Validation of photo‐identification as a mark–recapture method in the spotted eagle ray Aetobatus narinari

• Published in: Journal of fish biology Vol. 90; no. 3; pp. 1021 - 1030
• Main Authors: González‐Ramos, M. S., Santos‐Moreno, A., Rosas‐Alquicira, E. F., Fuentes‐Mascorro, G.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-03-2017; Wiley Subscription Services, Inc
• Subjects: Animal Identification Systems - veterinary; Animals; dorsal surface; double mark; I3S Spot; mark–recapture; microchip; natural marks; Photography - veterinary; Population Dynamics; Skates (Fish) - anatomy & histology; dorsal surface; I3S Spot; microchip; double mark; mark-recapture; natural marks
• ISSN: 0022-1112; 1095-8649
• DOI: 10.1111/jfb.13215

The spotted eagle ray Aetobatus narinari is characterized by pigmentation patterns that are retained for up to 3·5 years. These pigmentations can be used to identify individuals through photo‐identification. Only one study has validated this technique, but no study has estimated the percentage of correct identification of the rays using this technique. In order to carry out demographic research, a reliable photographic identification technique is needed. To achieve this validation for A. narinari, a double‐mark system was established over 11 months and photographs of the dorsal surface of 191 rays were taken. Three body parts with distinctive natural patterns were analysed (dorsal surface of the cephalic region, dorsal surface of the pectoral fins and dorsal surface of the pelvic fins) in order to determine the body part that could be used to give the highest percentage of correct identification. The dorsal surface of the pectoral fins of A. narinari provides the most accurate photo‐identification to distinguish individuals (88·2%).