Introduction
Marine copepods, such as T. Californicus are found along California’s coast and can be seen along United States’ western coast. The copepod is able to survive in various living conditions: fluctuating temperatures, small amounts of water, vast amounts of salinity, and are opportunistic feeders (Hawkins 1962). The life cycle of a copepod consists of 4 stages, which last about 2-4 days each depending on environmental conditions (Fisher 2018).
Previous studies show that food quality plays a big role in the progressive growth of copepods. Foods with no nutritional value to copepods may stunt the growth of plankton, (S.Twombly and C.W Burns)
The upcoming research focuses on the growth rate of the species dependent on their diet. The development of the T. Californicus is vital to the survival of other aquatic organisms that depend on this species as a source of food. The result of the growth rate of this copepod would provide new information for further research. The growth rate is an important factor because it determines how quickly the species will reach adulthood, which is the copepods’ reproductive prime. The following research tests whether micro-algae grow will increase the growth rate of T. Californicus.
Methods
Based off of these conditions, and investigating further to obtain new information, a conclusion can be drawn. The experiment will take three weeks to complete, therefore, each week will be equivalent to one trial in order to test which diet has the fastest growth rate. Within those three weeks there will be a margin of error due to lack of observation from the laboratories being off limits each Friday to Sunday. Although this margin of error will affect the experiment, three trials will be conducted to ensure sufficient statistical data. Many factors will remain the same in order to prevent more error in the experiment. This includes: retaining the starting age at C1 (copepodite stage 1), having a setpoint for salinity for all trials, maintaining a room temperature between 18 and 28 celsius and preserving the concentration of food at less than one milliliter. (Wang, 2015). Starting the experiment from the copepodite stage 1 is the basis of our experiment and is needed in order to avoid several ages as a factor. The environment has to be controlled because the copepodite needs to adapt to its environment before testing. Maintaining the temperature at a given setpoint is needed because T. Californicus is an organism who adapts quickly under various environmental stressors (Fisher 2018). With a set temperature, we can exclude it as an effect on our experiment. The chemical composition of the food will determine the effectiveness of each food source (Huntley 1987). The concentration of food is important because copepods have a high metabolic rate and are adaptive feeders. Therefore, they are required to have sufficient amounts of food, at a given rate. The experiment will begin by carefully selecting 60 copepods at the beginning of their copepodite stages. The sample size of 60 copepodites are needed to test 3 trials of 20 for the 2 different food diets. Copepodites will be separated (using a plastic pipette) into their own well. A pipette is used because it carefully siphons the organism and can easily place it in a different container. When feeding the copepodites consistently, the growth rate will be recorded, based on which diet sped up the process from C1 to adulthood. Feeding T. Californicus various diets such as “micro algae grow” from the lab and Tetraselmis chuii (algae), will have an effect on the growth rate from C1 to adulthood.
To begin the experiment all the copepods have to be selected, by using the 5 ml pipette and it’s pump. The temperature and salinity have to be adjusted before feeding the copepodites, in order to create a stable environment. Each microscope, P1000 pipettes, and wells will be prepared before collecting the initial data. Each copepodite will be measured and its magnitude will be recorded, using the micrometer on the microscope. The two algae will be measured using the P1000 pipette to have a constant rate of food being given to the planktons. Next, 600 microliters will be added to each well, to commence the process of ingestion. The plankton will be fed at the same time with the same amount of algae, every day. In order to prevent the accumulation of algae and suffocating the plankton, the water will be replaced every 2-3 days. The water will still maintain all the constants to guarantee all environments being the same. All group members will be alternating days to record size, feed the planktons, and address any complications that may arise. The Protocol expert and Analysis expert will be checking the experiment four days out of the week during the afternoons. The Principal investigator will proceed on Mondays at noon and Tuesdays in the evenings. The Data expert will follow on Wednesdays in the morning. A margin of error is taken into account due to the lab being restricted on Fridays and the weekends. Consequently, during the end of each week, transferring the copepodites into larger containers (i.e beakers) and giving them extra food should suffice for the gap of data being lost. This precaution will ensure their survival during the loss of data. The analysis and steps taken will provide a bridge for the research to develop, become concrete with sufficient data, and construct a conclusion.
Materials
- 50 mL total of Tetraselmis chuii (50,000 microliters)
- 50 mL total of Microalgae grow (50,000 microliters)
- Water salinity needs to be kept at a constant amount between 20ppt and 40ppt
- Temperature needs to remain constant between 18 and 28 degrees Celsius
- 2 – P1000 ( 200/1000 microliter)
- 9 well plates (20 wells – one trial)
- 2 pipette pump fillers
- Disposable plastic pipettes
- 60 copepodites
- Compound and Dissecting microscopes
- Slides and clay to view the copepod and algae
- Plastic gloves