Cerviniella danae, Kihara, Terue C. & Arbizu, Pedro Martínez, 2012

Kihara, Terue C. & Arbizu, Pedro Martínez, 2012, Three new species of Cerviniella Smirnov, 1946 (Copepoda: Harpacticoida) from the Arctic, Zootaxa 3345, pp. 1-33 : 4-12

publication ID	https://doi.org/ 10.5281/zenodo.281475
DOI	https://doi.org/10.5281/zenodo.5616005
persistent identifier	https://treatment.plazi.org/id/03D1840F-FFFB-597B-FF2A-15A7AB04F91E
treatment provided by	Plazi
scientific name	Cerviniella danae
status	sp. nov.

Treatment

Cerviniella danae sp. nov.

( Figs 1–6 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 A, B, 16–17)

Type locality. Arctic Ocean, Laptev Sea (77°10.74' N, 126°12.29' E), 1009 m depth.

Type material. Holotype female dissected on 13 slides (reg. no. SMF 37027) from station PS27#047/2465-1, multi corer 1–4, collected 08/09/1993. Undissected paratypes consist of 2 females (reg. nos. SMF 37028 and 37029) from station PS27#047/2465-1, MUC 1–4, collected 08/09/1993. All material collected from the type locality by the junior author during Expedition ARCTIC’93, Leg ARK-IX/4 of RV Polarstern.

Description. FEMALE. Total body length 835.2–888.0 μm (N = 3; mean = 864.5 μm; holotype = 888.0 μm). Largest width measured at midlength of cephalic shield: 320.0–335.2 μm (N = 3; mean = 328.2 µm; holotype = 320.0 μm). Body ( Figs 1 View FIGURE 1 A, 16A–C) with no clear distinction between prosome and urosome, body somites gradually tapering posteriorly.

Prosome ( Figs 1 View FIGURE 1 A, 16A–C) 4-segmented, with first pedigerous somite incorporated into cephalothorax. Cephalothorax with reticulated surface ( Fig 1 View FIGURE 1 B), anastomosing pattern more accentuated towards rostrum ( Fig. 17 View FIGURE 17 A) and along margins ( Figs 1 View FIGURE 1 A, 16A–B); additional ornamentation consisting of sensilla and pores as illustrated in Figures 1 View FIGURE 1 A, 16A–B; posterior margin slightly serrate. Pedigerous somites with reticulation along posterior margins ( Figs 1 View FIGURE 1 A, 16A–B, 17B) and ornamentation consisting of sensilla as illustrated in Figures 1 View FIGURE 1 A, 16A–B; epimera of second to fourth pedigerous somites expanded posteriorly; posterior margins serrate.

Urosome ( Figs 1 View FIGURE 1 A, 2A–B, 16A–C) 5-segmented, comprising P5-bearing somite, genital double-somite, 2 free abdominal somites and anal somite. Urosomites with surface ornamentation consisting of sensilla and minute spinules, spinules more conspicuous ventrally; posterior margin serrate and with reticulated surface.

Genital double-somite ( Figs 1 View FIGURE 1 A, 2A–B, 16A–B) original segmentation indicated by transverse, serrate surface ridge with reticulation and sensilla dorsally, and hook-like projections laterally ( Figs 17 View FIGURE 17 C–F), completely fused ventrally; genital field ( Fig. 2 View FIGURE 2 C) with surface striations, copulatory pore located in median depression; gonopores covered by opercula derived from sixth legs and by anteriorly directed flap arising from somite wall; P6 bearing 1 pinnate and 1 naked setae.

Anal somite ( Figs 1 View FIGURE 1 A, 2A–B, 16A–C) with reduced anal operculum; large anal opening with fringe of fine setules; surface ornamentation consisting of pair of sensilla dorsally, minute spinules and pair of pores ventrally; ventral posterior margin with minute setules.

Caudal rami ( Figs 1 View FIGURE 1 A, C–D) slightly asymmetrical; approximately 3.5X as long as maximum width, tapering posteriorly. Each ramus with 7 setae: seta I closely set to seta II, both setae pinnate and inserted at proximal third; seta III pinnate and positioned ventrolaterally; setae IV and V fused basally and naked, both bases covered by membranous extension; seta VI minute and flattened, displaced ventrally; seta VII tri-articulate at base and pinnate. Rostrum ( Figs 2 View FIGURE 2 D, 17A) fused to cephalic shield; bluntly triangular; with midventral tube-pore near apex.

Antennule ( Figs 3 View FIGURE 3 A, 17E) 5-segmented and surface ornamentation consisting of small denticles as shown in Figure 3 View FIGURE 3 A. Segment I with blunt protuberance on posterior distal corner; segment II longest, a double segment completely fused dorsally but with original segmentation apparent in ventral view (arrowed in Figure 17 View FIGURE 17 E), with aesthetasc fused basally to seta and set on distinct pedestal; segment V with aesthetasc fused basally to 1 pinnate seta. Armature formula: I-[1 pinnate], II-[10 pinnate + 4 pinnate spines + (1 + ae)], III-[3 pinnate], IV-[4 pinnate], V-[6 pinnate + (1 pinnate + ae)].

Antenna ( Fig. 3 View FIGURE 3 B) 3-segmented, comprising coxa, allobasis, and 1-segmented endopod. Coxa (not illustrated) small, with no ornamentation. Basis and enp-1 fused, forming elongate allobasis, with spinules along abexopodal margin and patch of spinules and denticles as shown in Figure 3 View FIGURE 3 ; abexopodal seta pinnate. Free endopod about half length of allobasis; ornamented with row of spinules proximally, row of minute spinules along distal corner and sparse spinules along outer margin; medial armature consisting of 2 setae (1 naked and 1 pinnate) and 1 spine; apical armature consisting of 4 spines and 3 setae (2 naked and 1 pinnate), subdistal seta shortest. Exopod 4- segmented; exp-1 as long as next 3 segments combined; armature formula: I-[2 pinnate], II-[1 pinnate], III-[1 pinnate], IV-[3 pinnate].

Mandible ( Figs 3 View FIGURE 3 C–D). Coxa with well developed gnathobase bearing several multicuspidate teeth and 1 pinnate seta around distal margin ( Fig. 3 View FIGURE 3 D). Palp well developed, comprising basis, endopod and exopod. Basis with 4 pinnate setae and surface ornamentation as indicated in Figure 3 View FIGURE 3 C. Endopod 1-segmented with 8 naked setae (3 lateral and 5 apical). Exopod 4-segmented, exp-1 as long as the next 3 segments combined; armature formula: I- [1 pinnate], II-[1 pinnate], III-[1 pinnate], IV-[2 pinnate].

Maxillule ( Figs 4 View FIGURE 4 A–B). Praecoxa with transverse fold and rows of spinules as shown in Figure 4 View FIGURE 4 A; arthrite well developed, with 2 pinnate setae on anterior surface, with 7 spines (3 pinnate and 4 striated) and 3 naked setae along distal margin, posterior surface with patches of spinules and 2 pinnate setae ( Fig. 4 View FIGURE 4 B). Coxa with spinules scattered on posterior surface and along outer margin; endite cylindrical, bearing 6 setae (1 pinnate and 5 naked) distally; epipodite represented by 1 pinnate seta. Basis and endopod fused; basis with 11 setae (3 pinnate and 8 naked); endopod incorporated into basis, represented by 3 naked setae. Exopod 1-segmented, with 3 pinnate setae.

Maxilla ( Fig. 4 View FIGURE 4 C) comprising syncoxa, allobasis and 3-segmented endopod. Syncoxa with 4 endites; proximal praecoxal endite with 4 setae (3 pinnate and 1 naked); distal praecoxal endite almost completely incorporated into syncoxa, with 3 naked setae; proximal coxal endite with 3 naked setae; distal coxal endite with 2 setae and 1 pinnate spine; rows of spinules and setules along outer margin and additional ornamentation as shown in Figure 4 View FIGURE 4 C. Allobasis endite forming strong claw; accessory armature consisting of 2 naked setae and 1 pinnate spine; endopodal armature of maxillary allobasis represented by 1 seta and 1 spine. Endopod with armature formula: I-[1 + 1 geniculate], II-[2 geniculate], III-[3 + 1 geniculate].

Maxilliped ( Fig. 4 View FIGURE 4 D) with elongated protopod and 2-segmented endopod. Protopod with rows of long setules along outer margin and rows of spinules along proximal inner margin and anterior surface; syncoxal endites represented proximal to distal by 1 pinnate seta, 1 pinnate seta and 1 pinnate spine, and 1 pinnate seta and 1 pinnate spine; basal endite represented by 1 pinnate seta and 1 pinnate spine. Endopod with armature formula: I-[1 pinnate], II-[3 pinnate spines + 1 pinnate seta].

P1 ( Figs 5 View FIGURE 5 A–B, 17D) biramous. Intercoxal sclerite well developed, approximately 4.0X wider than long, with reticulated surface and row of setules along distal margin. Praecoxa with row of spinules along outer margin. Coxa with rows of minute spinules and setules on anterior surface, patches of minute spinules on posterior surface, small setules along distal margin, and long setules along outer margin. Basis with long pinnate spine on inner distal corner and pinnate seta on outer distal corner; ornamentation consisting of patches of setules on anterior surface and along inner and distal margins. Exopod 1-segmented; with rows of setules along the margins and anterior surface of proximal area, and rows of minute spinules around bases of outer setae; 5 setae (with setules proximally and pinnate distally) along outer margin, 2 apical setae (1 pinnate and 1 with setules proximally and pinnate distally), and 3 pinnate setae along inner margin. Endopod 1-segmented, half length of exopod, and with rows of spinules along inner and outer margins; 3 pinnate setae along inner margin, 2 pinnate setae apically, and 1 pinnate seta on distal outer corner.

P2–P3 ( Figs 5 View FIGURE 5 C–D, 6A, 16C, 17D) biramous. Intercoxal sclerite well developed (cordiform in P2 and subrectangular in P3), with reticulated surface and row of setules along distal margin. Praecoxa well developed. Coxa with rows of minute spinules and setules on anterior surface, and small setules along distal margin. Basis with row of spinules along distal margin and rows of spinules on anterior surface, with (P2) or without (P3) pore on proximal outer corner, 1 pinnate seta on distal outer corner. Exopod-1 segmented and elongated; with row of setules along inner and outer margins, anterior surface with patch of setules proximally and pore distally; outer and distal margins with acute projections. Endopod 2-segmented; enp-1 outer corner drawn out into bifid (P2) or blunt (P3) projection, with row of setules along outer (P2–P3) and distal (P2) margins; enp-2 outer margin with rows of setules and conspicuous acute projection at midlength of segment. P2 enp-2 approximately 3X as long as enp-1; P3 enp-2 approximately 2X as long as enp-1.

P4 ( Figs 6 View FIGURE 6 B, 17F) uniramous. Protopod fused to supporting somite and with 1 outer pinnate seta. Exopod 1- segmented, with 1 outer and 1 apical pinnate seta. Endopod absent.

P1–P4 spine and seta formulae as follows:

P5 ( Figs 6 View FIGURE 6 B, 17F). Protopod fused to supporting somite and with 1 outer pinnate seta. Exopod with 1 outer and 1 apical pinnate seta.

MALE. Unknown.

Variability. P3 enp-2 presumably bears only 1 distal seta in the normal condition (formula [010], 3 females). However, in two females, P3 enp-2 displayed [110] on one side and [010] on the other side.

Etymology. The species name danae refers to Дана (Dana), goddess of the sea in Slavic mythology.