Praying Mantid Eggcase

What is the difference between complete and incomplete metamorphosis in insects?

Incomplete and complete metamorphosis differ in the number of life cycle stages insects go through during their transformation from egg to adult. Complete metamorphosis has 4 life cycle stages and incomplete metamorphosis has 3 life cycle stages.

Complete Metamorphosis

Complete metamorphosis has four distinct life cycle stages: egg, larva, pupa and adult. Examples of insects that go through complete metamorphosis are butterflies, silkworms, mealworms and ladybugs. The larva can be worm-like, although you can still see the six legs. The larvae for moths and butterflies are called caterpillars. Maggots are the larval stage of flies. The larvae eat constantly and grow rapidly. A hard, protective case forms around the larva…this is the pupa stage. The pupa stage for a butterfly is called a chrysallis. The pupa stage for a moth is called a cocoon.

Incomplete Metamorphosis

Incomplete metamorphosis only has three life cycle stages: egg, nymph, adult. The nymph looks similar to, but a smaller version of, the adult. The nymph is also wingless. Examples of insects that go through incomplete metamorphosis are stinkbugs, earwigs, crickets, grasshoppers, cockroaches, ants and praying mantids.

Keep the lid over your plate to prevent contamination.

All living organisms require energy. They can get their energy from multiple sources: organic chemicals(carbon containing compounds), inorganic chemicals and light. Bacteria use organic chemicals, such as, sugars, starch, protiens and fats to grow. Bacteria are called heterotrophs.

Most bacteria grow best at normal, human body temperature (98-99 degrees F). When growing the bacteria, incubate at a temperature as close to this as possible. The bacteria will grow slower at lower temperatures.

Aseptic technique is the process of growing and transferring bacteria without contaminating the culture by touching or breathing on the sample.

Nutrient agar is a general purpose prepared media and grows many types of bacteria and fungi. If you have a specific bacteria culture, you can spread the bacteria on the plate using a sterile swab or innoculating loop. The bacteria will grow and become visible in 24-48 hrs. If you would like to determine the types of bacteria growing on a sink, chair, table or other areas, a sterile swab can be used to rub across the area you would like to test. After the sample is taken, you can transfer the bacteria to the nutrient agar plate by swiping the swab across the surface of the agar plate. After 24-48 hrs, you may find many, different looking colonies growing on the nutrient agar plate. Each type of bacteria look a little different (color, shape, size) when they grow.

Bacteria can be differentiated based on how they react to a a procedure of dying cells called Gram stain. Bacteria are divided into a group that turns purple (gram positive) and a group that turns red (gram negative). Bacteria that are gram (+) include Staphylococcs, Streptococcus, Bacillus and Micrococcus. Gram (-) bacteria include E.coli and Salmonella. The Gram staining procedure is as follows:

Gram Staining Bacteria Procedure
1.Place a drop of distilled water on a slide and, using a swab or inoculating loop, mix the bacteria with the water an smear the mixture on the slide. The mixture will appear cloudy. Using a flame, heat fix the bacteria to the slide (pass the slide through the flame a few times to “dry” the bacteria and affix it to the slide).

2. Using a dropper, add crystal violet to the slide. Let stand for 1 minute.

3. Add iodine to the slide. Let stand for 3 minutes.

4. Decolorize the sample with alcohol. Let stand for 30 seconds.

5. Counter stain the sample with safranin. Let stand 1-2 minutes. Using a dropper, rinse with distilled water.
Gram Staining Results
Gram positive bacteria will appear purple under the microscope. They have a single, thick cell wall. The crystal violet and iodine combine to attach to this wall. The decolorizer (alcohol) dehydrates the cell wall, causing the pores to close, trapping the stain inside. the safranin added in the final step, does not penetrate the wall.

Gram negative bacteria will appear red. The have a cell wall and additional thin layers of fatty sugars. The decolorizer easily penetrates these thin sugar layers, washing away the crystal violet – iodine chemical (purple color). The safranin in the last step attaches to these layers and appears red.

How to Hatch a Chicken Egg

No other bird in the world has a larger population than the chicken, chickens are used mostly as a food source as well as for their eggs. Succesfully hatching chicken eggs is a 21 day process. By using an automatic egg turner and still air incubator, the process can be very simple and successful.

Day 1 – Place the chicken egg incubator on a level surface, fill trough with water, place automatic egg turner in (if you have one), adjust temperature to 97 degrees F and place the chicken eggs small end down in the turner.

Day 2-3 – Monitor temperature and water level. During the chicken egg hatching process, leave the chicken egg incubator closed except for adding water.

Day 4 – Remove the red plugs for ventilation and check water level.

Day 5-13 – Monitor temperature and water.

Day 14 – Chick development and metabolism during the incubation may cause the temperature to rise. The temperature may need to be reduced. Monitor this until day 18.

Day 15-17 – Monitor temperature and water trough

Day 18 – The eggs are getting close to hatching. Remove chicken eggs from turner and the turner from the incubator. Place chicken eggs on the wire tray and fill the large and small trough with water. Raise the temperature to 98 degrees.

Day 19-21 – Maintain the temperature at 98 degrees. Allow the chicks to hatch and dry in the incubator.

Some chicken eggs may hatch slower. Leave them in the incubator for 2 more days. Supply heat lamp, chick feed and water for the chicks.

Crayfish are marvelous classroom organisms. They are exciting and easy to care for. Through close observation, students can learn interesting details about animal structures while developing sensitivity to the needs of living organisms.

About
Crayfish are also known as crawfish, crawdads, mudbugs, and yabbies; they resemble and are related to lobsters. Crayfish most commonly live in freshwater, only a few have the ability to survive in salt water. There are over 500 different species of crawfish in the world and more than half of them are located in North America. Specifically, Louisiana produces 90% of the world’s crayfish for consumption as food.

Care
To keep your pet crayfish comfortable you will need to keep it in a freshwater aquarium, a fish tank will work just fine. Make sure to cover any holes in the lid of the tank to keep your crayfish from escaping. Feeding your crayfish is simple; many common fish foods will work. Pet crayfish will eat shrimp pellets, vegetables, fish food, algae wafers, goldfish, and minnows. Be careful which fish, if any, you put in the aquarium with your pet crawdad because they will attack and eat fish if they feel threatened or if they appear to be an easy snack. When using a prepared food, do not overfeed. The excess food will spoil the water.

Crayfish from the wild may have mud on their swimmerettes. The crayfish need to be purged (placed in clean, dechlorinated water) to remove the mud. Depending on how much mud is present, several water changes may be necessary.

Crayfish like to have a place to hide. The crayfish will molt, shed it’s exoskeleton. During the few hours after the molt, the crayfish has a soft exoskeleton and is vulnerable to predators. The larger the crayfish grows, the longer the time is in between molts. Crayfish have gills for breathing underwater, but can also breathe air.

What is a Geode Rock Formation
Geodes are a great way to view and learn about the formation of rocks. They occur in sedimentary as well as some volcanic rocks too. These geological rock formations are most commonly limestone on the outside, while the inside is hollow and full of quartz crystals. If there is no air pocket in the formation it is called a nodule instead of a geode.

How Do Geodes Form?

A geode starts off as a bubble or a void left by an animal burrow, tree root, or something else. Water is trapped inside of the void, which contains silica precipitation that has other minerals or elements present in it such as calcite, iron or manganese. The basic crystals of a geode are made of quartz (silicon dioxide) and are colored based on the contents of the surrounding soil.  Over thousands of years different layers of silica precipitation cool and create different layers of crystals. There is no way to tell what is on the inside of a geode without cracking it open. You can view the process of cracking open a geode below.

Earthworm Lifecycle

A species of the earthworm can be found on every continent in the world. They burrow through soil and help keep it healthy. Some species of earthworm can grow over 13 feet long, all though most are a lot smaller than that. Earthworms have been dissected in science rooms throughout the world, although if dissection is not an option, you can use lifelike plastic figures to represent the earthworm lifecycle.

Earthworms have both organs needed for reproduction; the term used for this is hermaphrodite. When earthworms mate they lay next to each other and pass mucus like substance that allows each worms organs to be fertilized. After the earthworms mate they form eggs inside their bodies, then the worms separate and form cocoons which seal when they rolls off of the worm. The cocoon is buried underground and the hardened walls protect the forming worm.

The worms hatch as smaller earthworms that lack reproductive organs; this is the main difference between newly hatched worms and the fully developed. The worms start to develop reproductive organs after they are hatched. They are able to use their reproductive organs at around 12 months. Earthworms can sometimes live for more than 10 years depending on the species. In the United States earthworms range in color from red to brown, and in other countries they can be blue or green.

Check Out These Large Earthworms

What is Magic Snow?

Magic snow is an absorbent polymer that is safe and non-toxic, it has the ability to expand up to 40 times its original volume. The snow starts out as a simple powder that looks similar to sugar or salt. The magic happens when water or other liquid is introduced to the magic snow, which quickly expands to absorb the liquid.

How is it Used?

Hollywood uses it for special effects, many people use it to decorate for parties, and thanks to its low price you can use
magic snow for fun. When using magic snow, use it on a dish, bowl, cup, test tube, or anything else that will help you contain the magic snow. First place the magic snow into the container of your choosing, next sprinkle a small amount of magic snow into the container. Then add a small amount of water and watch it grow. Use more in the following trials once an idea of the amount the magic snow expands is gained.

Example





Do not let magic snow into drains or pipes; it will expand causing them to clog. The best way to dispose of magic snow absorbent material is to put it in a plastic bag and then in the trash. Do not rinse the container you use for magic snow creation in the sink, even a little can cause clog. However if you do accidentally clog a drain, a small amount of bleach will clear the drain.

Hermit Crabs

The following information is general care information for a hermit crab and is provided by Heath Scientific. Heath Scientific has a full supply of live critters for educational institutions and home school environments. See the Live Critter section of our website.

If you want detailed information on caring for a hermit crab, visit the Hermit Crab Care Blog.

Temperature – 72-88F

Light Requirements – Indirect sunlight (Classroom lighting)

Feeding – Prepared invertebrate diet, supplement with fresh fruits and
vegetables.

Habitat – As a “tree crab” they live on land in coastal areas where it is
warm and humid.  They return to salt water to lay their eggs.

Handling – Crabs don’t bite but they will pinch very hard.  Handle them by
their shell.  They may be placed on the floor for exercise.  If they are
inactive, dip them in warm water and they will become active again.

Care – Hermit crabs need little care other than daily food and water
changes.

When an adult butterfly emerges from its chrysalis, it secretes a red liquid that often drips down to the bottom of the habitat.  This is not blood.  It is actually a liquid known as meconium that is the natural secretions created while in the chrysalis.  This is natural and you should explain this to children during a butterfly life cycle project so that they do not think the butterfly is injured or that something is wrong with the experiment.