Daphnia Lab Report

Ectothermic animals are animals whose body temperature is affected by their surroundings. This means that if the environment is cold the animal will be cold. If the environment is warm the animal will be warm. This is because the animal doesn’t have the capability of regulating its body systems to keep a constant body temperature. When an ectothermic animal is cold, its heart rate will lower. When the animal is warmer, the heart rate will raise – as long as the temperature isn’t sufficiently high to harm the animal. (Campbell, 2005)

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 this research paper I will talk about how a large decrease in the algae population in the Chesapeake Bay will cause problems for not just fish and other species but the people who fish and make a living off of it. A large decrease in algae population will have a domino effect on the food chain. Having a major decrease in algae will hurt how others species live and protect themselves.

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.

This experiment was done to test whether or not the drugs Nicotine, Alcohol, Pain Killers, Nyquil, and Caffeine were stimulants (increase in the body’s metabolism and consequently increase the heart rate) or depressants (slow the rate of metabolism and consequently slow the heart rate) of the homeostasis (the ability of one’s body to maintain a constant internal environment) of Daphnia.

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).

We tape the container with black tape and left some space that light can pass through the container.

The presence of herbivores has greatly altered the population density of the barnacles on Island B in comparison with Island A. While the population density of Chthamalus dalli has remained the same as on Island A, the population of Balanus glandula severely decreased (less than 10 percent coverage of the intertidal zone). Since only the population of Balanus glandula contrasts between the islands, it is most likely that the invasive herbivore species was only in completion with Balanus glandula and pushed the species out of its original habitat. These effects may be an example of the competitive exclusion principle, a hypothesis that no two species indefinitely occupy the same niche in the same community, and therefore are not able to coexist.

The exact scenario changes in each example, but the central idea remains that through a chain of interactions, a non-abundant species has an outsized impact on ecosystem functions.

Five jars were filled half way up with control water and 10 snails in each at all four set ups. The four set ups each included a fish tank that had either the control water, crayfish water, crayfish and crushed up snail water, or just crushed up snail water. From these tanks, 750mL of water was taken and then placed into the five containers containing the snails. In total we had 20 containers. We then counted the amount of snails at the surface of the water or above it at 15 minutes and 30 minutes. With our data we used an SPSS and Excel worksheet to run an ANOVA test with post hoc Turkey for above and at the surface snails for both time

The basic experimental design was that over 5 years researchers caught minkle whales and within 3 hours of death, analyzed the diet of the whale. They found the volume and weight of fore-stomach, verified what species the whale had eaten, and determined how frequent a species was eaten. The responding variable is the species found in the whale’s diet that year

However, during the subsequent days (day 25 and 31), the enhanced drinking behavior was noted only in the 0.4% NaCl group; while, birds provided with 0.7% NaCl returned to water consumption rates comparable to those observed in the tap water groups. This decrease in water consumption which occurred after an initial increase in the 0.7% NaCl group may suggest induction of an adaptive response due to a reduced ability to tolerate higher sodium levels in

depend on these prey are left to change their eating habits. A change to a particular organisms eating habits greatly creates gaps in the food web, which produces a ripple effect through the whole ecosystem. (12). For instance, Sharks when they are deprived of their prey, they switch to prey of other predators. With the sharks, eating the prey of the other predators, this causes a decline in the population of that specific prey. (13). When the population levels of that specific prey start to lower, this leads to competition between the shark and the other predator. As the shark and the other predator compete for the same species, this causes the prey to eat more smaller fish. With this continuous cycle of competition over food, several animals

A recent study conducted by Naslund and Johnsson (2014), found that environmental enrichment can be divided into groups. These groups include: physical enrichment, sensory enrichment, dietary enrichment, social enrichment, and occupational enrichment. Since, some of those are difficult to test, physical enrichment is what is being studied now. All species of fish are not the same and prefer certain substrates rather than others. Therefore, since the Fathead Minnows that we will be studying and conducting this research on, will depend on what they prefer.

A recent study conducted by Naslund and Johnsson (2014), found that environmental enrichment can be divided into groups. These groups include: physical enrichment, sensory enrichment, dietary enrichment, social enrichment, and occupational enrichment. Since, some of those are difficult to test, physical enrichment is what is being studied now. All species of fish are not the same and prefer certain substrates rather than others. Therefore, since the Fathead Minnows that we will be studying and conducting this research on, will depend on what they prefer.