Leucothoe makrommatos, White & Thomas, 2009

White, Kristine N. & Thomas, James Darwin, 2009, Leucothoidae *, Zootaxa 2260 (1), pp. 494-555 : 518-521

Leucothoe makrommatos sp. nov.

( Figs 15 , 16 , Pl. 4A)

Type material. Holotype, male, 5.6 mm, AM P 79820, Three Sisters Bommie, Yonge Reef (14°36.104’S 145°37.126’E), in ascidian host on a back reef bommie, 12 m, K. Klebba, 3 March 2005 ( QLD 1789 ) . Paratype, female, 6.0 mm, AM P 79821, same station data .

Additional material examined. 1 male, AM P 70697 ( QLD 1643 ) ; 1 male, AM P 71207 ( QLD 1755 ) ; 1 female, 1 male, AM P 71213 ( QLD 1760 ) ; 4 females, 3 males, AM P 71353 ( QLD 1789 ) ; 1 female, AM P 71458 ( QLD 1789 ) ; 1 male, AM P 79822 ( QLD 1820 ) .

Type locality. Yonge Reef , Queensland, Australia (14°36.104’S 145°37.126’E) .

Etymology. After the Greek ‘ makros ’, meaning ‘long’ and ‘ omma ’, meaning ‘eye’ and referring to the elongate eye shape of this species.

Description. Based on holotype, male, 5.6 mm, AM P79820.

Head. Head length less than pereonites 1+2, anterior margin rounded, without serrations or teeth, anterodistal margin rounded without cusp, ventral cephalic keel subquadrate, rostrum small to medium; eyes with 10 or more ocelli, elongate. Antenna 1 0.3 x body length; flagellum 7-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: 2.5:1.8, article 2 with 5 distal setae, article 3 with 2 distal setae, incisors strongly dentate; left mandible lacinia mobilis large, weakly toothed, with 10 accessory setae; right mandible lacinia mobilis small, with 10 accessory setae. Upper lip asymmetrically lobate, anterior margin setose. Lower lip inner lobes fused, bare; outer lobes with moderate gape, anterior margins strongly setose. Maxilla 1 palp 2-articulate with 4 distal setae; outer plate with 5 distal spines and 4 distal setae. Maxilla 2 inner plate with nine distal and 10 proximal setae; outer plate with 20 distal setae. Maxilliped inner plates fused, distal margin with v-shaped indentation, with short spines; 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 1.0:1.4:0.9:1.6. Gnathopod 1 coxa serrate, bare, anterodistal corner produced, narrowly rounded, distal margin straight, posterodistal margin rounded, facial setae absent; basis constricted proximally, anterior margin with 8–10 setae, posterior margin with 5 – 6 setae; ischium with 2 posterior setae; carpus and propodus distally tapered; carpus length 13.6 x width, proximal margin serrate, distal margin bare; propodus straight, palm serrate with 6 distal setae; dactylus smooth, reaching 0.5 x propodus length. Gnathopod 2 coxa length 0.8 x width, slightly wider than coxa 3, smooth, bare, anterodistally rounded, distal margin evenly rounded, posterior margin straight, facial setae absent; basis posterior margin slightly expanded, without tubercles or serrations, anterior margin with 15 – 16 setae, posterior margin with 5 – 6 setae; ischium with 7 posterior setae; carpus 0.6 x propodus length, recurved, distally expanded, anterior margin serrate; propodus posterior margin without teeth/serrations, with 1 mediofacial setal row slightly displaced to midline, subequal with propodus length, 1 row of 6 submarginal setae, palm convex with 6 minor projections; dactylus curved, proximal margin smooth, anterior margin distally acute, reaching 0.7 x propodus length. Pereopod 3 coxa length 1.4 x width, anterodistal corner overriding distal face of coxa 2 and extending below it, smooth, bare, anterior margin evenly rounded, distal margin oblique, posterior margin evenly rounded, facial setae absent. Pereopod 4 coxa serrate, bare, anterior margin evenly rounded, distal margin produced, posterior margin tapered, facial setae absent. Pereopods 5–7 coxa facial setae absent; basis width length ratios 1:1.2, 1:1.2, 1:1.2, posterior margins serrate, bare.

Pleon. Epimera 1–3 bare. Epimeron 3 posteroventral margin subquadrate. Uropods 1–3 relative lengths 1.0:0.7:1.1; inner and outer ramus with robust setae. Uropod 1 peduncle subequal in length with inner ramus. Uropod 2 peduncle 0.7 x inner ramus length; outer ramus 0.8 x inner ramus length. Uropod 3 peduncle 1.2 x inner ramus length. Uropod 1+3 outer ramus subequal to inner ramus length. Telson 2.1 x longer than wide, apex tridentate.

Female (sexually dimorphic characters). Based on paratype, female, 6.0 mm, AM P 79821. Gnathopod 1 basis anterior margin with 13 – 15 setae; posterior margin with 29 – 30 alternating short and long setae; ischium with 8 posterior setae. Gnathopod 2 basis anterior margin with 28 – 30 short and long setae; posterior margin with 15 setae; ischium posterior margin with 8 setae; distal margin with 10 setae; propodus with 17 submarginal setae in 2 indistinct rows .

Habitat. In branchial chamber of an unidentified ascidian species.

Remarks. The elongate eyes of L. makrommatos sp. nov. are distinct. Leucothoe makrommatos appears to be closely related to L. wuriti and Leucothoe epidemos sp. nov., both found in ascidian hosts. Leucothoe makrommatos differs from L. wuriti and L. epidemos in its gnathopod 1 basis posterior setae, its less displaced gnathopod 2 propodus mediofacial setal row and its less prominent gnathopod 2 propodus palm projections. The posterior setae on gnathopod 1 basis is shared with females of L. saron , L. ubouhu and L. bova sp. nov. The serrate coxa 1 and 4 anterodistal margins are shared with L. banwarthii , L. gracilis and L. serrata sp. nov. Leucothoe makrommatos 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 sp. nov., L. odontiskos sp. nov. and L. undulata sp. nov. in its gnathopod 2 propodus secondary mediofacial setal row.

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

Figures

FIGURE 15. Leucothoe makrommatos sp. nov., holotype, male, 5.6 mm, AM P79820; paratype, female, 6.0 mm, AM P79821 (QLD 1789), Yonge Reef, Great Barrier Reef.

FIGURE 16. Leucothoe makrommatos sp. nov., holotype, male, 5.6 mm, AM P79820; paratype, female, 6.0 mm, AM P79821 (QLD 1789), Yonge Reef, Great Barrier Reef.