Evaluation of the sensitivity spectrum of a video tracking system with zebrafish (Danio rerio) exposed to five different toxicants

Abstract

The aim of this study was to develop a biological early warning system for the detection of aquatic toxicity and test it with five toxicants with distinct chemical nature. This was done in order to verify the spectrum of sensitivities of the proposed system, as well as the potential identification capability of the tested contaminants, using only the analysis of zebrafish's behavior. Six experimental conditions were tested: negative control and five toxicants (bleach, lindane, tributyltin, mercury, and formaldehyde). The exposure time was 45 min, and the concentrations used corresponded to 9% of LC's-96 h for the tested compounds, to ensure ecologically relevant results. A total of 108 fish were used, with each individual experimental condition being tested 18 times. A statistical model of diagnosis was used, combining self-organizing map and correspondence analysis. The values of sensitivity, specificity, accuracy, false positive, false negative, positive predictive value (PPV), and negative predictive value (NPV) were calculated. The objectives of the work were accomplished and the system showed a good overall diagnostic performance with 79% in accuracy, 77% in sensitivity, and 88% in specificity. The lowest result of the predictive values was 78% (lindane and mercury), in the case of the NPV, and 86% (bleach and lindane), in the case of the PPV. The best result of the predictive values was 100% (bleach and tributyltin), for the NPV, and 89% (tributyltin), for the PPV. Regarding the five tested toxicants, the system was able to correctly identify the agent responsible for the contamination in 40% of the positive diagnoses.

Assessment of eco-toxic effects of commonly used water disinfectant on zebrafish (Danio rerio) swimming behaviour and recovery responses: an early-warning biomarker approach

“…Furthermore, the recommended levels for chlorine-based disinfectants on medical applications were 500 mg/L (without obvious contamination) and 1000 mg/L (with obvious contamination) (Wang et al 2020 ). Thus, the occurrence of disinfectants in the water ecosystem is well predictable (Amorim et al 2017 ). A maximum concentration of 2 mg/L of NaOCl was used in WWTP at Junglang (Park et al 2016 ).…”

Indication of Electromagnetic Field Exposure via RBF-SVM Using Time-Series Features of Zebrafish Locomotion

“…Differing from BEWS's propose of detecting low-concentration toxic substances by evaluating the behavior changes of the organisms exposed to it [8,9,12,13], the model of this work is dedicated to indicate the EMF exposure that is near the reference-level field intensity. The behavioral characteristics of zebrafish are selected as the objects for analysis and evaluation, while this study adopted the RBF-SVM model, which is different from existing machine learning models [13] or other statistical models [8][9][10]. Moreover, the features used to train the machine learning model in this study were obtained by the time-series of zebrafish swimming trajectories, which were highly related to EMF exposure conditions.…”

“…The mRMR algorithm was used to select features from the results of HCTSA for the classification. According to Equations (6)- (8), in this experiment, D represents the maximal relevance between each feature itself and its target class of the sham or real EMF exposure conditions listed in Table 1, and R represents the minimal redundancy between itself and other features. Therefore, the features were arranged from high to low according to their own Φ(D − R).…”

“…They detect the presence of toxic substances by continuously tracking the physiological performance of organisms [6] and could provide more reliable predictions of substance toxicity than the chemical concentration alone, especially in case of mixtures of substances [7]. The fast development of a fish tracking system supports enhancing the ability of biological monitors-or more specifically, a biological early warning system (BEWS)-to observe and sense the behavioral response of bio-organisms [8][9][10][11][12][13]. The tracking systems of BEWS could provide abundant and explicit information for the behavior and movement analysis, contributing to the satisfying result of water quality assessment when the concentration of pollutants in the water is relatively low.…”

Response of Olfactory Sensory Neurons to Mercury Ions in Zebrafish: An Immunohistochemical Study

“…However, Ung et al (2010) determined that a 4-day exposure to 300 μ g/L of mercuric chloride (~220 μ g/L of Hg 2+ ) induces mortality in less than 50% of adult zebrafish (30%). Due to a certain discrepancy in lethal values in literature (Vutukuru & Basani, 2013; Wang et al, 2013 a ; Macirella et al, 2016; Amorim et al, 2017), we decided to take into account also the concentration of 1 μ M HgCl 2 . Each of three 10 L tanks containing 50, 100, and 200 μ g/L of Hg 2+ respectively, housed 10 fish.…”