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

Abstract

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 4-8, ventrolateral tubes on segment 2, lateroventral tubes on segment 5, lateroventral spines on segments 6-9 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 6-9; glandular cell outlets type 2 are not present. Meristoderes taro sp. nov. is defined by the combination of long middorsal spines on segments 4-8, 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 6-9.

Description, redescription and revision of sixteen putatively closely related species of Echinoderes (Kinorhyncha: Cyclorhagida), with the proposition of a new species group – the Echinoderes dujardinii group

“…The three most common echinoderid dorsal patterns of glandular cell outlets type 1 on segments 1 to 9. Literature sources: Huys & Coomans 1989;Adrianov & Malakhov 1999;Adrianov et al, 2002a;Neuhaus & Blasche 2006;Herranz et al , 2014Herranz et al , 2018Sørensen et al 2012Sørensen et al , 2013Sørensen et al , 2016Sørensen et al , 2018Herranz & Pardos 2013;Sørensen & Landers 2014;Pardos et al 2016b;Yamasaki & Durucan, 2018;Yamasaki et al 2018aYamasaki et al , 2018bYamasaki et al , 2020bCepeda et al 2019bCepeda et al , 2019cGrzelak & Sørensen 2019;Sánchez et al 2019;Yamasaki & Dal Zotto 2019; present study. always present in middorsal positions on segments 1 to 3, and in subdorsal positions on segments 4 to 9.…”

Hadal Mud Dragons: First Insight Into the Diversity of Kinorhyncha From the Atacama Trench

“…vanhoeffeni Zelinka (1913) in the Guinea Basin at 5064 m and in the southeastern deep-sea region of Canary Island at depths between 5055 m and 5118 m. Sánchez et al (2014a,b) described three additional species, i.e., Mixtophyes abyssalis Sánchez et al (2014a,b), Cristaphyes nubilis (Sánchez et al, 2014a,b), and Krakenella farinelli (Sánchez et al, 2014a,b), from the Guinea Basin, at depths between 5100-5175 m. The remaining and more recent reports of identified abyssal kinorhynchs are restricted to five areas: (1) abyssal plains, 3100-3300 m, around North Atlantic seamounts, from where Yamasaki et al (2019) describe Echinoderes kaempfae Yamasaki et al, 2019; (2) the East Mediterranean, 675-4403 m, from where Yamasaki et al (2018a) describe Echinoderes pterus Yamasaki et al, 2018a,b; (3) abyssal plains, 3351-5766, in the vicinity of the Kuril-Kamchatka Trench, from where Adrianov and Maiorova (2015 describe Cristaphyes abyssorum (Adrianov and Maiorova, 2015), Condyloderes kurilensis Adrianov and Maiorova (2016), Meristoderes okhotensis Adrianov and Maiorova (2018a), and Parasemnoderes intermedius Adrianov and Maiorova (2018b); (4) the abyssal plains, 3250-3853 m, off the Northwest American continental slope, from where Sørensen et al (2018) describe E. anniae, E. dubiosus, E. hamiltonorum, E. juliae, E. lupherorum, E. hviidarum, E. yamasakii, and Sørensen et al (2018Sørensen et al ( , 2019 report three additional known kinorhynch species, E. cf. unispinosus Yamasaki et al (2018a,b), Fissuroderes higginsi Neuhaus and Blasche (2006), and C. kurilensis; (5) the Clarion-Clipperton Fracture Zone, 4319-5012 m, in the tropical East Pacific, from where Sánchez et al (2019) describe Cephalorhyncha polunga, Echinoderes shenlong, and Meristoderes taro.…”

Dragons of the Deep Sea: Kinorhyncha Communities in a Pockmark Field at Mozambique Channel, With the Description of Three New Species

“…Of these, some species seem to possess wider ranges of distribution than their congeners from the coastal zone. For instance, Condyloderes kurilensis Adrianov and Maiorova (2016), and Fissuroderes higginsi Neuhaus and Blasche (2006), were originally described from the Kuril-Kamchatka Trench (northwestern Pacific) and New Zealand (southwestern Pacific), respectively, and later found in the deep-sea waters off Oregon and California (northeastern Pacific) and the Clarion-Clipperton Zone (Neuhaus and Blasche, 2006;Adrianov and Maiorova, 2016;Sánchez et al, 2019a). More striking are the cases of Campyloderes vanhoeffeni Zelinka, 1913, distributed worldwide in both coastal waters and deep sea (Neuhaus and Sørensen, 2013) and Echinoderes unispinosus present in the deep sea of the Atlantic and the Pacific Oceans Yamasaki et al, 2019;Álvarez-Castillo et al, 2020).…”