Parameiropsis kodosensis Cho, Wi & Suh, 2016, n. sp.
Creators: name: Cho, Dae Hyun
name: Wi, Jin Hee
name: Suh, Hae-Lip
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Maxillopoda
Harpacticoida
Ameiridae
Parameiropsis
Parameiropsis kodosensis

description: Parameiropsis kodosensis n. sp.
(Figs. 1–4)
Type locality. Eastern central Pacific Ocean, 10˚30.98'N 131˚18.993'W, at a depth of 4988 m.
Material examined. Female holotype dissected and mounted on eight slides (MABIK CR00235259).
Etymology the specific name refers to the type locality in the Pacific Ocean (Clarion– Clipperton Fracture Zone; CCFZ): KODOS is the Korean license area for exploration of polymetallic nodules in the CCFZ.
Description of female. Body (Figs. 1 A, B) length 1.85 mm, almost cylindrical, widest at posterior margin of cephalothorax, tapering posteriorly, with slight demarcation, without clear distinction between prosome and urosome. Cephalothorax and second to fifth urosomites with distal hyaline membrane. Prosome 0.8 times as long as urosome excluding caudal rami, 0.7 times length including caudal rami.
Prosome (Figs. 1 A, B) comprising cephalothorax with completely fused first pedigerous somite and three free pedigerous somites. Second to fourth pedigerous somites with pointed posterolateral corners in dorsal view.
Urosome (Figs. 1 A, B) 5-segmented, comprising fifth pedigerous somite, genital double–somite (fused genital and first abdominal somites) and three free abdominal somites. Genital double–somite (Fig. 1 A) as long as wide in dorsal view, line of fusion marked only by a short lateral subcuticular rib (Fig. 1 B).
Anal somite (Figs. 1 A, B) elongated, tapering posteriorly, approximately 1.2 times as long as preceding somite; anal operculum not reaching distal margin of anal somite.
Caudal rami (Figs. 1 A, C) with almost straight inner and outer margins, about half as long as anal somite, approximately 2.5 times as long as wide, inner margin unornamented, with 6 setae: setae II and VII of similar length, seta III distally to seta II, about as long as seta VI, longer than setae II and VII, seta IV (Fig. 1 A’) 3.8 times as long as caudal rami, seta V (Fig. 1 A”) longest, approximately 2.3 times as long as seta IV.
Rostrum (Fig. 1 A) not fused to cephalothorax, nearly rectangular.
Antennule (Figs. 1 B, 2A) 8-segmented, approximately 0.7 times as long as cephalothorax, relative lengths (%) of segments measured from proximal end along caudal margin 20.2:19.3:25.4:7.9:8.8:4.4:3.5:10.5; first segment short, bearing 1 seta on outer distal margin and 4 spinules (1 anterior, 3 posterior); second segment with 5 simple setae on posterior margin and 1 naked seta on anterior margin, 1 seta on outer distal margin; third segment longest, with 1 seta each at proximal, middle and distal margin on outer margin and slender long apical aesthetasc fused basally with 2 apical setae; proximal 3 segments stronger than distal 5 segments; fifth segment with 1 long unipinnate seta on distal outer margin; sixth and seventh segments with 1 apical and 1 inner marginal seta, respectively; eighth segment with 3 inner simple setae, 3 long setae, and aesthetasc apically. Armature formula as follows: 1/7/3 + (1 + Ae)/0/1/2/2/6 + Ae.
Antenna (Figs. 2 B, C) comprising coxa, allobasis, free second enp, and exp: coxa thick, short, and bare; allobasis thick, about twice as long as wide, with three longitudinal rows of spinules on proximal edge (arrowed in Fig. 2 B), distal row of spinules longer than anterior; exp 1-segmented, with 1 setulose seta on inner medial margin, 3 subapical spinules, and 1 apical setulose seta; endopodal segment shorter than allobasis, with group of spinules on proximal inner margin, inner medial margin with 2 robust spines ornamented with crenulations along medial margin (arrowed in Fig. 2 B), 6 short blunt spinules, and 1 long simple seta, row of setules on outer distal margin, distal margin with 4 crenulated spines (3 spines missing), 1 modified spine bearing 11 simple spinules and 1 bipinnate seta fused to spine (arrowed in Fig. 2 C), 1 bipinnate seta and row of setules.
Labrum (Fig. 2 D) represented by a triangular plate, with bifid tip and fringed by hyaline membrane around apex.
Mandible (Fig. 2 E) with elongate coxa, with row of spinules subdistally; gnathobasis very long, with sharp cutting edge composed by 3 strong teeth apically, of which medial teeth multicuspidate, and 1 tooth and 1 long stout subdistal seta furnished with a row of spinules longitudinally; basis of mandibular palp unarmed; exp 1- segmented with 2 apical bipinnate setae; enp 1-segmented, stronger than exp, with 3 apical and 1 subapical seta.
Maxillule (Figs. 2 F, G) with elongate praecoxal arthrite with 6 slender apical setae, 2 very long and 1 short setae subdistally, 4 spinules proximally on oral margin; coxal endite with 3 slender setae apically; basal endite with 4 apical setae (1 bipinnate seta, 3 simple setae) and 2 subapical setae on oral margin; enp fused to basis and represented by lobe armed with 2 setae; exp represented by distinct segment.
Maxilla (Fig. 2 H) syncoxa with vertical row of prominent spinules on posterior surface, furnished with 2 endites; proximal endite armed with 2 bipinnate setae; distal endite with 1 short unipinnate seta, 1 long simple seta, and 1 long unipinnate seta; basis drawn into strong, sclerotized and serrated claw with strong accompanying spine.
Maxilliped (Fig. 2 I) syncoxa with transverse row of strong spinules, small spinule on distal inner side, and 2 setae on inner distal margin; basis longer than syncoxa, with longitudinal row of spinules along inner and outer margin; enp drawn into strong claw, with strong spinules along distal concave margin.
Armature formula of P1 to P4 as follows (Roman numerals indicate spines; Arabic numerals indicate setae): P1 (Figs. 3 A, B) coxa wide with one transverse row of spinules on middle side and some spinules along outer margin. Basis short, narrower than coxa, with inner spine (arrowed in Fig. 3 A), three transverse rows of spinules of which one along outer margin, one near base of enp, and one on distal middle side and 1 small outer seta (arrowed in Fig. 3 A’). Both rami subequal in length, tapering gradually toward distal segment: exp-1 about twice as long as wide, with 3 spinules on distal corner, row of spinules on near inner margin and armed with 1 unipinnate spine apically; exp-2 shorter than exp-1, with 1 inner seta, some spinules along inner margin, 2 spinules on outer distal corner and armed with 1 bipinnate spine subapically; exp-3 slightly longer than exp-2, with some spinules along inner margin and armed with 2 outer spines and 2 apical spines. Enp with row of spinules along outer margin of each segment: enp-1 armed with 1 long, flexible and slender seta subapically on inner margin; enp-2 shorter than enp-1, with 1 long seta subapically on inner margin; enp-3 as long as enp-2, with 1 outer subapical bipinnate spine and 2 apical setae.
P2 (Figs. 3 C, D) intercoxal sclerite, coxa, and basis not found. Exp-1 approximately 1.7 times as long as wide, with 1 long slender seta on inner lateral margin, 3 short strong spinules on outer lateral margin, 2 strong spinules and row of setules along anterodistal margin and armed with 1 subapical outer spine. Exp-2 approximately 1.8 times as long as wide, with 1 short strong spinule near base of outer spine, 3 strong spinules and row of setules along anterodistal margin and armed with subapical outer spine. Exp-3 approximately 3 times as long as wide, with 3 strong outer spines (distalmost one longest, proximal 2 spines shorter than those of exp-1 and exp-2), 1 long outer apical bipinnate spine armed with setules on outer margin and spinules on inner margin, 1 long inner apical bipinnate seta armed with spinules on outer margin and setules on inner margin, and with 2 bipinnate setae on inner margin. Enp-1 approximately 1.3 times as long as wide, with 1 inner seta, row of setules and 3 short strong spinules distally on outer margin. Enp-2 approximately 1.6 times as long as wide, narrower than preceding segment: inner margin with 1 subapical seta, biplumose on proximal half, unipinnate on distal half, and 1.2 times as long as segment; outer margin with row of spinules, with 2 short strong spinules distally. Enp-3 approximately 2.7 times as long as wide, with 2 inner and 2 apical setae, 1 outer spine accompanied by a small spinule, and some spinules along outer margin.
P3 (Fig. 4 A) intercoxal sclerite smooth, rostrocaudally elongated, with deeply concave distal margin. Praecoxa approximately 0.4 times as long as wide, bare. Coxa bigger than praecoxa, approximately 0.6 times as long as wide, bare. Basis short, narrower than coxa, with row of long spinules along inner margin and two transverse rows of strong spinules near base of exp and distal middle margin, respectively. Both rami tapering distally, 3- segmented. Exp approximately 1.3 times as long as enp. Exp-1 approximately 1.8 times as long as wide, with 2 short strong spinules near base of outer spine, 2 strong spinules on outer distal margin, row of setules on inner distal margin, and armed with 1 subapical outer spine. Exp-2 approximately 1.9 times as long as wide, with 1 subapical seta and row of spinules on inner margin, process on outer distal margin (arrowed in Fig. 4 A), 1 short strong spinule near base of outer spine, and armed with 1 subapical outer spine. Exp-3 approximately 3.7 times as long as wide, with 3 strong outer spines (distalmost one longest, 2 proximal spines shorter than those of exp-1 and exp-2), 1 long outer apical bipinnate spine armed with spinules on the outer margin and setules on the inner margin, 1 long inner apical bipinnate seta armed with spinules on the outer margin and setules on the inner margin and 3 bipinnate inner setae (distalmost one longest, almost twice longer than segment). Enp-1 approximately 1.2 times as long as wide, with 1 short strong bipinnate subapical seta and as long as segment on inner margin, row of setules on distomedial margin, and 2 spinules on outer margin and 2 strong spinules along outer distal margin. Enp-2 approximately 1.7 times as long as wide, inner margin with 1 subapical seta being biplumose at proximal half and bipinnate at distal half and as long as segment; outer margin with few spinules, with 2 short strong spinules apically. Enp-3 approximately 3.1 times as long as wide, with 3 inner setae: distalmost one longest, 1.6 times as long as segment, 2 proximal setae biplumose at proximal half, unipinnate at distal half; outer margin with 1 outer spine; medial margin with 2 apical setae.
P4 (Fig. 4 B) intercoxal sclerite smooth, with deeply concave distal margin. Coxa approximately 0.6 times as long as wide, bare. Basis short, narrower than coxa, with long spinules on inner margin and two transverse rows of strong spinules near base of exp and distal middle margin, respectively. Both rami 3-segmented. Exp approximately 1.5 times as long as enp. Exp-1 approximately 1.7 times as long as wide: outer margin with 1 subapical outer spine, 1 short strong spinule near base of outer spine, and 2 strong spinules distally; inner margin with 1 slender seta; distal margin with row of setules. Exp-2 approximately 2.1 times as long as wide: outer margin with process at distal margin (arrowed in Fig. 4 B), 1 subapical spine, 1 short spinule near base of spine; inner margin with 1 subapical seta and row of slender spinules. Exp-3 approximately 4 times as long as wide: outer margin with 3 strong outer spines (distalmost one longest, 2 proximal spines shorter than those of exp-1 and exp-2); apex with 1 long outer apical bipinnate spine armed with spinules on the outer margin and setules on the inner margin, 1 long inner apical bipinnate seta armed with spinules on the outer margin and setules on the inner margin; inner margin with 3 setae. Enp-1 approximately 1.1 times as long as wide: outer margin with 3 short strong spinules on distal margin; inner margin with 1 subapical seta. Enp-2 approximately 1.8 times as long as wide, narrower than preceding segment: outer margin with 2 short strong spinules on distal margin; inner margin with 1 subapical seta, ornamented with spinules medially and pinnate distally, approximately 1.5 times as long as segment. Enp-3 approximately 3 times as long as wide: outer margin with spinules medially and 1 strong spine distally; apex with 2 long bipinnate setae; inner margin with 2 setae.
P5 (Fig. 3 E) medially fused; benp with outer seta on basis and 3 long spines and 4 spinules on endopodal lobe; exp 1-segmented, longer than wide, with 1 short outer seta, 1 subapical seta, 1 apical seta and 1 inner short seta.
P6 (Fig. 3 F) represented by opercula closing off genital aperture on either side; each armed with 1 seta.
Remarks. The presence of a distal seta on the syncoxa of the maxilliped and the general features of the swimming legs of Parameiropsis kodosensis n. sp. shows a close relationship with P. magnus from the waters southeast of Mindanao Island (Philippines). Nevertheless, P. kodosensis can be differentiated from P. magnus by the following morphological characteristics: 1) the length-to-width ratio of the caudal ramus is greater in P. kodosensis than in P. magnus (2.5:1 vs. 1:1), 2) the labrum has a bifid tip in P. k o do s e n s i s, 3) the maxilliped basis has a less developed claw on enp in P. kodosensis (vs. prominently developed in P. magnus), 4) exp-3 of P1 has a different setal count in P. k o do s e n s i s (III, I1, 0 vs. II, II, 0), and 5) the exp and benp of P5 are separated in P. kodosensis, while they are fused in P. magnus. Of the other five previously described species for which the female is known, only P. peruanus has a separate P5 exp. It is similar to P. k o do s e n s i s in some ways, such as the relative length of the genital double–somite to the urosome excluding caudal rami, and the length-to-width ratio of the caudal rami. However, P. k o do s e n s i s and P. peruanus can be differentiated by the following morphological features: the proportional length of the sixth urosomal segment to the urosome including caudal rami is smaller in P. k o do s e n s i s (0.17 vs. 0.25); in the maxilliped, the syncoxa have 2 distal setae in P. kodosensis (vs. without seta), the claw on the enp with proximal seta (vs. without), and exp-3 of P1 has a short strong spine on the distal margin in P. kodosensis (vs. seta).
description: Published as part of Cho, Dae Hyun, Wi, Jin Hee & Suh, Hae-Lip, 2016, Two new species of the deep-sea genus Parameiropsis (Copepoda: Harpacticoida) from the eastern central Pacific, pp. 521-539 in Zootaxa 4132 (4) on pages 523-529, DOI: 10.11646/zootaxa.4132.4.4, http://zenodo.org/record/262818