Amphipod

Chydaekata Bradbury, 2000

Type species: Chydaekata acuminata Bradbury, 2000

Fauna Portal Genus Number: 3475

(after Bradbury 2000): Chydaekata displays a number of characters in common with Hurleya, Giniphargus, Pilbarus, and Uroctena. Although there are several significant similarities between Chydaekata and Hurleya particularly the presence of only DE setae on the mandibular palp and in the conformation of the inner plate of the first maxillae and disposition of the gills, the differences in size and form of the gnathopods, and the non parviramous third uropod of Chydaekata sufficiently distance the two taxa to warrant regarding them as individual genera. The most significant characters in common with Giniphargus are the presence of gills on coxae 2–6, their absence on coxa 7, and the presence of sternal gills on sternites 6–7 only; otherwise these taxa are not similar. Pilbarus, another Western Australian stygobiont amphipod from the Millstream, has similar gnathopods, pleopods, third uropod and the telson is similarly cleft. However, many differences clearly separate these two taxa, although they do share several characters and would appear to have more than distributional association. Despite some similarities, Toulrabia and Uroctena are distinctly different from Chydaekata in many ways, including the absence of calceoli on the second antenna, presence of AB or C setae on the third article of the mandibular palp, and absent or very weak emargination of the posterior edge of the fourth coxal plate. Chydaekata is thus regarded as a discrete genus, possibly associated with Hurleya, although the genus Hurleya is itself inadequately described and in need of review.