Description of three new species of Ampelisca (Crustacea: Amphipoda: Ampeliscidae) from Southwestern Atlantic, with a key of the genus for Brazilian species Author Valério-Berardo, Maria Teresa text Zootaxa 2007 1626 25 37 journal article 10.5281/zenodo.179283 89d05f5b-4436-4b97-b6c2-0774589b64ca 1175-5326 179283 Ampelisca longipropoda sp. nov. ( Figs. 1–2 ) Material examined : Holotype , female, 4.5 mm , 26º34’S – 47º59’W , 58 m , mud and broken shell, RV W. Besnard, 20/VI/1970 , MZUSP 17220; Paratypes : 29°23’S – 49°10’W , 54 m , mud, RV W. Besnard, 25/VI/1970 , MZUSP 17221, 2 females ; 26°34’S – 47°59’W , 58m , mud and broken shell, RV W. Besnard, 20/VI/1970 , MNRJ 20455, 1 female . Etymology: The name refers to the characteristic long propodus of pereopod 7. Diagnosis : Head with anteroventral margin oblique. Antenna 1 shorter than antenna 2 peduncle. Antenna 2 shorter than body. Pereopod 7 basis posterior margin oblique reaching to end of distal margin of carpus, merus with lobe posterior extending 1/4 of propodus length, propodus twice longer dactylus; dactylus curved apically. Epimeron 3 posterodistal corner with 1spine. Uropod 2 rami with 1 long distal robust setae. Uropod 3 rami lanceolate and subequal in length, inner ramus notched apically. Telson deeply cleft, distal margin pointed and notched, with dorsal setae. Description : Holotype , female 4.5 mm . Head ( Fig. 1 ) with anteroventral margin oblique, subequal in size to first three body segments combined. Antenna 1 ( Fig. 1 ) shorter than antenna 2 peduncle, peduncular article 2 slightly longer than article 3, without setae on ventral margin; flagellum longer than peduncle, with 5 articles. Antenna 2 ( Fig. 1 ) shorter than half body length, peduncular article 4 subequal in length to article 5; flagellum with 8 articles. M andible ( Fig. 1 ) with 6 robust setae in the accessory setal row; mandibular palp article 2 elongate and with 1 long distal seta on outer margin, article 3 0.8 X article 2, with 4 medial and 3 apical setae. Maxilla 1 ( Fig. 1 ) inner plate with 2 apical simple setae; outer plate with 5 setal-teeth; palp article 2 provided with 3 distal cusps accompanied by 4 apical robust setae, 4 apical and subapical setae. Maxilliped ( Fig. 1 ) inner plate rectangular distally with apical row of plumose and simple setae; outer plate reaching to middle of the palp article 3, bearing 7 chisel-shaped robust setae and simple setae along medial margin, and 2 apical plumose setae. Upper lip, lower lip and maxilla 2 ( Fig. 1 ) with basic characters for the genus. Coxae 1–4 longer than broad. Coxa 1, with a notch on posteroventral corner and with a row of plumose setae on ventral margin. Coxa 2 with a row of simple setae on ventral margin. Gnathopod 1 ( Fig. 1 ) shorter than gnathopod 2; basis with one row of simple and plumose setae on both margins; isquium with 3 plumose setae on posterodistal corner; merus with setae on posterior margin; carpus subequal in length to propodus, both articles with pectinate setae and simple setae on posterior margins; propodus with 4 robust setae on posterior margin; dactylus slightly curved, with 3 setules along inferior margin. Gnathopod 2 ( Fig. 1 ) basis with long simple and plumose setae on both margins; carpus longer than propodus (1.9 X), both articles with elongate simple and pectinate setae on posterior margins; propodus with 3 pectinate robust setae on posterodistal corner; dacylus short, with 3 setules on inferior margin. Pereopods 3 and 4 ( Fig. 2 ) similar in shape but the fourth is more massive and setose than third, both with dactyli longer than combined lengths of carpus and propodus. Pereopod 3 merus and carpus with plumose setae on posterior margins; propodus with plumose setae on anterior margin. Pereopod 4 merus length 3 X breadth, both margins with long plumose setae; carpus and isquium with long plumose setae on posterior margins; propodus with plumose setae on anterior margin. Pereopod 5 ( Fig. 2 ) basis subovoid; carpus subequal in length to propodus, sligthly produced posterodistally and bearing 2 long pectinate robust setae and 1 simple setae on posterodistal corner, anterior margin with a row of 6 simple long setae, without set of comb of robust setae; dactylus short and with 2 apical cups. Pereopod 6 ( Fig. 2 ) basis subquadrate, with 6 short simple setae on anterior margin; carpus subequal in length to propodus, posterodistal corner slightly produced, bearing 2 long pectinate robust setae, anterior margin with a row of simple setae, without set of comb of robust setae; dactylus short and with 2 apical cups. Pereopod 7 ( Fig. 2 ) basis posterior margin oblique, with plumose setae, reaching to end of distal margin of carpus; isquium and carpus very short; merus with lobe posterior extending 1/4 of propodus length, with 6 long plumose setae; propodus longer than carpus (4.9 X), length 2.2 X breadth, with a robust seta on anterodistal corner; dactylus shorter than propodus (0.5 X) and curved apically. FIGURE 1. Ampelisca longipropoda sp. nov. : female, 4.5mm, holotype, MZUSP 17220. Epimeron 3 ( Fig. 2 ) posteroventral corner with a spine. Urosomite 1 ( Fig. 2 ) weakly produced dorsally into a carina. Uropod 1 ( Fig. 2 ) reaching to end of uropod 2 rami; peduncle subequal in length to rami, with 2 robust setae on dorsal margin; rami subequal in length, inner ramus with 1 robust setae on anterior margin; outer ramus nacked. Uropod 2 ( Fig. 2 ) peduncle shorter than rami; rami subequal in length, both notched apically and with 1 long distal robust setae; inner ramus with 3 robust setae on dorsal margin. Uropod 3 ( Fig. 2 ) peduncle shorter than rami; rami lanceolate; inner ramus slightly broader than outer ramus but both subequal in length, notched apically and with 2 apical setae; outer ramus inner margin with 3 plumose setae and 2 apical setae. Telson ( Fig. 2 ) slender, deeply cleft (0.8 X), each lobe notched and pointed at apex, each notch bearing 1 seta and 1 robust seta, with dorsal setae. FIGURE 2. Ampelisca longipropoda sp. nov. : female, 4.5mm, holotype, MZUSP 17220. Remarks : Ampelisca longipropoda sp. nov. is closer related to A. araucana Galardo, 1962 , A. mexicana Barnard, 1954 , A. moreirai Valério-Berardo & Wakabara, 2006 and A. pugetica Stimpson, 1864 in having head anteroventral margin oblique; pereopod 7 merus posterior lobe passing distal end of carpus and uropod 3 rami lanceolate and weakly setose. Within this group, Ampelisca longipropoda sp. nov. is closer to A. araucana and A. mexicana in having gnathopod 1 propodus with robust setae on posterior margin; pereopod 7 basis with posterior margin oblique; rami of uropod 2 with 1 apical robust seta and telson narrow, with distal margin notched. However, the former can be distinguished by the following characters: antenna 1 shorter than antenna 2 peduncle; gnathopod 1 carpus as long as propodus; pereopod 7 propodus twice longer than dactylus and epimeron 3 posteroventral corner with a spine. Ampelisca longipropoda sp. nov. differs from A. moreirai and A. pugetica in pereopods 3 and 4 merus anterodistal corner not produced and dactylus longer than carpus and propodus combined; pereopod 7 propodus twice longer than dactylus, urosomite 1 dorsal carina weakly pointed; uropod 1 reaching to end of uropod 2 rami; uropod 2 rami with 1 apical robust seta.