Sensiava

Markhaseva, Elena L., 2014, New Sensiava species (Copepoda: Calanoida: Diaixidae) from the deep South Atlantic and first description of the female, Zootaxa 3802 (2), pp. 217-239 : 234-236

Sensiava sp.

( Fig. 14 A–D)

Material examined. Two adult females in poor condition, body length 2.00–2.05 mm. Collected on 30 July 2009 by the DIVA –III expedition above the sea bed, 14º59’S 29º56’W, at depths of 5131 m and 5148 m.

Description. Female. Body severely damaged, length 2.00–2.05 mm. Rostrum as 2 filaments. Spermatheca, narrow, elongate, directed anteriorly ( Fig. 14 A).

Antennule broken.

Antenna ( Fig. 14 B), coxa with 1 seta, basis with 2 setae, one seta shorter; proximal exopod segments armament 0, 0-0-1, setae; first endopodal segment with 1 seta, second with 8 + 6 setae.

Mandible, gnathobase without crest, cutting edge with 5 large and 3 small teeth near dorsal seta; basis with 3 setae; endopod segment 1 with 2 setae, segment 2 with 8 setae at one side and 9 setae at another side.

Maxillule, praecoxal arthrite with 9 marginal, 3 posterior and 1 anterior setae; coxal endite with 5 setae; coxal epipodite with 8 setae at one side and 9 setae at another side proximal basal endite with 4 setae, distal basal endite with 4 setae; endopod with 9 (3+6) setae; exopod with 8 setae.

Maxilla, praecoxal endite (previously considered as proximal praecoxal endite) with 5 setae, one of them is very thin and short; coxal endite (previously considered as distal praecoxal endite) with 3 setae; basal endites (previously considered as coxal endites) with 3 setae each, 1 seta of proximal basal endite sensory, worm-like; enditic-like lobe of proximal endopodal segment (previously considered as proximal basal endite) with 4 setae, 2 sensory, worm-like; setae of the maxilla basal endites and enditic-like lobe of endopod are similar in shape and size, curved distally; endopod with 3 worm-like and 5 brush-like sensory setae.

Maxilliped, syncoxa with 1 sensory worm-like seta on proximal praecoxal endite, 1 sclerotized setae and 1 sensory worm-like seta on middle praecoxal endite and 2 sclerotized and 1 sensory seta with very small brush on distal praecoxal endite; coxal lobe with 3 setae; row of thin long spinules present at syncoxa between the distal preacoxal and coxal setae group. Basis with 3 proximal setae and 2 distal setae, endopod damaged.

Swimming legs. P1 ( Fig.14 C), coxa with medial spinules; basis with medial spinules, small posterior spines at base of medial distal seta curved with setules; endopod 1-segmented with lateral lobe, lateral margin without spinules; exopod segments 1 to 3 with 1 lateral spine each, spines taper to stiff point. P2–P4 identical to S. peculiaris , except for P3 coxa which is much more spinulated on posterior surface. P5 identical to S. peculiaris , except for terminal, subterminal and lateral spines are not separate from the segment.

Remarks. Female specimens of Sensiava sp. are damaged. However, they can be distinguished from other congeners by: i) a narrow, elongated spermatheca (vs. shape is different in other congeners, Figs. 1 F–G, 9G, 13A); ii) shorter seta on the antenna basis is short, but not too reduced (shared with Sensiava cf. longiseta , vs. this seta is very short in S. secunda and S. peculiaris , Figs. 2 C, 10C); iii) maxillule praecoxal arthrite with 3 posterior setae (shared with S. peculiaris , vs. 4 setae in other congeners); iv) coxal endite with 5 setae (shared with Sensiava cf. longiseta , vs. 4 setae in other congeners); iv) maxilliped, syncoxa with 1 sensory worm-like seta on proximal praecoxal endite (vs. sclerotized seta in other congeners), 1 sclerotized setae and 1 sensory worm-like seta on middle praecoxal endite (shared with S. peculiaris , vs. sclerotized seta in other congeners), and 2 sclerotized and 1 sensory seta with a very small brush on distal praecoxal endite (small brush shared with S. secunda ; a sclerotized seta in all other congeners).

Figures

FIGURE 1. Sensiava secunda sp. nov. Female, holotype. A, habitus, dorsal view; B, habitus, lateral view; C, rostrum, lateral view; D, urosome, dorsal view; E, genital double somite, ventral view; F, urosome, lateral view; G, genital field, lateral view; H, P 5, posterior view. Scale bars: A – B 0.5 mm, C – H 0.1 mm.

FIGURE 2. Sensiava secunda sp. nov. Female, holotype. A, antennule, articulating segments 1 – 16 (ancestral segments I – XIX); B, antennule, articulating segments 17 – 24 (ancestral segments XX – XXVIII); C, antenna; D, mandible, palp; E, mandible, gnathobase cutting edge; F, P 1, anterior. Scale bars 0.1 mm.

FIGURE 14. Sensiava sp. Female. A, posterior prosome and genital double somite, sprematheca, lateral view; B, antenna, basis, distomedial and proximal part of endopod segment 1; C, P 1, endo- and exopod; P 4, coxa. Scale bars 0.1 mm.