Artemia Reaction to Different Light Sources

Bip105-8

March 11th, 2016

Artemia Reaction to Different Light Sources

Abstract:

        Artemia are genus of aquatic crustaceans that are mostly found in saltwater and have the ability to live in high salinity. During this experiment, Artemia were placed in different light levels in order to determine the preferred light intensity. There were significantly more Artemia found in dark light at 0.00µmol/meter2  than found in room light at 4.60µmol/meter2 and intense light at 103.1 µmol/meter2 (x2=56.28, P>.001). These average results were significantly higher than normal critical value and most Artemia would usually be found in places with more light to achieve higher productivity rates.  

Introduction:

Artemia are a genus of aquatic crustaceans known as brine shrimp. Populations of Artemia are mostly found in saltwater lakes, but never in oceans and have the ability to live in waters with very high salinity. Being able to live in high salinity and sensitivity to pollutants, they are ideal organisms to test the toxicity of chemical compounds. Artemia also have the ability to dormant eggs, known as cysts has aided the use of Artemia aquaculture as well as thin shelled eggs that hatch immediately. As Artemia grow and develop, they go through a series of different stages separated by molt. Warm water creates plenty food and high oxygen levels that allow adulthood to come quickly and reproduce quickly, whereas if temperatures drop food becomes minimize and females release dormant cysts. Cysts can remain dormant for many years, but when they are exposed to favorable conditions the cysts swell and development resumes. In example of a favorable conditions would be light, when Artemia cysts were incubated, hatching rates increased with increasing light intensities (Vanhaecke, 1981).

Cysts were able to hatch at and increasing rate with a high light intensities, the question that was studied during this experiment was what would happen with Artemia and different light intensity. During an experiment with ocean shrimp, Pandalus Jordan, and the effect of artificial light on bycatch reduction (Hannah, 2015). For this experiment, in order to try and determine how Artemia would be attracted to different light, we placed them in conditions.

Methods:

Use two clear glass tubing with three different sections, fill both tubes completely with Artemia and seawater. Once filled, lay the tubes on a flat surface. On one end of the tubes place two lamps directly facing the tubes, and on the other end cover the tubes with a dark cloth. The middle tubes should be left untouched, this is the control. Each tube must be placed with a screen on top to divide the light sources and keep error to a minimal. Let experiment sit for 30 minutes. Once the time is up, place tubing clamps on each divider and pour each section into individual beakers. From each of the six beakers, take four .25ml of Artemia in seawater and place them on different dishes. This should be done for the intense, room, and dark light to count the number of Artemia on each dish. There should be a total of 24 numbers. After observation, Chi-Squared analysis was used.

Results

[pic 1]

Figure 1. Average number of Artemia found at different light intense. Dark (no) light is at 0.00 µmols/m2. Room light is at 4.60 µmols/m2. Intense light is at 103.1µmols/m2.

The results show that majority of the Artemia preferred an environment that had no intense light. There is about 24 more Artemia found in no light than room light and around 97 more found in no light than intense light (Figure 1). Dark light is more favorable condition for the Artemia studied for this experiment than intense light and room light is still more favorable than intense light. There is a significantly more Artemia found in no light than in room light and intense light (x2=56.28, P>.001).  The Chi Square values tell us that the observed amount of Artemia was significantly different, each light level contained a different number of Artemia; no light had about 131, room light had 103, and intense light had 34.