Kyphocalanus atlanticus, Markhaseva, Elena L. & Schulz, Knud, 2009

Markhaseva, Elena L. & Schulz, Knud, 2009, A new family and genus of calanoid copepods (Crustacea) from the abyss of the Atlantic Ocean, Zootaxa 2304, pp. 21-40 : 24-30

publication ID	https://doi.org/ 10.5281/zenodo.275327
DOI	https://doi.org/10.5281/zenodo.6225629
persistent identifier	https://treatment.plazi.org/id/03FE0E70-FFA3-327E-F1E4-FE40FBF4FF5A
treatment provided by	Plazi
scientific name	Kyphocalanus atlanticus
status	sp. nov.

Treatment

Kyphocalanus atlanticus sp. nov.

( Figs 1–5 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 )

Holotype. Dissected adult female, body length 2.24 mm. ZMH Reg. no. K–41633. Collected on 28 July 2000, above the sea bed at abyssal depths (5390m).

The holotype is deposited at the Zoological Museum Hamburg ( ZMH), University of Hamburg.

Type locality. South Atlantic (16º18’S 05º27’E).

Description. Female. Prosome 5.2 times as long as urosome.

Rostrum with two strong prong-like rami ( Fig. 1 View FIGURE 1 C–D). Cephalosome and somite 1 and somites 4 and 5 of prosome separate; posterior corners prolonged as triangular lobes ( Fig. 1 View FIGURE 1 A–B, E–F). Urosome of 4 somites. Caudal rami with 4 terminal setae, 1 ventral and a dorsal seta ( Fig.1 View FIGURE 1 E-F).

Antennule ( Fig. 2 View FIGURE 2 A-B) extending to distal margin of pediger 4, of 24 free segments; armature as follows: I–2 s +?, II– IV–6 s + 1ae, V–2 s + 1ae, VI–2 s, VII–2 s + 1ae, VIII–2 s, IX–2 s + 1ae, X– XI-4 s + 1ae, XII–1 s, XIII–1s, XIV–2s + 1ae, XV–1s, XVI–2s + 1ae, XVII–1s, XVIII–1s, XIX–1s, XX–2s, XXI–1s + 1ae, XXII– 1s, XXIII–1s, XXIV–2s, XXV–2s, XXVI–2s, XXVII–XXVIII-5s + 1ae.

Antenna ( Fig. 2 View FIGURE 2 C), coxa with 1 seta, basis without seta; exopod of 8 free segments with 0, 1, 1, 1, 1, 1, 1, and 3 setae, about 1.8 times as long as endopod; first endopodal segment without seta, second with 4 + 6 setae. Mandible ( Fig. 2 View FIGURE 2 D), gnathobase long and slender, cutting edge narrow, with 4 acute and 4 or 3 small teeth plus dorsal seta; basis with 2 setae, proximal with basal part haft-like; exopod 5-segmented with 1, 1, 1, 1, and 1 setae; endopod segment 1 without setae, segment 2 with 9 setae.

Maxillule ( Fig. 3 View FIGURE 3 A), praecoxal endite with 3 terminal setae; coxal endite with 2 setae; proximal basal endite without seta, distal basal endite with 1 seta; endopod with 5 setae; exopod with 7 setae; coxal epipodite with 9 setae.

Maxilla ( Fig. 4 View FIGURE 4 ), proximal praecoxal endite with 2 setae; distal praecoxal endite with 2 setae; proximal coxal endite with 2 setae; distal coxal endite with 2 setae; proximal basal endite with 1 spine; distal basal endite plus endopod with 8 long and thick worm-like sensory setae.

Maxilliped ( Fig. 3 View FIGURE 3 B), syncoxa with 1 worm-like, comparably thin and short sensory seta on proximal praecoxal lobe, 2 long and thick worm-like setae on middle lobe extending to distal part of endopod; distal praecoxal lobe without setae; coxal lobe with 1 seta. Basis with 3 setae. Endopod 6-segmented with 2, 4, 2, 2, 2+1, and 4 setae.

Swimming legs. P1 ( Fig. 5 View FIGURE 5 A–B), basis with medial distal seta nearly straight, or slightly curved with setules; endopod 1-segmented without lateral lobe, outer margin with slight undulation in a proximal half of segment; exopod segments 1 to 3 with 1 lateral spine each, spine of segment 1 the shortest exceeding base of following spine; spine of exopod segment 2 not reaching base of distalmost spine. P2–P4 ( Fig. 5 View FIGURE 5 C), coxa with 1 seta; basis without seta; endopod 2-segmented in P2, 3-segmented in P3–P4; exopods 3-segmented (exopodal segments 2 and 3 of P4 broken); lateral spines of P2–P3 compact, that of exopod segment 1 the shortest. Posterior surface of P4 spinulate.

P5 ( Fig. 3 View FIGURE 3 C) 3-segmented, coxa and basis of equal length; coxa with distolateral row of 6 spinules, basis with patch of spinules distolaterally, exopod ornamented with rare surface spinules and 2 distal spines, terminal spine about 0.6 times length of subterminal inner spine.

Etymology. The species name “ atlanticus ” refers to the type locality of the species in the Atlantic Ocean. The name is an adjective agreeing in gender with the (masculine) generic name.