Counting Enchytraeus crypticus Juveniles in Chronic Exposures: An Alternative Method for Ecotoxicity Studies Using Tropical Artificial Soil

Author(s)

Felipe, Mayara C. ^[1] ; Bernegossi, Aline C. ^[2] ; Pinheiro, Fernanda R. ^[2] ; Castro, Gleyson B. ^[2] ; Moura, Lidia ^[2] ; Zaiat, Marcelo ^[1] ; Corbi, Juliano J. ^[2]

Affiliation

^[1] Univ Sao Paulo, Biol Proc Lab LPB, Dept Hydraul & Sanitat, Sao Carlos Sch Engn EESC, Ave Joao Dagnone 1100, Santa Angelina, SC - Brazil

^[2] Univ Sao Paulo, Sao Carlos Sch Engn EESC, Dept Hydraul & Sanitat, Aquat Ecol Lab LEAA, Ave Joao Dagnone 1100, Santa Angelina, SC - Brazil

• Document type: Journal article
• Source: Bulletin of Environmental Contamination and Toxicology; v. 107, n. 3 JUL 2021.
• Web of Science Citations: 0

Abstract

Soil toxicity tests are commonly applied using Enchytraeus crypticus to analyze reproductive outputs. However, the traditional method for counting potworms takes a long time due to the significant number of offspring. This paper compares the conventional total counting of E. crypticus juveniles (M1) and an alternative methodology (M2). The proposed methodology (M2) uses a simple random counting method (1/4) for the partial counting of juveniles and total estimation. Chronic bioassays (21 days of exposure) were performed in tropical artificial soil (TAS) using sugarcane vinasse as a hazardous substance. Comparing the final density of juveniles recorded in M1 and M2, no statistical differences were pointed out in either one. Applying analyses based on effective concentration (EC10 and EC50), no statistical differences were identified there either. The t-test showed that there was no statistical difference between the counting methods (M1 and M2) in each treatment (control and dilutions). Moreover, we ran the Tukey test for M1 and M2 methods separately and observed that 100 % of the vinasse showed a statistical difference compared to the control treatment in both (p <= 0.05), affirming that independent of the counting method, the ecotoxicological outputs were similar. Therefore, the proposed alternative is a suitable method for bioassay using. E. crypticus in tropical artificial soil, decreasing to 1/4 the total time required for counting. (AU)

• FAPESP's process: 15/06246-7 - Biorefinery concept applied to biological wastewater treatment plants: environmental pollution control coupled with material and energy recovery
• Grantee: Marcelo Zaiat
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 18/21901-0 - Environmental impact assessment of vinasse biodigested in anaerobic bioreactor using ecotoxicology assays
• Grantee: Mayara Caroline Felipe
• Support Opportunities: Scholarships in Brazil - Post-Doctoral