Aruga kieppe, Sorrentino & Moraes & Senna, 2019

Sorrentino, Rayane, Moraes, Elienai E. B. & Senna, André R., 2019, Four new species of Lysianassidae Dana, 1849 (Crustacea: Amphipoda) From Northeastern Brazilian coast, Zootaxa 4585 (1), pp. 1-26 : 8-13

Aruga kieppe sp. nov.

( Figs 5–8 )

Material examined. Holotype, female, 7.0 mm. April 2013, Quiepe (Kieppe) Island in Camamu Bay, Bahia (13°50'60''S 38°58'001''W), UERJ 75 .

Type-locality. Quiepe Island in Camamu Bay, Bahia, Brazil.

Etymology. Specific epithet corresponds to the name of the island. That can be Quiepe or Kieppe.

Diagnosis. Gnathopod 2, carpus, posterior margin concave and strongly setose. Urosomite 1, dorsal median margin with a dorsal forward turned keel and two lateral carinas.

Description. (Holotype). Head naked. Lateral cephalic rounded. Antenna 1, first peduncular article with plumose setae in dorsal and ventral margins; article 2, 0.3 × article 1 length, with plumose and simple setae in anterodorsal and anteroventral corners; primary flagellum with 10 articles, two fields of callynophore, one strong and another weak, articles with simple setae in corners; accessory flagellum with six articles. Antenna 2, articles 4 and 5 subrectangular, approximately the same length, with simple and plumose setae; peduncle 7-articulate.

Mouthparts forming a subquadrate bundle. Epistome and upper lip slightly separate, upper lip dominant, acute distally, ventral margin subquadrate, setose. Mandible, incisor smooth, lacinia mobilis in left mandible, modified a slender seta, simple accessory setae; molar slightly setose; palp 3–articulate, article 2 approximately 2,8 × longer than article 1, with four slender and three pectinate setae; article 3, surface setose, with apical setae. Maxilla 1, inner plate, small row of setae in outer margin, two plumose robust setae in apical margin; outer plate, 11 setalteeth in 5/6 arrangement: ST1–4 and ST6–ST7 2-cuspidate, ST5 3-cuspidate, STA–STD 2-cuspidate (with two cusps medially); palp, 2-articulate, serrate, with two small apical setae. Maxilla 2, plates narrow, inner plate with slender setae in apical margin, outer plate with pectinate setae in lateral margin, slender setae in apical margin. Maxilliped, inner plate, lateral and apical margin with plumose setae, small robust setae in apical margin; outer plate, apical margin slightly serrate and rounded; palp, 4-articulate, article 2 and 3, lateral and apical margins with slender setae, article 2, 1.5 × longer than article 1 approximately, 4.5 × longer than wide, dactylus with small subterminal setae and nail.

Pereonites 1–7: without setae. Gnathopod 1, simple, coxa, rounded anteriorly, basis; anterior margin setose, tuft of setae in posteroventral corner; ischium, 0.4 × length of basis, tuft of setae in anteroventral corner, posterior margin setose; merus, subtriangular, posterior margin with row of small setae and tuft of slender setae; carpus, approximately 1.5 × longer than wide, anteroventral and posteroventral corner with setae; propodus, approximately 2.0 × longer than wide, anterior margin with distal setae, posterior margin setose; dactylus, small, 0.6 × length of propodus, small setae in posteroventral corner, with nail, 0.4 × length of dactylus. Gnathopod 2, basis subrectangular, 1.8 × longer than wide; basis long, approximately 8 × longer than wide; ischium, 0.4 × length of basis, tuft of setae in distal surface; merus, posterior margin with row of setae, posteroventral corner with simple setae; carpus, 1.7 × longer than merus, anterior and medial margins with simple setae, posterior margin concave and strongly setose, with thin setae; propodus, margins setose, anteroventral corner with pectinate setae, posteroventral corner denticulated; dactylus, small, approximately 0.1 × length of propodus, with nail.

Pereopod 3, coxa subrectangular, 1.4 × longer than wide; basis, 0.6 × the length of coxa, anteroventral corner and posterior margin with simple setae; ischium small, approximately 0.3 × the length of basis, posterior margin with simple setae; merus, 2.7 × longer than wide, expanded anteriorly, one slender seta in anteroventral corner, posterior margin setose; carpus, posterior margin setose; propodus, 3.8 longer than wide, small seta in posterior margin; dactylus, elongated, approximately 0.6 × length of propodus, anterior margin with one plumose seta, with nail. Pereopod 4, coxa, elongated, 1.6 × longer than coxa 5; basis, posteroventral corner with simple setae; ischium, posterior margin with setae; merus, 2.5 × longer than wide, anterior margin with 5 small setae, anteroventral corner and posterior margin with simple setae; carpus, small, approximately 0,3 × of the length ischium, without setae; propodus, anteroventral corner with one setae, posterior margin with setae; dactylus, anterior margin with one plumose setae, with nail, with small setae. Pereopod 5, coxa, subquadrate, anterior margin slightly convex, posterior margin straight; basis, anterior and posterior margins with small setae, anteroventral corner with slender setae; ischium, small, 0.4 × length of merus, one seta with accessory seta in anterior margin and one in anteroventral corner; merus, anterior and posterior margin with setae with accessory setae, posterior margin rounded; carpus, anterior and posterior margin slightly rounded, with setae with accessory setae; propodus, subrectangular, setae with accessory setae in anterior margin, one seta in posterior margin and two in posteroventral corner; dactylus, posterior margin with one plumose seta, with nail. Pereopod 6, coxa, anterior margin slightly concave, posterior margin, slightly rounded; basis, 1.4 × longer than wide, anterior margin slightly convex, with simple setae, posterior margin setose; ischium, setae with accessory setae in anterior margin; merus, anterior margin slightly straight with setae with accessory setae, two setae in posterior margin; carpus, anterior margin with two tufts of setae with accessory setae and one in anteroventral corner, posterior margin with one setae; propodus, subrectangular, approximately the same length of carpus, three tufts of setae with accessory setae in anterior margin and in posteroventral corner; dactylus, 0.6 × the length of propodus, with one plumose setae in posterior margin, with nail. Pereopod 7, coxa, anterior margin straight, posteroventral margin rounded, with simple setae; basis, anterior margin with small setae with accessory setae, posterior margin with simple setae, anteroventral corner elongated, ventral margin concave; ischium, with two setae with accessory setae in anteroventral corner; merus, two setae with accessory setae in anteroventral corner, one in posterior margin and one in posteroventral corner; carpus, 1.4 × longer than carpus of pereopod 6, tufts of setae with accessory setae in anterior margin, one in posterior margin and one tuft in posteroventral corner; propodus, 1.6 × longer than propodus of pereopod 6, with tufts of setae in anterior, posterior and ventral margins; dactylus, 0.4 × the length of propodus, posterior margin with small setae, without nail.

Pleonite 1–3 and urosome 1–3 without setae, epimeral plates 1–3, posteroventral margin subquadrate to subacute. Urosomite 1, dorsal median margin with a dorsal forward turned keel and two lateral carinas. Uropod 1, peduncle, approximately the same length of rami, dorsal and ventral margins with thin setae; outer ramus, with nail. Uropod 2, peduncle, posterior margin with one seta; ramus, approximately the same length; inner ramus, tuft of slender setae in posterior margin, with constriction, with one long setae with accessory setae, with nail; outer ramus, with nail. Uropod 3, peduncle, approximately the same length of outer rami; rami with nail; inner ramus 0.7 × the length of outer ramus. Telson, entire, slightly longer than wide, posterior margin convex, with three plumose setae in surface.

Remarks: Although Aruga kieppe sp. nov. presents similar characters to the genus Shoemakerella , this species belongs to Aruga by the presence of two fields of callynophore on antenna 1, left mandible with lacinia mobilis like a long slender peg, and especially for presenting maxilla 1, outer plate, setal-teeth STA–D medial margin 2- cuspidate.

This species differs mainly from A. holmesi, and A. paracuru sp. nov. by having: coxa 1, anterior margin less expanded anteriorly; epimeral plates 1–3, posteroventral margin subquadrate to subacute; urosomite 1, dorsal margin with a keel and dorsal carinas; telson, apical margin convex. The shape of lateral cephalic lobe, the convex telson and the posterior margin of the epimeral plate 3 are the principal differences between this new species and A. oculata

Figures

FIGURE 5. Aruga kieppe sp. nov.: female, holotype, Quiepe (Kieppe) Island in Camamu Bay, Bahia, 13°50'60''S 38°58'001''W, UERJ 75. Scale bars: 1.0 mm.

FIGURE 6. Aruga kieppe sp. nov.: female, holotype, Quiepe (Kieppe) Island in Camamu Bay, Bahia, 13°50'60''S 38°58'001''W, UERJ 75. Scale bars: 0.1 mm.

FIGURE 7. Aruga kieppe sp. nov.: female, holotype, Quiepe (Kieppe) Island in Camamu Bay, Bahia, 13°50'60''S 38°58'001''W, UERJ 75. Scale bars: 0.1 mm for Mx1 and Mp; 0.5 mm for remainder.

FIGURE 8. Aruga kieppe sp. nov.: female, holotype, Quiepe (Kieppe) Island in Camamu Bay, Bahia, 13°50'60''S 38°58'001''W, UERJ 75. Scale bars: 0.5 mm for P5, P6, P7; and 0.1 mm for remainder.