Cray Fish Lab

Students observe and record some of the structures of a crustacean, the crayfish, and compare it to other organisms. They establish a feeding and maintenance schedule for the organisms. Students investigate crayfish behavior and map where the crayfish spend time within their habitat. Through readings, organism cards, and a video, students learn about adaptations of organisms in different environments. Students engage in an outdoor simulation activity to explore food chains.

After the Daphnia was given time to calm down, the team took a reading of its heart rate at room temperature (27 degrees C). The reading was taken by counting the heart beats for ten seconds and then multiplying by six to yield beats per minute. Next, a glass Petri dish was filled with ice water at five degrees Celsius. The cold water Petri dish was placed on the stage of the microscope, and the Daphnia was placed on top of the dish. When the Daphnia had been given a minute to acclimate to the changes, another heart rate reading was taken. Then the same procedure using the Petri dish to changed environmental conditions was used with cold tap water (23 degrees), warm tap water (30 degrees), and hot tap water (45 degrees). A heart rate reading was taken for each temperature.

Crawfish naturally excrete phosphorous as well as nitrogen, and have enabled the lake to have a faster turnover rate within its waters thanks to their large numbers (University of Davis Centers for Water and Wildlife Resources, 1996). Warm-water fish not native to the Lake Tahoe area have also begun to thrive within the near shore environments because of the increase in water temperature, and continue to intrude on native fish. The rise in water temperatures is most likely from an increase in algae production within the near shore areas caused by the production of nutrients by the Asian clams, which in turn then feeds the growing crawfish population.

Introduction: In the previous lab class, students did an experiment on a water flea known as the “Daphnia Magna”. The experiment consisted of locating the Daphnia’s heart and counting its heart rate. The heart rate is the number of times the heart beats per minute. The normal beats per minute in that the heart should endure is 60-100 BPM, (> 100 Tachycardia & <60 Bradycardia).

Crayfish are crustaceans that are a part of the phylum arthropoda. Similar to the lobster, an organism within the same phylum, crayfish breathe via feathered gills. It is the use of these gills that allows oxygen uptake and thus the ability to survive in freshwater environments.

To begin the experiment, we took a single Daphnia magna from the unused tank to run control tests with distilled water on the untampered heart rate of the species. The species was placed on a concave slide with a new drop of water on it. It was given 2 minutes of recovery time to adjust to its new environment; then, the heart rate was studied by intervals of 15 seconds to find beats per minute by multiplying the number of beats in 15 seconds by 4. The Daphnia magna was studied under a light microscope with 40x total magnification. After each round of data collection, the water was absorbed with a Kimwipe so a new water drop could be placed on the species. The same Daphnia magna was used for six rounds of control experiments. After

The purpose of the experiment is to observe    and analyze the subject. What should be learned is, what are the most important parts for the crayfish to be able to survive. You should also learn what organs help the crayfish survive out in the ocean.

The PCR technic reveals that CHH was produced in the nervous system of the crayfish. However, this observation was only made in the crayfish from the experimental group. There was no trace of CHH in the PCR products of the control group.

Before attempting this lab, we conducted some research on what conditions catfish need to survive in an area. Catfish are better off at temperatures ranging from 88-90 degrees Fahrenheit. Their preferred dissolved oxygen levels are at least 4 ppm.(http://www.thefishsite.com/articles/1907/water-quality-monitoring-and-management-for-catfish-ponds/). The diet of catfish often changes as they age. Younger catfish primarily feed on aquatic insects such as dragonfly larvae, water beetles and fly larvae. By the time they're adults, catfish consume small fish, seeds, aquatic plants, algae, crawfish and snails.(http://animals.mom.me/catfish-eating-habits-9466.html). The alkalinity of the water needs to be at least 40 ppm but the catfish will be happier

The median concentration (nM) of serine amino acid extracted from crayfish was higher (M = 98, IQR = 20.5), compare to the sculpin amino acid extract (M=1 5, IQR = 20.5) shown in table 1 and 2. Likewise, threonine amino acid concentration was absorbed at a lower medium from sculpin (M = 6, IQR = 32.5), then threonine extracted from crayfish (M = 67, IQR = ). Arginine (M= 57, IQR = 60.5) and lysine (M = 78, IQR = 59) amino acid concentrations was measured at a higher value in sculpin extract, than what was measured from catfish extract. The concentration was collected based on the highest two amino

Connective tissues, usually found in tendons and ligaments, are what establishes a structural framework for the body by holding muscle cells together. Collagen is the dominant fibrous protein found in connective tissues. In meats, the amount of collagen found in the animal’s muscle will affect the texture of the cut consumed. High amounts of collagen will result in a tougher chew. Less exercised animal muscles contain low amounts of collagen and high amounts of fat, making the cut much tenderer in texture. For example, the loin of a cow will result in a more flavorful, easy bite cut than the legs of a cow.

Signal crayfish has become widespread through Europe in the last century due to human activities. Signal crayfish poses a threat for the endemic noble crayfish in most of the European countries as a vector of the crayfish plague and competition. As an invasive species, signal crayfish can alter the energy flow of the ecosystem through the food webs since, as omnivorous, it can feed from several trophic level, modifying the ecosystem assemblage. On the other hand, the noble crayfish is endangered due to several factors like water pollution, ecosystem alteration and crayfish plague; consequently, their restauration may be not possible. Therefore, this review aims to compile the effects of the invasive signal crayfish in European freshwater

Serotonin (5-hydroxytryptamine, 5-HT) is a neurotransmitter in the brain that has an enormous influence over many brain functions. It is synthesized, from the amino acid L-tryptophan, in brain neurons and stored in vesicles. Serotonin is found in three main areas of the body: the intestinal wall; large constricted blood vessels; and the central nervous system. The most widely studied effects have been those on the central nervous system. The functions of serotonin are numerous and appear to involve control of appetite, sleep, memory and learning, temperature regulation, mood, behavior (including sexual and hallucinogenic behavior), cardiovascular function, muscle contraction, endocrine regulation, and

According to a study of adult Crocodylus acutus by Wheatley et al (2012), 80% of the water ingested by adult Crocodylus acutus in Florida, directly or through food, was saline. This demonstrates a high saltwater tolerance and suggests that this species can exist independent of freshwater sources and does not need to use behavioural osmoregulatory techniques such as seeking freshwater to maintain hydration and health (Wheatley et al. 2012, p. 211). However, access to freshwater may still be essential for hatchlings (Wheatley et al. 2012).

Crustaceans such as lobsters, crabs and craw fishes has been the top choice for most chefs and fine dining restaurants as materials for their seafood dish specialties. This is due to the unparalleled taste and texture of the meat that can be obtained from them. Certain parts of these crustaceans have been singled out as the tastiest ones. These are the claws and the legs. For lobsters, the tail part is sometimes left out in preparing dishes because, according to chefs, have less desirable qualities. This may be a mistake for them because lobster tails are superb materials for some high end dishes. Knowing how to cook lobster tails informatively will allow us to fully maximize the culinary experience we get from lobsters. Some people fear