Swimming patterns of marine microorganisms

• Main Author: Lee, Yaow Chen
• Other Authors: Tuan Tran
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2023
• Subjects: Engineering::Mechanical engineering
• Online Access: https://hdl.handle.net/10356/172773
• Institution: Nanyang Technological University

Daphnia belongs to a genus of zooplanktonic crustaceans and are commonly found in waterbodies such as ponds or lakes. Daphnia Magna are a species of Daphnia, where adults are typically between 1mm to 5mm in length, making them one of the largest species of the Daphnia genus. Daphnia have been a popular model organism for studies of external or foreign contaminants on aquatic ecosystems, with numerous studies on the effects various chemicals can have on Daphnia behaviour. Most of such studies today focus on the affects such chemicals or contaminants have on Daphnia mortality, often employing extensive timeframes. However, assessing mainly Daphnia mortality may not adequately capture the effects of these chemicals on Daphnia behaviour and aquatic ecosystems. As such, this project will focus on quantitative parameters to study how certain contaminants can affect Daphnia Magna behaviour in the short term instead of the mortality or long-term effects on Daphnia Magna. A baseline solution of 500 ppm of seachem equilibrium salt solution would be used as the baseline solution to compare the swimming behaviours of Daphnia Magna when exposed to 7 different concentrations of Nylon 12 (PA12) and Polyethylene (PE). The parameters to be used would be the hopping frequency of Daphnia per minute and tracking swimming distance of Daphnia per unit time. After the baseline experiments were conducted, a baseline behaviour for Daphnia Magna used in this experiment was established for both hopping frequency and swimming distance per unit time. 2 sets of recordings for each of the 7 concentrations of PA12 and PE were performed, 1 set at time, t = 2minutes and another at t = 32 minutes. The data obtained from 7 different concentrations of PA12 and PE was compared to that of the baseline solution and it was found that PA12 may not affect the hopping frequency of Daphnia Magna but affects the cumulative swimming distance of Daphnia per unit time, with the average swimming distance being lower than that of the baseline. The hopping frequency of PE experiments went increasingly higher than the baseline as concentration of PE exposure increased while the data collected for the cumulative swimming distance per unit time was not completed due to the interference of PE particles.