Survival analysis of African catfish and Nile tilapia briefly exposed to complex pesticide mixtures

Abstract

Background Pulse exposures are the consequences of the intermittent release of pollutants in the environment. Brief exposure of aquatic organisms to high concentrations of pesticides simultaneously occurs, particularly in small watercourses during high flows. The effects of pulse exposure often include effects occurring during and after the exposure. Despite this, routine toxicity tests procedures often ignore brief exposure scenarios and the role of time in toxicity. We conducted a pulse toxicity test by briefly exposing African catfish and Nile tilapia fingerlings to pesticide mixtures of atrazine, mancozeb, chlorpyrifos, and lambda-cyhalothrin. The study aimed to estimate pesticide mixture interaction in pulse-exposed fish and elucidate the influence of species differences on the response of fish to the pesticide mixture. Results Despite the similarity in fingerlings weight, African catfish had a significantly higher survival probability than Nile tilapia after exposure to atrazine-mancozeb mixture. However, the survival probability of African catfish and Nile tilapia fingerlings were similar after exposure to atrazine-chlorpyrifos, atrazine-lambda cyhalothrin, mancozeb-chlorpyrifos, mancozeb-lambda cyhalothrin, chlorpyrifos-lambda cyhalothrin, and quaternary mixture (p > 0.05). The survival probability of exposed fingerlings was significantly lower for continuous than pulse exposure to the mixtures (p < 0.01). Nevertheless, the survival probability of 60 min of pulse exposure to 13.49 mg/L mancozeb-lambda cyhalothrin was similar to continuous exposure for 96 h. Atrazine-mancozeb, atrazine-chlorpyrifos, atrazine-lambda cyhalothrin, mancozeb-chlorpyrifos, mancozeb-lambda cyhalothrin, and the quaternary pesticide mixture were antagonists in African catfish but not in Nile tilapia. At the same time, chlorpyrifos-lambda-cyhalothrin was antagonistic in Nile tilapia but not African catfish. Conclusions Pesticide mixture interaction was antagonist but specie-dependent. Innate intrinsic and extrinsic deterministic factors and, to a limited extent, stochastic processes may have influenced the survival probability of African catfish, and Nile tilapia pulsed exposed to complex pesticide mixtures. Pulse toxicity assessment using survival analysis is relevant in ecotoxicology as it enables the study of factors that can influence pulse toxicity.

Chicken Eggshell as an Innovative Bioflocculant in Harvesting Biofloc for Aquaculture Wastewater Treatment

“…2, a significant maximum bioflocs growth and surplus likely occurred on Day 21. Since the catfish was more endurance than the tilapia, this statement was in line with the research by Kanu et al [29], which found that catfish had a significantly higher survival probability than tilapia, so the surplus bioflocs should be more than 50 mg L −1 . Therefore, surplus bioflocs should be harvested.…”

Post-exposure Period as a key Factor to Assess Cadmium Toxicity: Lethal vs. Behavioral Responses

“…2006; Bundschuh et al 2013;Kanu et al 2022). Therefore, to improve the extrapolation of laboratory results to natural ecosystems the inclusion of post-exposure periods in experimental setups is a relevant issue in ecotoxicology.…”

“…Among toxicants, cadmium has been amply studied in ecotoxicology (Wright and Welbourn 1994;Irfan et al In natural ecosystems, the exposure of animals to pollution is not always chronic. Some toxicants can be in aquatic ecosystems during a short period, from a few hours to a few days (Handy 1994;Brent and Herricks 1998;Bundschuh et al 2013;Zhao and Newman 2006;Kanu et al 2022). Therefore, animals may face toxicants for a brief period and subsequently they could recover or not during the post-exposure period, which depends on the chemical compound, duration of the exposure and concentration of the toxicant (Zhao and Newman 2006;Hoang et al 2007;Alonso and Camargo 2009;Lahman and Moore 2015;Kanu et al 2022).…”

“…Some toxicants can be in aquatic ecosystems during a short period, from a few hours to a few days (Handy 1994;Brent and Herricks 1998;Bundschuh et al 2013;Zhao and Newman 2006;Kanu et al 2022). Therefore, animals may face toxicants for a brief period and subsequently they could recover or not during the post-exposure period, which depends on the chemical compound, duration of the exposure and concentration of the toxicant (Zhao and Newman 2006;Hoang et al 2007;Alonso and Camargo 2009;Lahman and Moore 2015;Kanu et al 2022). This post-exposure period can help animals to recover fitness if detoxification processes are efficient (Handy 1994;Schill et al 2003;Zhao and Newman 2006).…”