Three new meiobenthic species from a submarine cave in Japan:Echinoderes gama,E. kajiharaiandE. uozumii(Kinorhyncha: Cyclorhagida)

Three new species of echinoderid kinorhynchs are described from Daidokutsu, a submarine cave in Ryukyu Islands, Japan.Echinoderes gamasp. nov. is characterized by the presence of middorsal acicular spines on segments 4-8; lateroventral acicular spines on segments 7-9; lateroventral tubes on segment 5; sublateral tubes on segment 8; laterodorsal tubes on segment 10; and type-2 gland cell outlets in subdorsal and lateroventral position on segment 2.Echinoderes kajiharaisp. nov. is defined by the presence of middorsal acicular spines on segments 4, 6, 8; lateral accessory acicular spines on segment 9; lateroventral acicular spines on segments 6-8; lateroventral tubes on segments 2 and 5; midlateral tubes on segment 10; and type-2 gland cell outlets in laterodorsal position on segments 2 and 5, and subdorsal position on segments 8 and 9.Echinoderes uozumiisp. nov. is characterized by the presence of middorsal acicular spines on segments 4 and 6; lateroventral acicular spines on segments 6-9; lateroventral tubes on segments 2 and 5; sublateral tubes on segment 8; laterodorsal tubes on segment 10; type-2 gland cell outlets in subdorsal and lateral accessory position on segment 2; and blunt, short pectinate fringe teeth of primary pectinate fringe on segment 1. In addition, theEchinoderes multiporusspecies group includingE. kajiharaisp. nov., and theEchinoderes bispinosusspecies group includingE. uozumiisp. nov. are established. Furthermore, the distribution of the two species groups and the origin ofEchinoderesspecies in Daidokutsu are discussed.