Sebadexius cebuense Just 2018, sp. nov.
Creators: name: Just, Jean
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Dexaminidae
Sebadexius
Sebadexius cebuense

description: Sebadexius cebuense sp. nov.   
Figures 1, 2  
 Type fixation. Holotype, ♀, here designated.   
 Etymology. The species is named for the Philippine island of Cebu.   
 Material examined. Holotype. Female with oostegites, 2.2 mm, The Philippines, Cebu Island, off Maribago Marine Research Laboratory, ca. 1 m (low- water), wash from sand and detritus incrusted Galaxaura red algae inside reef, 17 November 1982, J. Just and T. Schiøtte, stn PH 26, NHMD-233130. (Together with many Pagurapseudes, caprellids, several siphonoecetine amphipods, a few pycnogonids, several small crabs).   
 Paratype. Same data as holotype, NHMD –233131 (1 subadult, 1 mm).   
 Description (holotype, female). Eye lobes extended into acute points, eyes filling most of lobes. Maxilliped palp article 3 0.75 length of article 2.   
 Antenna 1 as long as head and pereonites 1–4 combined; peduncle articles 1 and 2 of subequal length, 1 with short ventrodistal setiferous projection; 3 length 0.6 of 2; flagellum of 8 articles, as long as peduncle. Antenna 2 vestigial, about half length of 1, composed of short peduncle of 5 articles and single flagellar article.   
 Coxal plates 1–4 successively longer; coxa 1 rounded triangular; coxa 2 rectangular, distally rounded; coxa 3 pointed, anterior margin shorter than posterior margin; coxa 4 rectangular except posterior margin concave. Coxal plates 5 and 6 similar, with short anterior lobe and broadly rounded posterior lobe, lobes of equal depth. Coxal plate 7 broadly rounded, about as deep as plate 6.   
 Gnathopods with dorsal margin of fixed chela with submarginal row of tiny setae and 2 small robust setae apically. Gnathopod 1 propodus mid lateral length 1.8 greatest width. Gnathopod 2 more slender than 1, mid lateral length 2.3 width. Pereopods 3 and 4 similar, stout, with long, strong robust setae on all articles except dactylus. Pereopod 5 basis ovoid, length about 1.5 width, anterior margin with 2 hollow-headed robust setae (Fig. 2 arrow). Pereopod 6 basis broadly expanded posteriorly, length 1.3 width, anterior margin with simple setae and several hollow-headed robust setae. Pereopod 7 basis with rounded rectangular posterior expansion, posterior margin serrate with small simple setae in indentations, ischium to propodus with long, strong, mostly blunt-tipped (not hollow-headed) robust setae. Posteroventral corner of epimeron 2 and 3 acutely pointed. Gills simple elongate sacks, shortest on pereopods 2 and 7. Oostegites linear with a few apical setae, shortest on pereopods 2 and 7.   
 Uropod 1 peduncle with single robust seta on lateral apical corner and long simple seta on medial corner; rami of equal length, about 0.8 length of peduncle, with row of 3 robust setae and 2 robust setae on apex. Uropod 2 peduncle reaching to base of peduncle uropod 3, with row of 4 lateral robust setae; inner ramus as long as peduncle with 4 medial robust setae and 2 robust setae on apex; outer ramus length 0.7 inner ramus with 2 robust setae on apex. Uropod 3 peduncle with 4 lateral robust setae; broad, lanceolate rami of equal length, as long as peduncle, outer ramus with lateral row of robust setae, inner ramus with lateral and medial robust setae (possibly more than shown in Fig.1 us). Telson reaching 0.75 along rami uropod 3, length about 1.9 width at base, split nearly to base, each lobe with fine dorsal ridge parallel to lateral margins; distal 3/5 of lateral margins with a few small proximal simple setae and more distal row of 4 robust setae; apex of lobes truncate, finely serrate, with single robust seta.
description: Published as part of Just, Jean, 2018, Review of Sebadexius Ledoyer, 1984 (Amphipoda, Dexaminidae, Dexamininae) based on new material from The Philippines, with Sebadexius cebuense sp. nov., pp. 596-600 in Zootaxa 4500 (4) on pages 597-600, DOI: 10.11646/zootaxa.4500.4.9, http://zenodo.org/record/5297878