Chevalia Walker, 1904

Souza-Filho, Jesser F., Souza, Ana Maria T. & Valério-Berardo, Maria Teresa, 2010, Six new species of the genus Chevalia Walker, 1904 (Amphipoda, Corophiidea, Chevaliidae) from Brazilian waters, with a key to world species of the genus, Zootaxa 2713, pp. 25-51 : 26-27

Chevalia Walker, 1904

Chevalia Walker, 1904: 288 . ― Barnard, 1969: 271. ― Barnard, 1973: 16. ―Conlan, 1983: 60. ― Barnard & Thomas, 1987: 532. ― Barnard & Karaman, 1991: 182.

Neophotis Stout, 1913: 653 ( Neophotis inaequalis Stout, 1913 , monotypy).

Diagnosis. Modified from Barnard & Thomas (1987). Antenna 1, peduncle article 3 shorter than article 1, accessory flagellum 1–3 articulate. Mandible palp article 3 slightly shorter than article 2, thinly clavate. Inner plate of maxilla 2 with oblique facial row of setae. Coxae small, disjunct, coxae 1–2 larger than 3–7, coxa 5 anterior lobe absent. Gnathopods of sexes alike, gnathopod 1 feeble, subchelate, carpus elongate. Gnathopod 2 large, carpus lobate, propodus large, subrectangular, palm defined by a spine, dactyl thick. Dactylus of pereopod 3–4 simple, of pereopods 5–7 strongly curved and with a large accessory spine. Pereopods 5–7 short but increasingly elongate, feeble. Urosomites 1–2 fused, urosomite 3 free. Inner rami of uropods 1–2 styliform and unarmed apically. Uropod 1 inner ramus with a row of medial serrate spines. Uropod 3 rami subequal in length, setose apically. Telson short, as broad as long, squared, well setose dorsally.

Species composition. C. anomala sp. nov.; C. aviculae Walker, 1904 ; C. caetes sp. nov.; C. carpenteri Barnard and Thomas, 1987 ; C. convexa sp. nov.; C. hirsuta Lazo-Wasem, 1999 ; C. inaequalis ( Stout, 1913) ; C. marajoara sp. nov.; C. mexicana Pearse, 1913 ; C. pacifica Myers, 1995 ; C. thomasi sp. nov.; C. setosa sp. nov.; and C. tenuis Myers, 2009 .

Other undescribed species. Chevalia aviculae of Myers (1985) from Fiji; Chevalia aviculae of Barnard (1979) from Galapagos; Chevalia aviculae of Barnard (1970) from Hawaii; and Chevalia sp. B ( LeCroy, 2000).

Generic remarks. Barnard & Thomas (1987) subdivided the genus Chevalia into two groups, based on number of oostegites and pereopods 5–7. The first group, which groups the C. aviculae complex, was characterized by having three pairs of oostegites (pereopods 3–5) and basis of pereopods 5–7 with produced posterodistal corner. The second group included only C. carpenteri , because it possesses only 2 pairs of oostegites (pereopods 4–5), and the ovate basis of pereopods 5–7 with not produced posterodistal corner. However, some species described after showed features that represent an intermediate form with characters overlapping both groups. For example, C. hirsuta should be included in the second group by the shape of basis of pereopod 7, however it presents four pairs of oostegites, although in his description of holotype, Lazo-Wasen (1999) cited only three, but in the figure 4, the gnathopod 2 possesses a rudimentary and setose oostegite. Also, LeCroy (2000) cited an undescribed species of Chevalia , from Florida, very similar to C. carpenteri , which also could be placed in both groups, because it either has ovate basis of pereopod 7 with not produced posterodistal corner and three pairs of oostegites.

In this study we recognize three groups within Chevalia , based only on the shape of basis of pereopod 7:

group I – rectangular basis of pereopods 7 with a protuberant posteroventral corner, the C. aviculae complex, which includes: C. aviculae ; C. caetes sp. nov.; C. mexicana ; and C. tenuis ;

group II – rectangular basis of pereopods 7 lacking a protuberant posteroventral corner, which includes: C. inaequalis ; and C. thomasi sp. nov.;

group III – ovate basis of pereopod 7, which includes:

C. anomala sp. nov.; C. carpenteri ; C. convexa sp. nov.; C. hirsuta ; C. marajoara sp. nov.; and C. setosa sp. nov. and C. pacifica .