Early environment influences later performance in fishes

Area of Science:

• Developmental Biology
• Ecology
• Evolutionary Biology

Background:

• Early life conditions in fish can have long-lasting effects on morphology, growth, life-history, and behavior.
• Parental and maternal environments significantly influence offspring ecology.
• Phenotypic plasticity in fish is influenced by early developmental stages.

Purpose of the Study:

• To review the ecological influences of early life impacts on teleost species, with a focus on salmonids.
• To summarize how early environmental conditions affect various life-history and behavioral traits.
• To explore potential mechanisms, such as epigenetic changes, underlying these early impacts.

Main Methods:

• Literature review synthesizing existing research on early life impacts in fish.
• Focus on teleost species, particularly salmonids.
• Analysis of factors including thermal regime, early nutrition, and intraspecific density.

Main Results:

• Early influences affect growth, adult body size, sex ratio, egg size, lifespan, and migration tendency.
• Thermal regime during development is a critical factor.
• Early food availability and population density also contribute to life-history variation.
• Behavioral traits are influenced by early sensory and cognitive development, affecting boldness and social behaviors like mate choice.

Conclusions:

• Early life conditions induce significant phenotypic plasticity in fish, with lasting ecological consequences.
• Epigenetic mechanisms are likely central to mediating these environmentally induced changes.
• Future research should address the precise mechanisms and long-term implications of early life impacts on fish populations.