Diversity of white spot patterns in the eagle ray Aetobatus laticeps (Myliobatiformes: Aetobatidae) in the north Pacific coast of Costa Rica

Abstract

Introduction: The Pacific white-spotted eagle ray Aetobatus laticeps, has recently separated from the Atlantic A. narinari based on both morphological and genetic evidence. This species is characterized by a dark body with numerous white spots all over its dorsal side. Considering the type, shape, number, and distribution of these natural markings as potential identifiers at the individual level, we studied the variation in the spot patterns. Objective: Describe and compare the white spot pattern (type and distribution) of individuals and evaluate their potential use as identifiers at the individual level. Methods: We analyzed 54 videos (105 subsequent extracted photos) and 19 photographic records that were taken at different sites along the Pacific coast of northern Costa Rica. Results: Seventeen distinctive types of white spots were identified across the entire dorsal side of the rays. Significant differences between each major body section (pectoral fins, back, head, and pelvic fins) were found in the type and frequency of white spots. The type ‘single spot’ was commonly distributed across the entire dorsal side, and the spot pattern on the pelvic fins was informative to identify 72 individuals. Conclusions: The analysis of the type, shape, and distribution of white spots in A. laticeps determined several combinations of white spot patterns that be used for further taxonomic description and provide potential identification of the individual for future population studies along with its distribution.