Cymadusa tartarugae, Andrade, Luiz F. & Senna, André R., 2017

Andrade, Luiz F. & Senna, André R., 2017, Four new species of Cymadusa Savigny, 1816 (Amphipoda: Ampithoidae) and new records of C. filosa Savigny, 1816 from Brazilian coast, Zootaxa 4226 (3), pp. 359-389 : 373-378

Cymadusa tartarugae sp. nov.

( Figs 9–11 )

Etymology. The specific epithet was given after the Tartaruga Beach, which is located the type-locality of the new species.

Material examined. Holotype, male, dissected and drawn, 8.8 mm, 25 July 1997, Tartaruga Beach, municipality of Armação dos Búzios, Rio de Janeiro state, Brazil, P.S. Young, col.,without depth and substrate information, UFBA 1617 . Paratypes: 1 male and 1 female, 25 July 1997, Tartaruga Beach, municipality of Armação dos Búzios, Rio de Janeiro state, Brazil, P.S. Young, col.,without depth and substrate information, CRFFP 84 ; 1 male, dissected and drawn, 25 July 1997, Tartaruga Beach, municipality of Armação dos Búzios, Rio de Janeiro state, Brazil, P.S. Young, col.,without depth and substrate information, CRFFP 85 ; 1 female, dissected and drawn, 9.1 mm, 25 July 1997, Tartaruga Beach, municipality of Armação dos Búzios, Rio de Janeiro state, Brazil, P.S. Young, col.,without depth and substrate information, UFBA 1618 ; 1 female, 25 July 1997, Tartaruga Beach, municipality of Armação dos Búzios, Rio de Janeiro state, Brazil, P.S. Young, col.,without depth and substrate information, UFBA 1619 .

Diagnosis. Antenna 1, accessory flagellum 1-articulate; Antenna 2 weakly setose; Gnathopod 1, coxa strongly enlarged anteriorly, partially covering the eye; merus small and subacute with subacute lobe; carpus subtriangular; palm transverse; Uropod 3, peduncle with 3 distal stout setae and 3 simple setae. Telson subtriangular.

Description. Based on holotype, male, 8.8 mm, UFBA 1617; and paratype, male, CRFFP 85.Head, eyes rounded and well developed. Antenna 1 weakly setose; flagellum 35-articulate; accessory flagellum 1- articulate.Antenna 2 weakly setose; flagellum 19-articulate. Upper lip rounded, setose apically. Lower lip notched, inner and outer lobes setose apically. Right mandible, molar triturative with 1 long setae and 1 short setae; incisor and lacina mobilis multicuspidate; accessory setal row with 7 stout multicuspidate setae; palp 3-articulate, article 1 about 1.6× longer than wide, article 2 about 4.4× longer than wide, article 3 about 6.2× longer than wide with 7 long plumose setae apically. Left mandible, molar triturative 2 long setae; incisor and lacinia mobilis multicuspidate; accessory setal row with 6 stout multicuspidate setae; palp 3-articulate, article 3 with 7 long plumose setae apically.Maxilla 1, inner plate small and subrectangular, inner margin with 6 long plumose setae; outer plate with 11 stout multicuspidate setae apically; palp 2-articulate with 9 stout microserrate setae and 4 long microserrate setae. Maxilla 2, outer plate 1.4× longer than inner plate; inner plate, marginal and facial row of long setae; outer plate, row of short setae on the outer margin, long slender setae on the apical and inner margin. Maxilliped, inner plate about 2.9× longer than wide, inner and facial margins withwith long setae and 1 stout blunt spine, apical margin with 6 setae; outer plate, 1.6 × longer than wide, 1.1 × longer than inner plate, inner margin with 14 trifid robust setae, outer and apical margins with row of long setae; palp 4-articulate, 1.8 × longer than outer plate, article 1, subtriangular, outer margin with 1long setae, article 2 subrectangular, inner margin with row of long setae, article 3 subrectangular inner margin with 9 long and 2 long plumose setae, outer margin with 7 long setae, article 4 naked, nail present, inner margin slightly serrate.

Gnathopod 1, smaller than gnathopod 2; coxa strongly enlarged anteriorly, partially covering the eyes, ventral margin bearing row of setae; basis 2.3 × longer than wide, anterior margin with 3 setae, posterodistal corner with 2 short setae; ischium small and subrectangular, 1.1 ×longer than wide, posterior margin with 3 long setae; merus 1.5 × longer than wide, posterior margin setose; carpus 1.4 × longer than wide, anterior margin with 2 setae, posterior margin setose; propodus 1.7× longer than wide,anterior margin with 3 setae, anterodistal angle with 5 setae posterior margin setose, posterodistal corner with 1blunt stout seta with accessory seta; palm acute, slightly concave; dactylus 1.4 ×longer than palm, serrated, with 5 tiny setae. Gnathopod 2, coxa subrectangular, ventral margin with 5 long setae; basis 2.6 × longer than wide, anterior margin with 12 long setae, posterior margin with 5 longsetae; ischium small and subrectangular, 1.3 × longer than wide; merus, 1.7 × longer than wide, posterior margin with 9 setae; carpus, 1.1 × wider than long, anterior margin with 3 setae, anterodistal and posterodistal angles with a tuft of long setae each; propodus, 1.2 × longer than wide, anterior and posterior margins setose; palm transverse; dactylus subequal to palm, with 6 tiny setae. Pereopod 3, coxa absent; basis, subrectangular, 2.2 × longer than wide, anterior margin with 8 setae, posterior margin with 13 setae; ischium small and subrectangular, slightly longer than wide, posterior margin with 3 setae; merus 1.7× longer than wide, anterior margin with 1 slender simple setae, anterodistal corner with 3 setae, posterior margin with 7 setae; carpus 3× longer than wide, anterior margin with 3 setae, posterior margin setose; propodus 4.3× longer than wide, anterior margin with 8 setae, posterior margin setose; dactylus curved. Pereopod 4, coxa, subrectangular, ventral margin setose; basis subrectangular, 2× longer than wide, anterior margin with 2 setae, posterior margin setose; ischium small and subrectangular, 1.2 × wider than long, posterior margin with 3 long setae; merus, 1.8 × longer than wide, anterior margin with 4 setae, posterior margin setose; carpus, 2.6× longer than wide, anterior margin with 2 setae, posterior margin setose; propodus, 3.6× longer than wide, anterior margin with 3 setae, anterodistal angle with 5 setae, posterior margin with both short and long setae; dactylus slightly curved. Pereopod 5, basis almost as long as wide, ventral margin with both short and long setae, posterior margin with 3 short and 1 long setae; ischium small and subrectangular, 1.2× longer than wide, anterior margin with 3 setae; merus 1.6× longer than wide, anterior and posterior margins with setae; carpus 2× longer than wide, anterior margin with 7 setae, posterior margin with 4 setae; propodus 3.4× longer than wide, anterior margin with 7 long setae, posterior margin with 4 stout setae with accessory seta and 3 setae.

Epimeral plate 1-2 rounded, posteroventral margins with a short and blunt projection. Epimeral 3 rounded. Uropod 1, peduncle with long and acute distoventral spine (spur); peduncle 2.7× longer than wide, ventral margin with 4 stout setae; inner ramus 1.2× longer than outer ramus, ventral margin with 5 stout setae, apical margin with 3 stout setae; outer ramus, ventral margin with 4 stout setae, apical margin with three stout setae. Uropod 2, peduncle 2.1× longer than wide, ventral margin with 1 stout setae; inner ramus 1.1× longer than outer ramus, ventral margin with 7 stout setae, apical margin with 2 stout setae with accessory seta and 2 stout setae; outer ramus, ventral margin with 2 stout setae with accessory seta and 4 stout setae, apical margin with 4 stout setae and 1 stout setae with accessory seta. Uropod 3, peduncle slightly elongate, about 1.6× longer than wide, with 3 stout setae and 3 slender simple setae; inner ramus slightly longer than outer ramus, ventral margin with 2 stout setae, dorsolateral margin with 3 stout setae, apical margin with 5 slender simple setae and 1 stout setae; outer ramus, dorsolateral margin with 6 slender simple setae, 1 stout seta, apical margin with two curved stout setae.Telson subtriangular, lateral margins with both long and short setae, distolateral angles with 1 cusp and 1 short setae each.

Sexual dimorphic characters. Based on paratype, female, 9.1 mm, UFBA 1618. Gnathopod 1, smaller than gnathopod 2; coxa strongly produced anteriorly; basis 2.2 × longer than wide, anterior margi with 2 long setae, posterior margin with 5 long setae; ischium small and subrectangular, 1.3 × longer than wide, posterodistal angle with a tuft of 5 long setae; merus 1.5 × longer than wide, posterior margin setose; carpus 1.6 × longer than wide, anterior margin with 5 setae, anterodistal angle with 2 long setae, posterior margin setose; propodus 2.1 × longer than wide, anterior margin with 5 setae, anterodistal angle with a tuft of long setae, posterior margin setose, posterodistal angle with 1 blunt stout setae with accessory setae; palm acute, slightly concave; dactylus 1.8 × longer than palm, serrated, with 4 tiny setae. Gnathopod 2, coxa subrectangular, ventral margin with row of long setae; basis 2.1 × longer than wide, anterior margin with 5 short setae, posterior margin with7 setae; ischium small and subrectangular, slightly wider than long; merus 1.5 × longer than wide, posterodistal angle setose; carpus slightly wider than long, anterior margin with few setae, posterior margin setose; propodus 1.4 × longer than wide, anterior an posterior margins setose; palm slightly acute; dactylus 1.4 × longer than palm, with 4 tiny setae.

Remarks. Pereopod 6–7 are missing. Cymadusa tartarugae sp. nov. resembles C. mariabyrneae by the following characters: weakly setose articles of appendages; gnathopod 1, coxa anterior margin enlarged; gnathopod 2 with long simple setae on margins;. However, C. tartarugae can be distinguished from C. maribyrneae by the following characters ( C. maribyrneae characters in parenthesis): gnathopod 1, coxa strongly enlarged (regularly produced); telson subtriangular, not apically truncated (subtrapezoidal, apically truncated). The new species can be easily distinguished by the other in the genus by its strongly rounded and enlarged coxa 1.

Distribution. Known only to the type-locality, Tartaruga Beach, municipality of Armação dos Búzios, Rio de Janeiro state, Brazil.

Figures

FIGURE 9. Cymadusa tartarugae sp. nov. Holotype, male, 8.8 mm, UFBA 1617, Tartaruga Beach, municipality of Armação dos Búzios, Rio de Janeiro state, Brazil. Scale bars: 0.5 mm for A 1 – 2 and Hd; 0.2 mm for the remainder.

FIGURE 10. Cymadusa tartarugae sp. nov. Holotype, male, 8.8 mm, UFBA 1617, Tartaruga Beach, municipality of Armação dos Búzios, Rio de Janeiro state, Brazil; paratype, female, 9.1 mm, UFBA 1618, Tartaruga Beach, municipality of Armação dos Búzios, Rio de Janeiro state, Brazil. Scale bars: 0.5 mm.

FIGURE 11. Cymadusa tartarugae sp. nov. Holotype, male, 8.8 mm, UFBA 1617, Tartaruga Beach, municipality of Armação dos Búzios, Rio de Janeiro state, Brazil; paratype, male, CRFFP 85, Tartaruga Beach, municipality of Armação dos Búzios, Rio de Janeiro state, Brazil. Scale bars: 0.2 mm for U 3 and T; 0.5 mm for the remainder.