Three species of Asterocheres (Copepoda: Siphonostomatoida: Asterocheridae) from shallow Antarctic water

Three species of Asterocheres, including two new species, are reported as associates of sponges in shallow Antarctic water. Asterocheres spinosus sp. nov. has a combination of diagnostic features: mandibular palp is one-segmented, caudal ramus is 1.88 times as long as wide, antennule is 20-segmented in the female and 18-segmented in the male, urosome is spinulose, and legs 1 and 2 display weak sexual dimorphsims. In A. rai sp. nov., the body is large, 1.66 mm long in the female, the lateral margin of genital double-somite is smooth without setules or spinules, the exopod of antenna bears only a single seta, with two mucilaginous substances transformed from setae, and the third endopodal segment of leg 1 bears a prolonged distal process. A supplementary description is given for A. hirsutus Bandera, Conradi and Lopez-Gonzalez, 2005, recorded previously from the Antarctic.