Phoxocephalidae G. O. Sars, 1891 (Crustacea: Amphipoda) collected by the R / V Almirante Saldanha off the coast of Uruguay and Argentina
Author
Senna, Luiz F. Andrade André R.
text
Nauplius
2021
e 2021025
2021-06-11
29
1
42
https://doi.org/10.1590/2358-2936e2021025
journal article
10.1590/2358-2936e2021025
2358-2936
14668253
Metharpinia dentiurosoma
Alonso de Pina, 2003b
(
Fig. 13
)
Metharpinia dentiurosoma
Alonso de Pina, 2003b: 2523
, 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
, 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
)
;
4 females
, in 70 % ethanol, st. 2868,
36°23’S
53°32’W
,
Argentina
,
51 m
depth
,
February 1972
(
UERJ 462
)
;
4 females
, in 70 % ethanol, st. 2868,
36°23’S
53°32’W
,
Argentina
,
51 m
depth
,
February1972
(
MNRJ29882
)
;
4females
,in70% ethanol, st. 2868,
36°23’S
53°32’W
,
Argentina
,
51 m
depth
,
February 1972
(
MZUSP 41267
)
;
4 females
, in 70 % ethanol, st. 2868,
36°23’S
53°32’W
,
Argentina
,
51 m
depth
,
February 1972
(ColBIO
BT 655
)
;
1 female
, in 70 % ethanol, st. 2888,
37°56’S
57°07’W
,
Argentina
,
31 m
depth
,
February 1972
(
UERJ 463
)
.
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.
Figure 13.
Metharpinia dentiurosoma
Alonso de Pina, 2003b
, female (UERJ 461), Argentina (36°29’S 55°57’W). Ep1, epimeral plate 1, lateral view; Ep2, epimeral plate 2, lateral view; Ep3, epimeral plate 3, lateral view; Ur1, urosomite 1, lateral view; Ur2, urosomite 2, lateral view; Ur3, urosomite 3, lateral view; U1, uropod 1, lateral view; U2, uropod 2, lateral view; U3, uropod 3, lateral view. Scale bars: 1.0 mm for Ep1–3; 0.3 mm for the remaining.
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
)
.
Brazil
: states of
Rio de Janeiro
,
São Paulo
, and
Santa Catarina
.