Siler niser sp. nov.

Figs 1A-F, 2A-L, 3A-D, 4A, B, 5

Type material.

Holotype ♂ (ZSIC-I/SP 40) from India: Odisha, Bhubaneswar, Khordha, Jatani, NISER campus (20.16861°N, 85.68493°E), 46 m a.s.l., 06.v.2021, leg. A. Parag.

Paratypes: 4 ♀♀ (ZSIC-I/SP 41 to 44), data same as holotype, 05.v.2021.

Etymology.

The specific epithet is an acronym derived after the type locality, National Institute of Science Education and Research (NISER) campus from where the specimens were collected. The name is treated as a noun in apposition.

Suggested common name.

Glossy jumping spider.

Diagnosis.

Siler niser sp. nov. resembles Siler semiglaucus (Simon, 1901) in general morphology and colour pattern (cf. Fig. 1A, B, D, E with images 1a, b in Kulkarni and Joseph (2015)), but can be easily distinguished by the morphology of the copulatory organs which are rather most similar to S. cupreus Simon, 1889 and S. severus (Simon, 1901): male palp with short beak-like embolus (slender and needle-like in S. cupreus and S. severus); relatively smaller RTA (smallest of all congeners, remaining below the small retrolateral tegular lobe); RTA directed anteriad in ventral view, with pointed tip and broad base in retrolateral view, ventral margin vertical, dorsal margin gradually sloping, gently curved (RTA directed retrolaterally in ventral view, thick, relatively long reaching beyond the retrolateral tegular lobe and curved in S. cupreus and S. severus) (cf. Figs 2E, F, 3A, B with illustrations on pg. 133, 135 in Prószyński (1984), figs 246, 247 in Bohdanowicz and Prószyński (1987) and figs 12, 13 in Prószyński (1985)); females can be recognised by the short and bent copulatory ducts and globular spermathecae separated by more than their radius (copulatory ducts relatively longer, almost straight and copulatory openings closely placed along the median in S. cupreus) (cf. Figs 2K, L, 3C, D with illustrations on pg. 134, 135 in Prószyński (1984) and figs 249, 251 in Bohdanowicz and Prószyński (1987)).

Description.

Male (based on holotype ZSI-I/SP-40, colouration in alcohol) (Fig. 2A-F): total length 4.10; carapace 1.97 long, 1.50 wide; abdomen 2.13 long, 1.19 wide. Carapace greenish-brown; lateral sides with broad red patch; outer rim of carapace lined by blue scales (Fig. 2A). Anterior eyes surrounded by greyish-white orbital setae. Clypeus brown, ‘cheeks’ covered with bluish hairs (Fig. 2D). Eye measurements: AME 0.38, ALE 0.21, PME 0.07, PLE 0.19; AER 1.21; PER 1.34; EFL 0.95. Clypeus height 0.05. Sternum oval, yellowish-brown, covered with hairs; labium and maxillae brown (Fig. 2B). Chelicerae brown with two promarginal teeth and one fissident retromarginal tooth. Abdomen with an anchor-shaped red marking in the anterior three quarters; four grey spots composed of metallic scales present in the anterior portion; lateral and posterior half dark grey, composed of iridescent scales; venter brown, covered with iridescent scales; light brown below the epigastric region (Fig. 2A, B). Spinnerets yellowish-brown. Legs yellow with longitudinal brown streaks; leg I robust, brown, femur and patella with ventral fringe of dense black hairs, tibia with both ventral and dorsal fringe (Fig. 2A-C). Leg measurements: I 4.87 (1.64, 0.73, 1.08, 0.87, 0.55); II 3.45 (1.08, 0.54, 0.72, 0.68, 0.43); III 3.97 (1.20, 0.52, 0.80, 0.93, 0.52); IV 5.36 (1.63, 0.62, 1.18, 1.36, 0.57). Leg formula 4132. Palp as shown in Figs 2E, F, 3A, B.

Female (ZSI-I/SP-41, colouration in alcohol) (Fig. 2G-L). Total length 5.31; carapace 2.24 long, 1.69 wide; abdomen 3.07 long, 2.05 wide. Carapace brown; covered with black hairs; lateral margins covered with reddish hairs, outer rim lined by bluish-white hairs (Fig. 2G). Anterior eyes surrounded by greyish-white orbital setae. Clypeus brown, ‘cheeks’ covered with bluish hairs below ALEs (Fig. 2J). Eye measurements: AME 0.40, ALE 0.24, PME 0.09, PLE 0.23; AER 1.33; PER 1.50; EFL 1.04. Clypeus height 0.02. Sternum oval, yellow; labium and maxillae brown, maxillae apically paler (Fig. 2H). Chelicerae brown with two promarginal teeth and one fissident retromarginal tooth. Abdomen greyish-black with a median transverse black patch; venter yellow, lateral and posterior region brown (Fig. 2G-I). Spinnerets brown. Legs brownish-yellow with longitudinal black stripes (Fig. 2G, I). Leg measurements: I 4.30 (1.45, 0.77, 0.85, 0.76, 0.47); II 3.62 (1.18, 0.61, 0.69, 0.69, 0.45); III 4.13 (1.25, 0.62, 0.79, 0.99, 0.48); IV 5.59 (1.71, 0.72, 1.21, 1.40, 0.55). Leg formula 4132. Epigyne and vulva as shown in Fig. 2K, L, 3C, D.

Variation.

Total length of females ranges from 5.31 to 6.88 (n = 4).

Colour in life.

Male. Carapace covered with a mixture of bluish and greenish scales; blue scales extending below the ALEs and running along the rim; lateral sides covered with a thick band of red scales (Fig. 1A-C). Legs yellow brown with a few interspersed iridescent scales and dark brown longitudinal stripes; leg I dark brown with white proximal half of metatarsi and white tarsi. Palps brown, cymbium, tibia and patella covered with white hairs. Abdomen covered with iridescent scales along anterior, lateral and posterior regions; anterior half with a distinct pattern composed of a reddish anchor-shaped mark and four bright blue spots (Fig. 1A-C).

Female. Carapace covered with white and grey scales; lateral margins covered with reddish scales; outer rim covered with bluish-white scales. Legs yellow-brown with longitudinal dark brown and white stripes. Abdomen greyish with a similar, but incomplete pattern as seen in male; a median transverse red band sandwiched between two blue bands; anterior blue band discontinuous medially, posterior band broad and continuous (Fig. 1D, E). In darker females, the red band is completely black, this perhaps occurring in older females when the scales are lost (Fig. 1F).

Natural history.

Specimens were found in acute vicinity of the ant Camponotus compressus . Individuals were myrmecophagic like Siler semiglaucus (confirmed through visual observations). Both sexes waved the first pair of legs in the air, perhaps mimicking the antennae of the ants (Fig. 1B, F). This behaviour was observed both in the presence as well as in the absence of ants. Individuals were extremely agile and moved to the underside of leaves as soon as they detected any external movement. Specimens were collected from Hyptis suaveolens and Lannea coromandelica seedling foliage, both about 2 feet (ca. 60 cm) above the ground, during the month of May. The average humidity during the collection period was 63% (range: 62% to 64%).

Threat status.

The individuals of Siler niser sp. nov. were collected from a grassland-shrubland type habitat (Fig. 4A, B). These biomes are under threat as they are often labelled as unproductive and the biodiversity they harbour remains poorly documented (Nerlekar et al. 2022). Since Siler niser sp. nov. is known only from its type locality (Odisha, India), other possible locations of its occurrence are yet unknown. Due to lack of distributional data especially in grasslands where surveys are most often ignored, we categorise Siler niser sp. nov. as data deficient.

Distribution.

Known only from the type locality (Odisha, India) (Fig. 5).

Phylogeny.

The best model of sequence evolution according to BIC was TRN+I+G. The obtained ML tree (Fig. 6) was rooted using the branch leading to the two outgroup taxa. The new species was sister to a clade consisting of S. collingwoodi, S. cupreus and S. ruber, albeit with low bootstrap support. The uncorrected p-distance within Siler species ranged from 1.3% to 7.4%.

The new species was also morphologically different from all other congeners with a suite of morphological characters as described above. The members of the population we collected from Odisha State, India share characters like the body covered with iridescent scales, abdomen with transverse banding pattern and spots, tibia I in males with typical dense bottle brush-like setae, male palp with elongated bulbus and flattened, spatulate RTA, female with simple rounded epigyne and short copulatory ducts ( Prószyński 1985; Żabka 1985) with congeners, but are distinct both morphologically and phylogenetically. Therefore, we use the general lineage concept in order to delineate this population as a new species (de Quiroz 1998).