Seiitaoides Griffin & Tranter, 1986

Forges, Bertrand Richer De, Lee, Bee Yan & Ng, Peter K. L., 2021, The taxonomy of spider crabs of the genera Eurynome, Choniognathus, Seiitaiodes and Kasagia (Crustacea: Brachyura: Majidae) from southwest Indian Ocean, Zootaxa 5048 (3), pp. 301-333 : 313-314

Genus Seiitaoides Griffin & Tranter, 1986

Seiitaoides Griffin & Tranter, 1986: 200 (key), 251, 252.

Diagnosis. Carapace pyriform; dorsal surface with regions well demarcated, with several large plates on gastric, cardiac, intestinal and branchial regions; surfaces of plates covered by granules. Pseudorostral spines relatively short, cylindrical or dorsoventrally flattened, diverging, with U-shaped cleft. Supraocular eave wide completely protecting eye; proximal angle may form blunt tooth; postocular spine long flattened or as blunt tooth; intercalated spine distinct or short, tightly appressed against postorbital spine and/or supraorbital eave. Suborbital tooth forming wide lobe. Hepatic spine usually long or prominent, may be curved, with boletiform tubercle just above spine. Gastric region covered with strong tubercles; median part with 1 or 2 ovate or cardiform plates; protogastric part with 2 large tubercles. Deep groove between branchial and gastric areas with row of large granules. Branchial area with 2 large boletiform plates; 1 branchial, 1 epibranchial. Lateral margin of branchial region with 4 large boletiform tubercles which may coalesce to form plates. Cardiac region with large triangular or subovate shield-like plate, prominently granulated. Intestinal region and posterior carapace margin forming brace-like plate with plates on posterolateral margin, regions, sometimes visible as 3 plates but may be fused to form one wide contiguous structure. Nephridophore large, swollen; basal article wider at base with 3 blunt spines, distal part narrower; flagellum short, just exceeding length of pseudorostral spines. Epistome longer than wide or quadrate. Buccal cavity squarish; posterior margin of epistome uneven, with median part projecting downwards. Third maxilliped with large granules on merus and ischium; merus and ischium free; anteroexternal angle of merus distinctly produced, auriculiform. Margin of pterygostomial region with 4 large granules. Anterior part of male thoracic sternum deeply depressed; distal margin of rim of sternopleonal cavity smooth or with sharp spines; ventral surface setose. Adult male chelipeds long; merus with numerous short spines; carpus short flattened, covered with short spines; chela long, fingers forming gentle angle with palm. Ambulatory legs relatively short, covered of short setae, merus and carpus smooth or with short spines; dactylus long, curved, sharp. Male pleon with 6 free somites and telson; somite 1 with large round median swelling visible in dorsal view; somite 3 with lateral surfaces swollen; telson linguiform, much longer than broad. G1 slender, almost straight to sinuous; G2 short, with short distal segment.

Type species. Eurynome orientalis Sakai, 1961 , by original designation.

Remarks. Seiitaoides Griffin & Tranter, 1986 , was described for two species, S. orientalis , from Japan, and S. stimpsonii from Providence reef, Seychelles, following the revision of Eurynome ( Griffin & Tranter 1986) . With the fresh material collected from the southwest Indian Ocean, two new Seiitaoides species are described bringing the total now to four species for the genus.