The acute toxicity of the metaldehyde on the climbing perch

¹ Centre of Excellence of Advance Sensor Technology (CEASTech), Pusat Pengajian Jejawi 2, Taman Muhibbah, Universiti Malaysia Perlis, 02600 Arau, Perlis, Malaysia
² Water Research Group, School of Environmental Engineering, Universiti Malaysia Perlis, Pusat Pengajian Jejawi 3, 02600 Arau, Perlis, Malaysia
³ School of Mechatronic Engineering, Universiti Malaysia Perlis (UniMAP), Malaysia
⁴ Department of Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
⁵ Faculty of Science and Natural Resources, Universiti Malaysia Sabah, 88400 Kota Kinabalu, Sabah, Malaysia
⁶ Department of Biomolecular Sciences, Faculty of Applied Sciences, Universiti Teknologi MARA, 40150 Sec. 2, Shah Alam, Selangor, Malaysia
⁷ Department of Environment, Ministry of Natural Resources and Environment, Tingkat 2, Bangunan KWSP Jalan Bukit Lagi 01000 Kangar, Perlis, Malaysia

^* Corresponding author: farrahaini@unimap.edu.my

Abstract

In Asia, Climbing perch (Anabas testudineus) is commonly found in paddy fields and irrigation systems. Due to its habitat, Climbing perch is exposed to toxic pesticides used in paddy fields such as metaldehyde which is one of the most widely used molluscicide. This study aims to determine the acute toxicity Lethal Concentration₅₀ (LC₅₀) of metaldehyde and its effect on the behaviour and physical changes of the Climbing perch. The fish mortality responses to six different metaldehyde concentrations ranging from 180 to 330 mg/L were investigated. The 96-h LC₅₀ values were determined and analysed using three different analysis methods which is arithmetic, logarithmic and probit graphic. The LC₅₀ values obtained in this study were 239, 234 and 232 mg/L, respectively. After 96-h of exposure to metaldehyde, the fish showed a series of abnormal behavioural response in all cases: imbalance position, and restlessness of movement. The LC₅₀ values show that metaldehyde is moderately toxic to the Climbing perch indicating that metaldehyde is not destructive to Climbing perch. However, long term exposure of aquatic organisms to the metaldehyde means a continuous health risk for the fish population as they are more vulnerable and it is on high risk for human to consume this toxicated fishes.