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Updated: Jul 12, 2026
06:36
Incremental Temperature Changes for Maximal Breeding and Spawning in Astyanax mexicanus
Published on: February 14, 2021
Large fish eggs may lose their edge as temperature rises.
Francesca Leggieri1, Oscar Nordahl1, Markus Zöttl1
1Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Department of Biology and Environmental Science, Faculty of Health and Life Sciences, Linnaeus University, Stuvaregatan 4, Kalmar, SE-39231, Sweden.
Oecologia
|July 10, 2026
Summary
Climate change may alter fish reproduction. Rising temperatures reduce the survival advantage of larger fish eggs, favoring smaller eggs and potentially impacting fish populations.
Area of Science:
- Ecology
- Evolutionary Biology
- Climate Change Science
Background:
- Larger fish eggs generally have higher survival rates.
- Rising temperatures may impose oxygen limitations on larger eggs, negating their survival advantage.
- The impact of climate change on optimal egg size and life history trade-offs remains largely unknown.
Purpose of the Study:
- To investigate the effect of temperature on fish egg size and survival.
- To determine if climate change scenarios could alter the optimal egg size for fish species.
- To assess the potential consequences for fish population dynamics and life-history evolution.
Main Methods:
- Observational study of wild Esox lucius (northern pike) egg-laying phenology and female body size in relation to seasonal temperatures.
- Experimental manipulation of water temperatures to assess the survival rates of different-sized eggs.
- Analysis of the relationship between temperature, egg size, and offspring survival.
Main Results:
- Wild Esox lucius females laid smaller eggs later in the season at higher temperatures, correlated with a decline in female body size.
- Larger eggs exhibited higher survival at lower temperatures, but this advantage decreased as temperatures rose.
- The survival advantage of larger eggs was eliminated at approximately 18°C, a temperature projected under climate change scenarios.
Conclusions:
- Optimal egg size in Esox lucius is temperature-dependent.
- Future climate warming may shift reproductive strategies towards smaller, more numerous eggs from smaller females.
- These shifts could significantly influence fish population dynamics and the evolutionary trajectory of life-history traits.
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