Apocorophium curumim Valério-Berardo & Souza, 2009, sp. nov.
Creators: name: Valério-Berardo, Maria Teresa
name: Souza, Ana Maria Thiago De
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Corophiidae
Apocorophium
Apocorophium curumim

description: Apocorophium curumim sp. nov.
Figures 1–3.
Material examined: Holotype, male, 3.0 mm, 22º 55’ 9” S – 43º 50’ 5”W, intertidal, col. Villac, M. C., II/ 2001, MZUSP 19613; Paratypes, 2 males and 1 female, 22º 55’ 9” S – 43º 50’ 5”W, intertidal, col. Villac, M. C, II/2001, MZUSP 19614.
Etymolog y: named after the Brazilian Tupi-language noun for small children, and allusion to the small species size.
Diagnosis: Male antenna 1, peduncle article 1 with 1 distal and 1 proximomedial robust setae on ventral margin and 1 robust seta on proximal dorsomedial margin. Male antenna 2 pediform; peduncular article 4, distal ventromedial corner with 1 short and 1 long acute process, article 5 with distal flange and 1 acute process on dorsomedial margin. Female antenna 1 with 3–4 proximal robust setae on proximal dorsomedial margin Female antenna 2 peduncle article 3 with 2 robust setae on ventrodistal corner, article 4 with 4 robust setae on ventral margin and 6 on dorsomedial margin, article 5 with 1 distal robust seta on ventral margin. Male gnathopod 1 dactylus tip little exceeding palm, with 1 teeth on flexor margin. Female gnathopod 1 dactylus without tooth on flexor margin. Male gnathopod 2 dactylus with 2 teeth unequal in length in flexor margin. Uropod 2 rami outer margin with robust setae.
Description. Holotype. Male: 3 mm. Head (Fig. 1) rostrum short, not exceeding lateral head lobes; eyes developed. Antenna 1 (Fig. 1) peduncle articles sparcely setose, article 1 with 1 distal and 1 proximal robust setae on ventral margin and 1 robust seta on proximal dorsomedial margin; article 2 subequal in length to article 1; flagellum with 7 articles. Antenna 2 (Fig. 1) pediform; peduncular article 3 almost rectangular, peduncular article 4 longer than article 5, distal ventromedial corner with 1 short and 1 long acute process; article 5 with distal flange and 1 acute process on medial margin; flagellum short and 3-articulate. Mandible (Fig. 1) distal margin of palp proximal article produced distally, with 1 long pinnate seta. Maxilla 1 (Fig. 1) palp exceeding outer plate, distal margin with 6 robust setae; outer plate with 6 robust setae. Maxilla 2 (Fig. 1) inner and outer plate with a row of plumose setae. Maxilliped (Fig. 1) inner plate short, not broad, distal margin with 2 plumose setae and inner margin with 2 plumose setae and 1 robust seta; outer plate with 4 plumose setae and 2 simple setae along inner margin; palp 4-articulate, article 1 with 1 simple seta on inner margin, articles 2 and 3 with a row of plumose setae on distal and inner margins, article 4 with 1 distal strong robust seta.
Gnathopod 1 (Fig. 2) coxa anterior margin acute, with 3 plumose setae and 1 simple seta on anterodistal margin; basis slender, length 2 X breadth, with 3 simple setae on posterodistal margin; ischium with 4 plumose setae on posterodistal margin; merus subtriangular, subequal in length to ischium; carpus length 2 X breadth, with a row of plumose along posterior margin and 2 simple setae on anterior margin; propodus subequal in length to carpus, with 6 simple setae along posterior margin, 4 robust setae on palmar margin and 2 simple setae on anterodistal corner, palmar margin serrate; dactylus tip little exceeding palm, with 1 tooth on flexor margin. Gnathopod 2 (Fig. 2) coxa anterior margin acute, with 1 simple seta on distal margin; basis broad, length 1, 5 X bredth, with 1 simple seta on posterior margin; ischium subrectangular, short, with 1 simple seta on posterodistal corner; merus with a row of long plumose setae along posterior margin; carpus subtriangular; propodus 1.6 X longer than carpus, with 3 simple setae on anterodistal corner, 2 simple setae on posterodistal margin and 4 plumose setae in proximal part of posterior margin; dactylus with 2 teeth subequal in length on flexor margin.
Pereopod 3 (Fig. 2) coxa short and ovate; basis broad, 1.7 X longer than broad, anterior margin inflated medially and with 2 simple seta; ischium rectangular, with 1 simple seta on posterodistal corner; merus as long as wide, anterodistal margin produced, with 1 simple seta on anterior margin, 3 simple setae on anterodistal corner and 1 simple seta on posterodistal corner; carpus broader than longer with 3 simple setae on posterior margin; propodus subequal in length to merus, with 3 simple setae on posterior margin and 2 simple setae on anterodistal corner; dactylus long than propodus. Pereopod 4 (Fig. 2) coxa short and ovate; basis broad, length 1.7 X breadth, with 3 simple setae along anterior margin; others articles similar to pereopod 3, except for number of setae. Pereopod 5 (Fig. 2) coxa bilobate; basis broad, length 1.3 X breadth with 2 simple setae on posterodistal corner; ischium short, about ½ merus length, with 1 simple seta on posterodistal margin; merus bilobate, with 3-2 simple setae on antero and posterodistal margins; carpus with 1 simple seta on posterior margin, 1 simple seta and 3 robust setae on anterodistal corner; propodus elongate, with 1 robust seta on anterodistal margin; dactylus short, with 1 simple seta on posterior margin. Pereopod 6 (Fig. 2) coxa bilobate; basis 1.3 X longer than broader, with 2 simple setae and a row of plumose setae along anterior margin and 3 simple setae along posterior margin; ischium with 1 simple seta on posterodistal margin; merus bilobate, with 4 simple setae along posterior margin and 2 simple setae on anterodistal corner; carpus with 1 simple seta on posterior margin, 2 simple setae and 2 robust setae on anterodistal margin, 2 medial robust setae; propodus elongate, with 2 simple setae on posterior margin and 1 simple seta on anterodistal margin; dactylus longer than dactylus of pereopod 5 and curved anteriorly. Pereopod 7 (Fig. 2) coxa short and ovate; basis length 1.5 X breadth, with a row of plumose setae on both of margins; ischium about ½ merus length, with 1 simple seta on anterodistal corner; merus with 4 simple setae along posterior margin; carpus subequal in length to merus, with 3 robust setae on anterior margin; propodus elongate, about twice longer than carpus, with simple setae along posterior and anterior margin, 1 robust seta on anterodistal margin and 6 long simple setae on posterodistal corner; dactylus subequal in length to dactylus of pereopod 6, curved anterioly.
Epimeral plate 1 (Fig. 1) acute and smooth on ventral margin; epimeral plate 2 with 3 plumose setae on ventral margin; epimeral plate 3 slightly sinuous, posteroventral corner with 2 robust setae and a few of simple setae on posterodorsal margin. Pleopods 1–3 (Fig. 3) similar to each other; peduncle stout, outer margins with plumose setae, except pleopod 1, inner margins with 2 coupling spines; rami with basal articles longer and broader than distal articles, inner ramus little longer than outer ramus.
Urosomites 1–3 (Fig. 3) fused, with lateral marginal ridge of urosome smooth. Uropod 1 (Fig. 3) biramous, inserted ventrally; peduncle reaching apex of peduncle of uropod 2, with 1 interramal spine, 4–5 robust setae along outer margin; outer ramus with 4 robust setae along outer margin and 3 robust setae on apex of inner margin; inner ramus with 3 robust setae on outer margin and 2 robust setae on apex. Uropod 2 (Fig. 3) biramous, rami with 1–2 robust setae on outers margins, 1 robust seta on inner margin and 1 robust seta on apex. Uropod 3 (Fig. 3) uniramous; peduncle short, square, with 1–2 simple setae on outer margin; ramus ovate, subequal in length to peduncle, rounded apically, with a row of simple setae along distal margin. Telson (Fig. 3) small, rounded apically, with rows of spine on apex.
Female: 3.5 mm. Head (Fig. 1) rostrum similar to rostrum of male; eyes well developed. Antenna 1 (Fig. 1) peduncle sparcely setose, article 1 with 3– 4 robust setae on ventral margin and 3–4 proximal robust setae on dorsomedial margin. Antenna 2 (Fig. 1) peduncle article 3 with 2 robust setae on ventrodistal corner; article 4 with 4 robust setae on ventral margin and 6 robust setae on dorsomedial margin; article 5 with 1 distal robust seta on ventral margin and 2 robust setae on proximal dorsomedial margin; flagellum short with 2 articles, distal article with 3 robust setae. Gnathopod 1 (Fig. 2) dactylus slender, without tooth on posterior margin.
Remarks. Apocorophium curumim sp. nov. is very closely related with A. acutum, also registred from Brazil by Shoemaker1934, in having antenna 2 peduncular article 5 with distal flange and 1 robust seta on lateral margin, and gnathopod 1 with dactylus extending well beyond palmar angle. But the former can be distinguished by less setose antennae, antenna 1 peduncular article 1 with 2 robust setae on ventral margin (3–4 robust setae in A. acutum); antenna 2 peduncular article 4 without robust setae on ventral margin (2 robust setae A. acutum); proportion in length of articles 4–5 of peduncle of antenna 2; longer acute process on ventrodistal corner of peduncular article 4 of antenna 2; female antenna 1 with 3–4 robust setae on dorsoproximal margin (1–2 in A. acutum). Apocorophium curumim sp. nov. also differs from A. acutum by gnathopod 2 male dactylus with 2 teeth unequal in length (same length in A. acutum); and carpus shorter than propodus (A. acutum has propodus and carpus subequal in length) and uropod 2 rami outer margin with robust seta (without robust setae in A. acutum).
description: Published as part of Valério-Berardo, Maria Teresa & Souza, Ana Maria Thiago De, 2009, Description of two new species of the Corophiidae (Amphipoda, Crustacea) and register of Laticorophium baconi (Shoemaker, 1934) from Brazilian waters, pp. 55-68 in Zootaxa 2215 on pages 56-60, DOI: 10.5281/zenodo.189937