Sululana buta, Bruce & Shimomura, 2019

Bruce, Niel L. & Shimomura, Michitaka, 2019, A new genus and species of deep-water marine cirolanid isopod (Crustacea: Isopoda: Cirolanidae) from the Philippines, Raffles Bulletin of Zoology 67, pp. 1-13 : 4-12

Sululana buta , new species

Material examined. Holotype ♀ (non-ovig. 2.9 mm; dissected), Sulu Sea , Philippines, 118° 34.770E – 08°08.511′N, 118°34.452E, 23 November 2002, 1,012–1,016 m, 3 m ORE beam trawl, coll. R. V. HAKUHO-MARU (KMNH IvR 500923).

Description. Body 3.0 times as long as greatest width, dorsal surfaces smooth, widest at pereonite 5, lateral margins weakly sub-parallel. Head lateral margin with lateral flange. Eyes absent. Pereonite 1 with posteroventral angle rounded, lateral margin forming a flange; coxae 2–7 without carina; posterior margins narrowly rounded; posterior of pereonites 1–7 smooth. Pleonites each with acute posterolateral margins; posterior margin all smooth. Pleotelson 1.1 times as long as anterior width, dorsal surface without longitudinal carina; lateral margins weakly convex, margins smooth, posterior margin sub-truncate, without median point, weakly serrate, without RS.

Antennula peduncle article 2 1.9 times as long as article 1, articles 3 and 4 0.7 times as long as combined lengths of articles 1 and 2, article 3 2.1 times as long as wide; flagellum with 7 articles, extending to anterior of pereonite 1. Antenna peduncle article 4 1.8 times as long as wide, 1.5 times as long as article 3, inferior margin with distal plumose setae, anterior margin with 3 short simple setae; article 5 1.4 times as long as article 4, 3.2 times as long as wide, inferodistal margin with 3 pappose setae, anterior margin with 4 short simple setae; flagellum with 7 articles, extending to posterior of pereonite 1.

Frontal lamina posteriorly 0.9 times as wide labrum.

Mandible molar process; right mandible spine row composed of 9 spines; mandible palp article 2 3.5 times as long as wide, with 4 distal setae; mandible palp article 3 0.3 as long as article 2, with 3 pectinate setae. Maxillula mesial lobe with 3 large and weakly circumplumose RS; lateral lobe with 10 RS. Maxilla lateral lobe with 2 simple setae; mesial lobe 0.5 as long as lateral lobe, without setae. Maxilliped palp article 2 mesial margin with 3 slender setae, lateral margin distally with 1 plumose slender setae; article 3 mesial margin with 3 slender setae, lateral margin with 3 plumose setae; article 4 mesial margin with 5 slender setae, lateral margin with 2 slender setae; article 5 distal margin 6 setae; endite with 1 long CPS and two short simple setae.

Pereopod 1 basis 2.7 times as long as greatest width, superior posterior margin with 1 palmate seta, inferior margin with 2 short simple setae; ischium 0.6 length of basis, inferior margin with 2 short simple setae, superior margin with 1 RS; merus 0.5 length of ischium, inferior margin with 5 acute RS, superior distal angle with 2 setae; carpus inferior margin with 2 RS; propodus 1.8 times as long as wide, superior margin convex, inferior margin with 3 stout RS; dactylus weakly curved, 1.07 as long as propodus, 6.4 as long as proximal width. Pereopod 2 basis 4.5 times as long as greatest width, superior posterior margin with 1 palmate seta, inferior margin with 3 short simple setae; ischium 0.4 times as long as basis, inferior margin with 2 short simple setae, superior margin with 1 RS mid-length; merus equal in length to ischium, inferior margin with 2 acute RS, superior distal angle with 2 setae; carpus inferior margin with 4 RS; propodus 2.3 times as long as wide, superior margin convex, inferior margin with 1 RS; dactylus weakly curved, 1.2 as long as propodus, 7.7 as long as proximal width. Pereopod 3 ischium inferior margin with 2 short simple setae, superior margin with 1 RS (large); merus inferior margin with 1 stout acute RS, superior distal margin with 2 acute RS; carpus inferior margin with 3 RS and 1 simple seta; propodus 3.3 as long as wide, with 1 RS; dactylus 1.3 as long as propodus. Pereopod 6 similar to pereopod 7. Pereopod 7 basis 6.0 times as long as greatest width, margins subparallel, superior margin with 3 palmate setae, inferior margin with 3 short simple setae; ischium 0.5 as long as basis, inferior margin with 1 short simple seta, superior distal angle with 1 RS and 1 simple seta; merus 1.0 as long as ischium, 2.1 times as long as wide, inferior margin with 1 RS, superior distal angle with 2 RS, inferior distal angle with 2 RS; carpus 0.8 as long as ischium, 3.0 times as long as wide, inferior margin with 0 RS, superior distal angle with 0 RS, inferior distal angle with 3; propodus 1.3 as long as ischium, 4.7 times as long as wide, inferior margin with 1 RS, superior distal angle with 3 and 1 palmate slender setae, inferior distal angle with 3 RS; dactylus weakly curved, as long as propodus.

Pleopod 1 exopod 2.2 times as long as wide, mesial margin straight, lateral margin strongly convex, curving smoothly to distomesial point (i.e. no clearly defined distal margin), distal two-thirds with 8 PMS; endopod 0.3 as long and 0.11 as wide as exopod, 6.1 times as long as wide, margins straight, sub-parallel, distally narrowly rounded, with 1 PMS on distal margin only; peduncle 1.3 times as wide as long; mesial margin with 3 coupling setae. Pleopod 2 exopod 1.9 as long as wide, with 4 PMS, endopod 0.7 as long as endopod, 3.4 as long as wide, with 2 PMS; endopod. Pleopod 3 exopod 1.9 as long as wide, with 4 PMS, endopod 0.7 as long as endopod, 3.4 as long as wide, with 2 PMS; endopod. Pleopod 3 exopod with 4 PMS, endopod with 2 PMS. Pleopod 4 exopod with 4 PMS, endopod with 2 PMS. Pleopod 5 exopod with 4 PMS, endopod with 2 PMS. Pleopod 1 peduncle with 3 coupling hooks, pleopods 2–5 peduncle each with 2 weak coupling hooks RS, later margin with single acute RS.

Uropod peduncle ventrolateral margin with 1 seta, lateral margin with medial simple seta; rami not extending beyond pleotelson, without RS, apices with acute lateral process, not bifid. Endopod 2.9 as long as greatest width, lateral margin weakly convex, mesial margin convex; distal lateral margin with 1 long seta RS, mesial margin with 2 long sub-apical setae. Exopod 3.2 times as long as greatest width, 0.6 as long as endopod; lateral margin straight, with 1 long sub-apical seta, mesial margin straight, with 2 long sub-apical seta.

Male. Not known.

Remarks. The species can be identified by the generic characters, notably the operculate pleopod 1 exopod, broadly rounded pleotelson, slender legs with notably long dactylus, small body size and lack of pigmented eyes.

Etymology. The epithet is the Tagalog word meaning blind (noun in apposition).