Effects of Fluctuating Temperatures and Gill Parasites on Reproduction of the Fountain Darter,Etheostoma fonticola

Abstract

We assessed the effects of fluctuating temperature and gill parasitism on egg and larval production of the endangered fountain darter (Etheosfoma fonticola). Fountain darters, with and without the exotic digenetic trematode Cen~rocestrrs formosanus. were exposed in the laboratory to constant (24°C) and fluctuating (24 to 26°C. 26 to 28°C. and 28 to 30°C) water temperatures for 2 1 d. No differences were detected between the number of eggs produced (P = 0.78) or number of larvae produced (P = 0.1 1) between fountain darters with and without trematodes. Total egg production was greatest at 24°C and decreased (P < 0.05) by 42% at fluctuating temperature of 24 to 26°C. 65% at fluctuating temperature of 26 to 28°C. and 99.6% at fluctuating temperature of 28 to 30°C. Likewise, larval production was greatest at 24°C and decreased (P < 0.05) by 63% at 24 to 26°C 99.9% at 26 to 28°C. and 100% at 28 to 30°C. Water temperature (24 to 26°C) that fluctuated within previously considered optimum temperature (< 27°C) reduced the number of eggs and larvae produced by the fountain darter. Results of this study refined maximum optimum temperature requirements of the fountain darter reproduction with water temperatures 2 26°C reducing egg production and water temperatures 2 25°C reducing larval production.

Long‐term changes in flow regime and fish assemblage composition in the guadalupe and san marcos rivers of texas

“…Stenothermal artesian springs throughout the basin provide refugia for a number of non‐native taxa introduced by illegal dumping of ornamental organisms and by other means, including a parasitic trematode (Mitchell et al ., 2005), molluscs (Karatayev et al ., 2009) and fishes (Thomas et al ., 2007). Potential effects of introduced organisms on aquatic systems and fishes within the basin only recently have been explored (McDonald et al ., 2006, 2007; Cohen, 2008; Pray, 2009; Scott, 2009). Collectively, water quality and introduced taxa have caused localized problems within the basin, and their contribution to fish assemblage changes through time cannot be easily separated from flow modifications.…”

Stream and Retention Pond Thermal Response to Heated Summer Runoff From Urban Impervious Surfaces1

“…, 2007). Rapid changes of temperature can be stressful to organisms (McDonald et al. , 2007), inducing loss of coordination (Aslanidi et al.…”

Temperature-mediated feeding between spring-associated and riverine-associated congeners, with implications for community segregation

“…Similar to altitudinal gradients (Taniguchi et al, 1998; Taniguchi & Nakano, 2000), water temperature is a suggested mechanism in regulating richness, abundances, and densities of spring-associated fishes and riverine-associated fishes (Hubbs, 1995; Kollaus & Bonner, 2012) with spring-associated fishes being potentially more fit in stenothermal habitats and riverine-associated fishes being potentially more fit in eurythermal habitats. Dissimilar to altitudinal gradients, spring-associated fishes and riverine-associated fishes do not represent previously researched cold-water and warm-water forms with overlapping tolerances, but both are warm-water forms having similar temperature tolerances (Hagen, 1964; Brandt et al, 1993), and similar reproductive tolerances (Bonner et al, 1998; McDonald et al, 2007). In marine systems, species in stenothermal habitats might select away from eurythermal enzymes and proteins (Graves & Somero, 1982) and select for proteins and enzymes that are more energy efficient within a narrow range of temperatures (Pörtner, Peck & Somero, 2007), whereas species in eurythermal habitats are suggested to conserve temperature-dependent enzymes and proteins that enable tolerance of wide-ranging water temperatures (Somero, Dahlhoff & Lin, 1996).…”