Flowing water affects fish fast-starts: escape performance of the Hawaiian stream goby,Sicyopterus stimpsoni

Abstract

Experimental measurements of escape performance in fishes have typically been conducted in still water; however, many fishes inhabit environments with flow that could impact escape behavior. We examined the influences of flow and predator attack direction on the escape behavior of fish, using juveniles of the amphidromous Hawaiian goby Sicyopterus stimpsoni. In nature, these fish must escape ambush predation while moving through streams with high-velocity flow. We measured the escape performance of juvenile gobies while exposing them to a range of water velocities encountered in natural streams and stimulating fish from three different directions. Frequency of response across treatments indicated strong effects of flow conditions and attack direction. Juvenile S. stimpsoni had uniformly high response rates for attacks from a caudal direction (opposite flow); however, response rates for attacks from a cranial direction (matching flow) decreased dramatically as flow speed increased. Mechanical stimuli produced by predators attacking in the same direction as flow might be masked by the flow environment, impairing the ability of prey to detect attacks. Thus, the likelihood of successful escape performance in fishes can depend critically on environmental context.

Intra‐ and inter‐specific morphological diversity of amphidromous gobies influences waterfall‐climbing performance

“…This study was the first step to understand the relationship between morphology and performance for the waterfall‐climbing function of these two sympatric sicydiine species. However, in natural conditions, additional selective pressures such as predation (Blob et al ., ; Maie et al ., ; Diamond et al ., ) may also affect morphological selection, especially in rivers where the first waterfall is located farther inland. A more comprehensive evaluation of the factors influencing individual fitness in these species will, therefore, require field verification of the relationship between the anatomical variables highlighted experimentally during this study, across climbing and other functional demands.…”

Functional correlations of axial muscle fiber type proportions in the waterfall‐climbing Hawaiian stream fish Sicyopterus stimpsoni

“…This disparity in fiber type proportions between fish from these two islands could reflect differences in the primary functional demands faced by fish on these islands. With longer stream reaches before waterfalls on Kaua'i, gobies on this island may need to engage more frequently in fast-start escape responses from predators than fish from (awai'i (Blob et al 2010;Maie et al 2014;Diamond et al 2016Diamond et al , 2019, potentially making a relatively greater proportion of white, fast-twitch muscle fibers in the tail advantageous (Jayne & Lauder, 1993). However, it is noteworthy that even fish from This article is protected by copyright.…”

Effects of wave-driven water flow on the fast-start escape response of juvenile coral reef damselfishes

“…Recent studies have examined the effect of temperature, dissolved oxygen, turbidity, light and pH on fish escape performance (reviewed in Domenici et al, 2007;Wilson et al, 2010). However, the importance of water motion has been largely overlooked (Higham et al, 2015; but see Anwar et al, 2016;Diamond et al, 2016) . This oversight is surprising given that water flow is a ubiquitous and highly variable physical property of aquatic ecosystems (Denny, 1988;Webb et al, 2010).…”