Leucothoe undulata, White & Thomas, 2009

White, Kristine N. & Thomas, James Darwin, 2009, Leucothoidae *, Zootaxa 2260 (1), pp. 494-555 : 541-544

Leucothoe undulata sp. nov.

( Figs 29 , 30 )

Type material. Holotype, female, 3.2 mm, AM P 80178. Pioneer Bay , Orpheus Island (~ 18°36'S 146°29'E), red encrusting sponge on reef, 2 m, K. N. Klebba, 27 May 2004 ( JDT / OPH 27 ).

Type locality. Pioneer Bay , Orpheus Island, Queensland, Australia (~ 18°36'S 146°29'E) .

Etymology. After the Latin ‘ undulatus ’, meaning ‘wavy’ and referring to the undulating anterior margin of the gnathopod 2 carpus.

Description. Based on holotype, female, 3.2 mm, AM P80178.

Head. Head length less than pereonite 1+2, anterior margin rounded, without serrations or teeth, anterodistal margin rounded without cusp, ventral cephalic keel transverse, rostrum small to medium; eyes with 10 or more ocelli, round. Antenna 1 0.3 x body length; flagellum 6-articulate, peduncle width less than 2 x article 2. Antenna 2 0.2 x body length, shorter than antenna 1; flagellum 4-articulate. Mandibles lacking molars, palp 3-articulate, ratio of articles 1 – 3, 1.0:1.9:0.6, article 1 with a single seta, article 2 with 3 distal setae, article 3 with 2 distal setae, incisors strongly dentate; right mandible lacinia mobilis small, with nine 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 4 distal setae; outer plate with 7 distal spines. Maxilla 2 inner plate with 3 distal setae; outer plate with nine distal setae. Maxilliped inner plates fused, distal margin with v-shaped indentation, with short spines; outer plate serrate, reduced, reaching less than half of palp article 1, with 5 distal setae and 1 distal spine; palp 4- articulate, article 4 wide, slightly recurved.

Pereon. Coxae 1–4 relative widths 1.0:1.4:1.5:2.5. Gnathopod 1 coxa smooth, setose, anterodistal corner not produced, narrowly rounded, distal margin rounded, posterodistal margin excavate, facial setae absent; basis constricted proximally, anterior margin bare, posterior margin with 11–20 short setae; ischium bare; carpus and propodus narrow, distally attenuated; carpus length 20 x width, proximal margin smooth, distal margin setose; propodus straight, palm dentate with nine distal setae; dactylus smooth, reaching 0.1 x propodus length. Gnathopod 2 coxa length 0.9 x width, slightly wider than coxa 3, smooth, bare, anterodistally rounded, distal margin straight, posterior margin slightly concave, facial setae absent; basis constricted proximally, without tubercles or serrations, anterior margin with 15 setae, posterior margin with 12 setae; ischium with 4 posterior and 3 posterodistal setae; carpus 0.4 x propodus length, straight, distally tapered, anterior margin undulating; 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 6 setae, 1 row of 7 submarginal setae; palm convex with several minor projections; dactylus recurved, proximal margin smooth with seta, anterior margin distally subacute, reaching 0.6 x propodus length. Pereopod 3 coxa length 1.4 x width, anterodistal corner over-riding distal face of coxa 2 and extending below it, smooth, setose, anterior margin straight, distal margin slightly convex, posterior margin straight, facial setae absent. Pereopod 4 coxa smooth, bare, anterior margin evenly rounded, distal margin evenly rounded, posterior margin excavate, facial setae absent. Pereopods 5–7 coxa facial setae absent; basis width length ratios 1:1.4, 1:1.5, 1:1.2, posterior margins smooth, bare.

Pleon. Epimeron 1 with 4 ventral setae. Epimeron 2 with 2 ventral setae. Epimeron 3 bare, posteroventral margin produced. Uropod 1–2 relative lengths 1.0:0.6. Uropod 1 peduncle subequal to inner ramus length; outer and inner ramus subequal in length. Uropod 2 peduncle and outer ramus 0.7 x inner ramus length. Uropod 1+2 inner and outer ramus lined with short marginal setae, with robust setae. Uropod 3 missing. Telson 1.7 x longer than wide, apex tridentate.

Male (sexually dimorphic characters). Unknown.

Habitat. In red encrusting sponge from a patch reef.

Remarks. Leucothoe undulata sp. nov. shares its uni-articulate maxilla 1 palp with L. hipposideros sp. nov., L. laevipalma sp. nov., L. odontiskos sp. nov., L. pollexa sp. nov., L. sparsa sp. nov. and L. thula 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 undulata sp. nov. shares its serrate maxilliped outer plate with L. basilobata , L. cheiriserra ., L. ctenochasma , L. laurensi , L. orkneyi , L. squalidens , L. hipposideros , L. laevipalma , L. odontiskos and L. serrata sp. nov. Leucothoe undulata sp. nov. shares its dentate gnathopod 1 propodus palm with L. ashleyae , L. basilobata , L. hipposideros and L. odontiskos , but lacks the triangular teeth found in L. hipposideros . Leucothoe undulata is similar to L. ashleyae , females of L. assimilis , females of L. banwarthii , L. barana , L. kensleyi , L. ubouhu , L. bova sp. nov., L laevipalma , L. makrommatos sp. nov. and L. odontiskos in its gnathopod 2 propodus secondary mediofacial setal row. The posterior setae on gnathopod 1 basis are shared with females of L. saron , L. ubouhu and L. odontiskos .

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

Figures

FIGURE 29. Leucothoe undulata sp. nov., holotype, female, 3.2 mm, AM P80178 (JDT/OPH 27), Pioneer Bay, Orpheus Island, Great Barrier Reef.

FIGURE 30. Leucothoe undulata sp. nov., holotype, female, 3.2 mm, AM P80178 (JDT/OPH 27), Pioneer Bay, Orpheus Island, Great Barrier Reef.