Alan and Angella took me out for lunch to the Samuel Barlow @ Alvecote – a lovely little pub next to the canal. Before we left, we took a water sample from the canal. The sample proved to be relatively sterile – I suspect due to oil from the multiple boats in local marina.
On analysing the specimen, this diatom could be seen, viewed through my Zeiss IM35 microscope. I concentrated the specimen first using a centrifuge. Otherwise the following are live unstained views. Colours on the diatom are due to refraction as the organism’s shell is crenulated, refracting light, and has depth making it impossible to focus precisely upon it, worse when magnification increased.
For last few months, I have been cultivating a “pond” in a large pot in my garden.
The following photos are taken from a sample from the bottom of this pond today, using my Leitz Laborlux 11 microscope and Bresser Microcam SP 5.1 camera, with x4, x10, x40 objectives.
The photos and video below are all based around highly magnified microscopy of the antennae/legs of a small 2-3mm crustacean I found in the sample. In particular, I focus on other animal life (single and multicellular) living on or around these structures.
I used the centrifuge to concentrate down material from “open water” in the pot pond (i.e. not near edge or bottom or plants) and views the result in the LOMO Polam P-113 microscope, by bright field & crossed polarisation.
Note that such open water samples do not contain diatoms – which are famously birefringent.
Birefringement material pot pond slide 280518@1642, x20 objective:
Birefringent material slide from pot pond 280518@1703, x20 objective:
Insect on slide pot pond water 280518@1626 panorama, x20 objective:
Slide from pot pond: birefringent material shown in sequence as I moved the second polarised filter from 0-90 degrees so that the sample moved between crossed polarisation and bright field, 280518@1639 (below):
Slide from pot pond highly birefringent organisms brightfield x20 obj 280518@1635:
For the last few weeks, I have created myself a garden pond in a large plastic pot about 80cm across and similar height. Today, I noticed a large population of mosquito and other larvae.
I sacrificed one of these larvae today to view its structure under crossed polarisation on my LOMO Polam P-113 polarising microscope.
I had read online that muscle shows up on crossed polarisation. Certainly, the photos below show birefringence which might be muscle.
I am particularly pleased with the photo at the bottom. I managed to work out how to use layers in GIMP2 and change relative transparency between the layers and consequently combine the bright field and crossed polarisation images so that you can see where the colourful polarised tissue is located.
The strips of birefringence follows down the side of the larval body. The photo above this one shows this follows the organism around. From http://www.sciencephoto.com/media/74993/view/mosquito-larva-light-micrograph, it would appear that this represents muscle bundles down the side of the insect.