Presence of Remora remora on Mobula birostris in Revillagigedo National Park, Mexico.

The ecology of mantas and echeneids in the Tropical Eastern Pacific is poorly understood. In this study we describe the frequency of interactions between the vulnerable Mobula birostris and its symbiont Remora remora based on observations of scientists and tourists in a marine protected area. Data were obtained by analysing underwater photographs of observed mantas with remoras over 139 diving days at sea during the period 2016–17. In all, there were 271 photographic records of this symbiosis, corresponding to 207 mantas, with a mean (±s.d.) of 1.6 ± 0.6 remoras per manta. This study is the first to provide information regarding the sex ratio, length, morphotype frequency and echeneids per manta of M. birostris in the Tropical Eastern Pacific. This research explored, for the first time, interactions between mantas and remoras in a marine park in the Mexican Pacific. The aim was to provide general information about the preference of the remoras for this vulnerable species of mantas, because knowledge of both species is still scarce in the area. Ecological implications regarding this interaction are discussed. [ABSTRACT FROM AUTHOR]