Protecting vulnerable individuals in a population: is the avoidance response of juvenile soil invertebrates more sensitive than the adults response?

• Published in: Chemosphere (Oxford) Vol. 220; pp. 658 - 667
• Main Authors: Gainer, Amy, Akre, Robyn, Owojori, Olugbenga J., Siciliano, Steven D.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.04.2019
• Subjects: Behavioral toxicology; Heavy metals; Polycyclic aromatic hydrocarbons; Salts; Soil invertebrates; Soil invertebrates; Behavioral toxicology; Salts; Polycyclic aromatic hydrocarbons; Heavy metals
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2018.12.113

Juveniles are generally considered more sensitive to contaminants than adults. However, it is unknown if the behavioral responses of juvenile soil invertebrates is different than the adults. The absence of juvenile or adult soil invertebrates in contaminated soils due to avoidance adversely impacts the soil quality. Here, we assessed the avoidance response in two life stages (juvenile and adult) of three standardized soil toxicity test invertebrates (Folsomia candida, Enchytraeus crypticus and Eisenia fetida) exposed to phenanthrene, copper and sodium chloride contaminated soil. Interestingly, we found the juvenile's avoidance response could be more sensitive, less sensitive and the same as the adult's avoidance response, depending on the contaminant and test species. The juvenile avoidance response of E. fetida to sodium chloride, and E. crypticus and E. fetida to copper was more sensitive than the adult's response. In contrast, the avoidance response of juvenile F. candida to sodium chloride was less sensitive than the adult's response. No life stage differences were observed in the avoidance response of E. crypticus individuals exposed to sodium chloride, F. candida individuals exposed to copper and E. fetida individuals exposed to phenanthrene. Although life stage differences in avoidance responses were evident for some species and contaminants, it was not consistent. In terms of avoidance, the assumptions that juveniles are the most sensitive individuals in a population is not always true. [Display omitted] •Juveniles of the 3 test species were not consistently more sensitive than adults.•Adult and juveniles of some species displayed non avoidance to phenanthrene.•Adult and juveniles of the 3 test species consistently avoided sodium chloride.•Adult and juveniles of the 3 test species consistently avoided copper sulfate.•Sodium chloride is an ideal avoidance test reference toxicant.