Cyphocaris pedroi, Sorrentino, Rayane, Alves, Jessika, Johnsson, Rodrigo & Senna, André R., 2016

Sorrentino, Rayane, Alves, Jessika, Johnsson, Rodrigo & Senna, André R., 2016, A new species of Cyphocarididae (Crustacea, Amphipoda, Lysianassoidea) from off the northeastern Brazilian coast, Zootaxa 4161 (3), pp. 345-356 : 346-354

Cyphocaris pedroi sp. nov.

( Figs 1–5 )

Etymology. The specific epithet pedroi is given after the Portuguese Navy vessel São Pedro, under the command of Captain Manuel de Castro Alcoforado, who accidentally discovered the archipelago on April 20th, 1511, when the São Pedro was wrecked during an expedition from Portugal to India.

Material examined. Holotype: female (with non-setose oostegites), 3.9 cm, (collected from stomach contents of a tuna), preserved in 70% ethanol, dissected and drawn, appendages and mouthparts mounted on slides with glycerol gelatin, Saint Peter and Saint Paul Archipelago (0°56'2"N–29°20'6"W), 21/XI/2012, UFBA 2166. Paratype: 1 female, 3.4 cm (with non-setose oostegites), in 70% ethanol, same locality, 21/XI/2012, CRFFP 0 79.

Type-locality. Saint Peter and Saint Paul Archipelago.

Diagnosis. Anophthalmic. Antenna 1, small, article 1 elongate and tapering distally, dorsally naked. Pereonite 1 not produced. Gnathopod 1 simple, merus, with subtrapezoid serrated structure on the posterodistal corner, nail present. Pereopod 5, basis with anterior margin broadly rounded and posterior margin with large narrowly rounded acute spur, naked, slightly curved upwards.

Description. (Based on Holotype female, 3.9 cm). Head deeper than long, lateral cephalic lobes subacute and short, posteroventral corner not produced; eyes absent. Antenna 1 small, slightly longer than peduncle of antenna 2; peduncular article 3 longer than article 2; flagellum 15-articulate, article 1 elongate and tapering distally, dorsally naked, ventrally with well-developed callynophore in two fields; accessory flagellum 6-articulate, article 1 being the longest, anteroventral corner of each with a tuft of setae. Antenna 2, peduncle article 4 strongly broadened, rounded ventrally, with three small plumose setae and one simple seta, dorsal margin setose, article 5 with two small plumose setae and one simple seta distally in anterior margin, dorsal margin setose; flagellum elongate, 107- articulate, dorsal margin with small setae; calceoli present.

Mouthparts forming a subquadrate bundle. Epistome and upper lip separate, unequally produced. Epistome dominant in size, but upper lip more produced than epistome. Mandible, incisor smooth, with margin convex; molar well developed, triturative; lacinia mobilis well-developed, subtriangular shape, absent in right mandible, mandibular palp opposite to molar, 3-articulate, article 1 small, 1.3 × longer than wide; article 2 elongate, about 3.2 × longer than wide, bearing a row of facial setae, ventral margin slightly geniculate; article 3 suboval, about 0.7 × the length of article 2, ventral margin setose, apex with two slender setae and two subapical specialized setae, the first one serrate at the first half, and the second type serrate and widening distally at the first half, with distal part plumose and falciform. Maxilla 1, inner plate, apical margin with eight plumose and one simple seta, inner and outer margins setose; outer plate, setal teeth producing a distal corona in a modified 6/5 arrangement; STA 2- cuspidate, STB and STC 3-cuspidate, STD 4-cuspidate, ST1 slightly displaced, 1-cuspidate, ST2 simple, ST3 2- cuspidate, ST4 3-cuspidate, ST5 simple, ST6 3-cuspidate, and ST7 multicuspidate, lateral margins with tuft of setae; palp 2-articulate, article 1 short, distolateral corner produced in a sharp spine, article 2 robust, slightly widening distally, about twice longer than wide, apical margin covered by slender and stout setae, with one slender plumose seta at distolateral corner, dorsal surface with small setules. Maxilla 2, inner plate wide, slightly wider than outer plate, distomedial margin densely covered by plumose and simple setae, apical margin with simple and pectinate setae; outer plate, lateral margin with slender setae, apical margin with pectinate and long setae, basal margin with robust seta; facies of both inner and outer plates bearing tufts of slender setae. Maxilliped, inner plate with subquadrate dorsal flange, forming accessory inner and apical margins; primary apical margin with 3 nodular setae; dorsal flange, apical margin with 6 stout pectinate setae, a stout seta with accessory slender seta near the subacute corner and two subacute stout setae near junction to the main body of inner plate; outer plate, inner margin proximal third with simple slender setae, distal two thirds covered by row of very robust setae with accessory small slender setae, with submarginal row of sinuous setae, apical margin with simple, plumose and pectinate setae; palp well-developed, 4-articulate, article 1 suboval, about 2.3 × longer than wide, slightly longer than article 2, with simple setae in inner margin and a tuft of setae in apicolateral margin, article 2 ovatorectangular, about 2.6 × longer than wide, inner margin covered by plumose and simple setae, outer margin with two sets of simple setae (3–5), article 3 about 0.6 × length of article 2, inner and outer margins strongly convex, inner margin covered by plumose setae, outer margin with two sets of simple setae (3–4), dactylus about 2.6 × longer than wide, about 1.2 × longer than article 3, inner margin with plumose setae, outer margin with three simple setae distally, a tuft of setae subapically, unguis absent.

Pereonite 1 not produced. Gnathopod 1 simple; coxa small, partially covered by coxa 2; basis long, about 6.8 × longer than wide, with a tuft of slender setae on posterodistal corner; ischium short, posterodistal margin setose; merus subtriangular, about 1.7 × longer than wide, posterior margin setose, distally subtrapezoid serrated structure on the posterodistal corner of the; carpus, subrectangular, slightly expanded anteriorly, 1.2 × longer than merus, posterior margin with simple and plumose setae, anterodistal row of setae with simple and plumose setae; propodus cuneiform (wedge shaped), slightly elongate, 1.2 × longer than carpus, anterior and posterior margins setose, facial setae present; dactylus, posterior margin serrated, with distal spine, nail present. Gnathopod 2 weakly subchelate, coxa small, naked, deeper than long, anterior margin convex, anteroventral corner concave; basis elongate, distally bowed, 7.3 × longer than wide, margins naked; ischium elongate, 3.1 × longer than wide, anterior margin with two minute simple setae; merus subtriangular, about 0.8 × length of the ischium, posterior margin with one slender seta distally; carpus elongate, 1.5 × longer than merus, anterior margin setose, bearing one long plumose seta, posterior and posterodistal margins setose; propodus subrectangular, about half length of the carpus, anterior margin with short setae, posterior and distal margins with long slender setae, palm reduced, palmar corner not defined by stout seta; dactylus small, curved, reaching the palmar corner, with nail and subterminal spine, ventral margin distally setose.

Pereopod 3, coxa small, anterior margin slightly produced and convex, posterior margin concave; basis elongate, 4.6 × longer than wide, posterodistal corner with one slender seta; ischium short, with tuft of setae on posterodistal corner; merus, carpus and propodus, posterior margin with sets of setae; merus subrectangular, anterior margin with two small setae, anterodistal corner with two small setae with accessory setae; carpus subrectangular, anterior margin with sets of three setae, anterodistal corner with sets of three setae with accessory setae; propodus elongate, anterior margin with five sets of setae with accessory setae (2–3–1–2–4); dactylus long, slender, slightly curved, anterior margin with one small seta proximally, anterodistal and posterodistal margins minutely serrate, nail present. Coxae 4 and 5 large together, coxa 4 partially overlapping coxae 2–3. Pereopod 4, coxa large, 3.6 × longer than coxa 3, about twice longer than wide, expanded and round anteriorly, with scales in lateral surface, posterior margin with a small subacute projection; basis elongate, margins naked; ischium short, naked; merus, carpus and propodus, posterior margin with sets of setae; merus, anterior margin with one small seta, anterodistal corner with sets of three setae; carpus, anterior margin naked, anterodistal corner with sets of four setae; propodus, anterior margin with two sets of setae (1–2), anterodistal corner with a set of two setae; dactylus long, slender, slightly curved, anterior margin with one proximal small seta and minutely serrated distally, with small subterminal seta and nail. Pereopod 5, coxa, anterodistal margin with well-developed lobe, broadly rounded, and apically reverted, posterior margin greatly expanded, ventral margin with laminar projection, lateral surface with scales, posterior margin straight; basis, bearing a facial robust and plumose seta overlapped by the anterodistal lobe of coxa, anterior margin broadly rounded, setose, posterior margin with large subacute spur, slightly curved upwards, posterodistal lobe well-developed; ischium short, anterior margin with one small seta; merus, anterior margin with six small setae, anterodistal corner with set of four setae, posterodistal corner with tufts of setae; carpus, anterior margin with four sets of setae, anterodistal corner with one set of setae, posterior margin with one seta, posterodistal corner with two setae; propodus elongate, anterior margin with six sets of setae, posterior margin with three setae, posterodistal corner with one slender seta; dactylus slender, slightly curved, posterior margin with one proximal small seta, with nail. Pereopod 6, coxa small, subquadrate, anterior margin straight, posterior margin slightly concave, lateral surface with scales; basis narrowly suboval, anterior margin slightly setose, anterodistal corner with a tuft of setae, posterior margin slightly expanded, weakly serrate, posteroventral lobe acutely produced, extending well past ischium; ischium short, anterior margin with sets of setae; merus, anterior and posterior margins with sets of setae, slightly expanded posteriorly; carpus elongate, 4.2 × longer than wide, anterior and posterior margins with sets of setae; propodus elongate, slender, 1.2 × longer than carpus, 10.2 × longer than wide, anterior margin with sets of setae, posterior margin with three setae; dactylus elongate, half the length of the propodus, slender, 10 × longer than wide, anterior margin minutely serrated, with minute nail. Pereopod 7, coxa small, anterior margin slightly concave, posterior margin convex, lateral surface with few scales; basis suboval, anterior margin setose, posterior margin with 6-7 serrations, slightly expanded, posteroventral lobe weakly produced, not surpassing ischium; ischium flat, anterior and posterior margins slightly setose; merus and carpus, anterior and posterior margins with sets of setae, merus broadened proximally, narrowing distally; propodus elongate, slender, 8.2 × longer than wide, anterior margin with sets of setae, posterior margin with four setae, posterodistal corner with a tuft of setae; dactylus short, slightly curved, anterior margin minutely serrate.

Pleonites 1–3 broad, posteriorly naked and smooth. Epimeral plates 1–3, posterior and ventral margins naked; epimeron 1 and 2, posteroventral with oblique keel, ventral margin convex; epimeron 3, posteroventral lobe produced and subacute. Urosomite 1, 1.5 × longer than urosomite 2, posteroventral corner produced and subacute; urosomite 3, 1.4 × longer than urosomite 2. Uropod 1, peduncle elongate, 2.7 × longer than wide, 1.4 × longer than rami, ventrodistal corner acute, medial margin setose, dorsomedial corner rounded; inner ramus, medial margin serrate, proximally slightly expanded with four setae; outer ramus subequal in length to inner, inner margin weakly serrate. Uropod 2, peduncle, slightly longer than rami, distally slightly expanded and rounded, inner margin with 14 lateral setae; inner ramus, dorsal and ventral margins serrated, slightly expanded proximally, with three setae; outer ramus naked, notch absent. Uropod 3, peduncle short, about 1.2 × longer than wide, dorsomedial margin densely setose with long plumose setae; inner ramus, 1.5 × longer than outer ramus, all inner margin bearing a dense fringe of long plumose setae; outer ramus paddle-shaped, 1-articulate inner margin strongly expanded, convex, posterodistal margin bearing a dense fringe of long plumose setae. Telson about twice longer than wide, deeply cleft (70%), lobes tapering distally with scales on dorsal surfaces, bearing apical nail in each lobe.

Paratype. Similar in shape to holotype, without morphological variations, but slightly smaller in length.

Remarks. Since the archipelago is in a region of migration, fishes like tuna use the area especially for feeding. According to Hazin et al. (2005) and Campos, Neto et al. (2005), most of the fish reported in the archipelago are present due to aggregated feeding, and not for reproduction purposes in some particular periods of the year. Research conducted with Tunnus albacares ( Bonnaterre, 1788), demonstrate that the area is an important supply point for the species, it is a migratory path of the Gulf of Mexico into the Gulf of Guinea, where they can acquire more energy for migration during the months of November and April (Vaske Jr. et al. 2004).

Because of the migration path and the preserved state of the specimen collected in the tuna stomach, we believe that the studied specimens were swallowed/ingested by the tuna in the archipelago, instead of brought from outside.

The new species is closest to Cyphocaris faurei Barnard, 1916 because of the following characters: antenna 2, peduncle article 4 strongly convex on posterior margin; mandible, palp article 2 elongate, ventral margin slightly geniculate, article 3 suboval; pereonite 1 not produced; shape of the coxae of gnathopods 1–2, semi-circular and triangular, respectively; pereopod 4, coxa shape, anterior and inferior margins convex, posterior margin with a small subacute projection; epimeron 3, posteroventral lobe produced and subacute; uropods 1 and 2, rami narrow, lanceolate, subequal in length; and telson deeply cleft. However, the new species differs in the following ways (characters of C. faurei in parenthesis): head, without eyes (eyes present, pear-shaped); antenna 1, flagellum 15- articulate (32-articulate); first article of primary flagellum naked (strongly setose on inner and lower surfaces); accessory flagellum 6-articulate (7-articulate); antenna 2, flagellum 107-articulate (180-articulate); maxilla 1, inner plate, apical margin with eight plumose setae (12 plumose setae, decreasing and passing gradually into simple setae near base); maxilliped, inner plate with flange (ordinary), outer plate, distal two thirds covered by row of 22 very robust setae with accessory small slender seta (20 robust setae); pereonite 1 subequal in length to pereonite 2 (pereonite 1 equal in length to the sum of pereonites 2 and 3); pereopod 4, coxa as wide as coxa 5 (coxa 4, one third of coxa 5); pereopod 5, coxa with a well-developed lobe on anterodistal margin, broadly rounded and apically reverted backwards, (anterodistal margin rounded, slightly reverted posteriorly); basis, anterior margin more strongly convex than the basis of C. faurei , and bearing small slender setae; uropods 1 and 2, peduncle, inner margin setose (inner margin setose); uropod 3, outer ramus, 1-articulate (2-articulate); and telson with apical nail (entire), about half length of the urosome (equal in length to the sum of urosomites 1–3).

Another species, Cyphocaris challengeri , is also similar to the new species in having pereonite 1 not produced and basis of pereopod 5 expanded posteriorly, forming a spur. However, C. challengeri has seven spines on the dorsal margin of this spur, which is smooth in C. pedroi . Also, pereonite 1 is subequal in length to pereonites 3 and 4 together, but in the new species, the pereonites decrease gradually in length towards the head. Finally, the spur of pereopod 5 basis of Cyphocaris pedroi is different from the following eight species, C. ananke , C. anonyx , C. bellona , C. cornuta , C. geyserensis , C. ohtsukai C. tartaros and C. tunicola , as all of them have the dorsal margin of the spur with spines.

Figures

FIGURE 1. Cyphocaris pedroi sp. nov.: female, holotype, Saint Peter and Saint Paul Archipelago, 0 ° 56 ' 2 " N, 29 ° 20 ' 6 " W; UFBA 2166. Scale bar: 10.0 mm.

FIGURE 2. Cyphocaris pedroi sp. nov.: female, holotype, Saint Peter and Saint Paul Archipelago, 0 ° 56 ' 2 " N, 29 ° 20 ' 6 " W; UFBA 2166. Scale bars: 1.0 mm for A 1 - A 2; 0.5 mm for the remainder.

FIGURE 3. Cyphocaris pedroi sp. nov.: female, holotype, Saint Peter and Saint Paul Archipelago, 0 ° 56 ' 2 " N, 29 ° 20 ' 6 " W; UFBA 2166. Scale bars: 0.5 mm.

FIGURE 4. Cyphocaris pedroi sp. nov.: female, holotype, Saint Peter and Saint Paul Archipelago, 0 ° 56 ' 2 " N, 29 ° 20 ' 6 " W; UFBA 2166. Scale bars: 1.0 mm.

FIGURE 5. Cyphocaris pedroi sp. nov.: female, holotype, Saint Peter and Saint Paul Archipelago, 0 ° 56 ' 2 " N, 29 ° 20 ' 6 " W; UFBA 2166. Scale bars: 1.0 mm.