Description of Bradyetes paramatthei sp. nov. (Copepoda: Calanoida), a new aetideid species from the deep Pacific Ocean with notes on the genus Bradyetes Author Markhaseva, Elena L. Author Petrov, Anatoly Author Renz, Jasmin text Zootaxa 2020 2020-02-12 4732 2 258 280 journal article 24071 10.11646/zootaxa.4732.2.2 c8ee1c0b-5b75-4ec3-9567-4e4f51ce0f93 1175-5326 3663415 FF89C33B-A35D-4D21-AACE-2F3276851C05 Bradyetes paramatthei sp. nov. ( Figs 5–8 ) Holotype . Adult female, dissected, body length 2.10 mm . ZMH 45138. Collected above the sea bed in the Kurile- Kamchatka Trench at Sta. 2–10, 46° 14.76’ N 155° 32.81’ E , on 3 August 2012 by the KuramBio 1 expedition, Sonne cruise SO 223, at depths between 4859 and 4865 m . Paratypes . 5 adult females, partly dissected, body length 2.20, 2.20, 2.20, 2.30 and 2.30 mm . SMF 37208– 37212 , collected above the sea bed in the Kurile-Kamchatka Trench, by the KuramBio 1 expedition, Sonne cruise SO 223 at Sta. 9–12 on 24 August 2012 , 40°34.49’ N 150°59.85’ E , at depths between 5399 and 5392 m ; 2 adult females, 1 in poor condition, body length 2.00, 2.15 mm , ZIN 91147, Sta. 11–12, 31 August 2012 , 40°12.32 ‘ N 148° 05.73’ E , at depths between 5350 to 5348 m . Type locality . 46°14.77’ N 155°32.79’ E . Additional material . Four females from the Atlantic Ocean: 1 female , body length 2.15 mm , collected in the Angola Basin, Sta. 348, 27 July 2000 , 16°16.98’ S 005°27.27’ E , by the DIVA–1 expedition, Meteor cruise ME 48–1, at a depth of 5390 m ; 2 females collected in the Guinea Basin by the DIVA–2 expedition, Meteor cruise ME 63–2 from 2 stations – 1 female , body damaged, not measured, Sta. 64–5, 15 March 2005 , 00°13.27’ S 002°29.91’ W , depth 5055 m and 1 female , body length 2.05 mm , Sta. 89–6, 20 March 2005 , 00°45.30’ S 005°35.00’ W , depth 5154 m ; 1 female , body length 1.90 mm , collected at Meteor Seamount , Sta. 636, 18 August 2009 , 29°19.24’ N 28°37.94’ E , by the DIVA–3 expedition, Meteor cruise ME 79–1, at a depth of 4338 m . One female from the Pacific Ocean , body length not measured, collected above the sea bed in the Kurile-Kamchatka Trench , at Sta. 7–10 on 17 August 2012 , 40°01.82’ N 152°58.55’ E , by the KuramBio 1 expedition, Sonne cruise SO 223, at depths between 5223 and 5221 m . Description. Female. Body length 1.90–2.30 mm . Prosome 2.7–3.3 times as long as urosome ( Fig. 5 A–B). Rostrum as a significantly reduced blunt plate ( Fig. 5C ). Cephalosome and pedigerous somite 1 and pedigerous somites 4–5 incompletely separate; posterior corners oval-triangular in dorsal view; rounded in lateral view ( Fig. 5 A–B, E–H). Urosome of 4 somites ( Fig. 5 A–B). Genital double somite globular shape. Spermathecae large, round to oval round with very narrow duct leading to the genital atrium ( Fig. 5B , F–H). Caudal rami with 1 lateral seta, 1 ventral seta, and 4 terminal setae ( Fig. 5D ). Antennule ( Fig. 5 J–L) reaching pedigerous somite 3, of 24 articulating segments; armature as follows: I–3s, II–IV–6s+1ae (ae absent in holotype ), V–2s+1ae, VI–2s, VII–2s+1ae, VIII and IX–2s each, X–XI–4s+1ae, XII and XIII–2s each, XIV–2s+1ae, XV–2s, XVI–2s+1ae, XVII to XXI–2s each, XXII and XXIII–1s each, XXIV–XXVI– 2s each, XXVII–XXVIII–5s+1ae, aestethasc long, nearly as long as 3 preceding segments together. Antenna ( Fig. 6 A–C), coxa with 1 seta, basis with 2 setae; exopod of 8 segments, setation formula 1?0?1?1, 1, 1, 1, 1, 1, and 3 setae (uncertain whether proximal Enp 1 and 2, or Enp 2 and 4 are fused), all terminal setae long, of nearly the same length; first endopodal segment with 2 setae, second with 8–9 + 7 setae. Mandible ( Fig. 6 D–E), gnathobase with 4 large and 4 small teeth near dorsal seta; basis with 2 setae; exopod 5-segmented with 1, 1, 1, 1, and 2 setae; endopod segment 1 with 2 setae, segment 2 with 9+1, or 9 setae in paratype . Maxillule ( Fig. 6F ), praecoxal arthrite with 9 terminal, 4 posterior and 1 anterior setae, coxal endite with 5 setae; coxal epipodite with 7 long+2 short setae; proximal basal endite with 4 setae, distal basal endite with 5 setae; endopod with 16 setae; exopod with 9–10 setae. Maxilla ( Fig. 7 A–B), praecoxal to basal endites with 3 setae each, all endites decorated with denticles; enditiclike lobe of proximal endopod segment with 3 setal elements, two thicker, spine-like; endopod with 9 (2+2+2+3) setae. FIGURE 5. Bradyetes paramatthei sp. nov. Female, A, habitus, dorsal view; B, habitus, lateral view; C, rostrum, ventral view; D, caudal ramus, ventral view; E, posterior prosome and genital double-somite, dorsal view; F–H, posterior prosome and genital double-somite, lateral view; I, genital double-somite, ventral view; J, antennule, dotted line marks additions from another holotype limb and paratypes; K, antennule, ancestral segments I–V; L, antennule, ancestral segments XXVII–XXVIII, dotted line marks additions after additional specimen. A–C, F, I–J, L, holotype; E, G–H, K, paratypes (SMF) and D, additional material (DIVA–2, Sta. 89). Scale bars: A–B 0.5 mm, C–L 0.1 mm. FIGURE 6 . Bradyetes paramatthei sp. nov. Female. A, antenna; B, C, antenna exopod (part.), different positions; D, mandible, palp; E, mandible, gnathobase; F, maxillule, dotted line marks additions from paratype; G, P1. A, D–G holotype, B, C, additional material (DIVA1, Sta. 348 and DIVA 3, Sta. 636 respectively). Scale bars 0.1 mm. FIGURE 7 . Bradyetes paramatthei sp. nov. Female. A, maxilla, 2 endopod setae broken, not figured; B, maxilla, endopod; C–D, maxilliped, syncoxa; E, maxilliped, basis and endopod. A, C, E - holotype, B, D – paratype (SMF). Scale bars 0.1 mm. FIGURE 8. Bradyetes paramatthei sp. nov. Female, holotype. A, P2; B, P3, C, P4. Scale bars 0.1 mm. Maxilliped ( Fig. 7 C–E), syncoxa with 1 seta on proximal praecoxal endite, 2 setae on middle praecoxal endite and 3 setae on distal praecoxal endite; coxal lobe with 3 setae and conical tubercle. Basis with 3 setae. Endopod 6- segmented with 2, 4, 4, 3, 3+1, and 4 setae, first segment very small and fused to basis. Legs. P1 ( Fig. 6G ), coxa with lateral spinules; basis with small lateral spinule distally and medial distal seta curved with setules; endopod 1-segmented with lateral lobe, its lateral margin with spinules, anterior segment surface with distal spinules; exopod segments 1 to 3 with 1 lateral spine each; spine of exopod segment 1 usually exceeding base of segment 2 lateral spine, sometimes, reaching base of segment 2 lateral spine. P2–P4 ( Fig. 8 A–C), coxa with 1 medial seta and medial spinules; basis without seta; endopod 2-segmented in P2, 3-segmented in P3–P4; posterior surface spinules present on P2 endopod segment 2 (nude in holotype ), P3 endopod segment 3, and P4 endopod segments 2–3 (nude in holotype ); exopods 3-segmented. P5 absent. Male unknown. Etymology. The species name “ paramatthei ” refers to a close relation of the species to Bradyetes matthei Johannessen, 1976 . Remarks. The new species is closely related to B . matthei and shares with this species a significant number of morphological features ( Table 3 ), but differs from B . matthei in the shape of the posterior corners of Pd5, which are rounded ( vs drawn out into the triangular points in B . matthei ) and in the armament of the proximal segment of the antennal exopod, which bears a seta ( vs seta absent in B . matthei ). While Bradyetes paramatthei sp. nov. and B . matthei both inhabit the near-bottom biotope, they are widely separated geographically and live in distant depth zones. Bradyetes matthei is recorded only from its type locality (Fensfjord, about 60° N 05° E ) at depths between 548 and 580 m ( Johannessen 1976 , Markhaseva 1996 ), whereas the new species was collected at abyssal depths between 4338 and 5399 m in the North and South Atlantic Ocean (several localities between 29° N and 16° S : Angola and Guinea basins, Meteor Seamount) and in the Pacific Ocean (Kurile-Kamchatka Trench).