Little is known about elasmobranchs along the northern coast of South America. During five boat surveys in Suriname offshore waters we visually documented the presence and behaviour of the free-ranging whale shark Rhincodon typus and two mobulid rays: the giant manta ray Manta birostris and the Chilean devil ray Mobula tarapacana. Three sightings were made of R. typus at the surface in shallow coastal waters where the water depth measured 46–67 m. One of these sightings was confirmed by photographs. Manta birostris was positively identified on five occasions while at the surface, all in shallow waters of less than 57 m deep. Four additional sightings, not accompanied by photographs, were identified as Manta spp. One devil ray, photographed and identified as Mobula tarapacana, was recorded at the surface in deep waters (2491 m) in July 2012. These records of R. typus, Manta birostris and Mobula tarapacana are the first for Suriname and therefore add to the documented information of these species within the Wider Caribbean Region and contribute to the knowledge of the pelagic distribution of these species.

Manta ray (Manta birostris) is the largest ray species, but little information is available regarding its biology, distribution and migratory pattern. During an aerial survey conducted in French Guiana waters (South America) in 2006, the observation of several dozen individuals all swimming in the same direction prompted us to develop a research programme on this species as part of an environmental impact assessment for oil drilling. Overall, 117 aerial surveys were performed over 3 years in order to complete a database for this species. In 54 of these flights, a total of 138 individuals were observed. A phenological analysis of this species in French Guiana waters shows a peak presence between July and December, which correlates with sea surface temperature and net primary production in the ocean. The primary production in French Guiana waters is particularly active during this period and could explain the annual pattern for this filter-feeding animal.

Habitat use of Manta alfredi and M. birostris was assessed at 20 localities in the Indian and Pacific Oceans based upon 3328 photographic observations. Geographical relationships of the two species were scored as either microallopatry, microparapatry or microsympatry at each locality. Our study revealed a mosaic habitat occupancy by the two species within their macrosympatric range.