Paraclimenes frigo, Grave & Forman, 2025

Grave, Sammy De & Forman, Jeff, 2025, A new species of Paraclimenes from New Zealand waters (Crustacea: Decapoda: Palaemonidae), Zootaxa 5590 (1), pp. 124-132 : 125-128

Paraclimenes frigo sp. nov.

( Figs. 1–5 )

Material examined. Holotype: Ovigerous female, pocl 5.5 mm, 43.0561667°S 173.5470000°E to 43.0025000°S 173.54350000°E, 109 m depth, stn. TAN1108/ 39, 15.v. 2011, coll. Oceans Survey 20/20-Biogenic Habitats ( NIWA 82427 ) . Paratypes: i) ov. female, pocl 5.1 mm; same data as holotype ( NIWA 173398 ) ; ii) ov. female, pocl 5.5 mm, 45.90°S 170.97°E, 130–131 m depth, stn. TAN1108/122, 23.v.2011; coll. Oceans Survey 20/20-Biogenic Habitats ( NIWA 91442 ) ; iii) ov. female, pocl 5.2 mm, same data ( NIWA 173399 ) ; iv) male, pocl 5.0 mm, 48.1599998°S 179.2649994°E, 250 m depth, stn. I701, 20.iii.1979 ( NIWA 85188 ) ; v) male, pocl 5.2 mm, 45.90°S 171.04°E to 45.90°S 171.05°E, 197.0–215.0 m depth, stn. TAN 1108/117, 23.v.2011, coll. Oceans Survey 20/20-Biogenic Habitats ( NIWA 74759 ) ; vi) ov. female, pocl 5.3 mm, same data ( NIWA 173400 ) .

Description. Carapace largely glabrous ( Figs. 1A–B , 2A–E ), with robust hepatic tooth reaching or slightly overreaching anterior margin of carapace, supraorbital and antennal teeth absent. Rostrum overreaching antennular peduncle, about as long as scaphocerite, slightly up-curved in distal quarter, with 7–8 dorsal rostral teeth, two of which positioned postorbitally, postorbital teeth articulated, proximal tooth more spaced out than remainder of series; ventral lamina distinct, with 3–4 equidistant teeth, all placed anteriorly to eye; lateral carina distinct; single row of short setae between dorsal and ventral teeth. Inferior margin subacutely produced. Pterygostomial margin obtusely angular.

Abdomen ( Figs. 1E , 2G ) with pleura of first four somites rounded, pleuron of fifth somite obtusely angulate; sixth abdominal somite with posterolateral angles obtuse, median lobe dorsally acute. Telson ( Figs. 1D , 2H–J ) about 1.2 times as long as sixth abdominal somite, about 3.6–3.8 times as long as anterior width, tapering distally, with two pairs of dorsal, submarginal, spiniform setae present at 0.4 and 0.7 of telson length; posterior margin of telson convex, with small, median tooth; posterior margin with short, lateral pair and longer, intermediate pair of spiniform setae, submedian region with pair of plumose setae.

Eye ( Fig. 2F ) with hemispherical, pigmented cornea, eyestalk about 1.5 times as long as cornea, with distinct posterodorsal nebenauge.

Antennula ( Fig. 3C–D ) with peduncle falling short of rostrum and scaphocerite; basal segment of peduncle with distinct sharp, distolateral tooth, anterior margin rounded; stylocerite acute, about 0.5 times length of basal segment; intermediate segment of peduncle short, about as long as wide; distal segment of peduncle about 1.2 times as long as intermediate segment. Upper flagellum biramous, with proximal 10–14 divisions fused; short, free ramus with about 4–8 divisions, fused part and shorter ramus with long aesthetascs; longer free ramus filiform. Lower flagellum filiform, slender.

Antennal basicerite ( Figs. 1C , 2D ) with sharp, lateral tooth. Carpocerite short, reaching to proximal 0.3 length of scaphocerite. Scaphocerite ( Fig. 3E–G ) with distal margin of lamella overreaching antennular peduncle; lateral border straight, ending in well-developed distolateral tooth; anterior margin of lamella distomedially feebly angulate; distinctly overreaching distolateral tooth.

Epistome unarmed. Fourth thoracic sternite with median, rounded boss; fourth and fifth sternites posteriorly with oblique lateral ridges, separated by medial notch; posterior sternites unarmed, narrower.

Mouthparts not dissected, typical for genus in external observation. Third maxilliped ( Fig. 3A–B ) overreaching antennular peduncle by penultimate segment, without arthrobranch, coxa slightly medially produced, lateral plate rounded; basis short, weakly delineated; ischiomerus with 4–5 small spiniform setae distolaterally, about 6 times as long as distal width, setose; penultimate segment about 0.8 times length of ischiomerus; ultimate segment about 0.6 times as long as penultimate segment; exopod reaching to distal 0.75 of ischiomerus, distally with long, plumose setae.

First pereiopod ( Fig. 4A–D ) overreaching scaphocerite by distal half of chela; ischium about 0.45 times length of merus, ventrolateral margin setose; merus about 1.2 times length of carpus, about 9.5 times as long as distal width; carpus about as long as length of chela, unarmed, carpo-propodal brush well-developed; chela with subcylindrical palm, about 6 times a s long as largest width, non-spatulate, fingers about 0.7 times as long as palm, with grouped terminal setae, cutting edges entire, tips slightly hooked.

Second pereiopods similar in shape, somewhat unequal in size, major chela about 1.4–1.5 times as long as minor chela. Major second pereiopod ( Fig. 4E–G ) overreaching scaphocerite by whole length of chela; ischium tubular, unarmed, about as long as merus, about 8.5 times as long as distal width; merus tubular, unarmed, about 2.2 times as long as carpus, about 9.2 times as long as distal width; carpus vase-shaped, unarmed, expanding distally, about 0.3 as long as chela; chela subequal to pocl, about 4.2 times as long as carpus, palm sparsely adorned with tubercles and short setae; fingers about 0.6 times length of palm, pollex slightly bent, both fingers with low, triangular teeth at about 0.10–0.25 of cutting edge length, rest of cutting edge entire, fingers with subterminal groups of setae, tips hooked. Minor second pereiopod ( Fig. 4H–J ) overreaching scaphocerite by partial length of chela; ischium tubular, unarmed, about as long as merus, about 10 times as long as distal width; merus tubular, unarmed, about 1.4 times as long as carpus, about 10 times as long as distal width; carpus elongate, tubular, unarmed, about 2.2 as long as chela; chela about 4.2 times as long as carpus, palm sparsely adorned with tubercles and short setae; fingers about 0.45 times length of palm, both fingers with low, triangular teeth at about 0.15–0.25 of cutting edge length, rest of cutting edge entire, fingers with subterminal groups of setae cutting edges entire, tips demarcated, hooked.

Third pereiopod ( Fig. 5A–D ) overreaching scaphocerite by distal third of propodus; ischium, merus and carpus about 0.45, 0.95 and 0.51 of propodus length respectively; propodus about 11 times as long as distal depth, about 5.7 times as long as dactylus, with series (6–12) of serrulate setae along ventral margin, two pairs distoventrally; dactylus about 4.1 times as long as proximal depth, flexor margin of corpus unadorned, ending in large acute accessory tooth, low dorsal flange present; unguis poorly demarcated, simple, about 0.53 length of corpus, about 2.25 times as long as accessory tooth. Fourth pereiopod ( Fig. 4E–H ) similar in shape and size to third, overreaching scaphocerite by distal third of propodus. Fifth pereiopod ( Fig. 5I–L ) similar to third and fourth, overreaching scaphocerite by distal third of propodus, somewhat more slender, distoventral cleaning brush on propodus moderately developed.

Uropods ( Figs. 1D , 3H–J ) overreaching distal margin of telson by 0.25 of their length; protopodite unarmed; exopod with lateral margin straight, ending in acute distolateral tooth. First pleopod sexually dimorphic, lacking appendix interna, in males ( Fig. 3K ) endopod 0.35 times as long as exopod. Second pleopod of male ( Fig. 3L–M ) with appendix masculina, about 0.78 times as long as appendix interna, laterally and apically furnished with long setae.

Habitat. Specimens from Tangaroa voyage TAN1108 were caught from biogenic habitats termed “wire-weed”, off the Canterbury coast and “The Hay Paddock”, off the Otago coast, both of which refer to areas with high abundance of ‘straw-like’ chaetopterid worm tubes (mainly Spiochaetopterus sp. ). Other key associated sessile faunal groups included sponges, ascidians, and bryozoans ( Jones et al. 2018). No symbiotic associations were noted.

Etymology. Derived from the Latin frigor, meaning cold, in reference to the colder waters in which the species swims about; used as a noun in apposition.

Remarks. The new species can morphologically easily be separated from P. setirostris by the chela of the first pereiopod being simple, not subspatulate as in P. setirostris (see Bruce 1991), and the dorsal flange on the accessory tooth of the unguis (third to fifth pereiopods) being, although present, not as produced as in P. setirostris (see Bruce 1991). From the P. gorgonicola , the new species can be separated by the uropods distinctly overreaching the distal margin of the telson, including the tips of the intermediate spiniform setae (vs. about as long distal margin and not overreaching the setae in P. gorgonicola , see Park & Fransen 2021: fig. 7), the distal margin of the telson medially produced into a tooth (vs. rounded in P. gorgonicola ; Park & Fransen 2021: fig. 8) and the presence of a dorsal flange on the accessory tooth (vs. smooth in P. gorgonicola ; Park & Fransen 2021: fig. 10).

Figures

FIGURE 1. Paraclimenes frigo sp. nov., holotype, ov. female, pocl 5.5 mm (NIWA 82427): A) habitus; B) frontal region; C) frontal margin of carapace and basicerite; D) telson and uropods; E) sixth pleonite, detail.

FIGURE 2. Paraclimenes frigo sp. nov.: A) carapace, frontal; B) carapace; C) carapace frontal margin and appendages; D) basicerite; E) suborbital region; F) eye; G) sixth pleonite; H) telson; I) same, distal margin; J) same, detail. Scale bars indicate 1 mm (A–I) or 0.5 mm (J); A, E, G (ov. female, pocl 5.3 mm, NIWA 173400); B, F (ov. female, pocl 5.5 mm, NIWA 91442); C, D (male, pocl 5.2 mm, NIWA 74759); H–J (ov. female, pocl 5.1 mm, NIWA 173398).

FIGURE 3. Paraclimenes frigo sp. nov.: A) third maxilliped; B) same, detail; C) antennule; D) same, detail; E) scaphocerite, F) same, distal margin; G) same, detail; H) uropod, right; I) exopod, distal; J) same, detail; K) male first pleopod; L) male second pleopod; M same, appendix masculina and interna. Scale bars indicate 1 mm (A, C, E, F, H, I, K, M), 0.5 mm (B, D, G, L) or 0.25 mm (J); A, B (ov. female, pocl 5.1 mm, NIWA 173398), C–J (ov. female, pocl 5.2 mm, NIWA 173399), K–M (male, pocl 5.2 mm, NIWA 74759).

FIGURE 4. Paraclimenes frigo sp. nov.: A) first pereiopod, right; B) same, chela, dorsal; C) same, lateral; D) same, carpopropodal brush; E) major cheliped, right; F) same, chela; G) same, detail; H) minor cheliped, left; I) same, fingers of chela; J) same, detail. Scale bars indicate 1 mm (A–C, E, F, H, I, J) or 0.5 mm (D, G); A–D (ov. female, pocll 5.5 mm, NIWA 91442), E, H–J (ov. female, pocl 5.2 mm, NIWA 173399), F, G (male, pocl 5.2 mm, NIWA 74759).

FIGURE 5. Paraclimenes frigo sp. nov.: A) third pereiopod; B) same, propodus and dactylus; C) same, distal; D) same, tip of dactylus; E) fourth pereiopod; F) same, propodus and dactylus; G) same, distal; H) same, tip of dactylus; I) fifth pereiopod; J) same, propodus and dactylus; K) same, distal; L) same, tip of dactylus. Scale bars indicate 1 mm (A, B, E, F, I, J), 0.25 mm (C, G, K) or 0.15 mm (D, H, L); all from NIWA 173399 (ov. female, pocl 5.2 mm).