Habitat choice, size distribution, color variance, and feeding behavior of spotted moray eels, Gymnothorax moringa, in coastal waters of Bonaire, N.A.

The spotted moray eel, Gymnothorax moringa, is one of the most abundant moray eels found in the coastal waters of Bonaire, N.A. However, little is known regarding the factors that contribute to its choice of habitat, behavior, and times of activity. Contradictory evidence has been reported for many species of Gymnothorax as to whether they are nocturnal or diurnal, yet little is known concerning color and size, which may be correlated to diet and choice of habitat. This study sought to determine how size, behavior, and color correlate with reef flat and reef slope habitats and at what time (morning or evening) G. moringa is most active. Observations of G. moringa were conducted in the westward coastal waters of Bonaire. A “U”-shaped search pattern was utilized in locating spotted moray eels in 5 adjacent study areas extending perpendicular from the shore to a depth of ~ 15 m. Once an individual was located behavior, jaw size, and color, were recorded in order to assess differences among individuals on differing habitats (reef flat or reef slope), and times of day (morning: 6:00 - 7:30 or evening: 18:00 – 19:30). G. moringa was found to be in greater abundance on the reef flat in the evening displaying exposed venting behavior and individuals were predominantly white in coloration. In the morning G. moringa were found to be in greater densities on the reef slope, displaying foraging behavior, and were predominantly black in coloration. Representatives of all size classes were distributed on the reef flat regardless of time, however, small individuals were not observed on the reef slope in the evening.

This student research was retrieved from Physis: Journal of Marine Science VI (Fall 2009)19: 7-13 from CIEE Bonaire.