Rapid Life-History Diversification of an Introduced Fish Species across a Localized Thermal Gradient

Abstract

Climatic variations are known to engender life-history diversification of species and populations at large spatial scales. However, the extent to which microgeographic variations in climate (e.g., those occurring within a single large ecosystem) can also drive life-history divergence is generally poorly documented. We exploited a spatial gradient in water temperatures at three sites across a large montane lake in southwest China (Lake Erhai) to examine the extent to which life histories of a short-lived fish species (icefish, Neosalanx taihuensis) diversified in response to thermal regime following introduction 25 y prior. In general, warmwater icefish variants grew faster, had larger adult body size and higher condition and fecundity, but matured at smaller sizes. Conversely, coldwater variants had smaller adult body size and lower condition, but matured at larger sizes and had larger eggs. These life-history differences strongly suggest that key ecological trade-offs exist for icefish populations exposed to different thermal regimes, and these trade-offs have driven relatively rapid diversification in the life histories of icefish within Lake Erhai. Results are surprisingly concordant with current knowledge on life-history evolution at macroecological scales, and suggest that improved conservation management might be possible by focusing on patterns operating at microgeographical, including, within-ecosystem scales.

Metabolic theory explains latitudinal variation in common carp populations and predicts responses to climate change

“…Similar to common carp in this study, many other introduced species have been shown to rapidly adapt to localized conditions. For example, modified thermal habitats resulted in amphibian evolution after only 36 years (Skelly and Freidenburg 2000) and icefish Neosalanx taihuensis population characteristics rapidly adapted to thermal regimes less than 25 years following introduction (Zhu et al 2014). Clearly, strong selective pressures can result in rapid adaptation of introduced species and similar processes have likely produced the latitudinal variation in population characteristics of common carp documented in this study.…”

Effects of Temperature and Spatial Scale on Rio Grande Cutthroat Trout Growth and Abundance

“…For example, Zhu et al. () found that Icefish Neosalanx taihuensis within warmer areas of a mountain lake grew faster and were more fecund than individuals of the same species in colder areas of the lake. Therefore, considering fish populations and their environments as spatiotemporally hierarchical, heterogeneous, and dynamic is necessary for effective fisheries management (Schlosser ; Townsend and Hildrew ; Fausch et al.…”

“…Heterogeneity in temperature at finer spatial scales from within (e.g., network position and groundwater upwelling; Torgersen et al 1999;Kanno et al 2014;Snyder et al 2015) to among aquatic environments (e.g., between streams and lakes; Lisi et al 2013) may also generate diversity in phenotypic expression. For example, Zhu et al (2014) found that Icefish Neosalanx taihuensis within warmer areas of a mountain lake grew faster and were more fecund than individuals of the same species in colder areas of the lake. Therefore, considering fish populations and their environments as spatiotemporally hierarchical, heterogeneous, and dynamic is necessary for effective fisheries management (Schlosser 1987;Townsend and Hildrew 1994;Fausch et al 2002;Schindler et al 2010).…”

Species-specific variations in reproductive traits of three yellow catfish species (Pelteobagrus spp.) in relation to habitats in the Three Gorges Reservoir, China

“…The reproductive cycle of fishes primarily rely on temperature and photoperiod [ 16 , 53 ]. Water temperature can significantly affect breeding processes [ 53 , 54 ] and usually exhibits spatial variations within an aquatic ecosystem [ 54 , 55 ]. In the TGR, the water temperature decreases from the lotic to the lentic zones between March and June, indicating that the water temperature is a key cue for the spawning onset of the three species given the similar photoperiod conditions among the three zones at similar latitude.…”

“…Water temperature also affects fecundity and egg size [ 58 , 59 ], and some species of fish tend to exhibit low fecundity in cold environments [ 54 , 60 ]. Our results were inconsistent with those observations, as the highest fecundity was observed in the lotic zone with the lowest water temperature.…”