Sensiava cf. longiseta Markhaseva & Schulz, 2006

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

Sensiava cf. longiseta Markhaseva & Schulz, 2006

( Fig. 13 A–I)

Material examined. One adult female in poor condition, body length 4.80 mm. Collected on 30 July 2009 by the DIVA –III expedition above the sea bed, 14º59’S 29º56’W, at a depth of 5148 m.

Description. Female. Body very damaged, length 4.80 mm. Rostrum as 2 filaments. Spermatheca widening distally, rounded in distal part, directed anteriorly ( Fig. 13 A).

Antennule slightly exceeding genital double somite.

Antenna ( Fig. 13 B), coxa with 1 seta, basis with 2 setae, one seta shorter; exopod of 7 segments with 0, 0-0-1, 1, 1, 1, 1, 1, and 3 setae; first endopodal segment with 1 seta, second with 8 + 6 setae.

Mandible ( Fig. 13 C), gnathobase without crest, cutting edge with 5 large and 3 small teeth near dorsal seta; basis with 3 setae; exopod 5-segmented with 1, 1, 1, 1, and 2 setae; endopod segment 1 with 2 setae, segment 2 with 9 setae.

Maxillule ( Fig. 13 D), praecoxal arthrite with 9 marginal, 4 posterior and 1 anterior setae, distalmost terminal praecoxal arthrite seta curved at the apex; coxal endite with 3 long and 2 short setae; coxal epipodite with 7 long and 2 short setae; proximal basal endite with 4 setae, distal basal endite with 4 setae; endopod with 9 (3+6) setae; exopod with 8 setae.

Maxilla ( Fig. 13 E), praecoxal endite (previously considered as proximal praecoxal endite) with 5 setae; 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 ( Fig. 13 F–G), syncoxa with 1 sclerotized seta on proximal praecoxal endite, 2 sclerotized setae on middle praecoxal endite and 3 sclerotized setae, 1 of them poorly sclerotized; coxal lobe with 3 setae. Basis with 3 proximal setae and 2 distal setae, endopod damaged.

Swimming legs. P1 ( Fig. 13 I), coxa with medial spinules; basis with medial spinules and small posterior denticles at the base of medial distal seta curved with setules; endopod 1-segmented with lateral lobe, its lateral margin without spinules; exopod segments 1 to 3 with 1 lateral spine each, spines taper to stiff point. P2–P 5 in a bad condition, not described.

Remarks. The female specimen is damaged and can not be described in all details. It shares size (4.80 mm), antenna, maxilla and maxilliped syncoxa setation, P2–P4 and general characters of P1 with S. longiseta , a species originally described from the male alone. The female specimen differs from the male of S. longiseta in: i) mandible basis with 3 setae (vs. 2 setae in the male); ii) maxillule coxal endite setation as 3 long +2 short setae (vs. 3 setae in the male); iii) maxilliped endopod segment 5 all setae of common size (vs. 2 setae are much longer in males); iv) spinules on the endopod lobe of P1 absent (vs. present in the male), and in some other details. While these differences could be attributed to sexual dimorphism, the possibility that this female is not conspecific with specimens belonging to S. longiseta must be considered. Therefore these females are tentatively named as Sensiava cf. longiseta .

The female of Sensiava cf. longiseta differs from other Sensiava female specimens by: i) larger size; ii) shape of spermatheca (different compared to other congeners, Figs 1 F–G; 9G, 14A); iii) shorter seta on the antenna basis is not too reduced (shared with Sensiava sp. but this seta is extremely short in S. secunda and S. peculiaris , Figs. 2 C, 10C).

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 13. Sensiava cf. longiseta Markhaseva & Schulz, 2006. Female. A, spermatheca, lateral view; B, antenna, coxa, basis, endopod segment 1; C, mandible, cutting edge; D, maxillule (arrow marks distalmost terminal seta curved at the apex); E, maxilla; F, maxilliped syncoxa; G, maxilliped, basis, distal setae not figured; I, P 1. Scale bars 0.1 mm.