Cyphocaris nesoi, Hughes, Lauren E. & Lowry, James K., 2015

Hughes, Lauren E. & Lowry, James K., 2015, A review of the world Cyphocarididae with description of three new species (Crustacea, Amphipoda, Lysianassoidea), Zootaxa 4058 (1), pp. 1-40 : 21-26

Cyphocaris nesoi sp. nov.

( Figs 18–20 )

Types. Holotype female, 32 mm, dissected parts in vial, NMV J68203 , 61 km east-north-east of Cape Tourville, Tasman sea (41°58.49'S 149°04.41'E), 3 m Isaacs Kidd mid water trawl over bottom depth 1685–2524 m, 28 October 1988, coll. G.C.B. Poore et al., RV Franklin (stn SLOPE 75); paratype male, 26 mm, dissected parts in vial, NMV J68204 , 61 km east-north-east of Cape Tourville, Tasman sea (41°58.49'S 149°04.41'E), 3 m Isaacs Kidd mid water trawl over bottom depth 1685–2524 m, 28 October 1988, coll. G.C.B. Poore et al., RV Franklin (stn SLOPE 75); paratype female immature ‘k’, 13 mm, dissected 6 slides, NMV J68205 , 61 km east-north-east of Cape Tourville, Tasman sea (41°58.49'S 149°04.41'E), 3 m Isaacs Kidd mid water trawl over bottom depth 1685– 2524 m, 28 October 1988, coll. G.C.B. Poore et al., RV Franklin (stn SLOPE 75); paratypes 9 specimens, NMV J68206 , 61 km east-north-east of Cape Tourville, Tasman Sea (41°58.49'S 149°04.41'E), 3 m Isaacs Kidd mid water trawl over bottom depth 1685–2524 m, 28 October 1988, coll. G.C.B. Poore et al., RV Franklin (stn SLOPE 75).

Additional material examined. Tasman Sea. 10 specimens, NMV J68162 , 42 km north-west of Cape Farewell, King Island, western Bass Strait (39°19’S 143°38’E), 95 m, coarse sand, carbonate, 10 October 1980, coll. G.C.B. Poore, HMAS Kimbla (stn BSS 76); 3 specimens, NMV J15787 , south of Point Hicks, Victoria (38°27.20'S 149°09.70'E), 8 m rectangular midwater trawl, 22 July 1986, coll. M.F. Gomon et al., RV Franklin (stn SLOPE 24); 7 specimens (4 female, 3 immature), NMV J68161 , south of Point Hicks, Victoria (38°39.23'S 149°15.00'E), 1500 m over bottom depth 2900–3200 m, 8 m rectangular midwater trawl, 24 July 1986, coll. M.F. Gomon et al., RV Franklin (stn SLOPE 38); 1 specimen (Head and telson missing), NMV J15788 , south of Point Hicks, Victoria (38°39.23'S 149°15.00'E), 1500 m over bottom depth 2900–3200 m, 8 m rectangular midwater trawl, 24 July 1986, coll. M.F. Gomon et al., RV Franklin (stn SLOPE 38); 1 specimen, NMV J68163 , 48 km eastnorth-east of Cape Tourville, Tasmania (42°00.25'S 148°43.55'E to 41°57.77'S 148°42.08'E), 1264– 1130 m, gravel with lumps of sandy mud aggregate, WHOI epibenthic sled, 30 October 1988, coll. G.C.B. Poore et al., RV Franklin (stn SLOPE 81); 1 specimen, NMV J68160 , 51 km south-south-west of Cape Otway (39°18'S 143°03'E), 113 m, coarse carbonate sand, Smith-McIntyre grab, 10 October 1980, coll. G.C.B. Poore, HMAS Kimbla (stn BSS-69G); 6 specimens, AM P.68570, east of Sydney, New South Wales (33°50.9’S 152°15.2’E to 33°52.5’S 152°39’E), 1200 m over bottom 3178–4860 m, midwater trawl, 1745-0005 hrs, coll. J. Paxton, 26-27 April 1989, HMAS Cook (JP89-2); 5 specimens, AM P.68571, east of Sydney, New South Wales (33°44.5’S 152°24.4’E to 34°8.9’S 152°9.7’E), 1800 m over bottom 3828− 2994 m, midwater trawl, 1730–0210 hrs, coll. J. Paxton, 27-28 April 1989, HMAS Cook (JP89-5); 1 female specimen, AM P.68572, east of Sydney, New South Wales (33°58.9’S 152°19.3’E to 34°5.7’S 152°55.9’E), 3300 m over bottom 3393–4835 m, midwater trawl, 1415-0315 hrs, coll. J. Paxton, 28-29 April 1989, HMAS Cook (JP89-7); 1 female (setose oostegites), AM P.70172, east of Sydney, New South Wales (33°52'30"S 152°39'00"E), 1700–1800 m, over bottom 4856 m, Isaacs-Kidd midwater trawl, 27 April 1989, coll. J. Paxton (JP89-3); 1 female specimen, AM P.66409, Tasman Sea (35°25.94’S 161°47.62’E), 1197 m, 24 May 2003, coll. P.B. Berents, RV Tangaroa , NORANZ expedition (TAN0308/073).

New Caledonia: 1 immature female specimen, AM P.68568, off Noumea (21°5’S 166°45’E), 0−925 m over bottom 2125−2175 m, Isaacs-Kidd midwater trawl, 1830-2345 hours, 9 May 1971, coll. J. Paxton, HMAS Kimbla (K4/71-5); 5 specimens, AM P.68569, off Noumea (22°3’S 167°44’E), 0−800 m over bottom 2500 m, Isaacs-Kidd midwater trawl, 1830-2345 hours, 13 May 1971, coll. J. Paxton, HMAS Kimbla (K4/71-11).

Type locality. 61 km east-north-east of Cape Tourville, Tasman sea (41°58.49'S 149°04.41'E).

Etymology. Named ‘Nesoi’ from the Greek primordial deity of islands and sea, used as a noun in apposition. Description. Based on holotype, female, 32 mm, NMV J68203 . Body smooth, without setae. Pereonite 1 conspicuously produced anterodorsally, length 3 × basal width. Head narrow, much deeper than long, eyes present, subovate, abutting anterior margin; rostrum absent; lateral cephalic lobe subacute, anteroventral corner produced acute, ventral margin concave. Antenna 1 length extending beyond pereonite 6; peduncular article 1 longer than article 2–3 combined; accessory flagellum short, slender, 7-articulate, not reaching end of primary flagellum first article; primary flagellum article 1 very long, densely covered with aesthetascs, calceoli absent. Antenna 2 length subequal or longer than body (broken); calceoli absent. Lower lip unknown. Mandibles, mandible incisor smooth, lacinia mobilis multidentate, accessory setal row with 6 (left) and 5 (right) seta e; molar welldeveloped triturative; mandibular palp 3-articulate, article 1 much shorter than 2–3; article 2 posterior margin near straight, anterior margin with medial bulge, with dense row of submarginal setae distally, article 3 length 0.8 × article 2, lined with dense row of slender setae. Maxilla 1 outer plate with 11 (right) setal teeth, palp (right) broad with 18 robust dentate setae and with 15 submarginal slender plumose setae; inner plate tapering distally, inner margin lined with 9 robust plumose setae and 7 slender plumose setae. Maxilla 2 inner plate broad, triangular, with mediofacial and apical slender setae; outer plate with apical setae only. Maxilliped inner plate rectangular with 3 nodular apical robust setae, medial margin lined with plumose setae; outer plate subovate, apicolateral margin with long plumose setae, medial margin with 18 nodular robust setae; palp long, 4- articulate, articles 1–3 lined with long slender setae; article 1–2 length similar; article 3 shorter than article 2, surface lined with short fine setae; dactylus length subequal to article 3, straight, with 1 apical seta, unguis absent.

Pereon. Gnathopod 1 weakly subchelate; coxa small, ventrally rounded; basis long, length 4.9 × width; ischium broader than long; merus posteriorly produced, acute, posterior surface covered in short fine setae; carpus length 1.1 × propodus; propodus length 1.6 × width, palm margin finely serrate, palm defined by weak corner; dactylus posterior margin finely serrate, without distal spine, with 3 apical slender setae. Gnathopod 2 minutely subchelate; coxa tapering ventrally, rounded ventral margin; basis distally bowed, elongate, length 6 × width; ischium length 3.6 × width, merus length twice width; carpus length twice propodus, length 4 × width, surface lined with short fine setae; propodus length 3 × width, palm margin smooth, palm defined by corner with 2 robust setae; dactylus posterior margin smooth, 3 apical slender setae. Pereopod 3 slender, elongate; coxa subquadrate; basis slender straight; merus, carpus and propodus subequal in length; dactylus recurved, length 0.6 × propodus. Pereopod 4 coxa anterior margin rounded, posteroventral lobe produced rounded. Pereopod 5 coxa smaller than coxa 4; basis posterior margin not produced, weakly serrate; merus length subequal to carpus, length 3 × width; carpus 0.55 × propodus, length 2 × width; propodus length 7 × width; dactylus short length 0.4 × propodus, recurved. Pereopod 6 coxa subquadrate; basis posterior margin serrate, posterodistal lobe reach slightly beyond ischium, lobe margin serrate; merus length subequal to carpus, length 2.8 × width; carpus shorter than propodus, length 3.9 × width, propodus long, length 7.5 × width; dactylus slender, recurved, length 0.25 × propodus. Pereopod 7 coxa ventral margin subquadrate; basis subrectangular, posterior margin straight, weakly serrate, posterodistal lobe reaching beyond ischium, corner serrate; merus 0.8 × carpus; propodus subequal to carpus length, length 4.4 × width; dactylus long, straight, tapering, length 0.6 × propodus.

Pleon. Pleonites 1–3 smooth. Epimeron 1 subquadrate, corner rounded. Epimera 2–3 subquadrate. Urosomite 1 without anterodorsal notch. Uropod 1 elongate, peduncle with 9 robust setae, length 4 × width; outer ramus 0.7 × inner ramus length. Uropod 2 reaching end of uropod 3; outer ramus 0.9 × inner ramus length, subequal to peduncle length, with 2 robust setae; inner ramus with 2 robust setae; rami lateral margins lined with fine setae. Uropod 3 reaching end of telson; peduncle length 1.3 × width, dorsal margin with long slender setae; rami foliaceous, subequal in length, lined with plumose swimming setae, both rami 2-articulate, article 1 lined with plumose setae, article 2 small, length twice width. Telson elongate, deeply cleft to 85%, lobes tapering distally, lateral margin with 7 setae.

Male (sexually dimorphic characters). Based on paratype 26 mm, NMV J68204 . Pereopod 5 basis posterior margin heavily serrate; merus 1.1 × carpus; propodus length 5 × width; dactylus 0.5 × propodus length.

Depth range. 0−3300 m.

Remarks. Cyphocaris nesoi sp. nov. is most similar to C. latirama Hendrycks & Conlan, 2003 , C. richardi Chevreux, 1905 and C. polaris Gurjanova, 1951 in that the pereopod 5 posterior margin is without a spur.

Both C. nesoi and C. richardi have a more strongly developed pereonite 1 anterior projection which separates them from C. polaris and C. latirama where the projection is not pronounced

Comparisons between C. nesoi with C. richardi are restricted due to the limited illustration of the original material in Chevreux (1905) where mouthpart illustrations were not included. Enough significant morphological features are distinguishable to separate C. richardi and recognise C. nesoi as a distinct species. In C. nesoi the pereopod 5 propodus length is 8 times the width and the uropod 2 reaches the end of uropod 3, while in C. richardi the propodus length is only 6 times the width in pereopod 5 and the uropod 2 is shorter than uropod 3. The cephalic lobe in C. richardi appears more deeply excavate and the posterior margin of the basis of pereopods 6 and 7 is less serrate, however for this character it is difficult to be certain based on Chevreux’s whole animal illustration.

Cyphocaris nesoi can be separated from the other Tasman Sea species, C. ananke sp. nov., by eye size, which is proportionally larger with ommatidia abutting the head anterior margin, by the rounded rather than subquadrate coxa 4 posterior distal lobe and the absence of a spur on pereopod 5. Within the mouthpart bundle, the maxilla 1 palp has 18 robust setae in C. nesoi while only 10 setae are present in C. ananke . More subtle variation in mouthpart characters included the weakly developed accessory setal row on the mandibles and the greater number of projections on the maxilla 1 setal teeth in C. nesoi .

Distribution. SOUTH PACIFIC OCEAN. Bass Strait, Tasman Sea. New Caledonia: Noumea (current study).

Figures

FIGURE 18. Cyphocaris nesoi sp. nov., habitus holotype female 32 mm, NMV J 68203, Cape Tourville, Tasmania, Tasman Sea.

FIGURE 19. Cyphocaris nesoi sp. nov., holotype female 32 mm, NMV J 68203; paratype male 26 mm, NMV exJ 17157, Cape Tourville, Tasmania, Tasman Sea. Scale 0.5 mm.

FIGURE 20. Cyphocaris nesoi sp. nov., holotype female 32 mm, NMV J 68203, Cape Tourville, Tasmania, Tasman Sea. Scale 1 mm.