Research Paper On Daphnia

Title: Physiological Changes in the Heart Rate of Daphnia magna When Exposed to Stimulants (Caffeine and Alcohol).

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

They must be eukaryotic, meaning they have nucleus, and in the domain Eukarya. In the Linnaean classification this could be in the kingdom Protista like a paramecium. Another Linnaean classification of this could be in kingdom Animalia, since they are heterotrophs and their cells contain a nucleus. They could be grouped as predators, since the organism is engulfing another organism. They could also be grouped based on their locomotion. They could have cilia, legs, or even flagella.

Habitat: Commonly found in terrestrial. Forest light gaps, slips, margins, disturbed sites, open habitats, riverbeds, cliffs, inshore and offshore islands, fernland, herbfield,

Daphnia magna also commonly known as water fleas are tiny freshwater crustaceans. They are filter feeders, and can survive in culture by eating algae, bacteria, or yeast. They feed plankton and detritus. There are about 1.5-5mm long. Daphnia Magna have a brood chamber where eggs are located. Daphnia magna are located in freshwater areas throughout northern hemisphere and south Africa.

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

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)

Investigating the Effect of Alcohol on Heartbeat of Daphnia Daphnia are the organisms that are involved in this experiment to find out what effect alcohol has on their heartbeat. It is easy to study the effects of alcohol on the heart of Daphnia as the organ can be easily seen through the transparent body of Daphnia. The number of heartbeats may be counted before submersion in alcohol and after submersion in alcohol to investigate the effect of alcohol. Daphnia belong to the Phylum Arthropoda and are Branchiopoda which belong to the class, Crustacea. Daphnia are invertebrates and also have an exoskeleton, jointed appendages, a dorsal heart and open blood system.

This experiment investigated the effects of changing temperate and salinity on the heart rate of Daphnia sp.. The hypothesis states that the heart rate of Daphnia sp. will be significantly higher at 20oC compared to 10oC. Results showed that the heart rate of Daphnia sp. at a higher temperature correlates with an increased heart rate.

espite their small size, sea dragons are carnivorous animals and therefore have a purely meat-based diet. The sea dragon uses its pipe-like snout to suck its prey into its oddly tooth-less mouth. Sea dragons hunt crustaceans, plankton, shrimp and even small fish, using their camouflage to their advantage. Sea dragons have numerous natural predators in the south and western coastal waters of Australia but are rarely even spotted to the elaborate camouflage of the sea dragon. Those few sea dragons that are unlucky enough to be found, are usually spotted by large fish. As with sea horses, it is the male sea dragon who care for the eggs once they have been laid by the female. The female lays around 250 eggs onto the long tail of the male sea horse.

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).

Job in the Environment: The Angolensis is species of secondary consumers. It has sharp claws, and eats other small animals. Although, it is shown to be prey to a different species, but this species is unknown.

Diversity in planktonic marine animals stems from a shifting balance between competition for food and avoidance of predators. As a result, a wide variety of planktonic animals inhabit the oceans. Phytoplanktons are primary producers because they use solar energy to convert CO2 and nutrients into carbohydrates and other molecules used by life. Despite limited knowledge of what small copepods eat, it is clear that many higher-trophic level consumers eat them. Numerous studies have shown that copepod nauplii and other small copepods are important prey of fish larvae, and other planktivores. Most studies of larval fish feeding published since 1984 continue to document the importance of small copepods as fish prey. Small copepods are abundant and are very important links in marine food webs. They serve as major grazers of phytoplankton, as components of the microbial loop by preying upon bacterio-plankton and heterotrophic protists, and as prey for ichthyoplankton and other larger pelagic carnivores. Small copepods exhibit various reproductive and feeding strategies which help maximize population size, in order to counter heavy losses due to predation. Accordingly, small copepods can become extremely abundant, and presumably exert substantial feeding impact on their prey, but such data are scarce. Our biomass, trophic ecology, and roles of small copepods in

These are worldwide, live in all types of habitats and in all depths and in all types of sand.