Cyclocaris franki Horton & Thurston 2014, sp. nov.
Creators: name: Horton, Tammy
name: Thurston, Michael H.
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Lysianassidae
Cyclocaris
Cyclocaris franki

description: Cyclocaris franki sp. nov.
(Figures 8–11)
Cyclocaris tahitensis (not Stebbing, 1888).— Chevreux, 1903: 89–90.— Chevreux, 1935: 31, pl. 4, fig. 4.
Cyclocaris sp. Barnard & Karaman, 1991: 479. Lowry & Stoddart, 1994: 153.
Type material. Holotype: dissected female, 20.5 mm, carcass and seven slides; Sta. 56761#1, DEMAR, 30 October 2001 (bottom time 23 hours 15 minutes), 06˚ 18.68’S 10˚ 44.86’W, 2059 m, Angola Slope; NHMUK 2014. 459. Allotype: adult male, 15.5 mm, same data as holotype; NHMUK 2014. 460. Paratypes: 39 specimens, same data as holotype; NHMUK 2014. 461– 470.
Additional material examined. Specimens retained in the Discovery Collections, National Oceanography Centre, Southampton.
7822#7, BN 2.4, 5 March 1972, 08º 59.1’N 20º 16.3’W – 08º 59.9’N 20º 16.2’W, 1203 m, Sierra Leone Rise; 1 specimen.
56770#1, DEMAR, 1 November, 2001 (bottom time 27 hours 47 minutes), 06˚ 12.88’S 10˚47.14’W, 1850 m, Angola Slope; 1 female specimen.
56734#1, DEMAR, 26 October 2001, (bottom time 22 hours 14 minutes), 06˚ 10.14’S 10˚ 46.62’W, 1859 m; 6 female specimens.
Etymology. The species is named in honour of the first author’s son, Frank.
Description. Holotype female, 20.5 mm. Head: exposed, deeper than long, rather short dorsally but telescoped into peraeonite 1; lateral cephalic lobe moderate, subquadrate; rostrum small. Eyes: four, red pigmented, lacking ommatidea, pigment fades in alcohol; upper, undefined elongate shape spreading towards and covered by peraeonite 1; lower, larger, in cephalic lobe but partly covered by coxa 3. Antenna 1: short, 0.12 x body; peduncular article 1 short; peduncular article 2 short, 0.3 x article 1; peduncular article 3 short, 0.3 x article 1; primary flagellum nine-articulate; accessory flagellum long, 0.5 x primary flagellum, five-articulate, article 1 as long as articles 2–5 combined; callynophore strong two-field; calceoli absent. Antenna 2: short, 1.65 x antenna 1; peduncle without brush setae, not geniculate; peduncle article 1 not greatly enlarged; peduncle article 3 short, 0.5 x article 4; articles 4 and 5 not enlarged; flagellum well developed, 22-articulate.
Mouthpart bundle: subquadrate. Epistome and upper lip: separate, rounded, weakly produced, epistome dominant. Mandible: incisor smooth, weakly convex, with two small ventral ‘teeth’; lacinia mobilis present on left mandible only, a slender peg without ornamentation; accessory setal rows with ten simple robust setae and many setules; molar a setose, proximally directed, non-triturating flap; palp attached distally; article 1 short, broader than long; article 2 slender, length 3.9 x breadth, with 14 A2 setae on distal 0.4; article 3 slender, tapering, length 4.1 x breadth, with 17 D3 setae and three E3 setae. Lower lip: outer plates gaping, setose marginally, inner lobes present, small, molar processes prominent, rounded distally. Maxilla 1: inner plate slender, with eight pappose setae along inner margin; outer plate with 11 setal-teeth in a 7/4 crown arrangement, ST1–6 weakly one-, two- or threecuspidate, ST7 simple, ST7 displaced from ST6, STA–C one-cuspidate, STD, displaced from A–C, simple; palp large, two-articulate, article 1 short, article 2 broadened with three short robust setae on tridentate apical margin, one flag seta, three subapical robust setae, and one pappose seta on dorsal margin (not figured as damaged). Maxilla 2: inner plate short, 0.67 x length of outer plate, tapering, with rows of marginal and submarginal pappose and simple setae; outer plate with marginal and apical stout and slender setae. Maxilliped: inner plate large, subtriangular, with three very small nodular spines on strongly oblique apical margin, oblique setal row strong, with eight pappose setae; outer plate large, subovate, with 14 pappose setae and three robust setae apically and laterally, and about twenty minute nodular setae on medial margin; palp large, four-articulate, article 2 slender, length 2.4 x breadth, article 3 long, slender, length 3.1 x width, dactyl well-developed, slender, with three short subterminal setae.
Gnathopod 1: simple; coxa vestigial, anterior margin straight, posterior margin convex; basis long, slender, length 5.5 x breadth, anterior margin straight, with four simple setae, posterior margin straight, with two simple setae; ischium long, length 3.4 x breadth; carpus very long, subquadrate, lacking posterior lobe, margins subparallel, length 4.2 x. breadth, 1.3 x length of propodus; propodus long, subquadrate, length 4.9 x breadth, margins weakly convergent, anterior weakly convex, posterior weakly concave, palm absent; dactylus simple, length 0.34 x propodus, with subterminal setae. Gnathopod 2: subchelate; coxa vestigial, subrectangular; basis long, slender, curved, anterior margin convex, length 5.3 x breadth; ischium long, length 4.2 x breadth; carpus very long, length 5.6 x breadth, margins subparallel, posterior margin straight, 2.0 x length of propodus; propodus subovate, length 2.9 x breadth, setulose, palm acute, weakly convex, serrate distally; dactylus inserted near middle of propodus distal margin, reaching corner of palm. Peraeopod 3: coxa large, weakly expanded, broadly rounded distally; basis weakly sinuous, margins subparallel; merus narrowly produced anterodistally, extending 0.39 x length of carpus; dactyl slender, curved, 0.43 x length of propodus. Peraeopod 4: coxa as deep as wide, posteroventral lobe short, broadly rounded; distal articles as in peraeopod 3. Peraeopods 5–7: subequal in length. Peraeopod 5: coxa unequally bilobate, posterior lobe deeper, strongly produced posteriorly; basis expanded, subrectangular, posterior margin convex, posterodistal margin broadly rounded; merus produced posterodistally, extending 0.22 x length of carpus, propodus slender, length 6.4 x breadth; dactylus slender, curved, 0.38 x length of propodus. Peraeopod 6: coxa subrectangular, expanded posteriorly; basis expanded, posterior margin convex, distally bevelled, posterodistal lobe rounded; merus slender, posterior margin weakly convex, weakly produced. Peraeopod 7: coxa posterior lobate; basis expanded, tapering distally, posterior margin convex, posterodistal lobe narrowly rounded; merus slender, weakly produced posterodistally. Gills: gnathopod 2 to peraeopod 7; peraeopod 7 gill large. Oostegites: gnathopod 2 to peraeopod 5.
Pleonites 1 to 3: not carinate. Epimeron 1: broadly rounded ventrally. Epimeron 2: subrectangular; anteroventral corner rounded, posteroventral corner with acute tooth, posterior margin sinuous, ventral margin setose. Epimeron 3: expanded distally; anteroventral corner rounded, posteroventral corner with subacute tooth, posterior margin concave, ventral margin setose. Urosome: urosomite 1 lacking rounded boss; urosomite 2 occluded dorsally; urosomite 3 produced posterolaterally, markedly concave dorsally, with strong dorsolateral flanges. Uropod 1: peduncle with 5 dorsolateral robust setae and 5 dorsomedial robust setae; inner ramus 0.68 x length of peduncle, with 2 dorsomedial setae; outer ramus as long as inner ramus, with 3 dorsolateral setae. Uropod 2: peduncle with 1 dorsomedial robust seta; inner ramus as long as peduncle, with 2 lateral and 5 medial setae; outer ramus 0.83 x inner ramus, with 2 lateral and 3 medial setae. Uropod 3: peduncle short, with 3 dorsomedial setae; rami subequal, lanceolate, with plumose setae on medial margins; inner ramus 1.7 x peduncle, with 2 lateral and 2 medial robust setae; outer ramus 2-articulate, article 2 length 0.23 x article 1 with 2 lateral and 1 medial robust setae. Telson: long, lobes tapering, length 2.3 x breadth, cleft 85%; lobes with 4 dorsolateral robust setae, apices weakly notched, lacking robust setae.
Male. Similar to female except for calceoli on both antennae and a longer callynophore.
Remarks. This species is most closely related to Cyclocaris lowryi. It can be distinguished from that species by characters of pereopods 5–7. C. franki has the basis of peraeopod 5 produced posterodistally, the basis of peraeopod 6 emarginate posterodistally, and peraeopods 5–7 with broad meral articles (length/breadth ratios 1.6, 1.7 and 2.1 respectively). In contrast, C. lowryi has the basis of peraeopod 5 broadly rounded and produced distally, the basis of peraeopod 6 convex posterodistally, and peraeopods 5–7 with narrow meral articles (length/breadth ratios 2.2, 2.7 and 2.9 respectively). C. franki can be distinguished from C. tahitensis by the lack of eyelobes and the broadly rounded posterodistal lobe of coxa 4 of the latter.
C. franki differs from C. guilelmi in having subacute triangular eyelobes and four evanescent red-pigmented ocular patches in contrast to the broadly convex anteroventral head margin and permanent yellow-brown ocular pigment covering the whole head of the latter species.
The single specimen from Monaco Station 1206 close to the Cape Verde Islands, collected at a depth of 1477 m and recorded as C. tahitensis by Chevreux (1903, 1935) belongs to this species. Chevreux noted that the only differences he could find between the Tahiti specimen (C. tahitensis) and his specimen were that pereopods 5–7 were more spinose and the apices of the telson were a little different.
All known material of C. franki has been obtained from baited benthic traps.
Distribution. Atlantic Ocean. Angolan continental margin, 1850–2059 m; Sierra Leone Rise, 1203 m (present material); Cape Verde Islands, 1477 m (Chevreux, 1903, 1935).
description: Published as part of Horton, Tammy & Thurston, Michael H., 2014, A revision of the bathyal and abyssal necrophage genus Cyclocaris Stebbing, 1888 (Crustacea: Amphipoda: Cyclocaridae) with the addition of two new species from the Atlantic Ocean, pp. 507-527 in Zootaxa 3796 (3) on pages 518-523, DOI: 10.11646/zootaxa.3796.3.6, http://zenodo.org/record/4915303