Possible Role of the Posterior Lateral Line in Obstacle Entrainment by Brook Trout (Salvelinus fontinalis)

Abstract

Observations of position holding by brook trout (Salvelinus fontinalis) in a stream channel indicate that they choose specific locations probably related to flow patterns around bottom obstructions. Bilateral denervation of the posterior lateral line system of trout has no effect on their ability to entrain on objects placed in flowing water, providing sufficient visual cues are available. Unilateral ablation resulted in a lateral bias in swimming position relative to the flow obstruction even when visual cues were present. Bilateral denervation of the posterior line system reduced the degree to which trout could entrain on objects when visual cues were omitted. It is suggested that in stream-dwelling fish, such as the brook trout, the lateral line may serve as a detector of flow or pressure discontinuities, enabling the fish to maintain position with minimum expenditure of energy.

The spatiotemporal dynamics of rheotactic behavior depends on flow speed and available sensory information

“…In this study, fish with vision were able to maintain their streamwise position for up to 3min (maximum test period) at different locations along the upstream/downstream axis of the tank (red functions in Fig.9E) and without reference to any upstream bluff body, as previously reported for obstacle-entrainment behaviors (Sutterlin and Waddy, 1975;Montgomery et al, 2003;Liao et al, 2003;Przybilla et al, 2010). Visual, tactile and/or lateral line senses can all theoretically inform fish about their body position with respect to some external spatial reference.…”

“…Thus, when deprived of visual cues, midwater fish may need to alter their behavior so that they are periodically in contact with the substrate to provide a (tactile) external frame of reference, as suggested previously (Lyon, 1904;Baker and Montgomery, 1999a). The effect of these fundamental differences in sensory input on behavioral output remains largely undocumented, except in the context of obstacle entrainment behaviors (Sutterlin and Waddy, 1975;Liao et al, 2003;Montgomery et al, 2003;Przybilla et al, 2010), which have a rheotactic component.…”

Fish navigation of large dams emerges from their modulation of flow field experience

“…Inverting responses within the behavioral repertoire, B{1-3}, would appear to orient a fish toward the river's edge (e.g., shoreline, riverbed, water surface), obstacles, and shallow water habitat across a broad range of ecogeomorphic contexts. In these locations, energetic costs of upstream movement and holding position are reduced (53-57) and fish often feed (58) and seek refuge (59,60). By cueing on acceleration phenomena and their duration at multiple scales, fish could be sensitive to analogous phenomena implicated in sediment motion (61) that elicit invertebrate drift.…”

Rainbow trout consume less oxygen in turbulence: the energetics of swimming behaviors at different speeds

“…Studies from both laboratory and field demonstrate that altered flows created by bluff bodies in moving water can be exploited by fishes to enhance swimming performance (Beal et al, 2006;Breder, 1965;Hinch and Rand, 2000;Liao et al, 2003b;Streitlien and Triantafyllou, 1996). In particular, flow past a cylinder creates hydrodynamic microhabitats that are attractive to fish and that do not exist in free stream flow (Liao, 2007;Sutterlin and Waddy, 1975;Webb, 1998). On the upstream side of a cylinder a high-pressure bow wake develops whereby the flow velocity is reduced relative to the free stream (Blevins, 1990;Liao et al, 2003a).…”