Red Sea Leucothoidae (Crustacea: Amphipoda) including new and re-described species Author Kristine N. White Author Traudl Krapp-Schickel text European Journal of Taxonomy 2017 2017-05-31 324 1 40 journal article 32050 10.5852/ejt.2017.324 ab0a9802-739c-40b2-b5af-5d41f42f5619 2118-9773 896730 38BD13D5-2FC1-4DCD-87B2-BDE60B6FA8E2 Leucothoe reimeri sp. nov. urn:lsid:zoobank.org:act:469B3C52-F3F3-439F-B52C-D7C185CEC896 Figs 10–11 Diagnosis Head unusually small, anterior margin rounded. Right mandible lacinia mobilis with two layers. Eyes large, round. Gnathopod 1 basis distally expanded; carpus and propodus curved. Gnathopod 2 basis proximally expanded, stout; carpus reaching 0.2 times propodus length; propodus palm concave, smooth, with dense row of submarginal spine-setae. Coxae short. Pereopods 5–7 bases narrowly expanded, pereopods 6–7 bases posterior margins serrate. Telson apex rounded. Etymology Named for James Davis Reimer, the collector. Jamie has provided tremendous support for leucothoid amphipod research over the past several years, always willing to share knowledge and resources, eh. Type material Holotype RED SEA: ♂ , 5.9 mm , Jazirat Burcan , Shi’b Pelam , 27°49.003' N , 35°06.397' E , 29.8 m , inside sponge , 29 Sep. 2013 , J.D. Reimer leg. ( ZMB 29750 , slide 5096 , RS93 ). Paratype RED SEA: ♀ , 5.5 mm , same station data ( ZMB 29751 , slide 5097 ). Additional material examined RED SEA: 2 ♂♂, 6 mm, 3 juvs, 2–4 mm, same station data (K.N. White pers. coll.). Description Male LENGTH. 5.9 mm. HEAD. Small; anterior margin rounded, anterodistal margin rounded, distal margin straight; ventral cephalic keel anterior produced with cusp; anteroventral margin rounded, ventral margin tapered; eyes large, round. Antenna 1 length 0.2 times body length, flagellum 6-articulate, peduncle article 1 width less than 2 times article 2, accessory flagellum present, 1-articulate. Antenna 2 length 0.2 times body length, subequal in length with antenna 1, flagellum 4-articulate. Mandibular palp ratio of articles 1–3 1.0: 3.4: 2.1, article 2 with 2 distal setae, article 3 with 2 distal setae, incisors weakly dentate; left mandible with 14 raker spines, lacinia mobilis large, weakly toothed; right mandible with 14 raker spines, lacinia mobilis small, weakly toothed, with two layers. Upper lip asymmetrically lobate, anterior margin weakly setose. Lower lip inner lobes fused, setose; outer lobes with large gape, anterior margins setose. Maxilla 1 palp 2-articulate, with 3 distal slender setae; outer plate with 5 distal robust setae and 4 slender setae. Maxilla 2 inner plate with 4 distal slender setae outer plate with 7 distal slender setae and several marginal fine setae. Maxilliped inner plates distal margin rounded with v-shaped indentation, with short simple robust setae; outer plate inner margin smooth, reaching 0.4 times palp article 1, with simple marginal setae; palp article 4 subequal in length with article 3, distally acute. PErEON. Coxae 1–4 relative widths 1.0: 1.4: 1.5:1.3. Gnathopod 1 coxa smooth, anterodistal margin produced, rounded, distal margin rounded, posterior margin straight; basis distally expanded, anterior margin with 4 short setae, posterior margin bare; ischium bare; carpus curved, distal length 14.1 times width, proximal margin with two rows of dentition; propodus curved, palm dentate with 8 proximal setae; dactylus smooth, reaching 0.4 times propodus length. Gnathopod 2 coxa broader than long, subequal in size with coxa 3, smooth, anterior margin straight, anterodistally rounded, distal margin straight, posterior margin straight; basis proximally expanded, stout, anterior margin with 9 short setae, posterior margin bare; ischium bare; carpus 0.2 times propodus length, curved, distally tapered, anterior margin smooth; propodus with 1 mediofacial setal row displaced to midline, reaching 0.5 times propodus length, with dense row of submarginal spine-setae, posterior margin smooth, palm convex with 2 minor tubercles; dactylus curved, proximal margin smooth, bare, anterior margin distally acute, reaching 0.6 times propodus length. Pereopod 3 coxa length 0.8 times width, anterodistal corner overriding distal face of coxa 2, smooth, anterior margin rounded, distal margin slightly rounded, posterior margin straight. Pereopod 4 coxa smooth, anterior margin rounded, distal margin rounded, posterior margin straight. Pereopods 5–7 bases width to length ratios 1:2.2, 1: 1.4, 1: 1.6, pereopod 5 basis posterior margin smooth, bare; pereopods 6–7 posterior margins serrate, bare. Fig. 10. Leucothoe reimeri sp. nov. , holotype, ♂, length 5.9 mm (ZMB 29750, slide 5096); paratype, ♀, length 5.5 mm (ZMB 29751, slide 5097). Fig. 11. Leucothoe reimeri sp. nov. , holotype, ♂, length 5.9 mm (ZMB 29750, slide 5096). PLEON. Epimera 1–3 bare, epimeron 3 posteroventral corner rounded. Uropods 1–3 relative lengths 1.0: 1.0: 1.4. Uropod 1 peduncle 1.8 times inner ramus length, outer ramus 0.9 times inner ramus length. Uropod 2 peduncle subequal in length with inner ramus, outer ramus 0.8 times inner ramus length. Uropod 3 peduncle 1.2 times inner ramus length, outer ramus 0.9 times inner ramus length. Uropods 1–3 inner and outer rami with robust seta(e). Telson 1.8 times longer than wide, apex rounded. Female (sexually dimorphic characters) Gnathopod 1 basis slightly distally expanded, anterior margin with 6 short setae; carpus proximal margin with three rows of dentition. Gnathopod 2 basis slightly proximally expanded, stout, anterior margin with 5 short setae. Remarks Leucothoe reimieri sp. nov. is unique in having a dense row of submarginal spine-setae on the propodus palm. The narrowly expanded pereopod 5–7 bases are similar to those of L. acanthopus and L. pansa sp. nov. This species inhabits the interior canals of an unidentified marine sponge. Distribution Red Sea: Shi’b Pelam (present study).