Embryonic toxicity of 3,4-dichloroaniline (3,4-DCA) on Javanese medaka (Oryzias javanicus Bleeker, 1854)

Musa Adamu Ibrahim; Syaizwan Zahmir Zulkifli; Mohammad Noor Amal Azmai; Ferdaus Mohamat-Yusuff; Ahmad Ismail

doi:10.1016/j.toxrep.2020.08.011

Embryonic toxicity of 3,4-dichloroaniline (3,4-DCA) on Javanese medaka (Oryzias javanicus Bleeker, 1854)

Toxicol Rep. 2020 Aug 16:7:1039-1045. doi: 10.1016/j.toxrep.2020.08.011. eCollection 2020.

Authors

Musa Adamu Ibrahim^{1

2}, Syaizwan Zahmir Zulkifli^{1

3}, Mohammad Noor Amal Azmai¹, Ferdaus Mohamat-Yusuff^{3

4}, Ahmad Ismail¹

Affiliations

¹ Department of Biology, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
² Department of Biological Sciences, Faculty of Science, University of Maiduguri, P.M.B. 1069, Maiduguri, Nigeria.
³ International Institute of Aquaculture and Aquatic Sciences (I-AQUAS), Universiti Putra Malaysia, Batu 7, Jalan Kemang 6, Teluk Kemang 71050 Si Rusa, Port Dickson, Negeri Sembilan, Malaysia.
⁴ Department of Environment, Faculty of Forestry and Environment, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.

Abstract

Early-life exposure to toxic chemicals causes irreversible morphological and physiological abnormalities that may last for a lifetime. The present study aimed to determine the toxicity effect of 3,4-Dichloroaniline (3,4-DCA) on Javanese medaka (Oryzias javanicus) embryos. Healthy embryos were exposed to various 3,4-DCA concentrations for acute toxicity (5, 10, 25, 50, and 100 mg.L^-1) and sublethal toxicity (0.10, 0.50, 1.25, 2.50, and 5.00 mg.L^-1) for 96 h and 20 days respectively. Acute toxicity test revealed that the median lethal concentration (96h-LC₅₀) was 32.87 mg.L^-1 (95 % CI = 27.90-38.74, R² = 0.95). Sublethal exposure revealed that 1.25 mg.L^-1 at 3 days post-exposure (3 dpe) has a significant lower heartrate (120 ± 12.3 beats/min., p < 0.01), while at 7 dpe those exposed to 5 mg.L^-1 (141.8 ± 8.3 beats/min) had significantly (p < 0.01) lower heart rate compared to other treatments. Likewise, at 13 dpe, 5.00 mg.L^-1 (110.4 ± 17.3 beats/min) and 2.5 mg.L^-1 (130.4 ± 8.3 beats/min) were significantly lower (p < 0.001) compared to control. None of the embryos in 5.00 mg.L^-1 and 2.50 mg.L^-1 treatment groups survived at the end of the experiment. The results indicated a concentration-dependent response. The lowest observed effect concentration (LOEC) that exerted developmental deformities was 0.5 mg.L^-1. Javanese medaka embryo have low sensitivity to acute toxicity of 3,4-DCA, but developmental abnormalities at sublethal concentrations were observed.

Keywords: Antifouling biocide; Developmental toxicity; Endocrine disruptor; Javanese medaka; Pesticide.