Prochelator tupuhi, Brix, Saskia & Bruce, Niel L., 2008

Brix, Saskia & Bruce, Niel L., 2008, Prochelator tupuhi sp. nov., the first record of Desmosomatidae Sars, 1897 (Crustacea: Isopoda) from New Zealand waters *, Zootaxa 1866, pp. 482-492 : 485-489

publication ID	https://doi.org/ 10.5281/zenodo.183873
DOI	https://doi.org/10.5281/zenodo.6233713
persistent identifier	https://treatment.plazi.org/id/03938798-FFD1-FFC6-FF43-FDC970E44F8A
treatment provided by	Plazi
scientific name	Prochelator tupuhi
status	sp. nov.

Treatment

Prochelator tupuhi View in CoL sp. nov. ( Figs. 1–5 View FIGURE 1 View FIGURE 2 View FIGURE 4 View FIGURE 5 )

Material examined: Holotype: Ψ (preparatory, 3.1 mm), east of Christchurch, South Island, western Chatham Rise, 44°30.10'S, 174°18.79'E, 25 Oct 1979, 760 m, stn. S147 ( NIWA 33747).

Paratypes: 1 ɗ (adult, 3.2 mm; allotype), same data as holotype ( NIWA 33748). 2 Ψ (adult) 44°45.00'S, 174°30.00'E, 18 Aug 1966, 765– 854 m, stn F753 ( NIWA 33749). 1 Ψ (adult) stn. F755 and 2 Ψ stn. S/ 47( NIWA 33750).

Type locality: Western Chatham Rise, east of Christchurch, South Island, New Zealand, 44°30.10'S, 174°18.79'E.

Distribution: Eastern New Zealand; at depths of 760 to 864 m, from the general type locality at more than one station.

Diagnosis: Body widest at pereonite 2; length about 4.6 times longer than width of pereonite 2. Pereonites 1 – 4 in female slightly higher than pereonites 5 – 7 in lateral view, in male as high as pereonites 5 – 7. Pereonite 1 length 1.4 times pereonite 2 length. Pereonite 5 length 0.8 times width. Coxae 1 – 4 anteriorly produced, each with robust acute setae. Pereopod 1 carpus broadest at articulation of propodus, slightly produced at base of clawseta. Carpus of pereopods 2 – 4 about twice as long as carpus of pereopod 1. Pleotelson with posterolateral spines located at 0.6 of pleotelson length. Uropods biramous, exopod about half as long as endopod.

Description of holotype ( Fig. 1 View FIGURE 1 ): Body 3.1 mm long, 4.68 times longer than width of Prn 2. Prn 1 width 1.42 times cephalon width in dorsal view. Prn 1 length 1.5 Prn 2 length, 0.84 Prn 2 width. Prn 5 width 0.82 length, anterior margin straight, lateral margin slightly convex. Coxae 1 – 4 produced, with large acute robust setae. Pleotelson length 0.98 width, large posterolateral spines present. Lateral margins convex, posterior margin slightly rounded.

Antennula ( Fig. 2 View FIGURE 2 ) with six articles. Article 1 1.69 width, with four broom setae. Article 2 length 6.43 width, 2.01 article 1 length; distally with two large articulated broom setae and two small slender setae, marginally with two small slender setae. Article 3 length 3.5 width, with one short slender seta, article 4 length 3.3 width, distally with one broom seta, distal article length 3.5 width, terminally with one aesthetasc, one broom seta and two long slender setae. Articles 2 – 5 length relative to article 1: 2.01: 0.64: 0.5: 0.45: 0.32.

Antenna ( Fig. 2 View FIGURE 2 ) incomplete or partly missing, only four articles available.

Mandible ( Fig. 2 View FIGURE 2 ) palp article 1 with one small distal seta, article 2 ventrodistally with two small setulate setae, dorsally with rows of numerous fine microtrichia apical article with nine ventral seta, distal one longest. Incisor process with three teeth. Lacinia mobilis of left mandible with three teeth, spine row containing eight spines. Molar process with 13 fine setae.

Maxillula ( Fig. 2 View FIGURE 2 ) mesial lobe about 0.7 lateral lobe length, with 25 setae. Lateral lobe 3.75 times longer than wide, marginally with pairs of fine microtrichia terminally with 12 strong robust setae.

Maxilla ( Fig. 2 View FIGURE 2 ) mesial lobe 0.48 length of lateral lobes, terminally with 21 setae. Lateral lobe (one lobe lost during dissection) basally with two slender setae, terminally with 18 setae.

Maxilliped ( Fig. 2 View FIGURE 2 ) epipodite length 3.85 width, length 1.06 endite length. Endite with two retinaculae, terminally with numerous fine setae. Margin of endite and palp articles 1 – 3 with row of fine setae. Palp article 2 with three setae on mesial margin and two setae on lateral margin, article 3 with five setae on mesial margin and one seta on lateral margin, article 4 with two setae, article 5 with three setae. Article 1 length 0.45 width, article 2 length 0.76 width, article 3 length 1.04 width, article 4 length 2.4 width, article 5 length 1.5 width.

FIGURE 3: Prochelator tupuhi sp. nov., paratype female, pereopods (A–D): P 2 (A), P 3 (B), P 4 (C), P 5 (D).

Pereopod 1 ( Fig. 2 View FIGURE 2 ) Basis length 3.48 width, ventrally proximal to ischium with three slender setae, marginally with eight small setae. Ischium length 1.34 width, with few small setae. Merus length 0.32 width, ventrally with three small setae, ventrodistally with one robust distally setulate seta, dorsally one stout simple seta. Carpus length 1.42 width, distoventrally with large spinelike clawseta and slender penultimate seta, medioventrally with one small distally setulate seta, dorsally two small setae. Propodus length 2.82 width, dorsally with four small setae, ventrally fringed with fine setae inserted in cuticular membrane and 14 small setae. Dactylus length 6 times width. Claw of dactylus with one cuspidate and one conate setae, two slender setae medially.

Pereopod 2 (Fig. 3) Basis length 4.4 width, ventrally proximal to ischium with three slender setae. Ischium length 2.3 width, ventrally with three simple setae, dorsally with one small seta. Merus length 4.31 width, ventrally with four distally setulate setae, distodorsally with one simple seta. Carpus length 5.12 width, with ventral and dorsal rows of setae, ventrally with 12 distally setulate setae, dorsally 18 simple setae. Propodus length 5.12 width, ventrally with three small setae, distodorsally one simple seta. Dactylus length 6 times width. Claw of dactylus with one conate seta.

Pereopod 3 and 4 are similar to pereopod 2, differing only in the number of setae.

Pereopod 5 (Fig. 3) Basis length 3.9 width, medially with two broom setae. Ischium length 2.37 width, dorsally with row of five slender setae. Merus length 1.3 width, with two small setae. Carpus length 3.17 width, with ventral row of 13 long slender setae and dorsal row of 11 setae, distodorsally one small broom seta. Propodus length 2.75 width, with ventral row of nine long setae and dorsal row of 10 setae, additionally with two simple setae. Dactylus length 5.25 times width, mediodistally with two small slender setae. Claw of dactylus with one long conate seta, two adjacent slender setae.

Pereopod 6 and 7 are similar to pereopod 5, differing only in the number of setae.

Pleopod 2 (operculum) ( Fig. 4 View FIGURE 4 ) length 1.2 width. Lateral margins straight, distal margin straight, with 30 simple setae.

Pleopod 3 ( Fig. 4 View FIGURE 4 ) Endopod length 1.31 width, distally with 3 long plumose setae. Exopod length 0.73 endopod length, margins hirsute, with one small distal seta.

Pleopod 4 ( Fig. 4 View FIGURE 4 ) Endopod ovalshaped, length 1.97 width. Exopod length 12 times width, distally with one long plumose seta.

Pleopod 5 ( Fig. 4 View FIGURE 4 ) Endopod only, length 3.08 width.

Uropods ( Fig. 4 View FIGURE 4 ) biramous. Endopod length 1.4 protopod length, 7.9 times longer than wide, marginally with one slender and two broom setae, distally with three small, one slender and six broom setae. Exopod length 5 times width, 0.3 endopod length, terminally with two setae. Protopod length 4.6 width, with few small slender setae.

Male:

Habitus ( Fig. 5 View FIGURE 5 ) similar to female, but Prn 1–4 as high as Prn 5–7, Plt with larger posterolateral spines.

Pleopod 1 ( Fig. 5 View FIGURE 5 ) 4.72 times longer than distal width, tips with distal bulges bearing four slender setae.

Pleopod 2 ( Fig. 5 View FIGURE 5 ) Sympod ovalshaped, length 1.37 width, lateral margin rounded, with seven slender setae. Endopod inserting at 0.49 of sympod's length.

Discussion: Prochelator tupuhi sp. nov. is assigned to the genus Prochelator on the basis of the carpochelate pereopod 1 ( Wägele 1989, Brenke et al. 2005), one stout distally setulate seta midway on the ventral margin of the carpus, and the slender penultimate seta next to the large clawseta.

Prochelator tupuhi is easy to distinguish from P. incomitatus and P. angolensis by having biramous uropods. Both of the latter species possess a very compact anterior part of the body, with pereonite 1 being twice as long as pereonite 2. Characters distinguishing P. tupuhi from other species of the genus with biramous uropods are: relatively elongate body without spinelike ventral elongations on pereonites 1–4 (as in P. lateralis , P. uncatus and P. h a m p s o n i). The remaining species of the genus are anteriorly compact, pereonites 1–4 are higher than pereonites 5–7 from lateral view. In P. tupuhi pereonite 1 is as high as pereonite 5, the medial lobe of the maxilla is much shorter than in the other species of the genus, reaching only half the length of the outer lobe. The carpus of pereopod 1 is distinctly produced at the base of the clawseta, the propodus is broadest at the articulation to the carpus and tapers distally.

Etymology: The epithet is the Māori word tupuhi meaning thin (noun in apposition).