Major
Marine Biology
Advisor
Forrester, Graham
Advisor Department
Natural Resources Science
Advisor
Wilga, Cheryl
Advisor Department
Biological Sciences
Date
5-2013
Keywords
Escape responses; marine ecology; functional morphology; animal behavior; predator-prey interactions; Bridled Goby
Abstract
The Effects of Refuge Abundance on Escape Responses of the Bridled Goby (Coryphopterus glaucofraenum)
Russell P. Dauksis
Major
Marine Biology
Advisor
Dr. Graham Forrester
Advisor Department
Natural Resources Science
Date
5-2012
Keywords
Escapology, marine ecology, functional morphology, animal behavior, predator-prey interactions, Bridled Goby, Coryphopterus glaucofraenum
Abstract
Interactions between predators and prey species are arguably the most pervasive and important events in ecology. Predators have strong effects on the distribution and abundance of prey in virtually all environments. In the long-term, it is therefore hardly surprising that selective mortality imposed by predators has shaped a wide array of prey behaviors that can be viewed as evolved responses to avoid predators.
Although prey exhibit a bewildering diversity of “strategies” to avoid predators, including camouflage, hiding in safe places, confusion, distraction and confrontation, most animals will sometimes simply flee when approached by a potential predator. For fish, the flight response has a stereotypic form, during which escaping fish exhibit a lateral contraction of the body into a “C” (known as a C-start) followed by a contraction of the opposite lateral muscle. Prey fish are commonly assumed to escape from predators with a maximal locomotor effort, but this may not always be the case. The presence of refuges may alter this escape response by allowing for an area of safety in close proximity.
I will study escape responses of the bridled goby, a Caribbean reef fish, in laboratory tanks that are as close to natural as possible. This will create conditions that are ecologically realistic and also allow detailed filming of the escapes. My study will thus be novel in taking an interdisciplinary approach; spanning ecology as well as animal behavior and functional morphology. I will test the hypothesis that reaching a refuge, through more focused directionality towards them, takes priority over maximizing locomotor performance in determining the characteristics of escape responses.
The fleeing of startled bridled gobies will be recorded with high-speed video equipment under the two treatments of refuges absent and refuges present. I will first use a model predator as the stimulus and then use a live predatory fish to make sure that the escape responses of the gobies are the same under both conditions. Model predators have been used successfully in prior experiments, and allow for the direction speed and timing of the predator stimulus to be easily manipulated. Muscle contraction patterns, directionality, acceleration, and velocity will all be analyzed from the video footage acquired from these experiments. It is predicted that the gobies will exhibit a lower energetic investment in escaping when refuges are providing safety.