the image numbers below to view the photographs:
of genus Vorticella represent one of the
most impressive groups within the Protozoa. They occur
in nature as single organisms as well as in colonies looking
like a bunch of flowers. They are ubiquitous in freshwater
and seawater habitats where their favorite food, bacteria,
occurs in high concentrations.More than a hundred species
of Vorticella are recognised.
sp. feeding on bacteria, the complex pattern of
ciliary movement creates a vortex in the water like a
contrast photomicrograph of Paramecium bursaris,
showing the algal endosymbiont Chlorella sp
living within the cytoplasm.
bloom of the Ciliate Spirostomum sp. in
garden pond in late summer, the indevidual cells are clumping
together due to raised oxygen levels after increased photosynthesis
from aquatic plants during a hot sunny day, it has been
noted that microrganisms react quickly to changing gas
gradients, and this clumping behaviour is possibly an
that evolved during the mesoproterozoic era.
image of Euplotes sp..
ciliate phase contrast length: 50 microns
Contrast photomicrograph of unidentified Ciliate containing
of centric and pennate diatom frustules, cleaned and mounted
frustule made of silica
of valve view of the centric diatom Actinoptychus
senarius Ehrenberg 1843. Diatoms are extremely
abundant in freshwater and marine ecosystems, it is estimated
that 20% to 25% of all organic carbon fixation on the
planet is carried out by diatoms.Diameter approximately
100 micrometres,imaged using differential interference
of Volvox sp,each mature Volvox colony is composed of
numerous flagellate cells similar to Chlamydomonas
sp. is a nitrogen-fixing cyanobacterium, consisting
of chains of cells supended in a gelatinous matrix. Nostoc
species are widely distributed in illuminated portions
of the biosphere, including fresh waters and tropical,
temperate and polar terrestrial systems.
also known as Blue Green Algae are sometimes considered
to be photosynthetic bacteria having evolved during the
Mesoproterozoic era approximately 3.5 billion years ago.
They are credited with converting the earths atmosphere
from a reducing atmosphere to an oxidising one. This enabled
new life forms to evolve which required free oxygen. The
image shows strings of cells of Nostoc,
a common blue green alga. The larger cells are heterocysts
which are Nitrogen fixing. This sample is beginning to
decompose hence visible bacteria. Phase Contrast illumination,
approximate magnification x500.
of prokaryotic cells of Nostoc sp, the large
central cell is a heterocyst, a specialised cell for fixing
Nitrogen. Magnification about 1000x Differential Interference
photograph of Nostoc sp forming irregular
colonies in temporary water pocket in limeestone pavement,
Burren, Western Ireland,
diameter of colonies about 1 centimetre.
colonies on soil surface at the Burren, Western
sp (Vaucher) This
genus is well known for its motility, trichomes being
able to glide apparently by means of wave movements of
microfibrils, so long as the cells are in contact with
a solid substrate. Mucilage is secreted through pores
in the cell walls and may help to provide better contact
with the substrate surface. Movement has been timed at
up to 11 µm per second (van den Hoek et al., 1995).
dujardini (Doyere 1840)
colonial Rotifer Conochilus hippocrepis
(Schrank 1830) dark field photomicrograph. The colony
is about a millimetre in diameter and was found at Littlewick
Rotifers Conochilus hippocrepis
(Schrank 1830) The colonies are about a millimetre in
diameter and were found at Littlewick ponds, Surrey
of a Gastrotrich Chaetonotus sp. phase contrast
of a Gastrotrich swimming between algal filaments magnification
using Nomarski Interference Contrast illumination.
large Gastrotrich from the River Teifi in West Wales.
The name means "hairy stomach" as the ventral
surface is covered in cilia which allow it to glide smoothly
over objects such as algal filaments. They are transparent
microscopic creatures which range in size from approximately
0.1mm - 4.0.mm,
there are about 400 species known to science.
of the genus Collotheca use five tufts of relatively long
tentacle-like cilia known as setae, surrounding the very
large corona. Most rotifers possess chitinous jaws called
trophi that are used for grinding ingested food. Often
only the trophi are found as fossils, and the oldest,
embedded in amber, date them to the Eocene epoch (38 to
55 million years ago).