Odysseylana temasek, Sidabalok, Conni M. & Bruce, Niel L., 2015

Sidabalok, Conni M. & Bruce, Niel L., 2015, Revision of the cirolanid isopod genus Odysseylana Malyutina, 1995 (Crustacea) with description of two new species from Singapore, Zootaxa 4021 (2), pp. 351-367 : 360-366

publication ID	https://doi.org/ 10.11646/zootaxa.4021.2.6
publication LSID	lsid:zoobank.org:pub:78AB258C-42D4-4950-8682-DC2BE1B4855D
DOI	https://doi.org/10.5281/zenodo.6111025
persistent identifier	https://treatment.plazi.org/id/03E8879C-FF92-FFF7-FF10-FA57FA0CFD0C
treatment provided by	Plazi
scientific name	Odysseylana temasek
status	sp. nov.

Treatment

Odysseylana temasek View in CoL sp. nov.

( Fig 6–9 View FIGURE 6 View FIGURE 7 View FIGURE 8 View FIGURE 9 )

Odysseylana View in CoL sp. 6.— Bruce & Wong, 2015: 4. Odysseylana View in CoL sp.— Bruce & Wong, 2015: 4.

Material examined. All material from Singapore. Holotype: ♂ (8.6 mm), between St John’s Island and Lazarus Island, 31 May 2013, baited trap, 25 m, stn SW 137, SS 4942, coll. N.L. Bruce ( ZRC 2015.0363).

Paratypes: 1 ♂ (9.6 mm broken [part dissected]), 15 ♀ (6.1–9.4 mm, average 7.9 mm), same data as holotype ( ZRC 2015.0364, ZRC 2015.0365). 2 ♂ (9.5, 9.2 mm), 4 ♀ (7.0, 8.1, 8.2, 9.7 mm), between St John’s Island and Lazarus Island, 31 May 2013, 13.5 m, SW 138, coll. N.L. Bruce & J.K. Lowry ( ZRC 2015.0366). 1 ♀ (6.9 mm), St John’s Island jetty, 1°13.020'N, 103°51.122'W, 30 May 2013, 3– 5 m, SW 119, coll. N.L. Bruce (MTQ W34312). 3 ♀ (7.5, 8.5, 7.8 mm), SS 0854( ZRC 2015.0367); 1 ♀ 5718 ORI-39 coll. N.L. Bruce ( ZRC 2015.0368). 2 ♀ (unmeasured) St John’s Island lagoon, 1°12.913'N, 103°51.080'W, 29 May 2013, 3– 5 m, SW 106, coll. N.L. Bruce, H.P.S. Wong & J.K. Lowry (MTQ W34313).

Description. Body 3.5 times as long as greatest width, dorsal surfaces smooth, widest at pereonite 4, lateral margins ovate. Rostral point absent. Eyes separated by about 84% width of head, each eye made up of ~5–6 transverse rows of ommatidia, each row with ~5 ocelli, eye colour black. Pereonite 1 and coxae 2–3 each with posteroventral angle right-angled; coxae 5–7 with entire oblique carina; posterior margins of pereonites 5–7 smooth. Pleon with pleonite 1 visible in dorsal view; pleonites 3–5 posterior margin smooth; posterolateral angles of pleonite 2 forming acute point, not posteriorly produced; pleonite 3 with posterolateral margins not extending to posterior margin of pleonite 5, acute; pleonite 4 with posterolateral margin clearly extending beyond posterior margin of pleonite 5, rounded. Pleotelson 0.6 times as long as anterior width, dorsal surface without longitudinal carina; lateral margins straight, margins crenulate, posterior margin truncate, without median point, with 6 robust setae.

Antennula peduncle articles 1 and 2 fused, suture present; article 2 0.5 times as long as article 1, articles 3 and 4 0.8 times as long as combined lengths of articles 1 and 2, article 3 1.0 times as long as wide; flagellum with 10 articles, extending to posterior margin of eye. Antenna peduncle article 4 2.0 times as long as wide, 1.8 times as long as article 3, inferior margin with 5 plumose setae, and 1 short simple seta; article 5 0.9 times as long as article 4, 2.5 times as long as wide, inferior margin with 0 pappose setae, anterodistal angle with cluster of 5 short simple setae; flagellum with 17 articles, extending to posterior of pereonite 2.

Frontal lamina pentagonal, ventral surface entirely flat, 1.3 longer than greatest width, lateral margins straight, diverging slightly towards anterior, anterior margin acute, without small median point.

Mandible molar process anterior margin with 19 flat teeth; with proximal cluster of long simple setae; right mandible spine row composed of 11 spines, left with 2 spines; palp article 2 with 14 distolateral setae, palp article 3 with 14 robust biserrate setae. Maxillula mesial lobe with 3 large and circumplumose RS; lateral lobe with 9 RS. Maxilla lateral lobe with 4 long simple setae; middle lobe with 9 long simple setae; mesial lobe with 6 distal simple setae, with 9 proximal simple and plumose setae. Maxilliped palp article 2 mesial margin with 7 slender setae, lateral margin distally with 1 slender seta; article 3 mesial margin with 13 slender setae, lateral margin with 11 slender setae; article 4 mesial margin with 12 slender setae, lateral margin with 5 slender setae; article 5 distal margin 13 setae, lateral margin with 5 setae; endite with 5 long CPS, and 2 coupling setae.

Pereopod 1 basis 2.5 times as long as greatest width, superior distal angle without cluster of acute setae; ischium 0.5 times as long as basis, inferior margin with 6 setae, superior distal margin with 7 slender setae and 3 distal mid-margin setae; merus inferior margin with 6 molariform RS, set as single row, superior distal angle with 9 setae; carpus inferior margin with 1 RS; propodus 2.4 times as long as wide, inferior margin with 3 RS; dactylus 1.8 as long as propodus; inferior margin with setal fringe on propodus–ischium. Pereopod 2 basis superior margin convex, superior distal with 3 simple setae, inferior margin convex, inferior distal with 9 long simple setae; ischium inferior margin with 3 RS and 4 long simple setae, superior distal margin with 6 slender setae; merus inferior margin with 3 acute RS, 4 RS and 3 simple setae set as single row, superior distal margin with 4 acute RS and 6 slender setae; carpus inferodistal angle with 2 big RS, 1 small RS and 1 simple seta; propodus 2.7 as long as wide, half inferodistal angle with 2 acute RS, 1 blunt RS and 2 simple setae; dactylus 0.6 as long as propodus. Pereopod 3 similar to pereopod 2. Pereopod 6 similar to pereopod 7. Pereopod 7 basis 3.1 times as long as greatest width, superior margin straight with 1 long and 17 simple setae and, inferior margin convex with 10 simple small setae, inferior margin distal with 4 long simple setae; ischium 0.5 as long as basis, inferior margin with 3 clusters of 1 RS and 2 simple setae, 1 RS and 4 simple setae, 1 RS and 4 simple setae; superior distal angle with 3 long simple setae and 4 acute RS, mid distal angle with 1 RS; merus 1.1 as long as ischium, 2.4 times as long as wide, inferior margin with 2 clusters of 1 RS and 3 simple setae, 2 RS and 5 simple setae; superior distal angle with 2 RS, 6 long simple setae and 2 biserrate RS, inferior distal angle with 2 RS and 3 long simple setae; mid distal margin with 2 long simple setae; carpus 0.9 as long as ischium, 3.5 times as long as wide, inferior margin with 1 cluster of 1 RS and 4 simple setae and 1 RS, superior distal angle with 4 long simple setae and 5 biserrate RS, inferior distal angle with 2 RS, 2 simple and 4 biserrate setae; propodus 1.3 as long as ischium, 5.7 times as long as wide, inferior margin with 4 clusters of 2 RS and 1 simple seta, 1 RS and 1 simple seta, 2 RS and 1 simple seta and 2 RS; superior distal angle with 2 simple and 2 palmate setae, inferior distal angle with 2 RS; dactylus 0.5 as long as propodus.

Penes separated by 10% sternal width, opening flush with surface of sternite 7.

Pleopod 1 exopod 1.6 times as long as wide, lateral margin weakly concave, distally broadly rounded, mesial margin weakly convex, with PMS from base, with ~46 PMS; endopod 2.3 times as long as wide, distally subtruncate, lateral margin straight, with PMS on distal margin only, mesial margin with PMS from distal half, endopod with ~18 PMS; peduncle 0.8 times as wide as long; mesial margin with 4 coupling setae. Pleopod 2 exopod with ~53 PMS, endopod with ~20 PMS; appendix masculina with parallel margins, 0.9 times as long as endopod, distally acute. Pleopod 3 exopod with ~53 PMS, endopod with ~14 PMS. Pleopod 4 exopod with ~55 PMS, endopod with ~11 PMS. Pleopod 5 exopod with ~51 PMS. Pleopods 2–5 peduncle distolateral margin with prominent acute RS, 3–5 endopods with distomesial serrate scales.

Uropod peduncle ventrolateral margin with 0 RS, lateral margin without medial short acute robust seta, posterior lobe about one-third as long as endopod; rami extending to pleotelson apex, marginal setae in single tier, apices acute. Endopod apically not bifid; lateral margin straight, proximal lateral margin with 0 RS; distal lateral margin with 3 RS, mesial margin straight, with 5 RS. Exopod extending beyond end of endopod, 4.8 times as long as greatest width, apically deeply bifid; lateral margin straight, with 6 RS; mesial margin straight, with 4 RS.

Female. Non-ovigerous females as for male except sexual characters.

Size. Adult males 9.2–9.5 mm (2 specimens); non-ovigerous females 7.0– 9.7 mm (5 specimens).

Distribution. Known only from Singapore.

Remarks. Odysseylana temasek sp. nov. can be identified by the elongate body, weakly indented and subtruncate pleotelson posterior margin, smooth dorsum and the uropodal exopod extending posteriorly beyond the endopod. In addition to its similarity to Odysseylana sakijang (see ‘remarks’ for that species), Odysseylana temasek is also similar to Odysseylana sirenkoi , differing in having fewer plumose setae on antenna peduncle article 4, 2 coupling setae on maxilliped endite (vs 3), sub-truncate pleotelson posterior margin (vs deeply incised), more robust uropodal rami (vs slender and narrow exopod and posteriorly narrowed endopod), dorsally smooth pleotelson, weakly concave lateral and anterior margins of frontal lamina. Odysseylana temasek shares the smooth dorsal surface with Odysseylana setosa but differs in having a sub-truncate pleotelson posterior margin (vs rounded), the uropod exopod extending beyond the endopod, less setose pereopod 7, and the appendix masculina is shorter than the rami of pleopod 2.

Etymology: The species name temasek is the Malay word meaning “Sea Town”, the old name for Singapore.