Cosmophasis thalassina (C. L. Koch 1846 )

Hill, David Edwin, Hurni-Cranston, Tiziano & Tam, Truong Van, 2024, New synonymy for the jumping spider Cosmophasis thalassina (C. L. Koch 1846) (Araneae: Salticidae: Chrysillini), Peckhamia 312 (1), pp. 1-8 : 7

Cosmophasis thalassina (C. L. Koch 1846)

Plexippus thalassinus C. L. Koch 1846

Cosmophasis thalassina Simon 1901

Cosmophasis umbratica Simon 1903 , new synonymy not Cosmophasis umbratica Dyal 1935

Cosmophasis umbratica Prośzynśki 1984 , new synonymy not Cosmophasis thalassina Prośzynśki 1984

Cosmophasis thalassina Ż̇abka1988 (figs. 62-63)

Cosmophasis thalassina Ż̇abka & Waldock 2012 (figs. 1A-1E, 3A-3B, NOT 4D-4F, NOT 60A-60B) Cosmophasis thalassina Hurni-Cranston & Hill 2021

Cosmophasis umbratica Hurni-Cranston & Hill 2021 , new synonymy

Males have a distinctive appearance with iridescent colors that vary from yellow-green (or bronze and green) to blue-green. In Australia, they resemble male C. micarioides (L. Koch 1880) , but lack the black stripe that extends ventrolaterally below each ALE of that species. To a lesser extent, they resemble male C. bandaneira Hurni-Cranston & Hill 2021 , but the orientation of the embolus in that species is altogether different. Females are speckled ("salt and pepper") in appearance, with variable coloration that may include many brightly colored, iridescent scales, and dark bands across the dorsal opisthosoma. These tend to be less colorful and much less iridescent toward the southern part of their range, in Australia (see Donovan & Hill 2017, fig. 1).

The identity of Cosmophasis micans L. Koch 1880 (Figure 2.2) has been problematic (Hurni-Cranston & Hill 2021). In reviewing a new and improved English translation of Koch's description of this species (J only, ♀ not known) it appears that Koch's assertion that the AME are fast in der doppelten Breite ihres Durchmessers über dem Kopfrande stehend refers to the distance between the bottom of the AME and the lateral margins of the carapace (not the ventral margin of the clypeus). With this interpretation of the text, and the fact that Koch's drawing of his J C. micans (Figure 2.2) is very stylish and not at all accurate, this might be a rubbed C. thalassina . Given the fact that Koch's drawing was based on a specimen from Cape York, Australia, this is a reasonable assumption. The dorsal opisthosomal stripe of the latter species is lacking in the drawing, however. A single observation in iNaturalist (from Brisbane) has been tentatively identified as this species, but it has the dorsal opisthosomal stripe and cannot be distinguished from a male C. thalassina . It is noteworthy that the Arachne .org.au site reports that C. micans does not exist in Australia, and that C. thalassina has been misidentified as C. micans in the past.

It has also been suggested that C. modesta (L. Koch 1880) and C. obscura (Keyserling 1882) , both known from Queensland, represent misidentified C. thalassina (Whyte & Anderson 2017) . However, as figured, the C. modesta male has a prominent spine on the anterior surface of each paturon, overlapping the base of the respective fang. Ż̇abka & Waldock (2012) redescribed the latter species ( C. obscura ) with a female specimen (90043, Laloki, Central Province, PNG), not unlike Keyserling's drawing of the epigynum of a female from Cape York, and quite different from the epigynum of of C. thalassina . As we noted previously (Hurni-Cranston & Hill 2021) the Cosmophasis species of New Guinea and other islands associated with tropical Sahul need further study, preferably in the field.