In this experiment, 40 brine shrimp eggs are put into a test tube containing salt water at different temperature such as 25°C and 35°C respectively. The eggs are left from two days to hatch. After two days, the number of eggs successfully hatched are observed and counted. Introduction
Brine shrimp is the common name for a primordial crustacean that reaches less than 1.3 cm in length and is usually used as fish food in aquariums. Brine shrimp can be found almost everywhere in the world in inland saltwater. Although brine shrimp are considered to be members of a single genus, Artemis, and possibly a single species, there are a number of varieties. Brine shrimp are classified in the phylum Arthropoda , subphylum Crustacea, class Branchiopoda, order Anostraca.
Generally, they have stalked compound eyes and tapered bodies with a trunk that bears 11 pairs of legs. Females have a brood pouch where the young are released under favourable conditions. Otherwise eggs are laid parthenogenetically and eggs the can be dried and remain viable for many years. These eggs are extremely resistant to unfavourable environmental conditions. Brine shrimps are used for fish food. On the the hand, adult brine shrimp are also used as food in aquariums and are generally sold frozen.
Figure 1: Brine shrimp
Brine shrimps are categorised as a “rapid-cycling” animal. These simply carry the meaning that these organisms grow and complete their life cycles quickly. They grow quickly - within 24 hours and mature in 3 months time. Due to these special features, this animal is very ideal for this biology experiment. Once placed in water, the cyst-like eggs hatch within a few hours. The nauplii, or larvae, are less than 0.5mm in length when they first hatch. Brine shrimp have a biological life cycle of one year, during which they grow to a mature length of around one cm on average. This short life span, along with other characteristics such as their ability to remain dormant for long periods, has made them invaluable in scientific research, including space experiments. Problem statement
What temperature is most suitable for the hatching of brine shrimp eggs? Objectives
1. To develop certain experimental skills, namely considering the ethical issues arising from the use of living organism, presenting reliable results, identifying trends in data and drawing valid conclusion. 2. Develop an understanding of how the growth and survival of an organism depends on physical conditions of their environment. Aim
To investigate the effect of temperature on the hatching success of brine shrimps. Hypothesis
The hatching success rate of brine shrimp eggs is the highest at optimum temperature, 25oC.
40 brine shrimp eggs are put in a 2 test tube respectively containing saltwater. The test tubes are left in room temperature which is 25°C and a water bath of 35°C respectively. The number of eggs hatched successfully is counted after a day. Variables
Variables| Method of conducting the variables|
Manipulated : Temperature the test tubes containing the brine shrimps eggs left at.| The beakers containing brine shrimp eggs are left in different temperatures like room temperature (25°C) and a water bath of 35°C respectively.| Responding :Number of brine shrimp eggs hatched successfully.| The number of eggs hatched successfully is counted after a day by observing it under microscope.| Constant :The concentration and volume of salt water.| The standard salt water solution was prepared by dissolving 2g f sea salt and 100cm³ of de-chlorinated water and only 30cm³ of salt water was used in each beaker.| Apparatus
1. 100 cm³ beakers
2. Stirring rod
3. Access to refrigerator
4. Water baths or incubators (one for each temperature to be investigated)
5. Magnifying glass
6. Pair of forceps
7. Bright light...