Lanocira grebarree, Bruce, Niel L. & Sidabalok, Conni, 2011

Bruce, Niel L. & Sidabalok, Conni, 2011, The genus Lanocira Hansen, 1890 (Corallanidae: Isopoda: Crustacea) in tropical Australian waters, Zootaxa 2793, pp. 23-34 : 26-32

Lanocira grebarree sp. nov.

( Figs 3–6 )

Material examined. All material from Great Barrier Reef, Australia.

Holotype. 3 (5.9 mm), Bird Islet, Lizard Island Group, 14.69664°S, 145.4642°E, 13 February 2009, outer fore reef, stn CWLI 0 0 3, coll. C. Watson (MTQ W31113; + 1 microslide).

Paratypes. 1 3 (4.8 mm, dissected), Lizard Island, North Point reef, 13 December 1980, 11 m, coll. N.L. Bruce (MTQ W10788 + microslides). 1 3 (4.0 mm), Lionet Reef, 14.78058°S, 145.34940°E, 16 February 2009, back reef, fragment of Acropora on stalk, 5 m, stn LIZ09-08C, coll. M. Błażewicz-Paszkowycz (MTQ W32428). 1 3 (4.4 mm), Heron Island, 23.436°S 151.926°E, northern side, reef flat, 100 m back from reef edge, 14 April 2003, from large boulder, RW03.155, coll. N.L. Bruce ( LACM CR 2003-55). 1 Ƥ (6.7 mm, non-ovig.), south of Wistari Reef, Capricorn Group, 23.488°S 151.883°E, 13 April 2003, mixed dead coral, 5 m, RW03.138, coll. R. Wetzer, N.L. Bruce and D. Pentcheff ( LACM CR 2003-53). 1 3 (4.8 mm), Wistari Reef, northern side, 23°27.257’S, 151°52.840’E, 23 November 2009, dead coral on side of bommie, 3–5 m, stn HI09-084D, coll. N.L. Bruce & K. Schnabel (MTQ W32429).

Additional material. 1 3 (5.5 mm), 2 Ƥ (6.0, 4.8 mm, non-ovig.), 4 mancas (2.2, 2.6, 2.9, 3.2 mm), Lizard Island, 11 December 1980, central lagoon, 1–2 m, coll. N.L. Bruce (MTQ W10798). 1 3 (4.5 mm), 2 Ƥ (5.1, 4.5 mm, non-ovig.), manca (2.5 mm), between Palfrey Island and South Island, Lizard Island Group, 11 December 1980, 2 m, coll. N.L. Bruce (MTQ W10782). 1 3, 1 Ƥ, 1 inter-moult, 2 mancas (not measured), North Point, Lizard Island, 12 December 1980, 10– 12 m, coll. N.L. Bruce (QM W10793). 14 (1 adult, 13 mancas, not measured), Lionet Reef, 14.78058°S, 145.34940°E, 16 February 2009, back reef, fragment of Acropora on stalk, 5 m, stn LIZ09- 08C, coll. M. Błażewicz-Paszkowycz (MTQ W30484). 2 3 (6.2, 6.0 mm), south of Wistari Reef, 23.488°S 151.883°E, 13 April 2003, coral rubble from side of bommie, 16.1 m, RW03.143, coll. N.L. Bruce, R. Wetzer and D. Pentcheff ( LACM CR 2003-54). 1 Ƥ (5.2 mm, non-ovig.), southwest corner of Wistari Reef, Capricorn Group, 4 December 1979, 11 m, coll. N.L. Bruce (MTQ W10779).

Description. Adult male. Body 2.5 times as long as greatest width, dorsal surfaces smooth, widest at pereonite 4, lateral margins weakly ovate. Rostrum present, anteriorly upturned and rounded. Eyes separated by about 33% width of head, each eye made up of ~8 transverse rows of ommatidia, each row with ~6 ommatidia, eye colour black. Pereonites without transverse impressed line (absent on all pereonites); pereonite 1 and coxae 2–3 each with posteroventral angle rounded; coxae 5–7 with incomplete oblique carina; posterior margins of pereonites 5–7 smooth, without nodules or setae.

Pleon with pleonite 1 entirely concealed and pleonite 2 largely concealed by pereonite 7; pleonites 3–5 posterior margin smooth; posterolateral angles of pleonite 2 not visible; pleonite 3 with posterolateral margins rounded, not extending to posterior margin of pleonite 4; posterolateral margins of pleonite 4 broadly rounded, extending beyond posterior margin of pleonite 5; pleonite 5 posterolateral angles entirely overlapped by lateral margins of pleonite 4. Pleotelson 0.8 as long as anterior width, with paired sub-marginal lateral anterolateral depressions; lateral margins weakly convex, converging to sub-truncate posterior margin without median point; posterior margin with 6 RS and ~26 PMS.

Antennule peduncle articles 1 and 2 fused; articles 3 and 4 0.7 times as long as combined lengths of articles 1 and 2; article 3 2.8 times as long as wide; flagellum with 6 articles, extending to posterior margin of eye. Antenna peduncle article 4 2.4 times as long as wide, 3.0 times as long as article 3, anterodistal angle with 1 pectinate seta, and 2 simple setae; article 5 0.9 times as long as article 4, 2.0 times as long as wide, anterodistal angle with cluster of 2 pectinate and 2 simple setae; flagellum with 14 articles, extending to posterior of pereonite 2.

Frontal lamina pentagonal, 1.2 times wider than long, lateral margins weakly concave, diverging slightly towards anterior; anterior margins concave with distinct median point. Mandible incisor unicuspid, anterodistal margin with 6 prominent keratinized spines; molar process reduced, lobe-like, with 2 small scales; palp article 2 with 7 distolateral plumose setae, article 3 with 10, distal 3 longest. Maxillule as for genus. Maxilla article 2 with 3 mesial simple setae, article 3 with 2 long simple setae. Maxilliped palp article 2 mesial margin with 1 slender setae, lateral margin distally without slender setae, article 3 mesial margin with 2 slender setae, lateral margin without slender setae, article 4 mesial margin with 1 short and 1 long slender setae, lateral margin with 1 slender setae, article 5 distomesial margin with 4 setae, lateral margin with 2 setae; without endite.

Pereopod 1 basis 3.2 times as long as greatest width, inferior distal angle with cluster of 1 acute simple setae; ischium 0.4 as long as basis, inferior margin with 3 setae, superior distal margin with acute 1 RS; merus inferior margin with 4 molariform RS, set as single row, superior distal angle with 3 short setae; carpus inferior margin with 1 slender seta; propodus 2.5 times as long as wide, inferior margin without RS, 2 long simple setae and 1 RS opposing dactylus; dactylus 0.9 as long as propodus, strongly curved. Pereopod 2 ischium inferior margin with 2 stout RS, superior distal margin with 2 acute RS, one short one long; merus inferior margin with 4 molariform RS, 1 acute RS and 1 simples seta, superior distal margin with 3 slender setae; carpus inferodistal angle without RS. Pereopod 3 similar to pereopod 2. Pereopod 6 similar to pereopod 7. Pereopod 7 basis 2.1 times as long as greatest width, inferior margin weakly convex with 5 simple setae, proximal superior margin with 6 palmate setae; ischium 0.5 as long as basis, inferior margin with 2 RS (set as 1 and 1), superior distal angle with 6 RS, inferior distal angle with 3 RS; merus 0.8 as long as ischium, 1.4 times as long as wide, inferior margin with 1 RS, superior distal angle with 5 RS, inferior distal angle with 6 RS; carpus 0.8 as long as ischium, 1.6 times as long as wide, inferior margin with 1 RS, superior distal angle with ~20 RS, inferior distal angle with 6 RS; propodus 0.7 times as long as ischium, 2.3 times as long as wide, inferior margin with 1 RS, superior distal angle with 2 RS and 1 slender setae, inferior distal angle with 1 RS.

Penes opening flush with surface of sternite 7, narrowly separated (by <1% sternal width).

Pleopod 1 exopod 1.7 times as long as wide, lateral margin straight, mesial margin convex; distally broadly rounded; endopod 2.5 times as long as wide, distally subtruncate, lateral margin straight, with PMS on distal margin only, mesial margin with PMS from distal one-third; peduncle 2.2 times as wide as long; mesial margin with 4 coupling hooks. Pleopod 2 appendix masculina with parallel margins, 0.8 times as long as endopod, distally narrowly rounded. Pleopods 1–4 peduncle distolateral margin with small acute RS; pleopods 3–5 exopods without complete transverse suture.

.

Uropod peduncle ventrolateral margin with 1 RS, lateral margin with medial short acute RS, posterior lobe about 0.7 as long as endopod; rami extending beyond pleotelson, marginal setae in single tier, apices broadly rounded. Endopod apically not bifid; lateral margin straight, lateral margin with 1 RS, distolateral margin with 2 RS; mesial margin convex, with 6 RS. Exopod extending to 0.7 length of endopod, 2.3 times as long as greatest width, apically not bifid; lateral margin weakly convex, with 6 RS; mesial margin convex, with 3 RS.

Female: Similar to male but for the rostral process, which is weakly developed, and sexual characters.

Variation. The pattern and number of robust setae on the margins of the pleotelson (n = 5) and uropods (n = 11) is highly consistent: uropod exopod lateral margin 5 or 6 (82%) RS, mesial margin 2 or 3 (91%) RS; endopod later margin with 3 RS (100%), lateral margin with 4 (once), 5 (27%) or 6 (64%) RS; pleotelson always with 6 RS.

Size. Adult males 4.0– 6.2 mm (mean 4.7 mm; n =9); non-ovigerous females 4.5–6.7 mm (mean 5.4 mm; n =6); mancas 2.2–3.2 mm (mean 2.7 mm; n =5).

Remarks. Males of Lanocira grebarree sp. nov. can be identified by the combination of short and anteriorly rounded rostrum, lack of stiff setae on the dorsum of the pleotelson and the uropodal rami extending beyond the pleotelson apex. Lanocira grebarree is most similar to L. gardineri including having an upturned and anteriorly rounded rostral process, but consistently differs in the lack of setae on the dorsal surface of pleon and pleotelson.

Two male specimens from Wistari Reef (LACM CR 2003-54; Fig. 6 ) are only provisionally identified as L. grebarree sp. nov. as they are slightly larger than those of the type series, with the smaller male lacking any rostrum development while the larger specimen has a more strongly developed rostrum that males in the type series, and additionally has four distinct clumps of cephalic setae, a character not present in males in the type series.

Distribution. Lizard Island and Heron Island, Great Barrier Reef, Australia; at depths from the intertidal to 11 metres.

Etymology. The epithet is derived from the first three letters of each word of ‘Great Barrier Reef’.

Figures

FIGURE 3. Lanocira grebarree sp. nov. A, B, holotype, C, female paratype LACM CR 2003 - 53; remainder male paratype (MTQ W 10788). A, dorsal view; B, lateral view; C, dorsal view; D, mandible (in two parts); E, pleotelson posterior margin; F, maxilliped; G, maxilla; H, maxillule; I, antennule; J, antenna; K, frons.

FIGURE 4. Lanocira grebarree sp. nov. Male paratype (MTQ W 10788). A – E, pereopods 1, 2, 3, 6 and 7, respectively; F, uropod.

FIGURE 5. Lanocira grebarree sp. nov. A and B holotype; remainder male paratype (MTQ W 10788). A – E, pleopods 1 – 5 respectively; F, penial openings.

FIGURE 6. Lanocira grebarree sp. nov. Male 6.2, 6.0 mm (LACM CR 2003 - 54). A, dorsal view; B, lateral view; C, head with four groups of setae.