Caprellina plumea, Peart & Woods, 2025

Caprellina plumea sp. nov.

( Figs. 1 View FIGURE 1 , 25–27 View FIGURE 25 View FIGURE 26 View FIGURE 27 )

Type material. Holotype: NIWA 155560 View Materials , male (15 mm), Z18762, SA-3501, Cod Cavern , Snares Islands / Tini Heke, subantarctic, New Zealand, 48°1.272498’S 166°36.7708’E, on algae on rock, 11–13 m, coll. G.D. Fenwick, 17/01/1977 GoogleMaps . Paratypes: NIWA 155562 View Materials , female (10 mm) ; NIWA 155563 View Materials , 5 specimens (males and females, 10–13 mm), same collection data as holotype GoogleMaps .

Other material examined. NIWA 155564 View Materials , 6 specimens (5 males, 1 female, 10–15 mm), stn SA-3539, Seal Cove pool, Snares Islands / Tini Heke, New Zealand, 48°1.338’S 166°36.66’E, 0–1 m, coll. G.D. Fenwick, 04/02/1977 GoogleMaps ; NIWA 155565 View Materials , 3 specimens (2 males, 1 female, 10–18 mm), Z18763, SA-3396, north side of Seal Point , Snares Islands / Tini Heke, New Zealand, 48°1.281’S 166°36.754998’E, 0–1 m, coll. G.D. Fenwick, 04/02/1977 GoogleMaps ; NIWA 155566 View Materials , 6 specimens (5 males, 1 female, 8–13 mm), Z18764, SA-3456, Alert Stack , Snares Islands / Tini Heke, New Zealand, 48°22.42’S 166°34.597836’E, 5–10 m, coll. G.D. Fenwick, 20/12/1976 GoogleMaps ; NIWA 155567 View Materials , 3 specimens (2 males, 1 female, 10–15 mm), Z18765, SA-3403, Snares Islands / Tini Heke, New Zealand, 48°2.158164’S 166°b34.097334’E, 0–1 m, coll. G.D. Fenwick, 04/02/1977 ; NIWA 155568 View Materials , 1 female (11 mm), Z18765, SA-3552, Snares Islands / Tini Heke, New Zealand, 48°2.158164’S 166°34.097334’E, 0–1 m, coll. G.D. Fenwick, 04/02/1977 GoogleMaps ; NIWA 155569 View Materials , 4 specimens (3 males, 1 female, 8–12 mm), Z18766, SA-3401, Station Point , Snares Islands / Tini Heke, New Zealand, 48°1.391664’S 166°36.63333’E, 0–1 m, coll. G.D. Fenwick, 17/11/1976 GoogleMaps ; NIWA 155570 View Materials , 6 specimens (5 males, 1 female, 10–15 mm), Z18767, SA-3387, Senecio pool, Snares Islands / Tini Heke, New Zealand, 48°1.42717’S 166°36.6885’E, 3 m, coll. G.D. Fenwick, 14/11/1976 GoogleMaps .

Etymology. The species name is from the Latin adjective, plumeus, meaning downy or fuzzy, alluding to the presence of small setae on the margins of all the appendages.

Diagnosis. Head rounded, no projection; body smooth and robust. Antenna 1 approximately ¾ of body; peduncle articles 1–2 narrow, sparsely setose, longer than flagellum. Antenna 2 shorter than peduncle of antenna 1, no dense setae on ventral margin. Gnathopod 1 small and robust, with palmar margin of propodus setose with five of proximal grasping spines; palm somewhat convex; dactylus smooth but setose. Pereonite 2 without ventral projection. Gnathopod 2 in male arising at midlength of pereonite 2; basis slightly shorter than propodus and longer than pereonite 2; propodus with subacute corner mid-posterior margin defining palm, this corner armed with 2 robust setae/grasping spines; palm slightly convex and slightly sinuous and lined with small slender setae; dactylus strongly curved, reaching ⅔ along palm corner, inner margin smooth and lined with small setae. Gnathopod 2 in female inserted anteriorly on pereonite 2; palm of propodus convex. Gills small and oval, longer than wide. Pereopod 5 reduced with three articles, articles 2 with cusp on margin. Pereopods 6–7 similar in size and length; propodus wide, palmar margin of propodus concave bearing short dense setae with three grasping spines. Appendages with downy covering.

Description. (Based on male, 15 mm). Head rounded dorsally. Pereonites increasing in length with pereonite 5 longest and pereonites 1, 2 and 6 similar lengths (1: 1: 0.76: 1: 1.2: 1: 0.4), pereonite 5 about 1.2 × pereonite 4 and 1.2 × pereonite 6. Body smooth. Gills oval, length about 2.5 × width. Antenna 1 nearly ¾ body length; proportion of articles and flagellum changes with size. Antenna 1 peduncle article 1: 2: 3: flagellum is 1: 2.8: 2.4: 2.2 with 9 articles in flagellum, margins lined with fine setae. Antenna 2 ¼ antenna 1; flagellum with five articles; margins lined with fine setae Mandibles with three-articulate palp; distal article with six setae (in form of 1 + × + 1, where × = 4) and article is constricted to form distal setose beak shape; penultimate article with nine setae. Mandibular molar absent. Right mandible incisor with five teeth, lacinia mobilis slightly serrated, followed by accessory plates and setal row containing eight–nine serrated setae. Left mandible incisor with five teeth, lacinia mobilis with small teeth, with accessory plates and without setal row. Maxilla 1 outer plate with seven teeth; distal article of palp setose, with seven robust setae apically. Maxilla 2 inner plate slightly shorter than outer plate, both apically setose. Maxilliped inner plate with three strongly serrate robust setae; outer plate setose; palp article 4 about ¾ length article 3, with distal short, rounded setose projection; dactylus with setose inner margin and setal fringe medially.

Gnathopod 1 basis longer than ischium, merus and carpus combined; propodus rounded to subtriangular; palm slightly convex lined with row of robust setae defined by slight corner and five smooth robust setae (grasping spines); inner margin of dactylus smooth but strongly setose. Margins lined with small, fine setae. Gnathopod 2 inserted mid pereonite 2; basis longer than pereonite 2; ischium subequal in length to merus (0.9 ×), and both are shorter than carpus (0.75 ×); propodus slightly shorter in length to basis, with subacute corner mid posterior margin defining palm, this corner armed with two robust setae/ grasping spines; palm slightly convex and slightly sinuous and lined with small slender setae; dactylus strongly curved, reaching ⅔ along palm corner, inner margin smooth and lined with small setae. All margins lined with fine small setae. Pereopods 3 and 4 absent. Pereopod 5 reduced to three articles; articles 1 with cusp on posterior margin, article 2 with few lateral setae, article 3 curved as dactylus with numerous marginal setae. All margins lined with fine, small setae. Pereopods 6 and 7 subequal in robustness, similar in length, articles long but robust; propodus almost ovoid, broad, palm defining corner ½ way along margin armed with cluster of two–three large toothed robust setae (grasping spines); palm concave and lined with numerous robust setae, all margins lined with fine, short setae. Penes as long as wide.

Abdomen with pair of little protuberances, as reduced pleopods, medially setose, and two pairs of uropods. Uropod 1 cylindrical and straight; ramus same length as peduncle, both margins serrate. Uropod 2 subequal to uropod 1, both margins serrate without ramus.

Variation. Female paratype, 10 mm. Gnathopod 1 basis subequal in length to ischium + merus + carpus. Gnathopod 2 basis shorter than pereonite 2 and inserted at anterior end of pereonite 2, basis longer than propodus; ischium shorter than merus (0.8 ×), merus shorter than carpus (0.7 ×); propodus with prominent palm defining corner armed with three large robust setae (grasping spines) approximately ⅖ along posterior margin; palm sinuous and lined with both robust and slender setae; dactylus just reaching to defining corner.

Distribution. Southern New Zealand, including the subantarctic islands.

Remarks. Caprellina plumea sp. nov. is in the complex of species that are morphologically similar to Caprellina longicollis ( Nicolet, 1849) . The establishment of this new species and C. judyae are based on the morphological differences ( Table 4) compared with C. longicollis from Chile ( Guerra-Garcia 2001b —redescription) and detailed comments in DeBroyer et al. (2004).The latter paper noted that the variety and extent of morphological characteristics indicates the presence of a species complex rather than a single cosmopolitan species.

The primary characteristics that differentiate C. plumea from others in this complex include the increased setosity of the appendages, the proportions of the pereonites (pereonite 1 a similar size to pereonite 2 this is similar to Caprellina longicollis sensu stricto whilst differing to C. judyae and C. longicollis sensu lato). Caprellina plumea sp. nov. has the ramus of the uropod 1 at the same length as the peduncle, and both margins of peduncle and ramus serrate, whereas C. judyae has uropod 1 ramus longer than peduncle, serrate along length of only one margin, and Caprellina longicollis sensu stricto has the uropod 1 ramus slightly shorter than the peduncle, and is serrate only along ⅔ length of only one margin ( Table 4).