Species‐specific effects of subdaily temperature fluctuations on consumption, growth and stress responses in two physiologically similar fish species

Abstract

Fluctuations in water temperature can have important physiological consequences for fishes. Effects of daily thermal cycles are well studied and can be beneficial, increasing prey consumption and growth rates when mean and maximum temperatures of the fluctuations are at or below the species' optimum temperature. While less studied, subdaily temperature fluctuations are also common in many aquatic habitats and can be caused by both natural and anthropogenic processes. We performed laboratory experiments to examine how two fish species (yellow perch, Perca flavescens, and walleye, Sander vitreus) with similar thermal preferences respond to chronic exposure to subdaily temperature variability. We selected temperature treatments that reflected observed thermal variation after examining water temperature data from multiple aquatic systems. We then separately exposed yellow perch and walleye to a stable 23°C treatment and 12-h cycles of 23 AE 2°C or 23 AE 4°C for 45 days. Adult yellow perch exposed to fluctuations of 23 AE 4°C over 12 h expressed higher consumption, growth and food conversion efficiency than fish experiencing stable 23°C. Temperature fluctuations, though, resulted in mortalities and the development of skin ulcers in yellow perch that did not occur under stable temperatures. In contrast, the same 12-h temperature fluctuations did not result in mortalities or stress responses in juvenile walleye. Moreover, unlike yellow perch, growth rates of walleye were lower under 12-h temperature fluctuations compared with the stable 23°C treatment. Our results indicate that species with similar thermal preferences can respond differently to the same subdaily temperature fluctuations.

Plastic responses to diel thermal variation in juvenile green sturgeon, Acipenser medirostris

“…Although thermal variation is theorised to raise metabolic demands at the cost of growth gains (Ruel and Ayres, 1999), growth rates were accelerated under widely variable conditions, and remained unchanged under narrowly variable conditions (rejecting P 2 ). Similar responses have been observed in yellow perch (Perca flavescens), where exposure to a high magnitude of daily thermal variation (23 ± 4°C) significantly increased growth rates compared to a static temperature (23°C) but growth rates remained unchanged in fish exposed to a small magnitude of thermal variation (23 ± 2°C) (Coulter et al, 2016). Growth gains observed in P. flavescens were linked to increased feeding rates and food conversion efficiency (Coulter et al, 2016).…”

“…Depressed growth rates have been observed in a wide range of fishes exposed to daily thermal variation including: walleye (Sander vitreus; Coulter et al, 2016), brown trout (Salmo trutta; Spigarelli et al, 1982), Japanese medaka (Oryzias latipes; Dhillon and Fox, 2007) and zebrafish (Danio rerio;Schaefer and Ryan, 2006). Daily thermal variation has also been seen to induce sex reversal in fathead minnows (Pimephales promelas), cause skin ulcers in yellow perch (Perca flavescens) and increase disease susceptibility in an aquatic invertebrate (Ben-Horin et al, 2013;Coulter et al, 2015Coulter et al, , 2016. Exposure to high magnitudes of daily thermal variability can also directly affect fish fitness by lowering egg production and fertilisation rates, and increasing mortality rates (Coulter et al, 2016;Podrabsky et al, 2008).…”

“…Daily thermal variation has also been seen to induce sex reversal in fathead minnows (Pimephales promelas), cause skin ulcers in yellow perch (Perca flavescens) and increase disease susceptibility in an aquatic invertebrate (Ben-Horin et al, 2013;Coulter et al, 2015Coulter et al, , 2016. Exposure to high magnitudes of daily thermal variability can also directly affect fish fitness by lowering egg production and fertilisation rates, and increasing mortality rates (Coulter et al, 2016;Podrabsky et al, 2008).…”

A comparison of temperature regimes in dry-season waterholes in the Flinders and Gilbert catchments in northern Australia

“…For example, growth and development rates in fish increase with temperature up to an optimum, provided food or other factors are not limiting (McCauley and Casselman 1981;Elliott and Hurley 1997;Coulter et al 2016). Hence many species of fish have a preference for water temperatures close to their temperature optimum for growth, T pref (Elliott 2000; Pusey and Arthington Vic.…”

Modelling the possible impacts of climate change on the thermal regime and macroinvertebrate species of a regulated prairie river

“…The thermal regime is a key consideration for instream flow management (Olden & Naiman, 2010) as the ecological integrity of river ecosystems is dependent on the natural dynamics of temperature range and spatiotemporal characteristics. For example, temperature is known to determine physiology and metabolic rates of organisms (Catenazzi & Kupferberg, 2018;Tao, Kennard, Jia, & Chen, 2018), fecundity (Farrell, 2009), recruitment and mortality (Catenazzi & Kupferberg, 2018;Coulter, Sepúlveda, Troy, & Höök, 2016;Gaufin & Hern, 1971), and influence species distribution (Howell, 2017;Mee, Robins, & Post, 2016). Regulated rivers around the world generally exhibit altered temperature magnitudes, rates of change, and timing characteristics (Cai et al, 2018;Casado, Hannah, Peiry, & Campo, 2013) compared with preregulation conditions (Maheu et al, 2016).…”