Leucothoe laevipalma, White & Thomas, 2009

White, Kristine N. & Thomas, James Darwin, 2009, Leucothoidae *, Zootaxa 2260 (1), pp. 494-555 : 515-518

Leucothoe laevipalma sp. nov.

( Figs 13 , 14 )

Type material. Holotype, male, 2.2mm, AM P 79808, patch reef off southern tip of Lizard Island (14°41’S 145°26’E), rubble, 1 m, J. D. Thomas, 23 January 1989 ( JDT / LIZ 3 ) . Paratype, female, 2.5 mm, AM P 79809 , North Point , Lizard Island (14°41’S 145°27’E), rubble sample from vertical cliffs and unconsolidated bottom rubble, 12.2 m, J . D. Thomas, 28 January 1989 ( JDT / LIZ 13 ) .

Additional material examined. 1 male, AM P 79810 ( JDT / LIZ 5 ) ; 1 female, 1 male, AM P 79811 ( QLD 1760 ) ; 1 male, 1 juvenile, GCRL2889 ( SEL /LZI-2-3) .

Type locality. Southern tip of Lizard Island, Queensland, Australia (14°41’S 145°26’E) .

Etymology. After the Latin ‘ laevis ’, meaning ‘smooth,’ and ‘ palma ’, meaning ‘the palm of the hand’ and referring to the smooth gnathopod 1 propodus palm.

Description. Based on holotype, male, 2.2 mm, AM P79808.

Head. Head length less than pereonite 1+2, anterior margin rounded, without serrations or teeth, anterodistal margin rounded without cusp, ventral cephalic keel rounded, rostrum small to medium; eyes with 10 or more ocelli, round. Antenna 1 0.4 x body length; flagellum 7-articulate, peduncle width less than 2 x article 2. Antenna 2 0.3 x body length, shorter than antenna 1; flagellum 3-articulate. Mandibles lacking molars, palp 3-articulate, ratio of articles 1 – 3, 1.0:3.0:1.0, article 2 with 2 – 3 distal setae, article 3 with 2 distal setae, incisors strongly dentate; left mandible lacinia mobilis large, strongly toothed, with 7 accessory setae; right mandible lacinia mobilis small, with 8 accessory setae. Upper lip asymmetrically lobate, anterior margin setose. Lower lip inner lobes fused, bare; outer lobes with moderate gape, anterior margins weakly setose. Maxilla 1 palp 1-articulate with 2 distal setae; outer plate with 3 distal spines and 3 distal setae. Maxilla 2 inner plate with 5 distal setae; outer plate with 16 distal setae. Maxilliped inner plates fused, distal margin with v-shaped indentation, with short spines and long setae; outer plate serrate, reduced, reaching much less than half of palp article 1, with 4 distal setae and 1 distal spine; palp 4-articulate, article 4 slender, slightly recurved.

Pereon. Coxae 1–4 relative widths 1.0:1.2:1.2:1.5. Gnathopod 1 coxa smooth, setose, anterodistal corner produced, broadly rounded, distal margin straight, posterodistal margin rounded, facial setae absent; basis slightly constricted proximally, anterior margin bare, posterior margin with 1–5 setae; ischium bare; carpus and propodus distally tapered; carpus length 18.8 x width, proximal margin smooth, distal margin setose; propodus straight, palm smooth with 9 – 10 distal setae; dactylus smooth, reaching 0.2 x propodus length. Gnathopod 2 length 0.9 x width, subequal to coxa 3, smooth, bare, anterodistally rounded, distal margin evenly rounded, posterior margin slightly concave, facial setae absent; basis constricted proximally, without tubercles or serrations, anterior margin with 1–8 setae, posterior margin with 1–5 setae; ischium with 1 posterior seta; carpus 0.4 x propodus length, straight, distally truncate, anterior margin serrate; propodus posterior margin without teeth/serrations, with 2 mediofacial setal rows, primary mediofacial setal row above midline, reaching 0.8 x propodus length, secondary mediofacial setal row with 3 setae, 1 row of 4 submarginal setae, palm convex with 5 minor projections; dactylus recurved, proximal margin smooth, anterior margin distally acute, reaching 0.9 x propodus length. Pereopod 3 coxa length and width subequal, anterodistal corner over-riding distal face of coxa 2 and extending below it, smooth, setose, anterior margin evenly rounded, distal margin slightly convex, posterior margin slightly excavate, facial setae absent. Pereopod 4 coxa smooth, setose, anterior margin evenly rounded, distal margin evenly rounded, posterior margin tapered, facial setae absent. Pereopods 5–7 coxa facial setae absent; basis width length ratios 1:1.3, 1:1.5, 1:1.3, posterior margins smooth, setose.

Pleon. Epimera 1–3 bare. Epimeron 2 with 3 ventral setae. Epimeron 3 posteroventral corner subquadrate. Uropod 3 missing. Uropods 1–2 relative lengths 1.0:0.5. Uropod 1 peduncle subequal in length with inner ramus; outer ramus subequal in length with inner ramus. Uropod 2 peduncle 0.8 x inner ramus length; outer ramus 0.7 x inner ramus length. Uropods 1–2 inner ramus lined with short marginal setae, with 1 robust seta; outer ramus lined with short marginal setae, with robust setae. Telson 2.4 x longer than wide, apex tridentate.

Female (sexually dimorphic characters). Based on paratype, female, 2.5 mm, AM P 79809. Gnathopod 2 basis anterior margin with 1–3 setae; propodus single mediofacial setal row above midline, reaching 0.6 x propodus length .

Habitat. In coral rubble.

Remarks. Leucothoe laevipalma sp. nov. shares its uni-articulate maxilla 1 palp with L. hipposideros sp. nov., L. odontiskos sp. nov., L. pollexa sp. nov., L. sparsa sp. nov., L. thula sp. nov. and L. undulata sp. nov. This character has not been found in any described Leucothoe to date, although an “indistinct suture” in the maxilla 1 palp has been reported in L. assimilis , L. basilobata , L. cheiriserra and L. urospinosa . Leucothoe laevipalma shares its serrate maxilliped outer plate with L. basilobata , L. cheiriserra , L. ctenochasma , L. laurensi , L. orkneyi , L. squalidens , L. hipposideros , L. odontiskos , L. serrata sp. nov. and L. undulata . The smooth gnathopod 1 propodus palm is similar to L. flammosa , Leucothoe bova sp. nov., Leucothoe odontiskos and L. serrata . L. laevipalma differs from L. serrata in its gnathopod 1 propodus palm dentition. Leucothoe laevipalma is similar to Leucothoe ashleyae , Leucothoe barana , females of Leucothoella gracilis ( Haswell, 1879) , Leucothoe kensleyi , L. ubouhu , L. bova sp. nov., L. laevipalma , Leucothoe makrommatos sp. nov. and L. undulata in its gnathopod 2 propodus secondary mediofacial setal row.

Distribution. Australia. Queensland: Lizard Island (current study).

Figures

FIGURE 13. Leucothoe laevipalma sp. nov., holotype, male, 2.2 mm, AM P79808; paratype, female, 2.5 mm, AM P79809 (JDT/LIZ 13), southern tip of Lizard Island, Great Barrier Reef.

FIGURE 14. Leucothoe laevipalma sp. nov., holotype, male, 2.2 mm, AM P79808; paratype, female, 2.5 mm, AM P79809 (JDT/LIZ 3), Lizard Island, Great Barrier Reef.