Shoemakerella Pirlot, 1936

Sorrentino, Rayane, Moraes, Elienai E. B. & Senna, André R., 2019, Four new species of Lysianassidae Dana, 1849 (Crustacea: Amphipoda) From Northeastern Brazilian coast, Zootaxa 4585 (1), pp. 1-26 : 24-25

Key to world species of Aruga Holmes, 1908 and Shoemakerella Pirlot, 1936

1. Antenna 1 with 2-field callynophore in female and male. Antenna 2 in male, peduncular article 4 enlarged, strongly geniculate between peduncular articles 4-5. Mandible with protuberance on midposterior margin, with left lacinia mobilis. Pereopods 3 and 4 in male: merus and carpus with plumose setae in posterior margin. Uropod 3, outer ramus 2-articulate............................................................................................... Aruga Holmes, 1908 (2)

- Antenna 1, callynophore absent in female, weak field in male. Antenna 2 in male, peduncular article 4 not enlarged, not geniculate. Mandible without protuberance on midposterior margin, left lacinia mobilis absent. Pereopods 3 and 4 without sexual dimorphism. Uropod 3, outer ramus 1-articulate..................................... Shoemakerella Pirlot, 1936 (7)

2. Body, dorsal margin of pereon and pleon without scattered setae. Head, lateral lobe cephalic produced with acute triangular lobe or not produced.................................................................................. 3

- Body, dorsal margin of pereon and pleon with scattered setae. Head, lateral lobe quadrate or subacute.......................................................................................... A. falklandica ( K.H. Barnard, 1932)

3. Head, lateral lobe cephalic not produced. Epimeral plate 3, posterior margin rounded and posteroventral corner acute or subquadrate........................................................................................... 4

- Head, lateral lobe cephalic produced into an acute triangular lobe. Epimeral plate 3 with concave proximal half of posterior margin above straight distal half and posteroventral corner unproduced and rounded............ A. oculata Holmes, 1908

4. Upper lip with anterodorsal margin rounded to subacute. Gnathopod 1, dactylus with nail. Telson strongly emarginated or convex................................................................................................ 5

- Upper lip with anterodorsal margin rounded. Gnathopod 1, dactylus without nail. Telson slightly emarginated......................................................................................... A. holmesi J.L. Barnard, 1955

5. Upper lip with anterodorsal margin subacute. Urosomite 1 without dorsal keel. Urosomite 1–3 dorsal margin with carinas (two laterals and one medial). Telson apical margin strongly emarginated............................................ 6

- Upper lip with anterodorsal margin rounded. Urosomite 1, dorsal median margin with a dorsal forward turned keel and two lat- eral carinas. Urosomite 2 and 3 without carinas. Telson, apical margin convex....................... A. kieppe sp. nov. 6. Upper lip with conical anteroventral projection. Maxilla 1, setal-teeth: STA–D 2-cuspidate. Telson, subequal in length and width, laterally rounded................................................................. A. paracuru sp. nov.

- Upper lip with acute anteroventral angle. Maxilla 1, setal - teeth: STA–C 2-cuspidate, STD simple, without cusp. Telson longer than wide, lateral margins tapering..................................................... A. emarginata sp. nov.

7. Dorsal margin of body with setae. Gnathopod 2, chelate, subchelate or parachelate, propodus rounded or rectangular; dactylus small. Pereopod 6, posterior margin of basis convex or concave................................................ 8

- Dorsal margin without setae. Gnathopod 2, strongly subchelate, propodus subtrapezoidal and distally broadened, palm acute, concave, and palmar corner produced and rounded; dactylus with a robust nail, curved. Pereopod 6, basis, posterior margin concave....................................................... S. subchelata Sorrentino, Senna & Lowry, 2014

8. Pereopod 6, posterior margin of basis concave or slightly concave............................................. 9

- Pereopod 6, posterior margin of basis convex or nearly straight................................................ 10

9. Body with setae from head to pereonite 3, pleonite 3 and urosomite 1. Gnathopod 1, dactylus without nail. Gnathopod 2, parachelate, propodus not elongated......................................... S. lowryi Gable & Lazo-Wasem, 1990

- Body with setae in pleonite 2 and 3. Gnathopod 1, dactylus with strong nail. Gnathopod 2, minutely subchelate, propodus elongated............................................................................... S. ungulata sp. nov.

10. Body with setae in pereonites and pleonites. Pereopod 7, propodus 4.5 × longer than wide.................................................................................................... S. barnardi Lowry & Stoddart, 2009

- Body with setae from pereonite 1 to pereonite 3. Pereopod 7, propodus 5 × to 6 × longer than wide................................................................................................... S. cubensis ( Stebbing, 1897)