Ikuma larseni, Zonstein & Marusik, 2022

Zonstein, Sergei & Marusik, Yuri M., 2022, Redescription of the poorly known genus Ikuma Lawrence, with synonymy and description of a new species from Namibia (Araneae, Palpimanidae), African Invertebrates 63 (2), pp. 105-119 : 105

publication ID

https://dx.doi.org/10.3897/afrinvertebr.63.90530

publication LSID

lsid:zoobank.org:pub:9043366D-4428-449A-BC61-D7310BA183D4

persistent identifier

https://treatment.plazi.org/id/1F29B626-F711-4AE9-84A1-AC15B19E42CE

taxon LSID

lsid:zoobank.org:act:1F29B626-F711-4AE9-84A1-AC15B19E42CE

treatment provided by

African Invertebrates by Pensoft

scientific name

Ikuma larseni
status

sp. nov.

Ikuma larseni sp. nov.

Figs 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4 , 5 View Figure 5 , 6 View Figure 6 , 7 View Figure 7 , 8

Etymology.

The specific name is a patronym after Norman Larsen (Cape Town, South Africa) who kindly provided us with the macro-photographs of the preceding Ikuma species.

Types.

Holotype ♀, Namibia, Erongo Region, Namib-Naukluft National Park, Gobabeb, 23°34'S, 15°03'E, 8-9.ii.1969, B. Lamoral (NMSA-SPI-26895). Paratypes: 1♀, same collection data but 14.iv.1969, E. Holm (NMSA-SPI-26881); 1♀, same collection data but 14.iii.1970, no collector’s name indicated (NMSA-SPI-11682); 1♀, same collection data but 1-29.ii.1972, B. Lamoral (NMSA-SPI-11210); 1♂, same collection data but Narras Valley 10 km W Gobabeb, 570 m (1700 feet), 2.x.1984, C. Griswold (NMSA-SPI-26894).

Diagnosis.

Ikuma larseni sp. nov. can be distinguished from I. spiculosa by the colouration and pubescence (carapace with densest pubescence along margins vs. in subcentral part of the carapace); the new species has a uniformly pale abdomen vs. bicolorous in I. spiculosa (Fig. 2A, C View Figure 2 cf. Fig. 1 View Figure 1 ). The interdistance AME-AME is longer than AME-ALE in I. larseni sp. nov. and shorter in I. spiculosa . Since characters of I. spiculosa seem to be based on the juvenile or subadult specimens, the comparison of the copulatory organs remains impossible.

Description.

Female. NMSA-SPI-26895 (holotype).

Habitus: as in Fig. 2A, B View Figure 2 . Colour in alcohol: carapace and chelicerae dark carmine red; maxillae, coxae I-IV and abdominal scuta light to intensely orange; palp and legs I-IV from femora to tarsi pale yellowish orange (leg I slightly darker than legs II-IV, with more noticeable difference between corresponding tibiae and metatarsi); sternum, labium and pedicel tube medium carmine red; abdomen very pale yellowish orange, dorsally with large slightly darker oval median marking; spinnerets yellowish white. Carapace and abdomen laterally covered with dense flattened and adpressed whitish pubescence. Measurements: TL 11.15. CL 4.81, CW 3.22, CyL 0.56 (0.43), Femur I L/W 2.29 (3.41/1.49). Carapace: with moderately coarse granulations (Fig. 3A View Figure 3 ). Eyes (Fig. 3B, C View Figure 3 ): AME 0.27, ALE 0.16, PME 0.13, PLE 0.13; AME-AME 0.16, AME-ALE 0.11, AME- PME 0.20, ALE-PLE 0.41, PLE-PME 0.18, PME-PME 0.31. Mouthparts: labium with slightly notched anterior edge (Ln; Fig. 4B View Figure 4 ). Legs I-IV: tarsi with paired claw tufts of dense long setae and multipectinate paired claws each armed with 8-10 teeth (Fig. 7A View Figure 7 ). Abdominal sclerites: short pedicel tube (Pt) widely funnel-shaped (Figs 4C View Figure 4 , 5A, B View Figure 5 ); small hexagonal dorsal shield (Ds) clearly separated from and not fused with lateral sclerotized extensions (Le; Fig. 5A View Figure 5 ); epigastral plate (Eg) in intact specimen (before dissection) uniformly coloured, posterior part slightly concave; postgaster with one thin bow-shaped scutum (Fig. 4C View Figure 4 ); posterior edge nearly straight. Spinnerets as shown in Fig. 7B View Figure 7 .

Copulatory organs: as in Figs 5C-F View Figure 5 , 6 View Figure 6 . Endogyne weakly sclerotized (unlike partially heavy-sclerotized one in Palpimanus spp.); main supporting structure, wide trapezoidal endogynal fold (Rf), carries two lateral apophyses (La); membranous sacs of receptacles (Rs) bell-shaped, about as long as wide, each receptacle accompanied by brushes of fine threads (Ft) and approximately 7-8 grape-shaped glands (Gg), glands with stalks about as long as head, pore glands indiscernible (seems absent).

Leg measurements: female NMSA-SPI-26895 (male NMSA-SPI-26894 in brackets):

Male. NMSA-SPI-26894 (paratype).

Habitus: as in Fig. 2C, D View Figure 2 . Colour in alcohol: as in female, but coxae I-IV evenly orange and tarsus I pale yellow, much lighter than metatarsus I. Measurements: TL 12.37. CL 5.78, CW 3.95, CyL 0.29, Femur I L/W 1.91 (4.23/2.21). Carapace: longer, with slightly coarser granulations than in female (Fig. 3D View Figure 3 ). Eyes (Fig. 3E View Figure 3 ): AME 0.28, ALE 0.18, PME 0.15, PLE 0.14; AME-AME 0.22, AME-ALE 0.12, AME-PME 0.34, ALE-PLE 0.46, PLE-PME 0.22, PME-PME 0.35. Mouthparts: as in female (see Fig. 4B View Figure 4 ). Legs I-IV: metatarsi and tarsi armed with long ventral bristles as in female (Fig. 7C View Figure 7 ); claw tufts and dentition as in female. Abdominal sclerites: epigastral scutum with clearly darkened book-lungs; postgaster with two large long subtriangular scuta (distinguishable in form from the corresponding scuta in other palpimanids), and two pairs of dot-like scuta (see Fig. 4E View Figure 4 ).

Copulatory organs: Palp as shown in Figs 7D View Figure 7 , 8. Femur nearly 3 times longer than wide, 1.5 times longer than cymbium and tibia, 2.3 times longer than patella; patella elongate, 1.5 times longer than wide; tibia elongate, not swollen, length/maximal width ratio ca. 1.6, subequal in length to cymbium, covered with dense and long whitish setae; cymbium about twice longer than wide; bulb droplet-shaped; tegulum as wide as long, lacking any processes (apophyses), retrolateral part of tegulum membranous; embolic division with 2 outgrowths: slightly bent spine-like chitinized embolic process (Ep), sigmoid in anterior view (see Fig. 8A), and membranous embolus (Em).

Variation.

In paratype females, the length of the carapace varies from 4.4 to 5.6 mm.

Habitat.

According to the collecting data, the specimens were obtained by sand sifting.

Distribution.

Known only from the type locality.

Note.

Since the only available male of Ikuma larseni sp. nov. was found partially damaged (probably when collected), we preferred to designate one of the better preserved females as the holotype.

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae

Family

Palpimanidae

SubFamily

Palpimaninae

Genus

Ikuma