Deep-sea Kinorhyncha diversity of the polymetallic nodule fields at the Clarion-Clipperton Fracture Zone (CCZ)

Kinorhynch specimens were studied from abyssal sediment samples collected during seven cruises at the Clarion-Clipperton Fracture Zone (Eastern Central Pacific), a vast area that will be mined for polymetallic nodules in a near future. This study is the first in a series focused on kinorhynchs mainly collected at the German zone following requirements of the International Seabed Authority (ISA), who demands identification of fauna associated with nodules previous to the concession of the exploitation license. A total of 18 species were found, of which three new Echinoderidae species are described herein. Cephalorhyncha polunga sp. nov. is easily discriminated from its congeners by the presence of pointed and prominent tergal extensions together with middorsal spines on segments 4e8, ventrolateral tubes on segment 2, lateroventral tubes on segment 5, lateroventral spines on segments 6e9 and midlateral tubes on segment 10; plus subdorsal type 2 glandular cell outlets on segment 2 and midlateral ones on segment 8. Echinoderes shenlong sp. nov. is characterized by middorsal spines on segments 4, 6, 8, lateroventral tubes on segment 5 and lateroventral spines on segments 6e9; glandular cell outlets type 2 are not present. Meristoderes taro sp. nov. is defined by the combination of long middorsal spines on segments 4e8, remarkably increasing in length on posterior segments; short laterodorsal tubes on segment 10, ventrolateral tubes on segment 2 and lateroventral tubes on segment 5, plus lateroventral spines on segments 6e9