Fish Ventilation Essay
Goldfish (Carassius Autarus), when subjected to warm temperatures will have a high rate of ventilation compared to those exposed in colder environment. In a class experiment, we observed and recorded the effects of water temperature at [25 C] warm and [15 C] cold on ventilation and consumption rates in goldfish. For one hour at 15min intervals we observed differences in both ventilation and consumption rates in which, in warmer temperature were higher, while in colder setting there was a decreased. These findings suggest that temperature plays a major role on both oxygen consumption and ventilation rates in this species of fish. Temperature is one of many factors known to affect metabolic rates.
Introduction The survival of most animals requires a process in which oxygen is acquired and carbon dioxide is eliminated from the body. Oxygen is essential for the production of ATP from nutrients in cells and therefore must be delivered to cells in sufficient amounts. Diffusion takes place when air or water is drawn in from the environment by animals spreading from a region of high concentration to a region of low concentration. However, in larger sized animals diffusion is not very efficient, so most animals have developed respiratory organs that can be utilized for ventilation purposes. Ventilation is the process in which air or water containing oxygen can be drawn on. An attachment to the respiratory organs called the circulatory system, delivers oxygen and other nutrients throughout the entire body. Since the space between the respiratory surface and circulatory system are in such close proximity, diffusion is sufficient in providing the necessary amounts of oxygen needed. (Model, J., C. Hood, E. Kuck and B. Ruiz, 1971)
In the class experiment we used a goldfish, an animal that lives in water and has only limited amount of oxygen which has dissolved in water. They must find an equilibrium in which they absorb enough oxygen, and are supplied with unique set of organs. The secondary lamella of the gills is the site for gas exchange in fish. Water that is pumped in the mouth of the fish flows over the gills. The flow of the water and the flow of the blood held in the capillaries of the gills operate in different directions. Diffusion removes carbon dioxide via sending it through the blood and into the water passing over the gills and thus removes it from the animal’s body. Fishes that ventilate their gills and absorb oxygen while in a closed chamber can lead to decrease of oxygen that is present in the medium. The amount of oxygen consumed can be calculated in the fish by measuring the amount of oxygen available initially and then measuring the oxygen levels at later times. This is a measure of the overall metabolic rate of the fish. (Shields & Grossfield 1979).
The reason for our experiment was to examine the effect (s) of temperature in fish. We hypothesized that there will be a difference in metabolic rate in goldfish and our null hypothesis stated there will be no change in metabolic rate. We observed in our experiment the amount of oxygen that dissolves in water will decrease as temperature increases. Therefore, a fish that is in warm water faces two problems: increased demand and decreased supply. If fish are subjected to at different temperatures, then we will observe differences in the ventilation and consumption rates in the two groups. One way in calculating these effects is by calculating Q10, it represents an increase of 10 degrees Celsius temperature. Our expected Q10 is between two to three, which is common for most biological reactions. In the duration of our experiment, our recorded data provided evidence of the changes in temperature. We can conclude that goldfish metabolic rates are based upon its environment, based on temperature.
Materials and Methods Goldfish, or Carassius Autatus, were used in conducting this experiment. Each group retrieved two goldfish that weighed about the same. The groups then placed each fish in a small jar filled with aerated spring water in an aquarium in which they were housed to settle for 10 mins. This was done so the goldfishes could be accramated in their new environment. We measured the ventilation and metabolism of the fishes at two different temperatures. One fish housed at room temperature (approximately 25 C) and the other at a colder temperature (approximately 15 C).
The water in the cold tank was kept cold with a two liter bottle of ice. For each fish, a 250mL jar was filled half way in which the goldfishes were to be housed, one for cold and one for warm temperatures. The fish were then allowed to settle in their new environment for about 10 mins then goldfish was stabilized with a sponge placed inside of the jar. The sponge was to prevent the fish from interfering with the oxygen probes. The experiment was ready to begin after overflowing the jars with water. We then quickly inserted the calibrated oxygen probes to ok the initial oxygen concentration (mg/L) and temperature (C) readings. The groups then recorded their data by counting the operculum movements per minute every 15 minutes for one hour. The results of ventilation, oxygen concentration and temperature were recorded in a data sheet.
Calculations We converted those results from mg of O2/L of water, to mL of water by dividing each value by 1.43. Our second calculation involved dividing our values of mL of O2/L with the corresponding weight of our goldfishes. Those values (mL/g) were then subtracted by the concentration during the time period from the concentration at zero minutes to determine oxygen consumption.
Discussion Temperature is one of the most critical environmental factors influencing behavior of aquatic animals in their environment. The body temperature of ectoderms has to be in equilibrium with the surrounding water. In our experiment there was a gradual increase in mean of ventilation in our goldfish at 25 degrees Celsius in warmer setting and a decrease in ventilation at 15 degrees Celsius in colder temperature. Our hypothesis was supported because we expected there to be an increase in ventilation and oxygen consumption at the warmer temperature of 25 C, and a decrease in the colder setting of 15 C. Upon analyzing our data and graphing our results we the two trends were realized. A t-test indicated a 95% confidence level that there was a significant difference in O2 consumption between temperatures. We can accept our hypothesis as being supported.
In colder environment (15 C) less oxygen was available to the fish which likely affected the goldfish metabolic rate as well. In warmer temperature (25 C) we observed an increase in oxygen consumption, and metabolic rate was equally affected. Going back to our data, we follow this trend after each treatment. It can be deduced that temperature has an effect on the behavior of the goldfish and other sea animals, it is essential to their survival. Goldfish were built for cool temperatures, their metabolism work best at around 25 C, if they are colder their metabolism will slow down and initiates hibernation. This behavior will vary from species to species depending on how they evolved.
Although our data seems conclusive, we must take into account possible error (s) that may have skewed our data. For example we do not know the prior environment of our goldfish which is important to know, because our fish may not have been in the best of health resulting in erroneous data. Furthermore, the equipment used may have had slight malfunctions unkown to us that would cause false readings. In a further experiment we can include the metabolic rate and determine whether the increases and decreases in oxygen consumption in different temperatures, follows a similar trend in the goldfish’s metabolic rate.