Linking Cranial Kinematics, Buccal Pressure, and Suction Feeding Performance in Largemouth Bass

Abstract

The rate and magnitude of buccal expansion are thought to determine the pattern of water flow and the change in buccal pressure during suction feeding. Feeding events that generate higher flow rates should induce stronger suction pressure and allow predators to draw prey from further away. We tested these expectations by measuring the effects of prey capture kinematics on suction pressure and the effects of the latter on the distance from which prey were drawn-termed suction distance. We simultaneously, but not synchronously, recorded 500-Hz video and buccal pressure from 199 sequences of four largemouth bass, Micropterus salmoides, feeding on goldfish. From the video, we quantified several kinematic variables associated with the head and jaws of the feeding bass that were hypothesized to affect pressure. In a multiple regression, kinematic data accounted for 79.7% of the variation among strikes in minimum pressure. Faster mouth opening and hyoid depression were correlated with lower pressures, a larger area under the pressure curve, and a faster rate of pressure reduction. In contrast, buccal pressure variables explained only 16.5% of the variation in suction distance, and no single pressure variable had a significant relationship with suction distance. Thus, although expected relationships between head kinematics and buccal pressure were confirmed, suction distance was only weakly related to buccal pressure. Three explanations are considered. First, bass may not attempt to maximize the distance from which prey are drawn. Second, the response of prey items to suction-induced flow depends on prey behavior and orientation and is, therefore, subject to considerable variation. Third, previous theoretical work indicates that water velocity decays exponentially with distance from the predator's mouth, indicating that variation among strikes in flow at the mouth opening is compressed away from the mouth. These findings are consistent with other recent data and suggest that suction distance is a poor metric of suction feeding performance.

The benefits of planar circular mouths on suction feeding performance

“…This suction profile is shown in figure 2 and peaks at 10 ms. This is representative of suction pressures found in other experiments [22,23]. The time step for these calculations is 0.01333 ms.…”

Comparative feeding kinematics and performance of odontocetes: belugas, Pacific white-sided dolphins and long-finned pilot whales

“…Beluga feeding behavior may not always have a suction component, as indicated by the presence of pure ram feeding trials; ram feeding was also supported by RSI. However, suction is effective over limited distances (Svanback et al, 2002;Wainwright and Day, 2007), which results in prey movement due to suction that is limited and less variable . Kinematic analyses confirmed that the highest velocity prey movements were observed after belugas slowed forward velocity to near zero.…”

Sound production in the longnose butterflyfishes (genusForcipiger): cranial kinematics, muscle activity and honest signals

“…Cranial elevation is a major component of stereotyped prey capture in teleost fish feeding, occurs in taxa that span the ram-suction feeding continuum and involves a series of movement of cranial elements in order to lower the hyoid and expand the buccal cavity (Gibb and Ferry-Graham, 2005). The rapid cranial elevation velocities and accelerations seen during sound production rival and exceed (>2ϫ) those reported from feeding studies of voracious predators such as largemouth bass (Micropterus salmoides) (Svanbäck et al, 2002). Based on maximum cranial elevation displacement and time to maximum cranial elevation data from several fish families (Gibb and FerryGraham, 2005), cranial elevation during forcepsfish sound production is faster than most feeding strikes from all but zebrafish (Danio rerio) and bay pipefish (Syngnathus leptorhynchus).…”

“…Members of the seahorse and pipefish family Syngnathidae, however, produce cranial elevations during feeding that far exceed those measured during sound production in Forcipiger (Van Wassenbergh et al, 2008;Flammang et al, 2009;Roos et al, 2009). The relationship between suction feeding in fishes such as largemouth bass may be explained by both cranial kinematics (Svanbäck et al, 2002) and motor patterns of associated muscles (Grubrich and Wainwright, 1997). Thus the muscle activity patterns associated with kinematics observed during sound production may predict variation in acoustic signals in some fishes.…”