Metharpinia dentiurosoma Alonso de Pina, 2003b

Metharpinia dentiurosoma Alonso de Pina, 2003b View in CoL

( Fig. 13 View Figure 13 )

Metharpinia dentiurosoma Alonso de Pina, 2003b: 2523 View in CoL View Cited Treatment , figs. 1–7. — López-Gappa et al., 2006: 16, 52. — Alonso and Chiesa, 2014: 206, 207, 209, fig. 3C, E–I. — Andrade et al., 2015: 39. — Andrade and Senna, 2020c: 2 View Cited Treatment , figs. 1–6.

Material examined. 1 female, dissected and illustrated, st. 2861, 36°29’S 55°57’W, Argentina, 20 m depth, February 1972 ( UERJ 461 ) GoogleMaps ; 4 females, in 70 % ethanol, st. 2868, 36°23’S 53°32’W, Argentina, 51 m depth, February 1972 ( UERJ 462 ) GoogleMaps ; 4 females, in 70 % ethanol, st. 2868, 36°23’S 53°32’W, Argentina, 51 m depth, February1972 ( MNRJ29882 View Materials ) GoogleMaps ; 4females,in70% ethanol, st. 2868, 36°23’S 53°32’W, Argentina, 51 m depth, February 1972 ( MZUSP 41267 View Materials ) GoogleMaps ; 4 females, in 70 % ethanol, st. 2868, 36°23’S 53°32’W, Argentina, 51 m depth, February 1972 (ColBIO BT 655 ) GoogleMaps ; 1 female, in 70 % ethanol, st. 2888, 37°56’S 57°07’W, Argentina, 31 m depth, February 1972 ( UERJ 463 ) GoogleMaps .

Diagnosis. See Andrade and Senna (2020c). Additional description. Epimeral plate 1 anterior margin rounded, with 2 setae, ventral margin with 7 plumose setae, posteroventral corner with small, rounded hump, posterior margin convex. Epimeral plate 2 anterior margin weakly concave, with 6 facial plumose setae, posteroventral corner with small subacute hump, posterior margin weakly crenulate, with 4 setae. Epimeral plate 3 anterior margin concave, anteroventral corner rounded, posteroventral corner strongly produced into large spine, posterior margin weakly crenulate, with 6 setae and 1 setule, with oblique facial row of 8 stout setae extending from posteroventral margin to middle of plate, decreasing in length. Urosomite 3 produced as large acute hook dorsally. Uropod 1 peduncle dorsomedial margin with 4 stout setae, dorsolateral margin with 9 stout setae; outer ramus slightly longer than inner, dorsal margin with 7 stout setae, bearing 2 subapical nails; inner ramus dorsal margin with 4 stout setae, bearing 1 subapical nail. Uropod 2 peduncle dorsomedial margin with 7 stout setae; outer ramus slightly longer than inner, dorsal margin with 6 stout setae, bearing 2 subapical nails; inner ramus dorsal margin with 3 stout setae, bearing 1 subapical nail. Uropod 3 peduncle dorsomedial margin with 1 stout seta distally, ventrolateral margin with 6 stout setae; outer ramus 1.2 × longer than inner, article 1 ventrolateral margin with 3 sets of stout setae: 2-2-3, article 2 elongate, with 2 setae subapically; inner ramus ventrolateral margin with 2 setae, subapically with 1 seta.

Typelocality. Argentina, Buenos Aires, El Rincón

(39°49’58”S 61°35’02”W).

Remarks. This species was described from type material from southern Buenos Aires Province ( Argentina) and was recently recorded from southeastern and southern Brazil ( Andrade and Senna, 2020c).Some morphological differences are clear when comparing the drawings of the type material ( Alonso de Pina, 2003b) plus the Brazilian records ( Andrade and Senna, 2020c) with the ones belonging to this study. For example, while the epimeral plate 1 ventral margin presents five to six plumose setae here, and in Alonso de Pina (2003b), the plates from Andrade and Senna (2020c) show only two slender setae on the antero- and posteroventral corners. The posterior margin of epimeral plate 2 is weakly crenulate in the present material, whereas it is smooth in the other works. The facial row of setae of the epimeral plate 3 is composed of eight and nine setae in this study and in the type material respectively; however, the Brazilian material shows 10 setae.

Although it is possible to observe some other subtle differences regarding number of stout setae on the uropods, the species can be easily recognized by the produced spine on third epimeral plate and urosomite 3, and distal combs on peduncle of uropods 1–2.

Geographic distribution. Argentina: El Rincón (39°49’58”S 61°35’02”W), off Buenos Aires Province (36°29’S 55°57’W; 36°23’S 53°32’W; 37°56’S 57°07’W) ( Fig. 25 View Figure 25 ) GoogleMaps . Brazil: states of Rio de Janeiro, São Paulo, and Santa Catarina .