Leucothoidae * Author White, Kristine N. Gulf Coast Research Laboratory, The University of Southern Mississippi, 703 East Beach Drive, Ocean Springs, MS 39564 - 7000, USA. Author Thomas, James Darwin Nova Southeastern University Oceanographic Center, 8000 North Ocean Drive, Dania Beach, FL 33004, USA. text Zootaxa 2009 2009-10-08 2260 1 494 555 https://www.biotaxa.org/Zootaxa/article/view/zootaxa.2260.1.29 journal article 10.11646/zootaxa.2260.1.29 1175-5326 5323471 Leucothoe sparsa sp. nov. ( Figs 25 , 26 ) Type material. Holotype , male, 2.9 mm , AM P 71036, Picnic Beach , Palfrey Island , Lizard Island ( 14°41.69'S 145°26.89'E ), algal mat and fine sediment from rubble bottom, reef flat, 3 m , S . LeCroy , 27 February 2005 ( QLD 1708 ). Type locality. Palfrey Island , Lizard Island , Queensland , Australia ( 14°41.69'S 145°26.89'E ) . Etymology. After the Latin ‘ sparse ’, meaning ‘sprinkle’ and referring to the sparse mediofacial setal row on the gnathopod 2 propodus. Description. Based on holotype , male, 2.9 mm , AM P71036. 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, oval. Antenna 1 0.3 x body length; flagellum 6-articulate, peduncle width less than 2 x article 2. Antenna 2 0.3 x body length, longer than antenna 1; flagellum 4-articulate. Mandibles lacking molars, palp 3-articulate, ratio of articles 1 – 3, 1.0:2.8:2.0, article 2 with 2 distal and 3 proximal setae, article 3 with 2 distal setae, incisors strongly dentate; left mandible lacinia mobilis large, strongly toothed, with 8 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 3 distal setae; outer plate with 6 distal spines and 3 thin distal setae. Maxilla 2 inner plate with 3 robust and 5 thin distal setae; outer plate with 18 distal setae. Maxilliped inner plates fused, distal margin with v-shaped indentation, with short spines and long setae; outer plate smooth, reduced, reaching less than half of palp article 1, with 2 distal setae and 1 distal spine; palp 4- articulate, article 4 slender, slightly recurved. Pereon. Coxae 1–4 relative widths 1.0:1.1:0.9:1.5. Gnathopod 1 coxa smooth, setose, anterodistal corner produced, truncated, distal margin straight, posterodistal margin rounded, facial setae absent; basis constricted proximally, anterior margin with 4 setae; posterior margin bare; ischium bare; carpus and propodus distally tapered; carpus length 7.2 x width, proximal margin serrate, distal margin setose; propodus straight, palm serrate with 4 distal setae; dactylus smooth, reaching 0.4 x propodus length. Gnathopod 2 coxa length subequal to width, slightly wider than coxa 3, smooth, bare, anterodistally rounded, distal margin evenly rounded, posterior margin straight, facial setae absent; basis linear, without tubercles or serrations, anterior margin with 3 setae, posterior margin bare; ischium with 2 posterodistal setae; carpus 0.7 x propodus length, recurved, distally tapered, anterior margin weakly serrate; propodus posterior margin without teeth/serrations, with 1 sparse mediofacial setal row above midline, reaching 0.5 x propodus length, 1 row of 8 submarginal setae, palm convex with 3 minor projections; dactylus curved, proximal margin smooth, anterior margin distally subacute, reaching 0.7 x propodus length. Pereopod 3 coxa length 1.6 x width, anterodistal corner over-riding distal face of coxa 2 and extending below it, smooth, setose, anterior margin evenly rounded, distal margin oblique, posterior margin slightly concave, 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 length width ratio 1:0.9, posterior margins smooth. Pereopod 5 basis posterior margin setose. Pereopods 6–7 posterior margins bare. Pleon. Epimeron 1 with tuft of 4 anteroventral setae. Epimeron 2 with 4 ventral setae. Epimeron 3 bare, posteroventral corner subquadrate. Uropods 1–3 relative lengths 1.0:0.7:1.1; peduncle and outer ramus subequal to inner ramus length; inner and outer ramus lined with short setae. Uropod 1 inner ramus with robust setae, outer ramus without robust setae. Uropod 2 peduncle and outer ramus 0.8 x inner ramus length. inner ramus with 1 robust seta; outer ramus without spines. Uropod 3 inner and outer ramus with robust setae. Telson 1.9 x longer than wide, apex bidentate. Female (sexually dimorphic characters). Unknown. Habitat. In an algal mat and fine sediment from rubble bottom. FIGURE 25. Leucothoe sparsa sp. nov. , holotype, male, 2.9 mm, AM P71036 (QLD 1708), Picnic Beach, Palfrey Island, Great Barrier Reef. FIGURE 26. Leucothoe sparsa sp. nov. , holotype, male, 2.9 mm, AM P71036 (QLD 1708), Picnic Beach, Palfrey Island, Great Barrier Reef. Remarks. Leucothoe sparsa sp. nov. has a distinctly sparse mediofacial setal row on gnathopod 2 propodus. The anterodistal tuft of epimeron 1 setae is shared with L . alcyone , L . ashleyae , L . assimilis , L . bidens , L . furina , L . germanalcyone , L . saron and L . thula sp. nov. The bidentate telson is also found in L . basilobata , L . cheiriserra , L . commensalis , L . ctenochasma , L . diemensis , L . laticoxa and Leucothoe eumilli sp. nov. Distribution. Australia . Queensland : Lizard Island (current study).