behavioral plasticity

This study examines the importance of color in camouflage of the West Atlantic Trumpetfish, Aulostomus maculatus during shadow stalking behavior. Shadow stalking is a foraging technique where A. maculates disguises itself to prey by aligning along the dorsal line of another reef fish. The study was done in Bonaire, Netherland Antilles between October and November 2007. Data was taken snorkeling in the shallow waters in front of Kralendijk on the leeward side of the island and behavioral changes were recorded. Two morphotypes of A. maculates common to the study site were identical in size and phase range (shade) and varied only in the presence or absence of a blue nose. They provided the basis for testing the hypothesis that the blue-nosed A maculatus morph would shadow reef fish that are also blue/green more frequently. Though the blue-nosed A. maculates did not appear to shadow blue/green fish more often, an analysis of different morphotypes (blue-nosed or brown) and phases (pale or dark) in the area showed unexpected trends. Mainly that pale and brown A. maculates shadow a higher percentage of blue/green fish than dark or blue-nosed A. maculates respectively.

This student research was retrieved from Physis: Journal of Marine Science II (Fall 2007)19: 15-19 from CIEE Bonaire.

Behavioral and physical differences are sometimes the result of a particular color morphology of a species. Aulostomus maculatus, the west Atlantic Trumpetfish, has three color morphs, and was studied to determine if behavioral or physical differences exist between the three color morphs. This study was conducted at Yellow Sub dive site, located on the leeward side of Bonaire, Dutch Caribbean. Data were collected using SCUBA transects at four depths, and each transect was repeated 6 times. Size (total length, cm), depth (m), environment type (distinguishing corals or objects), substrate type, distance from substrate, body position, and body movement of A. maculatus was recorded for each trumpetfish observed. Significant differences were seen between size and color morph (One-way ANOVA: df = 2, 184, F = 4.30 , p < 0.05), depth and color morph (Kruskal-Wallis: df = 2, Chi-square = 35.11, p < 0.0), and mean density of color morphs at each transect depth (Kruskal-Wallis: df = 2, Chi-square = 11.15, p < 0.01). These results indicate that there are significant differences between the three color morphs of A. maculatus.

This student research was retrieved from Physis: Journal of Marine Science XI (Fall 2012)19: 15-20 from CIEE Bonaire.