How Does Daphnia Affect Small Fish

The purpose of the experiment was to investigate the physiological effects of epinephrine on the heart rate of the organism called Daphnia magna as well as to calculate the median effective dose. Daphnia magna are arthropods found in pools of freshwater or areas where freshwater meets seawater in Western Europe and the Atlantic Coastline of the United States (Elenbaas, 2013). They are about two to five millimeters in length and have a transparent shell. Their heart is located on the dorsal side of the organism and the gills are on the ventral side. Daphnia magna also has two antennae and six appendages that are used to bring food and oxygen to the organism’s gills and produce movements.

Brooks and Dodson, the authors of the article titled “Predation, Body Size, and Composition of Plankton”, conducted research on the effect the small fish called Alosa Pseudoharengus has on an ecosystem, more specifically, different lakes in New England. Along with the data they collected on the aforementioned matter, they studied the sizes and the composition of the miniscule zooplankton inhabiting the lakes, and compared it with that of the Alosa. Their research uncovered important facts regarding water ecosystems and how they are so easily thrown off balance.

Table 2: Mann-Whitney U statistical testing for the difference in average heart rate of Daphnia before and after the addition of aged water:

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

In the mid 70’s, my family bought a cabin on the Illinois River. We spent all our free time there, weekends and most of the summer. For years my family enjoyed their time at the “clubhouse” as we called it. It was our home away from home. There were about 20 cabins there, so it was like our own little community. Just about everyone there was like extended family. Any time someone needed help, the neighbors showed up. Everyone there had similar interests, hunting, fishing, boating and water skiing. I spent most of my days enjoying these activities.

to the body of Daphnia. For example, an experiment may test the effects of toxic chemicals on Daphnia, meaning that Daphnia can act as water quality indicators (Ren et al. 2009). The lack of Daphnia in certain areas signifies the presence of a toxic chemical, if the habitat meets the living requirements of Daphnia (Villegas-Navarro, 2003). Therefore, Daphnia act as indicators of environmental health as well as chemical responders reacting to potentially harmful

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,

Throughout my experiment my control acted normally, the daphnia had average movement and calm manner. On a scale from 1 to 5 I ranked the control group as a 3 for normal movement and health. When I introduced car antifreeze to my pure water daphnia there was an immediate change in the color of the daphnia, their bodies turned from a white opaque color to a light pink (the same color as the antifreeze). Not only did the physical appearance change but their behavior became more aggressive and panicked. As time passed the daphnia moved in a circular motion and the chemical caused one of their antennas to cripple. The antifreeze surprisingly resulted in no deaths so I gave the effect of antifreeze to daphnia a 2 (table 2 and 2B). When exposed

The additional species, Daphnia Pulex are a derivative from Daphnia Magna, which can be in located rain filled tire ruts and any stable body of water. These daphnia are established in fresh water and maintain the highest concentrations of daphnia compared to other species can be found in lakes and ponds. Daphnia magna is a water flea dependent on environmental conditions to breed and survive. Conditions such as temperature, salinity and oxygen levels can be detrimental to the lifespan of these organisms (Elenbaas, 2013. Within their existing environment daphnia consume algae, bacteria and detritus; it is this continual uptake of these organisms, which maintains the food chains integrity. Daphnia also host a number of bacteria, fungi, nematodes,

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.

In this experiment we find how caffeine can affect the heart rate of a culture Daphnia. Heart rate of a living organism’s can vary depending on the individual, age, body size, heart conditions, medication use and even temperature. This report will examine if the caffeine is good or bad for the living organism’s health and body. And discuss about where the caffeine is produced and used in daily life of human beings and on the environment. Daphnia is a water flea used in this experiment because of its genomic infrastructure with wide range of phenotypic diversity. This quality of Daphnia makes them a versatile model for the experiment. Also their transparent body allows the experimenter to visually see how the heart beats and count them under the light microscope during the experiment as required. The heart rate of Daphnia is monitored under different concentration of caffeine solution and the results are shown in a table and a graph. Experiment carried out to locate the effects of caffeine on a heart rate of Daphnia may or may not be a predictor of change in human heart rate under caffeine. The effects of caffeine can also be tested on humans but those experiment involving humans contains high risk, as Daphnia can only live for a short period of time and in nature most of them get eaten within their first few days or weeks of life.

In my experiment as the concentration of sugar increased the heart rate of the Daphnia decreased. The cause of this may have been to the possibility of having a defectuos daphnia. My prediction was that the more sugar concentration added the highest the Daphnia heart rate was going to be. It did affect my organism but not in a positive way if not in a negative way, by decreasing the heart rate of the organism.

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

There was no significant (p<0.05) difference between the initial weights of the lugworms in the 4 sample groups, avoiding any bias in treatments. As Figure 4 shows each sample group showed a large increase in weight after exposure to the diluted salinities with the lugworms that were placed in full strength seawater not showing an increase of more than 1.7%.