Bradyidius sp. C

Markhaseva, Elena L. & Renz, Jasmin, 2021, Description of three new species of Bradyidius (Copepoda: Calanoida), the new aetideids from the deep Pacific Ocean, with notes on the genera Bradyidius and Aetideopsis, Zootaxa 5004 (2), pp. 343-369 : 360-363

Bradyidius sp. C

( Fig 12 )

Material. One female (poor condition) from the Atlantic Ocean, Guinea Basin collected above the sea bed at Sta. 89 on 20 March 2005, 00°42.95’ N 05°31.29’ W, by the DIVA 2 expedition, Meteor cruise, at a depth of 5141 m .

Description. Female. Body length 2.50 mm. Prosome 3.60 times as long as urosome. Rostrum two-pointed, asymmetrical with divergent points ( Fig. 12D–E ). Cephalosome and pedigerous somite 1 and pedigerous somites 4–5 partly separate ( Fig. 12A–C ); posterior corners prolonged into points exceeding middle length of genital double-somite ( Fig. 12A–C ). Urosome of 4 somites. Genital double-somite symmetrical, with lateral swellings in its anterior half (dorsal view). Spermathecae narrow-elongate and oval in distal part ( Fig. 12C ). Caudal rami with 1 lateral seta, 4 terminal setae and ventral seta broken, and ( Fig. 12B ).

Antennule reaching pedigerous somite 4.

Antenna, exopod of 8 segments, setation formula 1,1-1-1, 1, 1, 1, 1, 1, and 3 setae.

Mandible, 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 long setae and 1 short setae.

Maxillule, praecoxal arthrite with 9 terminal spiniform setae, 1 anterior, and 4 posterior setae; coxal endite with 5 setae; coxal epipodite with 7 long and 2 short setae; proximal basal endite with 4 setae, distal basal endite with 5 setae; endopod setae could not be counted; exopod with 10 setae.

Maxilla, endites and enditic lobe of endopod typical for the genus, endopod setation not observed.

Maxilliped typical for the genus.

Legs. P1 ( Fig. 12F ), coxa lateral setules not observed; basis with 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 1–3 with 1 lateral spine each; spine of exopod segment 1 slightly exceeding the base of exopod segment 2 lateral spine.

P2–P4 as in B. kurilokamchaticus sp. nov., except for P4 coxa without lateral spinules. P5 absent.

Male unknown.

Remarks. Due to its poor condition of this specimen no biological name is assigned and it is herein designated as Bradyidius sp. C . This individual possesses asymmetrical rostral points. An asymmetry of rostral points is not typical for the genus Bradyidius and is herein considered as an abnormality of this individual. Bradyidius sp. C shares the form of the posterior corners of prosome, which are exceeding the middle length of the genital doublesomite, but not reaching its posterior border, as well as the divergent rostral points, with B. saanichi , B. hirsutus and B. similis , but differs in a longer lateral spine of P1 exopod segment 1 (not exceeding the base of the lateral spine of P1 exopod segment 2 in B. saanichi , B. hirsutus and B. similis ). Additionally, Bradyidius sp. C differs from B. saanichi and B. similis in the setation of the antenna exopod proximal segments as (1,1-1-1), while the setation in the latter two species is 0,0-1-1. It furthermore differs from B. hirsutus in the presence of 2 setae at the mandible basis, while the latter possesses 1 seta ( Park, 1966; Bradford, 1976; Shih et al., 1981; Markhaseva, 1996 and personal data herein).

Figures

FIGURE 12. Bradyidius sp. C. Female, A, habitus, dorsal view; B, posterior prosome and urosome, dorsal view; C, posterior prosome and urosome, lateral view; D, rostrum, ventral view; E, rostrum, lateral view; F, P1, left