Ectotherm Lab Report

Homeostasis is the maintenance of the internal environment despite changes in the external environment. One of these environmental conditions is temperature. Fish are ectotherms, or conformers, which means they can not maintain a constant body temperature. They change their body temperature, by moving from colder to

Individual Daphnia magna are transferred to a microscopic slide using a pipette. The Daphnia was moving freely in a drop of H2O on the slide. For the control, the heart rate of D. magna is observed for 15 seconds

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

1. Fischer studied if Daphnia magna had a positive or a negative phototactic response when expose to ultraviolet radiation (UVR). 2a. In this experiment the author manipulated the amount of UVR that the Daphnia were exposed to throughout the experiment. 2b.

Freeman (2008) furthers Eckert et al’s argument by stating that the actin filaments of the muscle cell in organisms are able to intake ATP (adenosine triphosphate) faster and will move the organism faster when higher temperatures are imposed. This is because of an increase in enzyme reaction rates (Freeman 2008). These arguments can be applied to our experiment to help explain the trends observed. It can be argued that as the Gammarus setosus experiences the cold treatments, the organ of Bellonci senses the cold temperature, which in turn signals the organism to preserve its energy to protect itself; therefore, the organism will swim slower. In addition, the enzymes in the muscle cells of the organism, when experiencing the cold treatments, will have decreased ability to carry out enzymatic reactions, therefore inhibiting the uptake of ATP, which will cause the organism to swim slowly. Conversely, as the organisms are put into the heated treatments, the organ of Bellonci senses the heat, and allows the organism to swim faster, since it does not have allocate as much of its energy towards survival. Furthermore, the enzymes in the cells will be able to catalyze reactions more quickly, therefore allowing the organism to swim faster. However, when the temperature of the surroundings is too high, the enzymes will denature, therefore, reducing the activity rate of

Referring to the experiment`s hypotheses that the A. franciscana prefers light, temperatures between 20-24 ̊ C, and a basic (pH 8) environment; the results regarding the first treatment, light, were initially vague. According to the experiment results, the A. franciscana did not show a clear preference towards light or dark because both sections contained high concentrations of them; the A. franciscana also strayed from the uncovered section. Several factors may shed light on the results such as the A. franciscanas physical appearance; they possess three light-sensitive eyes that can adjust to both low and high light intensities (Fox, 2001). This means that although they may prefer light they can survive in darker habitats as well; relating back to the experiment the A. franciscana may have been content with wherever they were, resulting in limited movement.

direct calorimetry. Furthermore, the amount of oxygen in the chamber reveals the amount of cellular respiration of the organism. While also, test the effects of decreasing oxygen, and later increasing the heat on the metabolic rate of goldfish. I hypothesize that an increase in temperature will increase their metabolic rate

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 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).

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.

We performed an experiment on crayfish focusing on their metabolic rates, via oxygen consumption, at two acclimated temperatures. Crayfish were either acclimated to a warm temperature (20 to 25C) or to a

The temperature decrease results in alterations of the autonomic sympathetic response[11] and in impaired conduction velocity of the electrical signals through the

Somewhat more precise descriptions can be made by using the terms poikilothermic and homoiothermic. The body temperature of poikllotherms is relatively variable, while that of homeotherms is relatively constant.

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

Discussion Report The change in temperature was effective in altering the breathing rates of the goldfish. As the temperature decrease from 20 degrees to 10 degrees, the average number of respiration also decreased from 106 to 44 breaths per minutes. The null hypothesis, that the change in temperature has no effect on the respiration per minute of a goldfish. The null hypothesis can be rejected because of the temperature of the water as a direct effect on the respirations of a goldfish.