Oedicerina, Stephensen, 1931, Stephensen, 1931

Jażdżewska, Anna M., Brandt, Angelika, Arbizu, Pedro Martínez & Vink, Annemiek, 2022, Exploring the diversity of the deep sea-four new species of the amphipod genus Oedicerina described using morphological and molecular methods, Zoological Journal of the Linnean Society 194, pp. 181-225 : 220

A KEY TO ALL KNOWN SPECIES OF OEDICERINA :

1a. Rostrum strongly deflexed, the angle between the head dorsal margin and rostrum margin c. 90 ° ( Fig. 1A ) ........................................................................................................................................................................... 2

1b. Rostrum curved but not strongly deflexed, the angle between the head dorsal margin and rostrum margin distinctly larger than 90 ° ( Fig. 1B ) ................................................................................................................. 5

2a. Coxa 1 distinctly wider than deep (width length ratio 1:0.7), anterodistal corner narrowly rounded ........... ............................................................................................................................................................ O. henrici

2b. Coxa 1 slightly wider than deep or as wide as long (width length ratio 1:0.8–1.0), anterodistal corner broad, bluntly rounded..................................................................................................................................................3

3a. Gnathopod 2 palm straight, maxilliped palp article 3 strongly produced along article 4 ..... O. megalopoda

3b. Gnathopod 2 palm strongly convex, maxilliped palp article 3 slightly or not produced along article 4 ...... 4

4a. Coxae 1–3 setose (long curled setae), pereopod 7 posterior margin of basis with long plumose setae, posterodistal lobe absent ............................................................................................................ O. denticulata

4b. Coxa 1–3 sparsely setose (short setae), pereopod 7 posterior margin of basis naked, posterodistal lobe absent ................................................................................................................................................... O. vaderi

4c. Coxae 1–3 naked, pereopod 7 posterior margin of basis naked, posterodistal lobe present, nearly as long as ischium ................................................................................................................................................ O. claudei

5a. Pereonite 7 with posteriorly directed tooth, gnathopod 1 dactylus distinctly longer than palm ... O. teresae

5b. All pereonites smooth posteriorly, gnathopod 1 dactylus as long as palm or only minutely longer than palm ........................................................................................................................................................................... 6

6a. Pleonite 3 smooth posteriorly, pereopod 7 posterodistal lobe present, almost as long as ischium. O. loerzae

6b. Pleonite 3 with small upright tooth, pereopod 7 posterodistal lobe absent................................................... 7

7a. Coxa 4 anterior margin slightly expanding distally, coxa the widest almost at the anterodistal corner, maxilliped palp article 3 distinctly produced along article 4 ............................................................... O. lesci

7b. Coxa 4 anterior margin slightly expanding distally, coxa the widest at 2/3 of its length, maxilliped palp article 3 slightly produced along article 4 ......................................................................................... O. ingolfi

Figures

Figure 1. A, B, Oedicerina sp. head presenting the curvature of rostrum. Dashed lines show the dorsal margin of the head and front margin of the rostrum. A, rostrum strongly deflexed (the angle between both margins c. 90°). B, rostrum curved but not strongly deflexed (wide angle between both margins). C, presentation of the measurement of the width to depth ratio of the posterior lobe of coxa 4. The dashed line indicates how the lobe was defined.