Rheotaxis revisited: a multi-behavioral and multisensory perspective on how fish orient to flow

Abstract

Here, we review fish rheotaxis (orientation to flow) with the goal of placing it within a larger behavioral and multisensory context. Rheotaxis is a flexible behavior that is used by fish in a variety of circumstances: to search for upstream sources of current-borne odors, to intercept invertebrate drift and, in general, to conserve energy while preventing downstream displacement. Sensory information available for rheotaxis includes water-motion cues to the lateral line and body-motion cues to visual, vestibular or tactile senses when fish are swept downstream. Although rheotaxis can be mediated by a single sense, each sense has its own limitations. For example, lateral line cues are limited by the spatial characteristics of flow, visual cues by water visibility, and vestibular and other body-motion cues by the ability of fish to withstand downstream displacement. The ability of multiple senses to compensate for any single-sense limitation enables rheotaxis to persist over a wide range of sensory and flow conditions. Here, we propose a mechanism of rheotaxis that can be activated in parallel by one or more senses; a major component of this mechanism is directional selectivity of central neurons to broad patterns of water and/or body motions. A review of central mechanisms for vertebrate orienting behaviors and optomotor reflexes reveals several motorsensory integration sites in the CNS that could be involved in rheotaxis. As such, rheotaxis provides an excellent opportunity for understanding the multisensory control of a simple vertebrate behavior and how a simple motor act is integrated with others to form complex behaviors.

Detecting Novel Ototoxins and Potentiation of Ototoxicity by Disease Settings

“…Therefore, an animal can have few lateral line hair cells and still show a robust acoustic startle response. Similarly, rheotaxis depends on multiple sensory systems, including vision and tactile responses ( 140 ). Conducting rheotaxis assays under far red light greatly reduces the visual component of the response but somatosensory cues are still present ( 135 ).…”

Hydrodynamic model of fish orientation in a channel Flow

“…The model is successful in predicting the emergence of rheotaxis in the absence of sensory information from the lateral line and visual cues (see Finally, the model anticipates the onset of periodic cross-stream sweeping, which has been studied in some experiments on fish swimming in channels without vision (Coombs et al, 2020).…”

“…Likewise, the current model does not describe contact and impact with the walls of the channel, which could be important in further detailing the onset of cross-sweeping motions that could involve stick-and-slip at the bottom of the channel (Van Trump and McHenry, 2013). The model could also be expanded to account for additional sensory modalities, such as vision, vestibular system, and tactile sensors on the fish body surface; however, any of these extension shall require detailed experiments to tease out the contribution of each of these sensory modalities (Coombs et al, 2020).…”

Development of behavioral rules for upstream orientation of fish in confined space

“…Setup 1 exhibited seven parameters of strong influence (μ � /μ � max > 0.6, Table 2), while setup 2 exhibited four parameters of strong influence. The lowest ranks (17)(18)(19) in Table 2) comprised three parameters of negligible influence in both setups (μ � /μ � max � 0.1). There was no first-order (independent) parameter (indicated by a high μ � and low σ M value).…”

“…The most widely used stimulus in fish orientation IBMs, regardless of whether the model considers upstream or downstream fish migration, is velocity direction [8,[11][12][13][14]. It is a fundamental stimulus, as it informs positive and negative rheotaxis, which are crucial for guiding upstream and downstream navigation, respectively [15][16][17]. Velocity magnitude is also commonly considered [8,[10][11][12][13][14] and especially important for upstream migration, since the energy demand for swimming against the flow is proportional to the cube of relative fish velocity [18].…”