Ampelisca meridionalis, Valério-Berardo, Maria Teresa, 2007

Valério-Berardo, Maria Teresa, 2007, Description of three new species of Ampelisca (Crustacea: Amphipoda: Ampeliscidae) from Southwestern Atlantic, with a key of the genus for Brazilian species, Zootaxa 1626, pp. 25-37 : 30-31

publication ID	https://doi.org/ 10.5281/zenodo.179283
DOI	https://doi.org/10.5281/zenodo.6248590
persistent identifier	https://treatment.plazi.org/id/039B87C2-FFA0-5B59-FF72-FCB728F05A05
treatment provided by	Plazi
scientific name	Ampelisca meridionalis
status	sp. nov.

Treatment

Ampelisca meridionalis View in CoL sp. nov.

( Figs. 3–4 View FIGURE 3 View FIGURE 4 )

Material examined: Holotype, female, 15 mm, 34º32’S – 53º33’W, 29 m, sand and broken shell, RV Almirante Saldanha, 04/XI/69, MZUSP 17218. Paratypes: 24°20’S – 45°12’W, 78m, sand and broken shell, RV Almirante Saldanha, 24/IX/1969, MZUSP 17219, 1 female; 34°32’S – 53º33’W, 29 m, sand and broken shell, RV Almirante Saldanha, 04/XI/69, MNRJ 20456, 1 female.

Etymology: The species is named in reference to the latitudinal region where the specimens are recorded.

Diagnosis: Head with anteroventral and anterodorsal margins parallel. Antenna 1 subequal in length to peduncle antenna 2. Pereopod 7 basis posterior margin oblique and pointed, reaching to middle of carpus, with plumose setae on posterodistal margin, carpus anterior margin slightly notched with 1 robust seta on notch, propodus longer than carpus, twice longer than wide. Epimeron 3 posteroventral corner quadrate. Urosomite 1 with saddle-shaped dorsal carina. Uropod 2 outer ramus with 1 long apical robust seta. Uropod 3 rami broad and foliaceous, with long plumose setae. Telson deeply cleft, apices of lobes notched.

Description: Holotype female, 15mm. Head ( Fig. 3 View FIGURE 3 ) shorter than first 3 body segments combined, anterior margin narrow, anteroventral and anterodorsal margins parallel. Antenna 1 ( Fig. 3 View FIGURE 3 ) subequal in length to peduncle antenna 2; flagellum with 19 articles. Antenna 2 (fig. 3) shorter than body length, peduncular article 4 longer than article 5; flagellum with 24 articles. Mandible ( Fig. 3 View FIGURE 3 ) with 10 robust setae in the accessory setal row; mandibular palp elongate, article 2 slightly inflated proximally, with setae on both margins, article 3 as long as article 2, with medial and apical setae. Maxilla 1 ( Fig. 3 View FIGURE 3 ) inner plate with two apical plumose setae; outer plate with 9 setal-teeth; palp article 2 provided with 3 distal cusps accompanied by 7 robust setae and 4 facial setae. Maxilliped ( Fig. 3 View FIGURE 3 ) inner plate rectangular distally, with apical and subapical rows of plumose setae; outer plate reaching to end of palp article 2, with 9 chisel-shaped robust setae along medial margin, apical margin with 2 robust setae and plumose setae; palp article 4 inserted at midlength of the article 3. Upper lip, lower lip and maxilla 2 ( Fig. 3 View FIGURE 3 ) with basic characters for the genus.

Coxae 1 – 4 longer than broad. Coxa 1 ( Fig. 1 View FIGURE 1 ) with 1 notch on posteroventral corner. Coxae 1 and 2 with a marginal row of setae on ventral margin. Coxae 3 and 4 with sparse and short setae on ventral margin. Gnathopod 1 ( Fig. 3 View FIGURE 3 ) basis slightly inflated distally, with a row of simple setae on posterior margin; isquium and merus with setae on posterior margin; carpus longer than propodus (1.2 X), posterior margins of both articles with a row of simple and pectinate setae, anterior margins with sparse simple setae; dactylus curved, with 3 setules along inferior margin. Gnathopod 2 ( Fig. 3 View FIGURE 3 ) basis inflated distally, with long setae on both margins; carpus longer than propodus (1.8 X), both articles with setae on posterior margins; dactylus curved, with 2 setules along inferior margin. Pereopods 3 and 4 ( Fig. 4 View FIGURE 4 ) similar in shape but forth is more massive and setose than third pereopod, both pereopods with dactyli longer than combined lengths of propodus and carpus (1.6 X). Pereopod 3 merus with plumose setae along half posterior margin. Pereopod 4 basis and merus with rows of plumose setae on posterior margins; merus length 2 X breadth, with rows of plumose setae on both margins. Pereopod 5 ( Fig. 4 View FIGURE 4 ) basis subquadrate, anterior margin with simple and plumose setae; carpus subequal in length to propodus, posterodistal margin produced and bearing 2 long setae and 5 short robust setae, posterior margin with 2 set of comb robust setae; propodus with setae along anterior margin, posterior margin with 3 robust setae; dactylus short, with 3 apical cusps. Pereopod 6 ( Fig. 4 View FIGURE 4 ) basis subquadrate, anterior margin with short plumose and simple setae; carpus slightly longer than propodus, posterodistal margin produced and bearing 2 long and 4 short robust setae; anterior margins of carpus and propodus with rows of robust setae and 2 long apical setae; dactylus short, with 3 apical cusps. Pereopod 7 ( Fig. 4 View FIGURE 4 ) basis posterodistal margin oblique and pointed, reaching to middle of carpus, with plumose setae; merus slightly longer than isquium, posterior lobe weakly produced, with plumose setae; carpus anterior margin slightly notched with 1 robust seta on notch, anterodistal corner with 3 robust setae; propodus longer than carpus, not stout, length 2 X breadth, with 3 robust setae on both distal margins; dactylus shorter than propodus (0.7 X) and curved anteriorly.

Epimeron 3 ( Fig. 4 View FIGURE 4 ) posteroventral corner quadrate. Urosomite 1 ( Fig. 4 View FIGURE 4 ) with saddle-shaped dorsal carina. Uropod 1 (fig. 4) reaching to the end of uropod 2, peduncle as long as rami, inner margin with 6 robust setae; rami subequal in length; inner ramus with 3 robust setae on inner margin; outer ramus nacked. Uropod 2 ( Fig. 4 View FIGURE 4 ) peduncle longer than rami, with 1 apical robust seta on inner margin; inner ramus shorter than outer ramus, inner margin with a row of robust setae; outer ramus with 3 setae on outer margin and 1 long apical robust seta. Uropod 3 ( Fig. 4 View FIGURE 4 ) peduncle with 3 apical robust setae on inner margin; rami broad and foliaceous, longer than peduncle, subapical and apical margins of both rami with long plumose setae. Telson ( Fig. 4 View FIGURE 4 ) deeply cleft (0.8 X), apices of lobes notched, each notch bearing 1 robust seta.

Remarks. Ampelisca meridionalis sp. nov. is closely related to Ampelisca bicarinata Goeke and Heard, 1983, Ampelisca cristata Holmes, 1908 A. cristoides Barnard, 1954 and A. flabellicaudata Valério-Berardo & Wakabara, 2006 , in having head anteroventral and anterodorsal margins parallel, urosomite 1 with a dorsal carina, uropod 2 outer ramus with a long apical robust setae and uropod 3 rami foliaceous and setose. However, Ampelisca meridionalis . sp. nov. can be distinguished from these species by pereopod 7 basis posterior margin oblique and pointed, reaching to middle of carpus and carpus anterior margin notched with 1 robust seta on notch.

Also there are clear distinctions between Ampelisca meridionalis sp. nov. with A. cristoides , A. cristata and A. flabellicaudata by size and setation of uropods and slender propodus of pereopod 7. In addition Ampelisca meridionalis is easily distinguished from A. bicarinata , A. cristata and A. cristoides by epimeron 3 posteroventral corner quadrate, without spine. Ampelisca meridionalis sp. nov also differs from A. flabellicaudata by urosmite 1 carina saddle-shaped and foliaceous uropod 3 rami.