Kasagia, Forges, Bertrand Richer De & Ng, Peter K. L., 2007

Forges, Bertrand Richer De & Ng, Peter K. L., 2007, On a new genus and new species of deep-water spider crab from the Philippines (Crustacea, Decapoda, Brachyura, Majidae), Zootaxa 1644, pp. 59-68 : 59-60

publication ID	https://doi.org/ 10.5281/zenodo.179714
DOI	https://doi.org/10.5281/zenodo.6237617
persistent identifier	https://treatment.plazi.org/id/03DB2654-FE09-FFEC-FF08-F8B0356BE458
treatment provided by	Plazi
scientific name	Kasagia
status	gen. nov.

Treatment

Kasagia View in CoL , new genus

Diagnosis. Carapace ovoid. Dorsal face almost round, ornamented with fungiform granules; regions weakly defined. Ocular peduncule short, eye rounded, totally concealed orbit when retracted. Front with 2 sharp pseudorostral spines, oval in cross-section. Supra-ocular margin forming a complete eave overlapping post-ocular spine; intercalated spine absent. Hepatic plate triangular. Basal antennal article triangular, formed by fused first 2 articles. Male cheliped very long, covered with setae; carpus short with spines; propodus long; fingers thin, tips crossing when closed. Ambulatory legs short, with merus carinated on upper part; other articles covered by setae. Male sternites 2–4 relatively wide. Abdomen with 6 free segments and telson. G1 with distal part dilated.

Etymology. The genus name is derived from Balicasag (“the island of the broken crab)”, the place where the crab was found, “kasag” meaning crab in Tagalog. Gender feminine.

Remarks. The new genus, Kasagia , has affinities with Eurynome Leach, 1814 , and its allies. Eurynome was established for E. aspera ( Pennant, 1777) from the Atlantic and Mediterranean, but over the years, 11 species have been attributed to this genus at one time or another (see Griffin 1964; Griffin & Tranter 1986). Griffin and Tranter (1986) reviewed the genus and separated its members into three genera: Eurynome Leach, 1814 , sensu stricto, Choniognathus Rathbun, 1932 , and Seiitaoides Griffin & Tranter, 1986 . Eurynome was restricted to E. aspera ( Pennant, 1777) (type species) (= E. scutellata Risso, 1827 , E. boletifera Costa, 1838 , E. longimana Stimpson, 1858 , E. aspera var. acuta ( A. Milne-Edwards & Bouvier, 1900) , E. bituberculata Griffin, 1964 , E. erosa A. Milne-Edwards, 1873 , E. parvirostris Forest & Guinot, 1966 , and E. spinosa Hailstone, 1835 . Choniognathus was redefined to accomodate C. elegans ( Stebbing, 1921) , C. granulosus ( Baker, 1906) , C. reini ( Balss, 1924) (= C. koreensis Rathbun, 1932 , type species), and C. verhoeffi ( Balss, 1929) . In Seiitaoides Griffin & Tranter, 1986 , only two species were included, S. orientalis ( Sakai, 1961) (type species) and S. stimpsonii ( Miers, 1884) .

Kasagia View in CoL differs from Eurynome View in CoL in that the carapace is covered by numerous small flattened or round granules except for a few small fungiform granules on the anterior and lateral regions ( Figs. 1 View FIGURE 1 , 2 View FIGURE 2 A) (versus numerous large fungiform and plate-like granules in Eurynome View in CoL , with some fusing to form large elevated plates, Figs. 2 View FIGURE 2 B), the anterior part of the thoracic sternum, notably around the margins of the sterno-abdominal cavity, is unornamented ( Fig. 3 View FIGURE 3 C) (versus with granules and with the margin of the sterno-abdominal cavity lined with large raised plates, Fig. 3 View FIGURE 3 D), the ambulatory legs have prominent and complete carinated meri ( Fig. 2 View FIGURE 2 A) (versus margins of meri serrated or uneven in Eurynome View in CoL , Fig. 2 View FIGURE 2 B), the pseudorostral spines are ovoid in cross-section (versus C-shaped in Eurynome View in CoL ), the base of the fused basal antennal article has a lateral projection which extends anteriorly towards the post-orbital tooth ( Fig. 3 View FIGURE 3 C) (versus without any projection in Eurynome View in CoL , Fig. 3 View FIGURE 3 D), the supra-orbital eave overlaps the post-ocular tooth ( Fig. 3 View FIGURE 3 A) (versus supra-orbital eave separated from the post-ocular tooth by a large gap in Eurynome View in CoL , Fig. 3 View FIGURE 3 B, see also Hartnoll 1961: 175, fig. 2), the adult male chelipeds are extremely long, being approximately three times the carapace length and covered with short spines and numerous short, stiff setae ( Figs. 2 View FIGURE 2 B, 4D) (versus at most two times carapace length with large lobiform teeth and scattered setae or almost glabrous, Figs. 2 View FIGURE 2 B, 4D), and the G1 is dilated distally ( Fig. 5 View FIGURE 5 B, C) (versus with a prominent hook-like projection subdistally, Fig. 5 View FIGURE 5 A). With regards to the gap between the supra-orbital eave and post-ocular tooth, an intercalated spine is present in E. bituberculata View in CoL (see Griffin 1964: 198, fig. 2), but in E. aspera View in CoL , this spine is small ( Fig. 2 View FIGURE 2 B, Hartnoll 1961: 179, 5a, b).

Kasagia View in CoL resembles Choniognathus View in CoL in having numerous granules and two pseudorostral spines separated by a U-shaped hiatus. As in Choniognathus View in CoL there is no preocular spine. However, Kasagia View in CoL is very different from Choniognathus View in CoL in that it has a supraorbital eave which overlaps the post-ocular spine but lacks an intercalated spine ( Fig. 3 View FIGURE 3 ) (versus with a distinct intercalated spine in Choniognathus View in CoL , see Griffin 1965: 30, Fig. 4 View FIGURE 4. A, B ), the adult male chelipeds are approximately three times the carapace length, covered with short spines and numerous short, stiff setae ( Figs. 2 View FIGURE 2 A, 4C) (versus at most two times carapace length with large teeth or spines and scattered setae) and the G1 is curved with a prominent expansion in the distal third and not setose ( Fig. 5 View FIGURE 5 B, C) (versus G1 simple, straight with numerous setae in Choniognathus View in CoL , see Griffin & Tranter 1986: 204, Fig. 69c, d).

Compared to Seiitaoides , Kasagia differs in that the dorsal surface of the carapace only has small squamiform granules ( Fig. 1 View FIGURE 1 , 2 View FIGURE 2 A) (versus prominent large plates in Seiitaoides, Griffin 1970 ; Griffin & Tranter 1986), a supraorbital eave which overlaps the post-ocular spine but does not have an intercalated spine ( Fig. 2 View FIGURE 2 A) (versus with a distinct intercalated tooth in Seiitaoides , see Griffin 1970; Griffin & Tranter 1986), and the G1 has an expanded distal part and with only sparse setae ( Fig. 5 View FIGURE 5 B, C) (versus evenly straight with setae in Seiitaoides , see Griffin & Tranter 1986: 204, Fig. 69e, f).