Cryptic Species in Ecotoxicology.

Area of Science:

• Ecotoxicology
• Evolutionary Ecology
• Conservation Biology

Background:

• Genetic methods reveal numerous cryptic species previously indistinguishable morphologically.
• Cryptic species are rarely considered in ecotoxicology, hindering understanding of ecological differentiation and pollutant sensitivity.
• The use of species with unknown cryptic diversity may cause experimental irreproducibility and false extrapolation of findings.

Purpose of the Study:

• To assess the prevalence of cryptic diversity in species commonly used in ecotoxicological assessments.
• To highlight the implications of cryptic diversity for ecotoxicological testing and environmental risk assessment.
• To provide guidance on incorporating cryptic diversity into ecotoxicological studies and risk assessment procedures.

Main Methods:

• Critical review incorporating database and literature searches.
• Investigation of commonly used ecotoxicological species for evidence of cryptic diversity.
• Analysis of evolutionary histories to understand ecological and sensitivity differences.

Main Results:

• A high proportion of commonly used species, especially invertebrates, exhibit cryptic diversity.
• Cryptic species complexes were found in at least 67% of terrestrial and 54% of aquatic invertebrates.
• Evidence of cryptic diversity was found in 27% of aquatic and 6.7% of terrestrial vertebrates.

Conclusions:

• Cryptic diversity significantly impacts ecotoxicological test results and environmental risk assessments due to varying ecological traits and pollutant sensitivities.
• Failure to account for cryptic species can lead to inaccurate scientific conclusions and flawed regulatory decisions.
• Practical guidelines are needed for integrating cryptic diversity considerations into ecotoxicological research and risk assessment frameworks.