Caffeine On The Asexual Reproduction Of Daphnia Magna

Daphnia, also known as water fleas, are small crustaceans about 1mm-5mm long and are part of the freshwater zooplankton (Ebert 2005, Hutchinson 2005 & Clifford 1991). Daphnia can be found in most fresh water habitats such as freshwater springs, ponds and reservoirs and are the predominant food for planktivorous fish. Dapnia are ‘filter feeders’ meaning they feed on small particles suspended in the water which can include algae. It has been found that daphnia tend to migrate to the upper parts of the water at night and return to the lower parts of the water in the day to hide from predators (Ebert 2005) (Hutchinson 2005). Daphnia can reproduce through sexual reproduction and also asexual

Overall, the more macroinvertebrates in the water, the healthier the stream. pH is a measure of how acidic or basic water is. It is measured on a scale from 0-14. 0 is the most acidic, 14 is the most basic, and 7 is neutral. It is the measure of the relative amount of free hydrogen and hydroxide ions in the water. Acidic water has more hydrogen ions, and basic water has more hydroxide ions. When water’s pH is around neutral (7), that is a suitable and healthy living environment for fish, and indicates a healthy stream. If the water is too acidic or too basic, it can be harmful to the aquatic life. Dissolved oxygen is a measure of how much oxygen is dissolved in the water. As the amount of dissolved oxygen drops below normal levels in water bodies, the water quality is harmed and creatures begin to die off as a result of eutrophication. The higher the level of dissolved oxygen, the healthier the stream. When there is a lot of dissolved oxygen present it makes for a safe environment for fish to live and reproduce. Having all this healthy fish can provide us with food, so overall the more dissolved oxygen, the better. Nitrates are a compound found in fertilizers that is used to help plants grow. It is what is given off as a result of the use of nitrogen in water. The organisms in the soil eat the nitrates and it helps the metabolism and the health of organisms. Plants, such as Algae use nitrates as a source

To conduct this study a culture of living Daphnia were collected from a nearby natural water source area.

The purpose of this experiment was to test the affect of caffeine on the heart rate of Daphnia by observing their behavior and heart rate under a microscope when exposed to different concentrations of caffeine. Caffeine is a stimulant drug used in many energy drinks and causes large amounts of stimulatory neurotransmitters to be released. Therefore, as caffeine is a stimulant drug it was hypothesized that the Daphnia heart rate would increase immensely. Daphnia is a group of microscopic, planktonic crustaceans that are arthropods that measure 1-5 millimeters in length. Daphnia live in multiple aquatic environments such as freshwater lakes, ponds and rivers. “The development of genomic infrastructure coupled with a wide range of phenotypic diversity make Daphnia a versatile model

Studies of Daphnia presented information which elluded to the idea that Daphnia would react to environmental pollutants within a relatively short timeframe; therefore, a lab was constructed to find the effects of copper sulfate in a Daphnia’s system. Before beginning, the hypothesis was gathered: if the concentrations of copper sulfate in the water are high, then the Daphnia would be afflicted with symptoms associated with physical decline. Daphnia, known as water fleas, are small crustaceans who get their common name from their jerky movements. The organisms reside within lakes and ponds often in limestone-based areas found all over the world. Daphnia consume algae, specifically the free-living green type, yeasts, and bacteria; therefore,

The daphnia relies on an osmotic gradient, as they are able to take in ions with their chloride absorbing glands, which help the organism to secrete and absorb ions by supporting the inadequate effectiveness of excretory organs to complete homeostasis under dehydration and extreme conditions. Therefore under the influence of increasing salinity, daphnia will face dehydration from high levels of concentration and will lead to the death of the species (Komnick, 1986).

These findings were consistent with Gerristen’s findings. In another experiment though, he placed a hormone that is created by the Daphnia’s natural predator to simulate that there was a predator in the mesocosm. Glaholt determined that Daphnia would swim deeper into the cold water to avoid the hormone of their predator (Glaholt et al. 2016). A future study can be conducted to allow a better understanding of Daphnia, and how far they are willing to go to avoid

Daphnia, or water fleas (named after the jerky, jumping way in which they move), are tiny planktonic crustaceans measuring around 1mm in length. They live in freshwater lakes and ponds, filter feeding on green algae, bacteria, yeast and phytoplankton, before being the prey of small fish such as sticklebacks and minnows. As a primary consumer, Daphnia provide an important link in the human food chain; increasingly larger fish such as salmon are dependant on their numbers. In terms of their nutritional values, adult Daphnia have a protein content of approximately 50% dry mass and a fat content of 20-27%. (Clare) (Background information on Daphnia)

Daphnia usually eat algae and other small bacteria. They are filter feeders which allow them to eat because they are eating the bacteria that is found in the water as they filter it.

The diatom Didymosphenia Geminata, often referred to as, “Didymo,” or “Rock Snot,” is native to many parts of the world. Didymo lives in freshwater streams and rivers and thrives in nutrient rich waters such as those that are in southern Missouri and Arkansas. This alga, not to be confused with algae, is a moss-like substance that until lately hadn’t been a cause for concern for anyone. Recently though, thanks mostly to anglers, Didymosphenia Geminata has begun to spread into rivers and streams that are, or at least were, not originally native habitats for this diatom. Scientists and ecologists are only now beginning to understand how damaging this substance really can be. While, “Didymo” has yet to be found in Missouri’s

The experiment took place in a laboratory setting, and the first step was obtaining sixty individual Daphnia magna (that were neither adults nor tiny offspring) from a large tank in the lab. These individuals were equally divided into three groups; low density, medium density, and high density. The twenty Daphnia assigned to the low density group were split into four groups of five and pipetted into one of four tubes filled with 10mL of Chlamydomonas algae. The twenty Daphnia assigned to the medium density group were split into two groups of ten and placed into one of two tubes also filled up to 10mL with Chlamydomonas. The final twenty Daphnia were all placed into a single tube filled with 10mL of the algae. In order to avoid suffocation-related

Daphnia are used to test water toxicity, they are a vital part of fresh water ecosystems. They are a food source for smaller fish and invertebrates and considered to be a consumer of algae and bacteria (Elbert, 2005). These small crustaceans range in size from 2-5mm long and are commonly referred to as water fleas. Daphnia belong to the group called Daphniidae, which is a relative of freshwater shrimp. It is easy to see the internal organs of daphnia because of a transparent taco shell like carapace. A carapace is the hard outer part of a shell or covering. A daphnia’s life span can range between 1-56 days. (Elenbaas, 2013; Clare 2002). The comfortable pH level for daphnia is between 7.2 and 8.5 (Clare, 2002).

The study “Caffeine levels and Plant Mortality” explains how caffeine can affect plant mortality during germination. In the study, high doses of caffeine reacted with the plants causing plant death. In the article scientists

Caffeine, or 1,3,7-trimethylxanthine, is a psychostimulant which, just like other classical psychostimulants, such as cocaine and amphetamines, increases motor activity, induces arousal, and creates reinforcing effects (Griffith & Woodson, 1998). It has multiple side effects which are produced by many biological mechanisms, the most important one being the inhibition of adenosine receptors (Green & Stiles, 1986).

Different species have different temperature and pH tolerances, but some of them, like the Amano shrimp, tolerate cool water very well. The