Determination of concentration boundaries for the toxicity of Terminalia catappa Linn. leaves extract on healthy Carassius auratus

Terminalia catappa from Family Combretaceae or locally known as Ketapang is naturally grows plant and abundantly available in many tropical areas. The medicinal properties such as anti-parasitic and antibacterial of the leaves have been proven repeatedly in many scientific studies of aquaculture to treat infected fish. In the present study, toxicity level of different leaves extract concentrations on the healthy Carassius auratus or goldfish was investigated before the next study on its efficacy to treat the unhealthy C. auratus could be initiated. Ten C. auratus in 30-L tank aquarium were tested with five different concentrations of leaves extract; 400 mg/L, 500 mg/L, 600 mg/L, 800 mg/L and 1000 mg/L respectively and pH of bath extracts were determined before performing the tests. The results of pH are reduced or became acidic when the concentrations of leaves extract are increased significantly. During the test, toxicological signs were detected by physiological changes such as increased respiration frequency or erratic behavior. Overall results showed the methanolic extract of T. catappa leaves demonstrated a significantly high safety margin for the host of C. auratus. The C. auratus were well-tolerated with methanolic extract of T. catappa at the concentration of 400 mg/L for 3 hours without any visible effect. At 500 mg/L concentration, C. auratus also managed to survive for 3 hours but number of survived fish is reduced significantly different at (P<0.05) throughout 3 hours exposure time compared to control. Exposure to 600 mg/L, C. auratus were managed to survive up to 2 hours; meanwhile at 800 mg/L only up to 1 hour survived. At the highest concentration of 1000 mg/L, C. auratus have demonstrated an increased operculum movement and inconsistent behavior within few minutes of exposure time. However, no lethality of C. auratus was observed in the experimental period

Evaluation on toxicity level of Terminalia catappa leaves extract on selected cyprinids under different bath concentrations

This study aimed to determine the lethal concentration (LC50) of Terminalia catappa leaves extract on three cyprinid species; carp (Cyprinus carpio), goldfish (Carassius auratus) and tiger barb (Puntigrus tetrazona) through the acute toxicity test. The leaves of T. catappa were extracted with methanol and prepared in various immersion concentrations (40, 80, 100, 150, 200, 250, 300, and 350 mg/L). These extracts were immersed in the aquarium and left for 24 h before performing the acute toxicity test. The water quality was also analyzed before and after adding the extract immersions into the aquarium. The acute toxicity test conducted for 96 h with 10 fishes of each cyprinid species (4.0-6.0 cm length) in 30 L water capacity aquarium. The mortality of each cyprinid species was recorded at 24 h time interval and LC50 of the extracts throughout 96 hours was determined through the probit analysis application. Specifically, the LC50 of T. catappa leaves extract were 349.89, 338.65 and 318.48 mg/L exhibited for carp, goldfish and tiger barb, respectively. A high concentration range of any plant-based extract has the potential to become toxic to particular fishes. Thus, it is an effort from this study to identify the safety margin of T. catappa leaves extract before its therapeutic values can be further manipulated and elucidated in aquaculture research