Penteparatanais laevicarpus sp. nov.

Figures 33 –35

Material examined.

Other material :

Description. Female : Habitus ( Fig. 33A ) fairly slender, 6.3 times ltb; length quantity4.6–6.9 mm ( typeStatusholotype quantity6.9 mm ). Cephalothorax 0.9 times as long as wide, just shorter than pereonites 1 and 2 combined. Pereonites slightly expanded mid-ventrally, pereonites 1–3 with single anterolateral setae; pereonite-1 shortest, pereonite-2 1.5 times as long as pereonite-1, pereonites 3–6 subequal, 1.8 times as long as pereonite-1 (pereonites respectively 2.7, 1.7, 1.4, 1.5, 1.3 and 1.3 times as wide as long). Pleon 1.2 times ltb, with pleotelson 0.27 times as long as total length; each pleonite four times as wide as long. Pleotelson almost semicircular, short, 2.3 times as long as pleonite-5, 1.7 times as wide as long.

Antennule ( Fig. 33B ) as long as cephalothorax, article-1 nearly twice as long as broad, article-2 as long as broad, about one-third length of article-1, lateral simple seta longer than article width; article-3 0.6 times as long as article-2; article-4 naked, as long as article-3, twice as long as broad; article-5 almost as long as article-4. Antenna ( Fig. 33D ) article-2 twice as long as article-3, weakly expanded distally, with large inferior apophysis and seta, superodistal seta short, superior margin naked, with distolateral seta; article-3 as long as wide, superodistal spine acute; article-4 as long as article-2, with one medial and three distal simple setae; article-5 two-thirds as long as article-4; article-6 with five distal setae.

Labrum ( Fig. 34E ) typical paratanaidinid. Mandibles ( Fig. 34F–G ) typical, left with slightly crenulate lacinia mobilis , molar with ca . 15 fine spines. Labium ( Fig. 34A ) typical. Maxillule ( Fig. 31B ) endite with eight terminal spines. Maxilla ( Fig. 34C ) typical. Maxilliped ( Fig. 34D–E ) basis seta exceeding distal margin of palp article-1; palp article-2 medial margin without modified seta; article-3 with two of the four medial serrulate setae also geniculate. Epignath ( Fig. 34F ) typical, distally setulose.

Cheliped (Fig. 35A) basis as long as broad, posterior lobe smaller than anterior, naked; merus typical; carpus 1.7 times ltb; chela slightly longer than carpus, propodus slightly longer than broad, medial comb with eight spines ( Fig. 32B ); dactylus with two lanceolate spines on incisive margin.

Pereopod-1 (Fig. 35C) basis 5.3 times ltb; merus 2.2 times ltb, as long as carpus, with inferodistal seta; carpus with three superodistal setae; propodus 1.2 times as long as carpus; unguis 1.8 times as long as dactylus, together as long as propodus. Pereopod-2 (Fig. 35D) more compact than pereopod-1; basis 4.6 times ltb; merus with inferodistal seta and finely serrate spine (as in detail on Fig. 35H); carpus slightly longer than merus, spines finely serrate; propodus about twice as long as carpus or merus, with one superodistal seta; dactylus-unguis combined shorter than propodus. Pereopod-3 (Fig. 35E) similar to pereopod-2.

On pereopods 4–6, all spines on the merus, carpus, and on inferodistal margin of the propodus, are finely serrate (as in detail on Fig. 35H). Pereopod-4 (Fig. 35F) basis robust, 2.9 times ltb, with one inferior PSS; merus typical; carpus as long as merus; propodus 1.3 times as long as carpus, superodistal seta as long as dactylus; shorter; dactylus-unguis combined 0.7 times as long as propodus. Pereopod-5 (Fig. 35G) similar to pereopod-4, but basis with two inferior PSS, carpus with four spines. Pereopod-6 (Fig. 35H), similar to pereopod-5, but propodus lacking superior PSS, and with three superodistal spines.

Pleopods ( Fig. 34H ) all alike, endopod twice as long as broad, lateral margin with 19 setae and one distal on setulose medial margin; exopod three times ltb, proximal seta on lateral margin separated from remaining 23 setae by short gap.

Uropod ( Fig. 34G ) peduncle 1.3 times ltb: exopod slender, one-segmented, and longer than segment-1 of endopod; endopod two-segmented, segment-2 with three simple setae and one PSS.

Non-ovigerous female : as female but smaller, length quantity3.1–4.1 mm (Stn O. specimenCount651 specimen quantity2.67 mm ).

Manca-II: similar to non-ovigerous female but smaller (length quantity1.35–1.7 mm ), pleopods and sixth pereopods absent; antennule ( Fig. 33C ) of only four articles.

Male: unknown.

Distribution and ecology. So far, Penteparatanais laevicarpus sp. nov. is known with certainty only from the bathyal location ( quantity908 m ), off the east coast of North Island, although there is a possible record from much shallower depths ( quantity123–128 m ) north-east of the Three Kings Islands. It may be the deepest record of a Paratanais - like taxon, although comparable to that of Paratanais oculatus from quantity903 m ( Sieg 1986b ).

Remarks. This species should be distinguishable from the two Paratanais species known from shelf and shallow bathyal localities in the same geographical area, P. hamulus and P. incomptus , by the characters given in the diagnosis, although the former is potentially a greater confusion species because of the similarity of the