Leucothoe, Leach, 1814

Krapp-Schickel, Traudl & Broyer, Claude De, 2014, Revision of Leucothoe (Amphipoda, Crustacea) from the Southern Ocean: a cosmopolitanism concept is vanishing, European Journal of Taxonomy 80, pp. 1-55 : 4

Key for Antarctic and sub-Antarctic Leucothoe -species:

1. Cx 2 and Cx 4 anterodistally with acute angle [eyes yellowish]......................................................... .......................................................................... L. merletta sp. nov. (2.5 mm, depth range unknown)

– Coxae anterodistally never acutely pointed....................................................................................... 2

2. P 5-7 basis ratio l:w clearly> 2, proximally widest ............................................................................ ............................................................................. L. longimembris sp. nov. (15 mm, depth: 1030 m)

– Basis P 5-7 ratio l:w <2, medially widest ......................................................................................... 3

3. Gn 1 propodus and carpus distally very narrow and elongate, propodus ratio l:w> 5, dactylus ≤ 1/3 of propodus length; Gn 2 propodus with palmar corner; peraeopod dactyli> 1/2 length of propodus; Ep 2 posterodistally acutely lengthened [eyes small, compact and dark red]..................................... L. orkneyi Holman & Watling, 1983 (4-9 mm, depth-range 11-1584 m)

– Gn 1 propodus ratio l:w ≤ 5, dactylus ≥ 1/3 of propodus-length, Gn 2 propodus without palmar corner; peraeopod dactyli ≤ 1/2 length of propodus.......................................................................... 4

4. Gn 1 propodus robust, ratio l:w = 3.0-3.5. [Cx 3 narrow with nearly parallel margins; P 5-7 basis ovoid, hind margin in P 7 scarcely serrate, Ep 3 posterodistal corner minutely lengthened, posterior margin excavate]........................................ L. macquariae sp. nov. (6-10 mm, depth-range 5-111 m)

– Gn 1 propodus ratio l:w more than 3.5 .............................................................................................. 5

5. Gn 2 dactylus very long, reaching up to about 2/3 of propodus length; Gn 1 propodus ratio l:w = 5; Ep 3 posterodistal corner rectangular ............. L. campbelli sp. nov. (5-7 mm, depth-range 10-25 m)

– Gn 2 dactylus about half length of propodus or little more............................................................... 6

6. P 7 basis regularly rounded, ratio length to width about 1.3. Eyes large, ommatidia separated ......... .......... L antarctica Pfeffer, 1888 (4-9 mm, depth-range 24-335 m, doubtful material from 1584 m)

– P 7 basis ratio length to width about 1.7. Eyes large, ommatidia fused .............................................. ................................................................ L. weddellensis sp. nov. (10-24 mm, depth range 9-602 m)