Chapter 16: Behavior
Julianna P. Kadar, Catarina Vila Pouca, Robert Perryman, Joni Pini-Fitzsimmons, Sherrie Chambers, Connor Gervais, and Culum Brown
Kadar, J. P., C. V. Pouca, R. Perryman, J. Pini-Fitzsimmons, S. Chambers, C. Gervais, and C. Brown. 2022. Pages 593–642 in S. Midway, C. Hasler, and P. Chakrabarty, editors. Methods for fish biology, 2nd edition. American Fisheries Society, Bethesda, Maryland.
Humans interact with fish in a wide variety of contexts. Fish are rapidly becoming the go-to model for medical research because of the conservative nature of vertebrate physiology. We catch and grow fish in captivity for human consumption and frequently rear fish for release into the wild either to supplement wild populations to enhance fisheries or as a conservation measure. In all cases, understanding fish behavior is vital whether you are interested in stock management, conservation biology, or animal welfare (Brown 2015).
Gone are the days when fish were viewed as mindless automata. We now know that fish behavior is highly flexible, providing the plasticity to allow individuals to adjust to prevailing conditions or contexts (Bshary and Brown 2014). Their level of cognitive and behavioral sophistication is on par with the rest of the vertebrates (Bshary and Schäffer 2002; Vila Pouca and Brown 2018a; 2018b). Unsurprisingly, a change in behavior is often the first sign that something has shifted in the environment; thus, behavioral studies are at the forefront of environmental and ecotoxicological research (Brown 2012; Oulton et al. 2014). The massive diversity of fishes (currently more than 32,000 described species), and the range of niches they occupy, means that generalization is nearly impossible. Thankfully, the approaches for studying fish behavior are also many and varied and rapidly developing with changes in technology.
Here we provide a brief overview of some of the emerging methods for studying fish behavior. We will not be reviewing fish behavior in general since this is the topic of multiple books (e.g., Magnhagen et al. 2008; Brown et al. 2011), nor will we be providing a general overview of how to study animal behavior. Such details can readily be found in any of the many excellent texts on animal behavior or behavioral ecology (Davies 1991; Dugatkin and Earley 2004; Alcock 2005; Goodenough et al. 2009). Many people study fish behavior under captive conditions where it is possible to control the environment and observe behaviors that can be attributed to specific cognitive processes. In most instances, it is simply a matter of refining the standard methods to suit the aquatic environment and the species of interest. The main difficulties of studying fish behavior arise when trying to observe them in their natural environment. The underwater world is not a place with which most people are comfortable or familiar. Humans can stay only so long in the watery world of fishes, so many of the methods we describe here attempt to overcome these problems by studying fish behavior remotely.