Essay by yasminaaaUniversity, Bachelor'sA, May 2006

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The effect of temperature, pH and lighting on the habitat preferences of Artemia Franciscana


Artemia franciscana, known more commonly as brine shrimp inhabit salt swamps and saline lakes. Few other organisms can tolerate such a high concentration of salt as is found in these locales. They thrive in extreme environmental conditions such as high salinity and temperature where predators cannot survive. Since few organisms can grow at such high concentrations found in certain lakes, brine shrimp have little selection in the way food. They live almost entirely on the photosynthetic green alga. The larvae (Nauplii) hatch from resting eggs in the spring. Temperature is a significant factor in control over hatching. Artemia populations are often dominated by asexually reproducing females. The eggs lain do not require fertilization, and rapidly hatch to produce more females. At certain times the eggs may give rise to both males and females. Often the appearance of males is attributed to a factor, such as a decline in temperature or increase in salinity.

Sexual reproduction produces different eggs, which fall to the lake bottom and can tolerate both freezing and drying. These eggs require a period of drying or low temperature before they hatch, some may stay dormant for years. In nature Artemia is found in neutral to alkaline waters, at temperatures generally below 34ºC. (Marques et al., 2005)

In this experiment we are attempting to figure what habitat preferences Artemia have. We are measuring the distribution of Artemia and the effect that various variables such as light, temperature and pH have on their distribution. A habitat preference experiment places the organism under study in a range of habitats intensifying single factors, in our case the lighting, temperature and pH conditions. Because Artemia is a mobile animal, when various conditions are made equally available to...