Exhippolysmata oplophoroides Holthuis, 1948

Examined material. Municipality of Oiapoque: Parque Nacional do Cabo Orange, Oiapoque river estuary (4°24’11,11”N, 51º34’13,71”W), 22.viii.2013, I.M. Vieira, A.G. Santiago and E. O. Galeno, 1 female with eggs and 1 juvenile (IEPA2026) (Figure 2) .

Geographic distribution. Western Atlantic, North Carolina, Gulf of Mexico, Venezuela, Suriname and French Guiana. In Brazil it occurs from the state of Amapá to Rio Grande do Sul; Uruguay (Christoffersen 1979; Christoffersen 2016; Ramos-Porto et al. 2003).

Distribution in Amapá state. Estuary of the Oiapoque River, in the municipality of Oiapoque.

Previous records. (Ramos-Porto & Coelho 1991; Christoffersen 1979, Christoffersen 2016)

Ecological notes. It occurs in both mud and sand bottoms (José Fausto-Filho & Neto 1976), (José Fausto-Filho 1979) but predominates in the first type of substrate. In this study, they were collected in an estuarine environment with a muddy bottom, mangroves, and specimens were collected with a sieve (54 cm in diameter) at high tide.

Remarks. The two specimens examined correspond to descriptions of Cervigon et al. (1992).