Aquatic prey capture in ray‐finned fishes: A century of progress and new directions

Abstract

The head of ray-finned fishes is structurally complex and is composed of numerous bony, muscular, and ligamentous elements capable of intricate movement. Nearly two centuries of research have been devoted to understanding the function of this cranial musculoskeletal system during prey capture in the dense and viscous aquatic medium. Most fishes generate some amount of inertial suction to capture prey in water. In this overview we trace the history of functional morphological analyses of suction feeding in ray-finned fishes, with a particular focus on the mechanisms by which suction is generated, and present new data using a novel flow imaging technique that enables quantification of the water flow field into the mouth. We begin with a brief overview of studies of cranial anatomy and then summarize progress on understanding function as new information was brought to light by the application of various forms of technology, including high-speed cinematography and video, pressure, impedance, and bone strain measurement. We also provide data from a new technique, digital particle image velocimetry (DPIV) that allows us to quantify patterns of flow into the mouth. We believe that there are three general areas in which future progress needs to occur. First, quantitative three-dimensional studies of buccal and opercular cavity dimensions during prey capture are needed; sonomicrometry and endoscopy are techniques likely to yield these data. Second, a thorough quantitative analysis of the flow field into the mouth during prey capture is necessary to understand the effect of head movement on water in the vicinity of the prey; three-dimensional DPIV analyses will help to provide these data. Third, a more precise understanding of the fitness effects of structural and functional variables in the head coupled with rigorous statistical analyses will allow us to better understand the evolutionary consequences of intra- and interspecific variation in cranial morphology and function.

Kinematics of suction feeding in the seahorseHippocampus reidi

“…This strongly differs from the situation with other suction-feeding fish, where neurocranial elevation and hyoid depression typically coincide with the major volume increase of the head (e.g. Ferry-Graham and Lauder, 2001). When maximal cranial rotation is reached (black line, T 1 , in Figs4, 6, 7 and 8), there is no additional ventral expansion anymore (Fig.7, upper panel).…”

“…Feeding by means of suction is common in aquatic vertebrates such as teleost fish (Muller and Osse, 1984;Ferry-Graham and Lauder, 2001;Gibb and Ferry-Graham, 2005) and elasmobranchs (Wilga et al, 2007). This feeding mode consists of a rapid and coordinated expansion of the buccal cavity in order to generate a flow of water from the environment in front of the fish's head towards and into the mouth opening (Lauder, 1985).…”

Sensing the strike of a predator fish depends on the specific gravity of a prey fish

“…A broad diversity of fish prey on smaller fish using suction feeding (Lauder, 1980;Ferry-Graham and Lauder, 2001;Juanes et al, 2002). The flow created by a feeding strike can be detected by the lateral line system of the prey to trigger an evasive escape response (Eaton et al, 1977;McHenry et al, 2009).…”

Coordination of feeding, locomotor and visual systems in parrotfishes(Teleostei: Labridae)

“…Recent studies of skull mechanics have revealed the biomechanical basis of suction feeding (e.g. Ferry-Graham and Lauder, 2001;Grubich, 2001;Svanbäck et al, 2002;Waltzek and Wainwright, 2003;Carroll, 2004), biting behaviors (Alfaro and Westneat, 1999; and differences between these feeding modes (Alfaro et al, 2001). Similarly, research on the morphology and kinematics of fin-based swimming has resolved many of the questions of pectoral fin propulsion in fishes (Westneat, 1996;Walker and Westneat, 1997Westneat and Walker, 1997;Walker, 1998;Lauder, 2002, 2003;Lauder and Drucker, 2002;Thorsen and Westneat, 2005).…”