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

Andrade, Luiz F. & Senna, André R., 2017, Two new species of Ampithoidae (Crustacea: Amphipoda) from northeastern Brazil, Zootaxa 4282 (3), pp. 487-500: 494-499

publication ID

https://doi.org/10.11646/zootaxa.4282.3.4

publication LSID

lsid:zoobank.org:pub:8BADAC19-7326-48F9-A31A-C0C38D224617

persistent identifier

http://treatment.plazi.org/id/038B87F9-1302-6A2F-FF03-FB94FC75FE6B

treatment provided by

Plazi

scientific name

Cymadusa ygara
status

sp. nov.

Cymadusa ygara  sp. nov.

( Figs 6–9View FIGURE 6View FIGURE 7View FIGURE 8View FIGURE 9)

Material examined. Holotype, female, dissected and drawn, 10.7 mm, 0 2 June 2012, Icapuí  Beach, municipality of Icapuí  , Ceará state, Brazil, in sandstone reefs in the intertidal zone, J. Alves Col., CRFFP 73 

Diagnosis. Antenna 1, accessory flagellum 2-articulate. Mandible palp 3-articulate. Maxilla, inner plate with 6 plumose setae. Gnathopod 1 weakly setose. Gnathopod 2, coxa bilobate; palm slightly concave, with a stout setae defining palm. Pereopods 3–5, coxa bilobate. Uropod 3, peduncle with 6 distal stout setae. Telson  distally convex, with 2 apical cusps.

Description. Based on holotype female 10.7 mm, CRFFP 73.

Head. Eyes rounded and well developed. Antenna 1 weakly setose, longer than antenna 2; peduncular article 1 slightly shorter than article 2, article 2 about 3.7 × longer than article 3; flagellum 34-articulate; accessory flagellum 2-articulate. Antenna 2 weakly setose; peduncular article 5 slightly shorter than article 4; flagellum 24- articulate. Upper lip rounded, apically setose. Lower lip notched; lateral lobe longer than medial. Right mandible molar triturative with two long setae; incisor and lacinia mobilis multi-cuspidate; accessory setal row not observable; palp 3-articulate, article 2 subequal to article 3 and 1.8 × longer than article 1, article 3 with 10 pectinate long setae apically. Left mandible molar triturative with a long setae; incisor and lacinia mobilis multicuspidate; accessory setal row with 7 stout multicuspidate setae; palp 3-articulate, article 2 subequal to article 3 and 1.5 × longer than article 1, article 3 with 10 pectinate long setae apically; Maxilla 1 inner plate small and subrectangular, with 6 plumose setae; outer plate with 8 stout multicuspidate setae apically; palp 2-articulate, inner margin with 2 setae, apical margin with 7 stout and 1 long setae, lateral margin with 5 long setae. Maxilla 2 inner plate 3.1 × longer than wide, inner and apical margins covered with long plumose setae; outer plate slightly longer than inner plate, about 2.4 × longer than wide, inner and outer margins covered with small setules and long setae. Maxilliped inner plate 3 × longer than wide, inner and apical margins covered with long plumose setae, presenting a stout setae apically; outer plate 1.9 × longer than wide, inner margin covered with small stout setae, apical margin with 4 long setae; palp 4-articulate, about 1.5 × longer than outer plate; article 1 with 7 setae on the inner margin, article 2 with a row of setae on the inner margin, article 3 inner margin covered with long setae, apical margin with 3 pectinate and 1 regular long setae, outer margin with 6 long setae, article 4 with 2 pectinate setae on the inner margin, nail present.

Pereon. Gnathopod 1 weakly setose; coxa slightly produced anteriorly, ventral margin bilobate with a row of long and short setae; basis 3.2 × longer than wide, posterodistal lobe small and rounded with 1 short setae, posterior and lateral margins with short and long setae; ischium small and subrectangular, posterior margin with 2 setae; merus produced to form a small subacute lobe with 3 long setae; carpus subtriangular, 1.7 × longer than wide, anterior margin with 1 setae and 2 long setae distally, posterior margin covered with long and short setae; propodus anterior margin with sparse setae and a tuft of setae distally, inner margin with a row of short setae; palm acute, covered with short setae; dactylus slightly longer than palm. Gnathopod 2 weakly setose; coxa, ventral margin bilobate with short and long setae; basis 2.8 × longer than wide, posterodistal lobe small and rounded; posterior margin with 1 setae distally; ischium small and subtriangular, posterior margin with 3 setae; merus produced to form a small subacute lobe with 7 long setae; carpus subtriangular, anterior margin with 2 short setae and a tuft of long setae distally, posterior margin with row of short and long setae; propodus anterior margin with sparse setae and a tuft of long setae distally, posterior margin with a row of long setae; palm acute, slightly concave, covered with short and long setae, palmar corner with a stout setae defining palm. Pereopod 3 coxa bilobate, ventral margin covered short setae; basis 2.8 × longer than wide, anterior margin with 3 short setae, posterior margin with plumose long and short setae; ischium small and subquadrate, posterior margin with 3 short setae; merus subrectangular, about 1.8 × longer than wide, anterior margin with 1 setae and a tuft of setae distally, posterior margin with 3 setae and a 4 setae distally; carpus subrectangular, anterior margin with 2 short setae, posterior margin with short and long setae; propodus 3.8 × longer than wide with sparse setae and 3 setae distally. Pereopod 4 very similar to pereopod 3, differing only by some arrangements of setae on coxae, merus, carpus and propodus. Pereopod 5 coxa bilobate, ventral margin with row of tiny setules; basis subovoid, about 1.2 × longer than wide, anterior margin with 5 short stout setae; ischium small and subquadrate; merus subrectangular, about 1.8 × longer than wide; carpus broad, subrectangular, about 1.6 × longer than wide; propodus weakly prehensile, anterior margin with sparse setae and 3 stout short setae, posterior margin with a row of short and long setae, dactylus curved. Pereopod 6 coxa absent; basis about 1.6 × longer than wide, anterior margin with 4 short stout setae, posterior margin with 2 short stout setae; ischium small and subquadrate; merus and carpus very similar, with sparse long and short setae, bearing tuft of setae distally; propodus prehensile, anterior margin with 8 stout setae and sparse long setae, posterior margin with row of short and long setae; dactylus curved. Pereopod 7 coxa small and rounded, anterior margin with 3 setae; basis 1.8 × longer than wide, anterior margin with tiny setules, posterior margin with 3 short stout setae; ischium small and subquadrate; merus and carpus very similar, with sparse long and short setae, bearing tuft of setae distally; propodus prehensile, anterior margin with 11 stout setae and sparse long setae, posterior margin with sparse short and long setae, bearing a tuft of long setae distally; dactylus curved, anterior margin with 1 tiny setule.

Pleon. Epimeron 1, margins rounded. Epimeron 2 anterior margin concave, posteroventral corner with a small subacute tooth. Epimeron 3 anterior margin slightly concave, posteroventral corner with a subacute tooth. Uropod 1 peduncle 3.5 × longer than wide, with 12 stout setae and a long and acute distoventral spine (spur); inner ramus 1.1 × longer than outer ramus, with 5 marginal and 4 apical stout setae; outer ramus with 5 marginal and 4 apical stout setae. Uropod 2 peduncle 2.2 × longer than wide, with 5 stout setae; inner ramus slightly longer than outer ramus, with 4 marginal and 4 apical stout setae; outer ramus with 5 marginal and 4 apical stout setae. Uropod 3 peduncle 1.8 × longer than wide, with 7 marginal long setae and 6 stout and 5 long setae distally; inner ramus slightly longer than outer ramus, with 3 marginal stout setae, 4 stout and 6 long setae distally; outer ramus with 1 marginal stout setae with accessory setae and 2 large recurved distal robust setae. Telson  subtriangular and distally convex, with 2 small cusps.

Etymology. The specific epithet is derived from an indigenous word that means “quick canoe”, that latter originated the city name Icapuí  .

Remarks. Cymadusa ygara  sp. nov. is close to C. herrerae Ortiz & Winfield, 2015  and C. crassicornis ( Costa, 1857)  by the following characters: antenna 1 accessory flagellum 2-articulate; epimeron 3 posteroventral corner with an acute tooth; gnathopod 2 weakly setose, palm entire with a stout setae defining palm. However, it presents an exclusive character within the genus: coxae 2–5 bilobate. The new species is established based on a unique female holotype.

Habitat. Cymadusa ygara  sp. nov. occurs in sandstone reefs in the intertidal zone.

Distribution. Known only from Icapuí  Beach, Ceará state, Brazil.