Sea slugs (Gastropoda: Heterobranchia) from Rio Grande do Norte, Northeastern Brazil Author Delgado, Marlon Author Freire, Fúlvio Aurélio de Morais Author Meirelles, Carlos Augusto Oliveira de Author Padula, Vinicius Author Bahia, Juliana Author Brandão, Simone Nunes text Papéis Avulsos de Zoologia 2022 2022-11-01 62 1 26 http://dx.doi.org/10.11606/1807-0205/2022.62.063 journal article 10.11606/1807-0205/2022.62.063 1807-0205 7617672 04. Chelidonura hirundinina (Quoy & Gaimard, 1833) ( Fig. 2D ) Material examined: Parrachos de Rio do Fogo, Rio do Fogo, 20. VI .2015 , two specimens , 14-16 mm (body length), leg. T . Accioly ( GEEFAA 1320). Description: Body yellowish-orange with a darker sub-margin. A blue mark on the head shield (T-shape), on the edge of the parapodium and on the tail (V-shape). On the dorsum, two small black droplet-shaped spots on the anterior portion and posterior to cephalic shield, large, white rectangle-shaped mark on posterior shield near tail and ventral portion completely darkened. Tail formed by two pointed projections, the left longer than the right. Geographic distribution: Indo-Pacific: Australia , Japan , USA ( Hawaii and Palmyra Atoll ), Philippines , Indonesia and Madagascar ( Valdés et al., 2006 ). Western Atlantic: Aruba , Bahamas , Bonaire , Cayman Islands , CuraÇao , Guadeloupe , Puerto Rico , USA (Florida), Venezuela and Brazil ( Rio Grande do Norte – present study) ( Valdés et al., 2006 ; Camacho-García et al., 2014 ; Zamora-Silva & Malaquias, 2017 ). Remarks: Valdés et al. (2006) recorded a broad geographic range for Chelidonura hirundinina in the IndoPacific and tropical Western Atlantic. Camacho-García et al. (2014) presented a phylogenetic molecular study on the family Aglajidae (Pilsbry, 1895) showing genetic divergence between populations of C. hirundinina from the Indo-Pacific and the Western Atlantic. Zamora-Silva & Malaquias (2017) performed new molecular analyses, revising some specimens of C. hirundinina from the IndoPacific and Western Atlantic, promoting reclassification of some specimens. The authors emphasized that the genus Chelidonura is valid and although it is predominantly present in the Indo-Pacific Ocean, there are two species in the Western Atlantic Ocean, C. cubana Ortea & Martinez, 1997 and C. hirundinina . This is the first record of C. hirundinina from the South Atlantic Ocean.