Cirolana peisanae, Bruce, 2017

Bruce, Niel L., 2017, Review of the species of the Cirolana ‘ parva - group’ (Cirolanidae: Isopoda: Crustacea) in Indonesian and Singaporean waters, Zootaxa 4317 (3), pp. 401-435 : 423-428

Cirolana peisanae sp. nov.

( Fig. 13–16 )

Material examined. Holotype, ♂ (6.5 mm), Pulau Tekukor, Singapore, 01°13.879'N, 103°50.318'E, 12 March 2014, trap at 1.6 m, coll. Razali and party, OTR 320 OTC 0 0 43 ( ZRC 2017.0765 ).

Paratypes, Indonesia series. 1 ♂ (4.5 mm), 9 ♀ (3.9–6.1 mm, average 4.6 mm), Teluk Medana , Lombok, 8°21'34.00''S, 116°07'25.59''E, 14 August 2014, diving 6 m, rubble and dead coral head, coll. C.M. Sidabalok and party ( MZB Cru.Iso. 071) . 1 ♂ (4.9 mm), Gili Air , Lombok, 8°21'27.238''S, 116°05'17.206''E, 13 August 2014, diving 10 m, rubble and dead coral head, coll. C.M. Sidabalok and party ( MZB Cru.Iso. 072) . 4 ♂ (3.4, 3.5, 3.7 [dissected], 3.8 mm), 1 ♀ (3.1 mm), Teluk Mentigi , Lombok, 8°21'.26.94''S, 116°07'19.32''E, 13 August 2 0 14, trap 20 m, coll. C.M. Sidabalok and party ( MZB Cru.Iso 070).

Singapore series. 11 ♂ (7.5, 7.5, 7.5, 7.6, 8.4, 8.5, 8.5, 8.6, 8.7, 9.0, 9.0 mm), 4 ♀ (8.0, 8.0, 8.4, 8.4), Pulau Tekukor , 01°13.879'N, 103°50.318'E, 12 March 2014, trap at 1.6 m, coll. Razali and party, OTR 320 OTC 0 0 38 ( ZRC 2017.0766 ) . 4 ♂ (5.5, 6.2, 6.5 [dissected], 7.5 mm), same data as previous, OTC 0 0 39 ( ZRC 2017.0767 ) . 4 ♂ (5.7, 6.0 [dissected], 6.3, 6.9 mm), same data as previous, OTC 0 0 42 (MTQ W52900) . 7 ♂ (5.5, 5.9, 5.9, 6.2, 6.5, 6.5 [dissected], 6.7mm), same data as previous, OTC 0 0 43 ( ZRC 2017.0768 ) . 2 ♂ (5.8, 6.0 mm), 1 manca (2.7 mm), Singapore Strait , 01°12.974'N, 103°52.960'E, 30 May 2013, beam trawl 113–128 m, coll. Lim Swee Cheng and party, TB127 SS2008 ( ZRC 2017.0769 ) . 1♂ (4.5 mm), Singapore Port Limit , 22 May 2013, 01°13.181' N, 103°52.900' E, beam trawl on gravel and rocky, coll. N.L. Bruce and party, TB28, SS0829 ( ZRC 2017.0770 ) . 1 ♂ (4.5 mm), 5 ♀ (5.2, 5.2, 5.5, 5.6, 6.0 mm), Tanjong Lokos, St John’s Island, 01°12.851' N, 103°51.045' E, 30 May 2013, hand collection on intertidal rocky shore, coll. J.K. Lowry and N.L. Bruce, IT 118, SS4938 ( ZRC 2017.0771 ) . 1 ♂ (5.5 mm), Pulau Jong , 01°12.901' N, 103°47.194' E, 28 May 2013, hand collection on intertidal reef, coll. Lee Yen-Ling and party, IT93, SS0848 (MTQ W52899).

Description. Body widest at pereonite 5, lateral margins subparallel. Eyes separated by about 80% width of head, eye colour black. Pereonite 1 and coxae 2–3 each with posteroventral angle rounded; 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, extending posteriorly to anterior of pleonite 3; pleonite 3 with posterolateral margins extending clearly beyond posterior margin of pleonite 5, acute; posterolateral margin of pleonite 4 rounded, clearly extending beyond posterior margin of pleonite 5. Pleotelson 0.8 time as long as anterior width; pleotelson lateral margins weakly convex, margins weakly serrate, pleotelson posterior margin evenly rounded, with small distinct median point, with 8 RS.

Antennula peduncle articles 1 and 2 distinct, articulated; article 2 0.8 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 2.3 times as long as wide; flagellum with 8 articles, extending to anterior of pereonite 1. Antenna peduncle article 4 1.4 times as long as wide, 1.6 times as long as article 3, and 4 short simple setae (distal); article 5 1.2 times as long as article 4, 1.9 times as long as wide, inferior margin without pappose setae. Anterodistal angle without cluster of plumose setae. Anterodistal angle with cluster of 3 short simple setae; 1 long simple setae; antenna flagellum with 22 articles, extending to posterior of pereonite 4.

Frontal lamina 1.5 longer than posterior width, 1.3 longer than greatest width, lateral margins straight, diverging slightly towards anterior, anterior margin acute, forming median point.

Mandible molar process anterior margin with 25 flat teeth; with proximal cluster of long simple setae; right mandible spine row composed of 10 spines; palp article 2 with 7 distolateral setae, palp article 3 with 1 robust biserrate setae. Maxillula mesial lobe with 3 large and CPS RS; lateral lobe with 11 RS. Maxilla lateral lobe with 4 long simple setae; middle lobe with 4 long simple setae; mesial lobe with 7 distal simple setae, with 6 proximal simple and plumose setae. Maxilliped palp article 2 mesial margin with 5 slender setae, lateral margin distally with 1 slender seta; article 3 mesial margin with 11 slender setae, lateral margin with 5 slender setae; article 4 mesial margin with 11 slender setae, lateral margin with 3 slender setae; article 5 distal margin 11 setae, lateral margin with 4 setae; endite with 3 long CPS, and 2 coupling setae.

Pereopod 1 basis 2.4 times as long as greatest width, superior distal angle without cluster of acute setae, inferior distal angle with cluster of 1 acute seta; ischium 0.6 times as long as basis, inferior margin with 1 setae, inferior distal margin without RS, superior distal margin with 2 RS; merus inferior margin with 5 molariform RS (set as 2 and 3), set as single row and 1 simple seta, inferior distal margin with 1 RS, superior distal angle with 2 setae; carpus inferior margin with 8 simple setae; propodus 1.8 times as long as wide, inferior margin with 2 RS and 1 simple seta, inferior distal margin with 1 large RS, superior distal with 1 simple seta; dactylus 0.6 as long as propodus; inferior margin with setal fringe lacking. Pereopod 2 ischium inferior margin with 1 simple seta, distal margin with 2 RS, superior distal margin with 2 RS; merus inferior margin with 4 stout RS, set as single row, inferior distal margin with 2 stout RS, superior distal margin with 2 stout RS and 1 acute RS; carpus inferior distal margin with 4 RS; propodus 2.9 as long as wide, with 2 clusters of acute RS, inferior margin with 2 RS, inferior distal margin with 1 long and 2 simple setae; dactylus 0.5 as long as propodus. Pereopod 3 similar to pereopod 2. Pereopod 6 similar to pereopod 7. Pereopod 7 basis 2.3 times as long as greatest width, superior margin convex, inferior margin without palmate setae; ischium 0.6 as long as basis, inferior margin with 3 RS, superior distal angle with 5 RS, inferior distal angle with 2 RS; merus 0.6 as long as ischium, 1.4 times as long as wide, inferior margin with 1 RS, superior distal angle with 6 RS (1 biserrate), inferior distal angle with 5 RS; carpus 0.9 as long as ischium, 2.5 times as long as wide, inferior margin with 2 RS, superior distal angle with 6 RS (2 biserrate), inferior distal angle with 5 RS (1 biserrate); propodus 0.9 as long as ischium, 3.4 times as long as wide, inferior margin with 2 clusters of RS, superior distal angle with 3 slender setae, inferior distal angle with 2 RS; dactylus 0.5 as long as propodus.

Penes opening flush with surface of sternite 7, openings separated by 14.5% of sternal width.

Pleopod 1 exopod 1.7 times as long as wide, lateral margin weakly convex, distally narrowly rounded, mesial margin weakly oblique, mesial margin weakly convex, with PMS from distal one-third, with ~23 PMS; endopod 2 times as long as wide, distally subtruncate, lateral margin straight, with PMS from distal one-third, mesial margin with PMS on distal margin only, endopod with ~11 PMS; peduncle 1.5 times as wide as long; mesial margin with 4 coupling setae. Pleopod 2 exopod with ~25 PMS, endopod with ~15 PMS; appendix masculina with parallel margins, 1.6 times as long as endopod, distally acute. Pleopod 3 exopod with ~29 PMS, endopod with ~12 PMS. Pleopod 4 exopod with ~28 PMS, endopod with ~9 PMS. Pleopod 5 exopod with ~26 PMS. Pleopods 2–5 peduncle distolateral margin with prominent acute RS, 3–5 endopods with distomesial serrate scales.

Uropod peduncle ventrolateral margin with 2 RS, lateral margin with mesial short acute RS, posterior lobe about as long as endopod; rami extending beyond pleotelson, marginal setae in single tier, apices acute. Endopod apically deeply subequal bifid, lateral process prominent; lateral margin weakly convex, proximal lateral margin with 2 RS; distal lateral margin with 1 RS, mesial margin strongly convex, with 4 RS. Exopod not extending to end of endopod, 2.5 times as long as greatest width, apically deeply subequal bifid, lateral process prominent; lateral margin weakly convex, with 7 RS; mesial margin straight, distally convex, with 3 RS.

Female. Similar to male.

Variation. Thirteen specimens were measured for the uropod RS (ZRC 2017.0766). Uropod exopod RS mesial margin with 3 (100%), lateral with 5–7 (6 = 61.5%, 5 = 23.1%, 7 = 15.4%); uropod endopod RS mesial margin with 3–5 (4 = 53.8%, 3 = 30.8%, 5 = 15.4%), lateral margin with 2–3 (3 = 69.2%).

Remarks. Cirolana peisanae sp. nov. is most similar to Cirolana leptanga in having antennula peduncle article 2 distinctly articulated, pereopod 1 without setal fringe, the appendix masculina with a pointed tip and separate penial openings (separated by 14.5%–17.0% sternal width). The two species are different in the ratio of uropod width and length, with Cirolana peisanae having a wider uropod endopod (length vs width 50% vs 40% in C. leptanga ) and exopod (length vs width 40% vs 30%). Cirolana peisanae is also similar to Cirolana phangnga Rodcharoen, Bruce and Pholpunthin, 2016 , differing by having more widely separated penial openings (14.5– 17.0% and 12%, respectively) and the shape of uropod and exopod (narrower in the former).

Distribution. Indonesia (Lombok) and Singapore; intertidal to 128 metres ( Fig 1 ).

Etymology. Cirolana peisanae is named for Wong Pei San Helen who collected the Singaporean specimens and gave excellent assistance in the preparation of specimens for this paper.

Figures

FIGURE 1. Distribution map of Cirolana ‘ parva group’ in Indo-Australian region (C – H, Indonesia; I, PNG; J – K, Australia). LoCation symbols: A = Thailand, B = Singapore, C = Lombok, D = Bitung, E = Pulau Pombo, Maluku, F = Raja Ampat, G = Kei Islands, H = Kaimana, I = Madang, J = Lizard Island, K = HinChinbrook Island. SpeCies symbols: Cirolana andamanensis (-), Cirolana arafurae (×), Cirolana improceros (v), Cirolana leptanga (O), Cirolana siamensis (O), Cirolana stenoura (A), Cirolana thailandica (Ł), Cirolana molari (Ɨ), Cirolana peisanae (+), Cirolana duo (Ŧ).

FIGURE 13. Cirolana peisanae sp. nov., holotype ♂ (6.5 mm, ZRC 2017.0765) (A – B, E – G), paratype ♂ (6.5 mm, ZRC 2017.0767) (C – D, H – J): A, dorsal view; B, lateral view; C, antennula; D, antenna pedunCle; E, frons; F, head; G, penial openings; H, uropod; I, uropod apiCes; J, pleotelson.

FIGURE 14. Cirolana peisanae sp. nov., paratype ♂ (6.5 mm, ZRC 2017.0767) (A – D): A, maxilla; B, maxilliped; C, maxillule; D, right mandible.

FIGURE 15. Cirolana peisanae sp. nov., paratype ♂ (6.5 mm, ZRC 2017.0767): A, pereopod 1; B, pereopod 2; C, pereopod 6; D, pereopod 7.

FIGURE 16. Cirolana peisanae sp. nov., paratype ♂ (6.5 mm, ZRC 2017.0767): A, pleopod 1; B, pleopod 2; C, pleopod 3; D, pleopod 4; E, pleopod 5.