Cosmophasis ambonensis, Hurni-Cranston & Hill, 2021

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 : 6-11

1. Cosmophasis ambonensis , new species

Figures 7 :1, 8-11, Map ( Figures 1-2 ) #3

Type material. The holotype ♂ ( HC-AM 1m) was collected as a penultimate by the senior author on a outdoor gravel floor near food stands in Ambon (collected 8 FEB 2016, specimen preserved in alcohol 20 FEB 2016). This single specimen, lacking the left pedipalp as an adult, will be deposited in the Florida State Collection of Arthropods ( FSCA), Gainesville .

Etymology. The species name, ambonensis , is a reference to the fact that this species is at present only known from Ambon.

Diagnosis. The 390° rotation of the embolus is unusual (see Appendix 1). The pattern of scales on the carapace and dorsal opisthosoma also distinguishes this species from related species with similar scale patterns, many not described ( Figure 7 ).

Description of male (holotype HC-AM 1m; Figures 7 :1, 8-11). Body length including spinnerets close to 5.5 mm. Chelicerae typical of males for this genus, about as long as distance from top of paturon to top of carapace, honey or yellow-brown in colour. The front of each paturon is flat, covered with transverse grooves or striae. One very large, unidentate, anterolateral (prolateral, near base of fang) tooth that projects anteroventrally, two small, unidentate anteromedial teeth, and one large, unidentate, posteromedial (retrolateral, medial) tooth are present on each chelicera ( Figure 10 :2). The flexible articulation of the chelicerae is about as high as the clypeus, and the height of each is about 1/2 the diameter of an AME. Near the median, white setae extend ventrally from the clypeus, discontinuous with a thin marginal band of white setae that extends from the front around the sides of the carapace, and, above the marginal band, a second thin band of white setae on either side of the face.

The anterior eye row is surrounded by white scales below, by bright red-orange scales of the anterior eye region above. Toward the front the sides of the carapace are covered with golden-iridescent scales. The dorsal carapace is covered with three tracts of bright red-orange scales, separated by a narrower, transverse band of light-blue iridescent scales between the PME that is interrupted at the median, about half-way between the ALE and PLE, a somewhat wider transverse band of light-blue iridescent scales just behind the PLE, extending to the rear to meet the margin at either side, and a somewhat triangular, median tract of light-blue to gold iridescent scales at the rear of the carapace ( Figure 9 :2). Similarly, mostly transverse tracts of light-blue iridescent scales are separated by three wide bands of bright redorange scales on the dorsal opisthosoma, the first, at the front, interrupted by a median tract of light-blue iridescent scales ( Figure 9 :3).

To the front and rear of the dorsal opisthosoma are bands of white to iridescent light-blue setae. The spinnerets are grey-black, with iridescent violet scales on the upper surface of each posterior spinneret. In life the legs are mostly honey or yellow-brown, with some light-blue iridescence above each coxa and femur.

In life the proximal segments of each pedipalp, to include the tibia, are dull yellow, the cybium light yellow-brown, with light-blue iridescence above the distal femur and patella ( Figure 9 :4). Each tibia has three marginal lobes, one rounded and ventral, one more acute and dorsal, and one retrolateral (lateral) between these, bearing the small, black RTA. Each RTA is hooked at the end ( Figure 10 :10). The round tegulum is relatively wide, and the distal cymbium extended but relatively short, for spiders of this genus. The 390° rotation of the embolus (see Figure 6 and Appendix 1) is unusual for this genus.

When immature ( Figure 11 ), this male was very similar to the adult in colouration. Since immature males usually have a colour pattern similar to that of females, we can expect to find females of the same appearance at some time. This differs from the high degree of sexual dimorphism that is seen in other Cosmophasis species. Presently the female of this species in not known.

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 2. Records of Cosmophasis in Ambon and the Banda Islands. Ambon is the type locality for C. viridifasciata. The other records are all new. 2, Detail of Banda Islands corresponding to inset rectangle in (1). See Hurni-Cranston Hill (2020) for more views of the Banda Islands. Background images courtesy of NASA/USGS/Landsat.

Figure 6. Diagrammatic ventral views of left pedipalp of male Cosmophasis, showing the convention used here to estimate the rotation of the embolus (in red) from its tegular origin to its apex in the cymbial furrow. See Appendix 1 for estimates of this rotation by species, based on published drawings or photographs.

Figure 7. Comparative dorsal views of representative male Cosmophasis (drawings not to scale). 1, C. ambonensis, sp.nov., Ambon. 2, Cosmophasis sp. A, found at Warimak, Waigeo Island, West Papua (Baum 2019) and at Pulau Penem, Fam Islands, Indonesia (Smutný 2020). 3, Cosmophasis sp. B, found on Leilei Island (Sustainable Strategies Network 2018), Halmahera Island (Harris 2019), and Ternate Island (Knowles 2021a) in the Bacan Islands, Indonesia. 4, Cosmophasis sp. C, found at Manokwari, West Papua (Knowles 2021b). 5, C. bitaeniata, Queensland. 6, C. valerieae, Bali. 7, C. bandaneira, sp.nov., Banda Neira.

Figure 9. Holotype male C. ambonensis (HC-AM1m). 1-4, Detailed views of living spider. 5-7, Views of spider, preserved in ethanol. 1, Note transverse groves on the front of each paturon. 2-3, Tracts or bands of iridescent ligh-blue scales are separated by tracts of bright red-orange pigmented scales on both the carapace (2) and the dorsal opisthosoma (3). 4, In this dorsal view, the dorsal (at left) and ventral (at right) distal tibial lobes of the male pedipalp can be seen. To follow the left pedipalp convention for purposes of comparison, this is a mirror image of the right pedipalp.

Figure 10. Holotype male C. ambonensis (HC-AM1m) in ethanol. 1, Ventral/rear view of protracted chelicerae, endites and labium. 2, Detail from (1) showing one large and two small teeth of the promargin (blue line), and one large medial tooth of the retromargin (green line). 3, Ventral view showing anterior projection of the large promarginal teeth (arrows). 4-11, Medial (4-5) to ventral (6-8) to lateral (9-10) to dorsal (11) views of right pedipalp (mirror images).

Figure 11. Views of the holotype male C. ambonensis (HC-AM1m) as a penultimate, with both pedipalps intact.