Ipanema talpa Barnard and Thomas, 1988

ALONSO DE PINA, GLORIA M., 2003, A new species of Phoxocephalidae and some other records of sand-burrowing Amphipoda (Crustacea) from Argentina, Journal of Natural History 37 (9), pp. 1029-1057 : 1054-1057

Ipanema talpa Barnard and Thomas, 1988

( figure 15 )

Ipanema talpa Barnard and Thomas, 1988: 617–621 , figures 1–4 .

Material examined

Buenos Aires: El Rincón , 39 ° 49 ∞ 58 ◊ S, 61 ° 35 ∞ 02 ◊ W (Sta 28), 21 m depth, 55% fine sand, 2 November 1993, one ♀ (with setose oostegites) dissected 2.85 mm, MACN No. 34693; one ♀ (with setose oostegites) 3.15 mm, MACN No. 34694; two 33 (with penis papillae) 2.45 and 2.8 mm, MACN No. 34695. Collectors and donors: D. Roccatagliata and M. Torres Jordá .

Remarks

The female and male specimens examined ( figure 15a ) agree closely with the description and illustrations given by Barnard and Thomas (1988) for the male of Ipanema talpa , only this sex having been reported for South America, Brazil. A few minor differences were observed when both males and females from Argentina were compared with the male from Brazil. Some of these differences are sex linked, such as the sexual dimorphism of antennae 1 and 2 ( figure 15b, c ). Other differences could be due to geographical localities and/or variations among individuals, especially those related to spination and setation. The Argentine material displays a maxilla 1 palp bearing three huge apical setae ( figure 15d ), versus two in the Brazilian material; in the specimens from Argentina maxilla 1 outer plate has 10 or 11 spines ( figure 15e ) whereas there are nine in the specimen from Brazil. Finally, the uropod 2 inner ramus bears two apicomedial spines in the material from Argentina ( figure 15f ) while the material from Brazil has one.

Both females and males of Ipanema talpa were found in El Rincón area of the Argentine continental shelf, inhabiting fine sand at 21 m depth .

Biogeographical notes

Metharpinia iado n. sp. is widely distributed in the north part of the Bonaerensian district in the Argentine province and poorly represented in the south of the district. This zoogeographic region is characterized by warm-temperate waters under the influence of the Brazilian current. Microphoxus cornutus ( Schellenberg, 1931) is recorded in the Argentine province and, to a lesser degree, in the traditionally termed Magellanic province; this latter zoogeographic region is typified by cold-temperate waters under the influence of subantarctic waters of the Malvinas current. Fuegiphoxus fuegiensis ( Schellenberg, 1931) is also recorded in the Bonaerensian district, but only in its southern part, where probably the faunistic limit between both zoogeographic provinces fluctuates, at about 42 ° – 43 ° S; the species’ distribution extends towards the Magellanic province. Ipanema talpa Barnard and Thomas, 1988 is present in the South Brazilian and Bonaerensian districts, thus belonging to the warmer faunistic area of the Argentine zoogeographic province.

The present records are shown on a map ( figure 16 ) in order to indicate their frequency and latitudinal distribution in the south-west Atlantic Ocean.

Figures

FIG. 15. Ipanema talpa Barnard and Thomas, 1988. Female: (a) head, lateral view; (b, c) antennae 1, 2; (d) maxilla 1; (e) outer plate of maxilla 1; (f) uropod 2. Scales (µm): A: (a); B: (b,c, f); C: (d); D: (e).

FIG. 1. Metharpinia iado n. sp. Allotype, ovig. female: (a) head, lateral view; (b) head, dorsal view; (c, d) antennae 1, 2; (e, f) right and left mandibles; (g) mandibular palp. Scales (µm): A: (a, b); B: (c, d); C: (e, f); D: (g).

FIG. 2. Metharpinia iado n. sp. Allotype, ovig. female: (a) lower lip; (b, c) maxillae 1, 2; (d) maxilliped; (e) gnathopod 1; (f) propodus and dactylus of gnathopod 1; (g) gnathopod 2; (h) propodus and dactylus of gnathopod 2. Scales (µm): A: (a–d); B: (e, g); C: (f, h).

FIG. 3. Metharpinia iado n. sp. Allotype, ovig. female: (a) peraeopod 3; (b) propodus and dactylus of peraeopod 3; (c) coxa 4; (d) peraeopod 4; (e) propodus and dactylus of peraeopod 4. Scales (µm): A: (a, c, d); B: (b, e).

FIG. 4. Metharpinia iado n. sp. Allotype, ovig. female: (a) peraeopod 5; (b) dactylus of peraeopod 5; (c) peraeopod 6; (d, e) right and left dactyla of peraeopod 6; (f) peraeopod 7; (g) dactylus of peraeopod 7. Scales (µm): A: (a, c); B: (b, d, e, g); C: (f).

FIG. 16. Maps showing location of sampling sites for Metharpinia iado n. sp. (solid circles), Microphoxus cornutus (Schellenberg, 1931) (solid diamonds), Fuegiphoxus fuegiensis (Schellenberg, 1931) (solid triangles) and Ipanema talpa Barnard and Thomas, 1988 (solid squares). Study areas are indicated by arrows.