E retrolateral aspects. Abbreviations: am – accompanying membrane, cl – claw like extension, co – “conductor”, em – embolus, cy – cymbium rt – retrolateral thorns, sco scopula. Scale bars: 1mm (A, B), 0.2mm (C–E).
Male. Fig.
Femur | Patella | Tibia | Metatarsus | Tarsus | Total | |
---|---|---|---|---|---|---|
Palp | 0.66 (0.61) | 0.24 (0.21) | 0.38 (0.37) | – | 0.35 (0.39) | 1.63 (1.58) |
I | 1.38 (1.41) | 0.65 (0.81) | 1.00 (1.09) | 0.38 (0.38) | 0.40 (0.38) | 3.81 (4.07) |
II | 0.88 (0.85) | 0.69 (0.70) | 0.80 (0.80) | 0.50 (0.41) | 0.40 (0.28) | 3.27 (3.04) |
III | 0.90 (1.00) | 0.60 (0.75) | 0.60 (0.69) | 0.60 (0.74) | 0.40 (0.44) | 3.10 (3.62) |
IV | 0.90 (1.38) | 0.80 (0.80) | 0.90 (1.00) | 0.84 (1.00) | 0.40 (0.50) | 3.84 (4.68) |
Female. General appearance as in Fig.
Scelidocteus taitave sp. nov., female paratype A, B habitus C endogyne ventral D same, ventral E same, enlarged F leg I. Abbreviations: ch – receptive chamber, Ft – fine threads, Gr – grape-shaped glands, Re – rigid extensions of posterior wall of epigastric fold, Sr – sac like receptacle. Scale bars: 1mm (A, B).
This species is currently known only from the type locality.
Hybosida lucida Simon, 1898, by monotypy.
All four described species of this genus have six eyes, PMEs are absent (
Holotype ♂, Kenya, Nyeri County, Naro Moru Town, Mount Kenya National Park, Naro Moru Gate, Forest Valley, 37°10.16'E, 00°10.61'S, 2488 m, 25.VII.2017, Grace Kioko leg.
2 ♂ subadults, Kenya, Uasin Gishu County, Endebbes Town, Mount Elgon National Park, Mutamaiyo Camp Site, 34°43.07'E, 01°4.02'N, 2824 m, 7.VII.2017, Grace Kioko leg.
The specific name is a combination of two Swahili words “macho”, meaning eyes, and “ndogo’’, meaning small, referring to the indiscernible posterior median eyes of this species.
Like other members of Chediminae, Hybosida machondogo sp. nov. possess contiguous lateral eyes and accessory structures of the male palp (see
Male. Fig.
Femur | Patella | Tibia | Metatarsus | Tarsus | Total | |
Palp | 0.60 | 0.24 | 0.38 | – | 0.29 | 1.51 |
I | 0.80 | 0.55 | 0.45 | 0.25 | 0.30 | 2.35 |
II | 0.60 | 0.30 | 0.45 | 0.35 | 0.35 | 2.05 |
III | 0.55 | 0.30 | 0.45 | 0.40 | 0.30 | 2.00 |
IV | 0.60 | 0.30 | 0.65 | 0.50 | 0.35 | 2.40 |
Hybosida machondogo sp. nov. male holotype A–C habitus: A dorsal B ventral and C prolateral aspects) D–F palp: D prolateral E ventral F retrolateral. Scale bars: 1 mm (A–C), 0.2 mm (D–F). Abbreviations: cy – cymbium, ds – dorsal portion of scutum, em – embolus, pa – patella, Ta – tegula apophysis.
Palp yellowish, femur longer than tibia, patella about 2 times shorter than femur. Tibia enlarged, almost conical in prolateral view, 1.86 times wider than patella, about 2 times wider than femur. Cymbium about 1.5 times longer than tibia, slightly shorter than apophysis. Tegular region is membranous, apophysis pointed, extends anteriorly. Embolus short, blunt and directed laterally (Fig.
Female. Unknown.
This species is currently known only from the type locality.
This species is peculiar because it is at odds with the initial description of the type species of the genus Hybosida, which states that the number of eyes is 6. It does, however, resemble Hybosida in the shape of the carapace, the fovea and the general structure of the male palp. It is therefore treated as belonging to this genus.
The manuscript benefited greatly from comments by Galina N. Azarkina, Yuri Marusik and Yanfeng Tong. The English was kindly checked by Sarah Crews (USA). The fieldwork was facilitated by Kenya Wildlife Service (KWS), Kenya Forest Service (KFS), National Environment Management Authority (NEMA) and the National Commission for Science, Technology and Innovation (NACOSTI). The study was financially supported by the National Natural Science Foundation of China to Shuqiang Li (NSFC-31530067).