Cosmophasis squamata Kulczyński 1910

Hurni-Cranston, Tiziano & Hill, David E., 2021, Three new jumping spiders of the genus Cosmophasis from Wallacea (Araneae: Salticidae: Chrysillini), Peckhamia 228 (1), pp. 1-84 : 33-38

7. Cosmophasis squamata Kulczyński 1910

Figures 3 :1-2, 31-33, Map ( Figure 1 ) #49

Almost all that we have known of this spider is based on a single female specimen collected on Bougainville Island in the Solomon Islands in the month of September, at some time prior to 1910. When Kulczyński (1910) described this specimen in Latin, he provided only a simple drawing of the epigynum, later redrawn from this specimen by Prószyński (1984). The C. squamata male and female later described by Saaristo (2002) are actually C. lami , and the male C. squamata remains unknown. We have considered the possibility that C. bandaneira sp.nov. represents the male of this species, but that relationship is only speculative at this point.

Material examined. One adult female ( HC-BB1 f) was collected 8 FEB 2016 from a small plant on Banda Besar . This specimen will be deposited in the Florida State Collection of Arthropods ( FSCA), Gainesville . A second female was photographed on Banda Neira ( Figure 32 ) but not collected.

Diagnosis. To identify this species we must rely on characters that were described by Kulczyński, as well as Proszynski's subsequent drawing of the epigynum ( Figure 33 :12-13; Appendix 2) Other than the epigynum, the characters given by Kulczyński are insufficient to distinguish this spider from several other species. Nonetheless the epigynum is distinctive, bearing two nearly parallel furrows running lengthwise on either side of the median ( Figure 33 :7-13).

Description of female. Pedipalps are uniform light yellow with a few white setae; they probably fluoresce brightly in ultraviolet light as do the pedipalps of female C. umbratica (Lim, Land & Li 2007) . The chelicerae are dark amber, glabrous. There is one prominent tooth on the retromargin, and two small denticles on the promargin of the fang groove. Below, the AME are surrounded by white scales, above all four anterior eyes are surrounded by orange scales. The carapace is covered with iridescent green to gold scales, with one dark band passing through the posterior eye row, and a second dark band behind this. On either side of the carapace these dark bands are wider, violet iridescent. There are two narrow white marginal bands, the upper only present near the front of the carapace. The dorsal opisthosoma is covered with dense, overlapping, large, dark round scales, interrupted by bands of overlapping large, light-yellow round scales, one wrapping around both sides from the front margin, and three oriented transversely. In addition there are several median patches of the same light-yellow scales.

The spinnerets are black, with iridescent violet scales above the posterior spinnerets. There are three pairs of large white patches on the venter, the rear pair smaller and contiguous ( Figure 33 :2). The legs are mostly light yellow, with some white banding on the patellae and distal metatarsus, and an iridescent sheen, particularly on the dorsal surface of the coxae. The epigynum ( Figure 33 : 7-13) is elevated and highly sclerotized, with a longitudinal furrow on either side of the elevated septum. These furrows diverge at the rear where more dark pigment is visible, and also diverge toward the front. Overall the epigynum is triangular in shape, with a well-defined posterior margin.

The male Cosmophasis squamata is not known. As noted previously, It is possible that C. bandaneira sp.nov. is the male of either this species, or a closely related species. Two somewhat different penultimate males that have been photographed by the senior author (THC) on Banda Besar, but not reared to the adult stage, are shown in Figure 34.

Figures

Figure 1. Known occurrence of Cosmophasis species in Sunda, Sahul and adjacent oceanic islands. Better-known species are identified in the key at upper right. See Appendix 1 for identification of the other species, most know from a single locality, by number. The new species described here are from Ambon and the Banda Islands within the Wallacean region (small yellow rectangle near the center), shown in more detail in Figure 2. Localities are based on references cited in Appendix 1, as well as reliable photographs posted in iNaturalist and FLICKR. Note that some records of C. thalassina (52, generally found to the south) and C. umbratica (57, generally found to the north) are most likely confused, as separation of these species may not be possible. Background image courtesy of NASA/USGS/Landsat.

Figure 3. Opisthosomal scale cover of Cosmophasis. 1, Adult female C. squamata (HC-BB1f, Banda Besar, 8 FEB 2016). 2, Detail of overlapping scales from inset rectangle in (1). 3-4, Camera lucida drawings of dark (olive-green transparent) and light (white granular) opisthosomal scales from a female Cosmophasis sp. collected in Brunei in 1975 (after Hill 1979, 2009). 5, Schematic diagram of overlapping opisthosomal scales (posterior direction at the top).

Figure 32. Adult female Cosmophasis squamata from Banda Neira.

Figure 33. Adult female Cosmophasis squamata from Banda Besar (HC-BB1f), preserved in alcohol. 1, Dorsal view. 2, Ventral view. 3-6, Posteroventral views of chelicerae, showing large retromarginal tooth, and two small promarginal denticles, on either paturon (3, arrows). Rectangles (3) identify arrays of 3-4 stout setae near the base of the retromargin of each fang groove. 7-11, Exterior or ventral views of the epigyum. The first (7) is best illuminated to show the long furrow on either side of the septum. 12-13, Drawings of epigynum. 12, Kulczyński 1910. 13, Prószyński 1984, used by permission.

Figure 34. Two different penultimate male Cosmophasis sp. photographed on Banda Besar. 1-3, This penultimate male is closer to the female C. squamata in colouration. 4-6, Penultimate male with more iridescent blue, black and white.