Leucothoe akaisen White & Reimer 2012

Head. Anterior margin rounded, anterodistal margin evenly rounded, distal margin straight; ventral cephalic keel anterior margin transverse, anteroventral margin rounded, ventral margin straight; eyes present with more than 10 ommatidia, round. Antenna 1 0.3 × body length, flagellum 5–articulate, peduncle article 1 width less than 2 × article 2, accessory flagellum absent. Antenna 2 0.2 × body length, shorter than antenna 1, flagellum 3–articulate. Mandibular palp ratio of articles 1–3 1.0: 2.6: 1.0, article 2 with 5 distal setae, article 3 with two distal setae, incisors weakly dentate; left mandible with 11 raker spines, lacinia mobilis large, weakly toothed; right mandible with 8 raker spines, lacinia mobilis small. Upper lip asymmetrically lobate, anterior margin setose. Lower lip inner lobes fused, setose; outer lobes with large gape, anterior margins setose. Maxilla 1 palp 1–articulate, with 4 distal setae; outer plate with 6 distal robust setae and 2 distal setae. Maxilla 2 inner plate with 9 distal and 1 proximal setae; outer plate with 4 distal and 11 marginal setae. Maxilliped inner plates distal margin rounded with v-shaped indentation, with large and small robust setae; outer plate inner margin smooth, reaching 0.4 × palp article 1, with simple marginal setae, facial setae present; palp article 4 subequal in length with article 3, distally acute. Pereon. Coxae 1–4 relative widths 1.0: 1.2: 0.7: 1.6. Gnathopod 1 coxa smooth, with tiny marginal setae, anterodistal margin produced, subquadrate, distal margin straight, posterior margin excavate, facial seta present; basis slightly inflated, anterior margin with 1 short and 2 medium setae, posterior margin bare; ischium bare; carpus linear, distal length 10.7 × width, proximal margin smooth, distal margin with 2 setae; propodus straight, palm dentate with 2 large and several small distal setae; dactylus smooth, reaching 0.3 × propodus length. Gnathopod 2 coxa longer than broad, slightly larger than coxa 3, smooth, with tiny marginal setae, anterior margin straight, anterodistally rounded, distal and posterior margins straight, facial setae absent; basis slightly inflated, anterior margin with 4 setae, posterior margin with 1 posterodistal seta; ischium with posterodistal seta; carpus 0.4 × propodus length, curved, distally tapered, anterior margin smooth; propodus with 1 mediofacial setal row displaced past midline, reaching 0.8 × propodus length, with 1 row of submarginal setae, posterior margin smooth, palm convex, with 3 small rounded tubercles; dactylus curved, reaching 0.5 × propodus length, proximal margin smooth, bare, anterior margin distally acute. Pereopod 3 coxa length 1.9 × width, anterodistal corner overriding distal face of coxa 2 and extending below it, smooth, with tiny marginal setae, anterior margin straight, distal margin oblique, posterior margin straight, facial setae absent. Pereopod 4 coxa smooth, with tiny marginal setae, anterior margin tapered, distal margin produced, posterior margin excavate, facial setae absent. Pereopods 5–6 coxae, facial setae present, pereopod 7 coxa, facial setae absent. Pereopods 5–7 bases width length ratios 1: 1.2, 1: 1.3, 1: 1.0, posterior margins smooth, setose. Pleon. Epimeron 1 with anteroventral tuft of setae, epimeron 2 with ventral setae, epimeron 3 bare, posteroventral corner subquadrate, produced. Uropods 1–3 relative lengths 1.0: 0.7: 1.0. Uropod 1 peduncle subequal in length with inner ramus, outer ramus 0.9 × inner ramus length; inner and outer rami each with 2 robust setae. Uropod 2 peduncle subequal in length with inner ramus, outer ramus 0.8 × inner ramus length; inner and outer rami each with 2 robust setae. Uropod 3 peduncle 0.9 × inner ramus length, outer ramus subequal in length with inner ramus; inner ramus with 3 robust setae, outer ramus with 1 robust seta. Telson 2.2 × longer than wide, apex rounded.

East China Sea: Ishigaki–jima Island, Iriomote–jima Island, Okinawa–jima Island (both Okinawa), Tokunoshima Island, Yakushima Island (both Kagoshima), Japan.