Calculating measurements under microscope

Calculating measurements under a microscope
You have an object under the microscope. The field of view is a circle of light. Using a low power objective, place a steel rule under the microscope. Let's say the field is 2.5mm, or 2500 microns under a 4x objective. Using a 40x objective, therefore reduces the field by 10, so it is now 250 microns
The object is smaller than that. You have already roughly measured the field and for that lens on your microscope You already know the object's length is smaller than 250µm. If your calculation gives something bigger than that, there is an error. Next, to calculate the object's length, first identify what you mean by the length. Once you have identified the length, figure out what portion of the field it covers. It may help you to imagine dividing the field into half, then dividing a half into two quarters, then dividing a quarter into two eighths, until you get to the size of the organism. That fraction times the field is the approximate length of the organism. Here, the organism's length is about 1/4 of a field, or 0.25 X 250µm = 62.5µm. To get the width: either do all of that again for the width, or eyeball the animal and estimate the width as a fraction of the length. For our organism we might say width = about 1/3 of length.
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Feeding Time October 24, 2008

Feeding Time October 24, 2008
On Thursday October 24, 2008 one pellet of "Atison's Betta Food" was added to each Micro Aquaria. It is made by Ocean Nutrition, Aqua Pet Americas, 3528 West 500 South, Salt Lake City, UT 84104. Ingredients: Fish meal, wheat flower, soy meal, krill meal, minerals, vitamins and preservatives. Analysis: Crude Protein 36%; Crude fat 4.5%; Crude Fiber 3.5%; Moisture 8% and Ash 15%

Male Adult Copepod (Cyclops)

From http://fmel.ifas.ufl.edu/COPEPODS.HTM

This is the twitchy moving clear critter seen on Oct 22.

Macrocyclops as Biological Mosquito Control

From: http://fmel.ifas.ufl.edu/COPEPODS.HTM

Larval Control with Copepods
Biological control is an attractive alternative to chemical .
Macrocyclopspesticides for the supression of mosquito pests and disease vectors (Lounibos and Frank 1994) Copepods for biological control have not yet been field tested in south Florida. We are maintaining cultures of several copepod species at FMEL and are conducting experimental trials with Macrocyclops albidus, one of the more promising predatory species.

Copepod predation (AVI)
We are testing the cyclopoid copepod Macrocyclops albidus (Jurine) for biological control of mosquitoes in laboratory microcosms, in controlled field conditions, and in a long-term field experiment using discarded tires. Preliminary results indicate that this predator is highly efficient in controlling mosquitoes in all three settings, reaching close to 90% reduction in larval survival under field conditions and exceeding the recommended predation rates for

Visiting Scientist from the PedroKouri Institute of Tropical Medicineprepares larvae for experiment.effective mosquito control in laboratory experiments. The predator is most effective on 1-4 day old larvae. Alternate food and habitat structure significantly influenced the predation rates on mosquito larvae.

Introducing copepodsand mosquito larvae intothe experimental tires.Once established, the copepod has been able to maintain long-term reproducing populations in the field. This copepod species is a promising candidate for control of mosquito larvae because it is a widespread and highly effective predator that is capable of establishing and maintaining populations under a wide variety of field conditions. Additionally, M. albidus is relatively easy to culture, maintain, and deliver to the target areas.
Summary

Mosquito larvae survival in the Roundhouse experiments. M. albidus is an effective predator of mosquito larvae in artificial containers and capable of drastically reducing larval populations. Marten, considers that other species, such as Mesocyclops longisetus and Mesocyclops aspericornis may be better suited for biological control in tropical areas because they maintain larger population sizes than M. albidus (Marten 1990b and pers. comm.). However, in this study, population sizes of M. albidus in field tires were much higher than previously reported from more temperate (Marten 1990b) and tropical (Marten et al. 1994) areas. Also, because of its cold-hardiness M. albidus should be better able to maintain year-round populations in subtropical areas than species recommended for the tropics, and may be able to survive even under extreme conditions (e.g. record cold weather) which in the sub-tropics are usually of short duration For example, Schreiber et al. (1996) reported sharp declines in the populations of Mesocyclops longisetus in field tires when water temperatures dropped below 5 C, but, as previously stated, M. albidus is known to survive for months at 0 C. This species demonstrated kill rates that are more than appropriate for mosquito control and is able to survive on alternate prey when larval mosquito populations are low. In the practical sense, this species is also a good candidate for use as a mosquito control agent. The species has a worldwide distribution so seed stocks should be easy to obtain, and practical and legal problems associated with exotic species introductions would not apply. Large numbers of copepods can be produced in a small space as they can be grown in small plastic pools, plastic garbage cans, and similar inexpensive containers; and cultures do not require heavy maintenance and are relatively inexpensive to maintain. Large numbers of copepods can be kept in water in a refrigerator for months, they can survive in soil and detritus that is only slightly damp (Marten 1989), and they are not killed by many pesticides commonly used for mosquito control (Marten 1989, Tietze et al. 1994). The lag (if any) between introduction of predator populations and effective mosquito control can be eliminated by initial treatment with larvicides or Bti (Tietze et al. 1994) or simultaneous introduction of other predators such as Toxorhynchites spp. (Schreiber et al. 1996). Another attractive strategy to eliminate the lag is to introduce the copepods in early spring, when mosquito populations have not built up yet and mosquito control personnel are not as busy as during the "heavy" part of the mosquito season. Work still needs to be done on effective strategies for large-scale deployment of the copepods. However, standard spray equipment can be easily modified and calibrated to dispense intact copepods (Marten 1989), and the fact that they can withstand almost-dry conditions means that storage and transport can be accomplished without having to also store and transport large quantities of water.

Pond Life Identification Page 10/26/08

http://extension.usu.edu/aitc/teachers/pdf/microorg/activities/pondlife.pdf

Excellent chart of basic pond life

Observation 10/22/08

Notable Changes this week:

Water had evaporated substantially, leaving about ony 25-30% of original moisture. Added fresh water from lab source (distilled?) as a refill. Noted several green organisms not noticed before. One is a Desmid, about 12 of these near center of tank, slowly moving, more like floating. These are identified under 40x microscoope, look like European cucumbers, and are apparently single celled because of the single nucleus at the restrictum. Also noted 3 or 4 Pleurotonea, also green, stick-shaped, also single cell with a distinct dividing line in the center.

Also, one prevously unnoticed animal, possible the Cyclops from last week in another life phase. Also, what were previouslt thought to be paramecia are more likely Spirostome, pictured and described below. Information from: http://www.microscopy-uk.org.uk/index.html?http://www.microscopy-uk.org.uk/pond/index.html

The genus Spirostomum contains some of the largest Ciliates. The species pictured on this page, Spirostomum ambiguum, can grow to to a size of more than 4 millimetres. It can therefore be seen without the help of a microscope. When observed swimming in a little jar of pond water it looks like a little worm. Only with the help of a microscope you can see that it is a ciliate. The cell of this unicellular is totally covered with hairlike 'cilia'. On the picture you can see the rows of cilia running like a spiral along the body.
One of the remarkable things of Spirostomum is the way it can contract. The organism can contract it's body to 1/4 of it's length in 6-8 millisec which is the fastest contraction known in any living cell. When observing the creature under the microscope it is easy to watch the contraction by gently touching the sample.

Like many large single celled organisms (giant amoebas, or Stentor: the trumpet animalcule) it has not one nucleus but many. The nucleii form a long strand, like a string of pearls, visible as the lighter structure in the right image.
Spirostomum, like many cilates, feeds on bacteria. They are swept into the mouth opening with a row of specialized fused cilia. The mouth opening is very small and can be found on the side of the body.

These critters move in a spiral, slow fashion.

A variety of Desmids are shown below. The cucumber shaped one ant the more stick-shaped Pleurotoneum are in the study tank. Photo from
DESMIDS
by Wim van Egmond

http://www.microscopy-uk.org.uk/index.html?http://www.microscopy-uk.org.uk/pond/index.html

Microaquarium Assignment/Setup 10/15/08

According to the Term Project Assignment posted at http://botany1112008.blogspot.com/, a microaquarium was set up including the following items/organisms:

A) Pond water sample from Tommy Schumpert Pond, Seven Islands Wildlife Refuge, Kelly Lane , Knox Co. Tennessee. Partial shade exposure Sheet runoff around sink hole. N35 57.256 W83 41.503 947 ft 10/12/2008

B) Plants include those native to water sample above, and added plant sample B. Utricularia vulgaris L. Flowering Plant. A carnivous plant. Collection from: Greenhouse in White Ave Biology Annex. The University of Tennessee. 1400 White Ave. Knox Co. Knoxville TN.Partial shade exposure N 35o57' 33.45" W083o55' 42.01". 932 ft 10/13/2008


Initial setup included a small layer of sediment, mossy vegetation from water sample, and a small sample of plant B. All directions under Botany 111 Bolgspot were followed closely. In addition, all sources used for identification and information will be cited throughout the study. The following observations were made immediately after initial setup:

Many paramecia, especcially near the "buffet" at the bottom of the tank. Lots of small rotifers and a few unidentified flagellates. Two apparent insect larvae, appearing as worm-shaped sgmented slow moving objects. One cyclops, apparently female due to the egg sacs on both sides. See following information from http://www.microscope-microscope.org/applications/pond-critters/animals/cyclops.htm

Cyclops are crustaceans and related to lobsters, crabs and shrimp. They are invertebrates with a hard outer shell. They swim freely about.
The cyclops has 5 pair of legs and a divided tail-like appendage called a furca. The Cyclops is very small about 2-3mm long with one black or red eye in the middle of its head. The cyclops is named after the one-eyed monster of Greek legend. It is greenish, straw yellow, or grayish in color. It goes jerking through the water usually in very large numbers. The females carry the eggs (shown in picture) in little side sacs and they multiply rapidly. The cyclops is often seen near water fleas or Daphnia. Many water animals feed upon the cyclops. It has a very important role in the food chain.

10/19/2008

Initial Blog Setup for Botany Lab