Six new species of the genus Chevalia Walker, 1904 (Amphipoda, Corophiidea, Chevaliidae) from Brazilian waters, with a key to world species of the genus Author Souza-Filho, Jesser F. Author Souza, Ana Maria T. Author Valério-Berardo, Maria Teresa text Zootaxa 2010 2713 25 51 journal article 10.5281/zenodo.199662 c9e923c4-f0c9-4bfe-9269-0ee2a6c04555 1175-5326 199662 Key to world species of Chevalia 1. Pereopod 7 with basis rectangular .............................................................................................................................. 2 - Pereopod 7 with basis ovate........................................................................................................................................ 8 2. Gnathopod 2 palm transverse ...................................................................................................................................... 3 - Gnathopod 2 palm oblique............................................................................................................................................ 7 3. Basis of pereopod 7 distally expanded, with a protuberant posteroventral corner ....................................................... 4 - Basis of pereopod 7 not distally expanded, without a protuberant posteroventral corner ........................................... 6 4. Mandible palp more than 3 X length of body of mandible, article 2 longer than article 3; dactylus of gnathopod 2 more than half length of propodus and with inner proximal hump ............................................................................. 5 - Mandible palp less than 3 X length of body of mandible, article 2 and 3 subequal in length; dactylus of gnathopod 2 less than half length of propodus and without inner proximal hump ........................................... C. tenuis Myers, 2009 5. Palm of gnathopod 2 defined by acute projection and weakly sinuose; basis of pereopod 7 about 3.3 X longer than wide ........................................................................................................................................ C. mexicana Pearse, 1913 - Palm of gastropod 2 defined by square dentate projection and with a large crenulate “U”–excavation near hinge of dactylus; basis of pereopod 7 about 2 X longer than wide ............................................................... C. caetes sp. nov. 6. Accessory flagellum 2–articulate; coxa 1 with anteroventral angle not produced forward; gnathopod 2 with carpus about one half of propodus length ............................................................................................ C. pacifica Myers, 1995 - Accessory flagellum 3–articulate; coxa 1 with anteroventral angle produced forward; gnathopod 2 with carpus as long as propodus length ................................................................................................................ C. thomasi sp. nov. 7. Anteroventral corner of coxa 1 attenuate and sharp; basis of pereopod 7 with a projection on posteroventral corner. ................................................................................................................................. C. aviculae complex Walker, 1904 - Anteroventral corner of coxa 1 blunt; basis of pereopod 7 without a projection on posteroventral corner .................. ............................................................................................................................................ C. inaequalis ( Stout, 1913 ) 8. Posterodorsal margins of pereon and pleon with a line of +10 long simple setae in adults, in subadults about 6 long simple setae ........................................................................................................................................ C. setosa sp. nov. - Posterodorsal margins of pereon 6 and/or 7 and pleon 1–3 with a pair of long simple setae, in subadults about 6 long simple setae.................................................................................................................................................................. 9 9. Mandible palp elongate, more than 3 X length of body of mandible ........................................ C. marajoara sp. nov. - Mandible palp short, 2X length of body of mandible ............................................................................................... 10 10. Carpus of pereopods 5–7 with 4 submarginal robust setae on anterodistal corner; uropods 1–2 with long setae on the dorsal margin of peduncles; epimera 1–3 without notch on posteroventral corner ........ C. hirsuta Lazo-Wasem, 1999 - arpus of pereopods 5–7 with 2 submarginal robust setae on anterodistal corner; uropods 1–2 without setae on the dorsal margin of the peduncles; epimera 1–3 with a notch on posteroventral corner ............................................... 11 11. Gnathopod 2 coxal gill short, 1/2 length of basis; pereopod 3 of female oostegite absent or very short; telson with distal margin bearing a middle process...................................................................................................................... 12 - Gnathopod 2 coxal gill about 1/2 of basis; female oostegite of pereopod 3 at least one half the length of the basis; telson with distal margin convex and lacking middle process ............................................................ C. convexa sp. nov. 12. Female oostegite of pereopod 3 very reduced; uropod 1 inner ramus with 9 serrate spines, extending on almost half length of medial margin; male gnathopod 2 palm defined by acute projection and dactylus the same length of palm ....................................................................................................................................................... C. anomala sp. nov. - Female oostegite of pereopod 3 absent; uropod 1 inner ramus with 14 serrate spines, extending on almost 2/3 length of medial margin; male gnathopod 2 palm defined by rounded projection and dactylus shorter than palm ................. ......................................................................................................................... C. carpenteri Barnard & Thomas, 1987