Megalobrachium mortenseni Haig, 1962

(Fig. 2A)

Megalobrachium mortenseni Haig, 1962: 189, figs. 2–5.

Material examined. Brazil, São Paulo: 1 ♀ ov, CCDB 5664, Ubatuba, Praia do Itaguá, colls. F. Mantelatto et al., 2.xii.2004 ; 1 ♀ ov, CCDB 6709, Cananéia, Ilha da Figueira, colls. F. Zara et al., 26.xi.2020 .

Distribution. Western Atlantic— Honduras, Panama, Virgin Islands, Colombia, Venezuela, Brazil (Pará, Piauí, Rio Grande do Norte, Paraíba, Pernambuco, Alagoas, Sergipe, Bahia, Espírito Santo, Rio de Janeiro, São Paulo) (Werding et al. 2003; Rodríguez et al. 2005; Coelho et al. 2007; Ferreira & Melo 2016; Mendonça et al. 2019).

Remarks. Megalobrachium mortenseni is found in the intertidal region down to depths of 30 m, usually on rocky substrates (Ferreira & Melo 2016); in sandy bottoms with patches of coral and sea grass beds ( Thalassia Banks ex König, 1805 and Syringodium Kützing, 1860) (Poupin & Lemaitre 2014). The two specimens obtained were collected in colonies of the bryozoan Schizoporella errata (Waters, 1878) (in Ubatuba) and colonies of leuconoid sponges (in Cananéia). Sequence accession numbers (GenBank): CCDB 6709—16S (MW753221), COI (MW753222).