Testing the Effect of Differing pH Levels on the Heart Rate of Bivalve Mollusks

Taking about a week to fully mature into an adult and living for several months, the shrimp do have a surprisingly long life cycle being also able to reproduce up to 300 cysts every 4 days in the right conditions. Other variables such as salinity, temperature, light, pH levels, water levels and predatory presence play a large role in the hatching rate of the crustacean. The brine shrimp are an extremely versatile micro-crustacean as they can survive up to 10x salt concentration of ordinary sea water (Eol.org, 2016) and are able to protect themselves during drought or when conditions are not ideal for survival. This is called highly resistant encysted gastrula embryo (cyst) that is easily able to hatch under conditions that can be replicated at home.

The dive response is known more popularly as a mammalian dive reflex. It is a survival mechanism built into mammal’s bodies, essentially. Over the years, scientists have been determined to find what triggers mammals to have a decreased heart rate when submerged under water allowing them to stay under the water longer when they do not typically live under water.

Table 5. The effects of Atropine measured by the ventricle of the frog’s heart by amplitude, period, and BPMs.

To determine the principals of osmoregulation, we sampled two lobsters from each tank and there were three different tanks which the water ranged in salinity. The experiment is to determine whether the six lobsters tested are osmoregulators or osmoconformers, this is done by obtaining a sample of hemolymph. The first step of the lab is to prepare the needle and syringe that will be taking the hemolymph. The syringe size was 1 ml, and the intention is to collect between 0.5 and 1.0 ml of hemolymph. The needle size was 20 gauge, because anything smaller would destroy the hemolymph cells. Then the lobster was picked up with a firm grim around the dorsal celphao-thorax region and flipped over to expose the ventral side. The

The two drugs that have been used in this experiment to test their effects on the heart rate and depolarization rate of the P wave of the crayfish. Depolarization is defined as the contractions of heart muscle, and it is shown in P wave pattern of the ECG. Comparing the results of the trials of epinephrine drug to the resting state, it shows that this drug increases the heart rate, decreases beat period, and decreases the time that take

Daphnia magna, arthropods of the subphylum Crustacea, are widely used during laboratory experiments because they are very sensitive to many environmental parameters including temperature and chemical contaminants (Cornell, 2009). In this experiment, Daphnia magna were tested under different experimental factors, including temperature changes and exposure to different chemical, in order to observe the effect of environmental conditions on their heart rate.

Their bodies are encased by an uncalcified shell, carapace, and they can reach lengths of 5mm with a kidney bean shape (Ebert, 2005). The Daphnia magna live in mostly freshwater environments, but can live in certain brackish water areas. In comparing males and females the males have smaller body sizes, larger antennas a modified post-abdomen (Ebert, 2005). The Daphnia magna are good test subjects to assess the effects of the plant defense compounds of caffeine and Kava-kava, as they are easy to care for, inexpensive, and the effects of the compound are easily noted through looking at the heart rate of the organism under a microscope. This experiment required the use of a two-tailed t-test to determine whether there was a difference in heart of the Daphnia magna before and after the plant defensive compounds (caffeine and Kava-kava) were introduced. This test also helps to see if the difference in the test is statistically significant, which determines if the results obtained occurred by chance. A t-value is obtained to get the probability value and as the t-value increases it “signifies a larger meaningful difference between the two groups” (Blanar, 2017) and as it decreases the opposite happens. If a t-value is smaller than the t-critical value the null hypothesis is accepted, but if the obtained t-value is larger than the t-critical value the null hypothesis is rejected. A p-value is also important for this experiment, as it is the probability the null hypothesis is correct. The null hypothesis for this experiment was that there was no difference in the Daphnia magna heart rate after the plant defense compounds (caffeine and Kava-kava) were added compared to before, while the alternative hypothesis generated was that there is a difference in the Daphnia magna heart rate after the plant defense compounds (caffeine and Kava-kava) were added compared

In testing the respiration rate of two crayfish, one smaller than the other, 100 ml of water are placed in three separate beakers. One a control, two for the different crayfish. The separate crayfish are then measured for their volume. This is done by placing 50ml of water in a 300ml graduated cylinder, the placing each crayfish in the graduated cylinder, noting the increase in volume, that is the crayfish’s volume. The crayfish are then placed in their individual beakers. The beakers are then covered with Para film and allowed to sit and respire for 15 minutes. After 15 minutes the crayfish are removed and returned to their water tanks. Four drops of phenolphthalein are added to each beaker. Nine test tubes are obtained, 3 test tubes for

The most likely environment in which these organisms lived would not be terrestrial or freshwater but a coastal marine environment with varying levels of salinity since the sea water would advance and retreat with the tides. The gastropods would require moisture from the ocean to prevent desiccation while the bivalves would be able to survive longer periods exposed since the shell could be closed temporarily until conditions were favourable.

Shells before 1884, were high-spiraled with thin walls. Compared to the shells found after 1884 were low-spiraled with thick walls. After doing some research, Seeley found that an intertidal crab, Carcinus maenas, had sought after the snails for food.(Seeley) It was found that the shell size had changed due to the harmful

They appeared at about the same time as the ammonites. The two groups have some anatomical and developmental traits in common that set them apart from the nautiluses, but they are much different. Ammonites relied on their shells for defense as well as buoyancy while coleoids had internal shells that they did not use for defense. Some coleoid groups have also discarded the shell as a buoyancy aid. Seen in Figure 3, Octopuses, and their close relatives, the vampyromorphs, have lost their shells independently. The squids have shells that no longer provide buoyancy but unlike octopuses, the squids kept their shell for support

The intention of the experiment was to measure how different pH levels affect the heart rate of daphnia. The objective of this experiment was to measure the heart rate of

Lobsters were once the biggest organism on the earth. Aegirocassis benmoulae was the name of this massive beast. It had lived around 480 million years ago. It had fins on the body on the bottom of its body. It has adapted to its surrounding by using claws. It uses its claws to snatch food. Also to fight off attackers. The lobster also has a hard shell to protect itself. These are some fascinating adaptions of the lobster.

Many bivalves are infauna organisms where they burry deeply more than 30 cm and live as permanent burrows where they will move deeper as they grow larger (Gosling, 2003). Although most of them are burrowing organisms, there is also group that live permanently attached on the surface or known as epifauna and epibenthos is groups that live in association with seafloor but also swim temporarily above it (Huber, 2013). Bivalve possess two halves of the mantle that are fused around the edges, with openings anteriorly for the foot and posteriorly for the exhalant opening where the water will expelled from the pallial cavity (Bunje, 2001) as shown in Figure 2.1. In addition, within this posteriorly is also located the inhalant opening that carried

An investigation into the effects of varying seawater concentrations on two marine invertebrates’ osmoregulatory abilities; Carcinus maenas and Arenicola marina.