L.M.Whitehouse Science Reviews - Biology, 2024, 3(4), 24-30

The effect of thermal stress on fish development: a

mini-review

L.M.Whitehouse PhD, Independent Researcher, France

ORCID: https://orcid.org/0000-0001-5385-7591

Scopus: https://www.scopus.com/authid/detail.uri?authorId=57195605595

DOI: https://doi.org/10.57098/SciRevs.Biology.3.4.3

Received October 18, 2024. Revised November 05, 2024. Accepted November 08, 2024.

Abstract: Projected temperature increases are predicted to significantly affect fish populations globally,

impacting fish recruitment processes and altering population distribution. Fish embryos are perhaps at the most

risk from temperature changes due to their sessile nature and overall sensitivity to temperature changes which

could impact how well a fish population performs in a changing world. Research has shown that temperature

can alter developmental trajectories, induce damage and abnormalities, increase development, and early

hatching, and reduce survival. Other studies have shown that exposure to thermal stress can prime stress

responses and result in changes in metabolic enzyme activity that persists post-hatch. Moreover, exposure to

fluctuating temperature, which most closely mimics natural environments, can have a protective effect,

increasing thermotolerance and survival while appearing to have no impact on developmental processes or

hatching rate. Understanding how these early life stages respond to thermal stress and fluctuations is important

for predicting how fish populations will respond to climate change.

Keywords: Fish, embryos, thermal stress, fluctuating temperatures, development, physiology

Introduction

Climate change is leading to an increase in global

water temperatures which is having a significant im-

pact on fish populations (Pörtner and Peck, 2010). As

ectotherms, fish are particularly vulnerable to temper-

ature changes; the ambient environmental tempera-

ture determines their body temperature (Jeyachandran

et al., 2023). As a result, rising water temperatures are

influencing the abundance and distribution of fish spe-

cies globally, and having a significant impact on the aq-

uaculture industry (Islam et al., 2022; Stuart-Smith,

2021).

Embryonic and larval stages are more sensitive

to temperature changes than juveniles and adults

(Rombough, 1997), since warming temperatures im-

pact fish development by changing the timing of em-

bryonic development and the formation and function

of key tissues and structures (Koumoundouros et al.,

1999). An increase in the temperature of the develop-

mental environment accelerates developmental pro-

cesses which can result in early hatching and mismatch

with environmental conditions for feeding. Moreover,

changes in developmental processes can result in

abnormalities that negatively impact the fish’s chance

of survival (Pepin, 1991).

This short review will assess what we know

about the impact of temperature on fish develop-

ment. An understanding of how temperature im-

pacts fish development is crucial to developing

management practices and conservation efforts for

fish species considering increasing global tempera-

tures.

Embryological development

Fish embryonic development is complex and

varies from species to species. Some species lay eggs

on the bottom of a river, lake or close to shore, some

make nests, and for some fish, their eggs are sus-

pended in open water (Bessa et al., 2022; Prichard et

al., 2017; Yohannan, 1998). Eggs that are produced

by warm water fish often have a short developmen-

tal time, whereas eggs produced by fish that live in

cool waters can take months to develop. These eggs

laid in cool waters are often deposited under the

cover of ice and then hatch in the spring (Kar-

jalainen et al., 2015). These differences mean that