Caprella scauroides Mayer, 1903

Peart, Rachael A. & Woods, Chris, 2025, Caprellidae (Crustacea: Amphipoda) of Aotearoa New Zealand waters: a constantly changing landscape, Zootaxa 5568 (1), pp. 1-65 : 32-34

Caprella scauroides Mayer, 1903

( Figs. 1–2 , 15 , Appendix 1)

Caprella californica .— McCain & Steinberg, 1970, 14 (in part).—Arimoto & Kikuchi, 1977: 91–92, fig. 1b.— Takeuchi, 1995,

199, fig. 21–181.— Takeuchi 1999: 7.— Aoki & Takeda, 2006: 67.—Lee & Hong, 2009: 318.— Montelli, 2010: 726, fig.

1. Caprella (Spinicephara) californica .— Arimoto, 1976: 139–146, figs. 75–77.— Arimoto, 1978: 27. Caprella scaura f. d (?).— Mayer, 1890: 72, pl. 4: figs 43–44. Caprella scaura f. scauroides — Mayer, 1903: 118–119, pl. 5: figs. 16–18.— Utinomi, 1947: 77. Caprella scaura scauroides .— Krapp et al., 2006: 3. Caprella scauroides .— Takeuchi & Oyamada, 2013: 371–381.— Peart et al., 2019: 361–375.—Schnabel et al., 414–415, 456,

fig. 28.1.

Type Locality. Hong Kong / Japan .

Material examined. NIWA 136876 ( MITS 73603 ), 121 specimens (very large males, ovigerous females, over 82 juveniles), Station BNZ ( AAP) 14933 - AM, The Landing , Ōkahu Bay, Waitematā Harbour, New Zealand, 36°51.0316’S, 174°48.60498’E, coll. Phil Johnstone & Jeff Tyrell, 29/05/2017 ; NIWA 136877 ( MITS 73604 ) ,

over 50 specimens (very large males, ovigerous females, juveniles), Ōrakei Marina, Waitematā Harbour , New Zealand, 36°51.0084’S, 174°48.849’E, mooring line, AKL24 ExtraDive1, coll. NIWA, 24/05/2017 ,; NIWA 136878 ( MITS 73858 ), 202 mature males, 132 ovigerous females, 150 juveniles, WRE 26236 - AM 7/11/2017 , McLeod Bay , Whangārei Harbour, New Zealand, 35°48.9012’S, 174°29.9718’E, 5 m depth from a mooring ; NIWA 136879 ( MITS 24429 ), 10 specimens, NIW193BTI, hull of the vessel Aoix , Nelson Marina, New Zealand, 41°15.51252’S, 173°16.87602’E, coll . NIWA, 12/01/2005 ; NIWA 155336 , 25 specimens (males, females and juveniles), stn Z18758, Mathesons Bay , Leigh, North Island, New Zealand, 36°17.4168’S 174°47.8836’E, 2–3 m, from Carpophyllum plumosum , coll . R. Taylor & S. Patke, 16/06/2017 ; NIWA 155335 ( MITS 75145 ), OPX30232, Ōpua , North Island, New Zealand, 35°15.718’S 174°7.2492’E, 0–1 m, collected from a pontoon, coll . NIWA, 13/11/2019 ; NIWA 155337 , many males, females and juveniles, 4–20 mm, stn Z18759, off Yusu , Uwajima, Ehime, Japan, 33°11.85’N 132°27.768’E, 0–1 m, on oyster aquaculture, coll. I. Takeuchi, 22/07/2019 ; NIWA 155338 , 15 specimens (males, females, juveniles, 7–22 mm), stn Z18760, off International coastal research Centre, Otsuchi, Iwate, Japan, 39°21.036’N 141°56.1’E, 2–5 m, coll. I. Takeuchi, 13/05/1993 .

Diagnosis. Head rounded, with long, acute forward-directed projection; anterior body smooth and slender, posteriorly pereonites more sculptured. Antenna 1 over ½ of body (× 0.6); peduncle articles 1–2 robust in male, slender in female, sparsely setose; peduncle articles 1 and 2 longer than flagellum. Antenna 2 reaching to ½ length of peduncular article 2 of antenna 1 (male) and longer than antenna 1 peduncle (female), bearing short to long dense setae on ventral margin. Gnathopod 1 small and robust, with palmar margin of propodus setose with pair of proximal grasping spines; palm somewhat straight; dactylus slightly serrate. Gnathopod 2 arising at distal end of pereonite 2 (male), and mid pereonite 2 (female); basis subequal to propodus and the length of pereonite 2; propodus produced to form rounded, setose distal lobe; palmar region of propodus primarily straight, strongly setose on anterior margin, weakly setose on posterior margin, palm with three teeth, posterior tooth subacute and triangular, small acute mid-palmar tooth, large predactylar ledge-like tooth; dactylus strong, inner margin sinuous, apex pointed and unconstricted with distal end smooth; outer margin setose. Gnathopod 2 in female palm of propodus convex, palm bearing three small teeth and weakly setose; propodus anterior margin weakly setose. Gills long and ovoid in both sexes. Pereopod 5 shortest, pereopods 6–7 similar in length; palmar margin of propodus slightly concave bearing short dense setae with two median grasping spines and expanded posterior corner.

Distribution. North Island, New Zealand. Australia (Cockburn Sound, Western Australia; Hobsons Bay, Victoria; Port of Cairns, Queensland; and Sydney Harbour, New South Wales), coastal Japan (Honshu, Kyushu and Shikoku islands, Sea of Honshu Island, Seto Inland Sea, Uwa Sea), Korea (South Jeolla Province (Jeollanam-do )) and the Yellow Sea.

New Zealand biosecurity status. Adventive ( Peart et al. 2019).

Genbank Accession Numbers: SUB 14807870 M58 Cscauroides_nSSU PQ521245; SUB 14807890 M58 Cscauroides COI PQ522033.

Remarks. Caprella scauroides has been only recently recorded in New Zealand waters ( Peart et al. 2019) and is close in morphology to C. californica Stimpson, 1856 . It differs from C. californica by the rounded shape of the gnathopod 2 propodus distal lobe (angular in C. californica ), the straight angle of the anterodistal head projection (curved in C. californica ) and pereonites 3 and 4 equal in length to pereonite 5 (shorter than pereonite 5 in C. californica ). Caprella scauroides is non-indigenous in New Zealand waters, originally recorded from Hong Kong and adjacent waters.

This species has been found on numerous shallow-water artificial substrates from ship hulls to moorings and wharf piles. It has also recently been recorded from the brown alga Carpophyllum spp. Collections from Japan were sampled from key localities were received too late to be analysed by Peart et al. (2019), and have now been sequenced ( Fig. 27 , Appendix 1) and determined to all represent the same species.

Figures

FIGURE 1. Distribution of caprellid species in the New Zealand Exclusive Economic Zone (map: E. Leunissen, NIWA).

FIGURE 2. Maximum likelihoodphylogram basedon COIsequence data.Support values areshown on each branch:approximate Likelihood Ratio Test (aLRT, %) and ML bootstrap (%) values above, and Bayesian PP values below. Only values greater than 80% (aLRT), 80% (bootstrap) and 0.9 (PP) are shown; all support values are shown if two support methods for a clade reach the cutoff value. Sequences from New Zealand taxa in bold.

FIGURE 15. Caprella scauroides Mayer, 1903, Ōkahu Bay, Waitematā Harbour, New Zealand.A, male 22 mm, NIWA 136876; B, female 11 mm, NIWA 136876.

FIGURE 27. Caprellina plumea sp. nov., paratype female, 10 mm, NIWA 155562, Snares Island/Tini Heke, New Zealand. Scales: 0.2 mm ABD, G2; 0.5 mm, A1–2.