Exploration of the Pond - This gallery is an exploration of the microscopic flora and fauna found in fresh water ecosystems.

On sunny summer days when not at work you can expect that I have packed up my backpack with my collection tools and headed off on sampling expeditions. Ponds are fascinating habitats which are home to a treasure throve of wonders. Every pond is a unique ecosystem hosting an abundance of species. The pond consists of four spheres; the water itself, the mud on the bed of the pond, the pond bank and the air above the pond. If you visit a wild countryside pond or walk along the canal on such a warm sunny day in June and July, you may see dragonflies and colourful damselflies buzzing among the reed banks. If you sit at the bank of a wild pond and are quiet and patient, you might even by lucky enough to see newts coming up for a gasp of air, take a break, before diving back down to the muddy bed. Whirling beetles glint in the light of the sun, and tadpoles wiggle side to side as they swim by. Water boatmen cling to the underside of the waters surface whilst pond skaters skitter across the outer surface of the water. In some ponds, the water may appear green, but it is not the water that is green, it is what is living in the water - countless numbers of Euglena or dense carpets of spirogyra for example. On closer inspection you will notice that the cells are actually transparent, but the green colour derives from the presence of chlorophyll within them.

Various Sampling Ponds

The banks of this large pond are lined with dense reeds that include Iris and Bullrushes, among others. The deeper water contain numerous plants including Elodea canadensis and water lillies.

The large pond at the Altamont gardens in Co. Carlow contains an impressive amount of water lillies. The banks are lined with numerous plants including, Purple-Loosestrife, seen here.

This pond in Castletown estate is a haven for Daphnia and various kinds of aquatic larvae.

The portion of the grand canal at the Lyons estate in Co. Kildare.

Sample Collection

Below are two vials containing some unfortunate creatures collected fresh out of their natural habitats. The movie on the left hand side shows a vial containing fresh water shrimp, whilst the creatures seen wiggling in the vial on the right are Chironomidae larvae. The movies intend to give you a sense of the scale of the creatures before seeing them under the microscope in polarised light. You can see that great patience is required when create the high resolution imagery as you must contend with the movement of the creatures. The imagery are large composits made of a multitude of focus stacks which are combined and then seamlessly blended into one complete image.

Gammarus pulex, fresh water shrimp. Focus stacked montage, magnification x100.

Gammarus pulex, fresh water shrimp. Focus stacked montage, magnification x100.

Midge Larva

Very high resolution panoramic focus stack of the aqautic dwelling midge larva. Photographed in compensated polarised darkfield illumination.

Diptera Midge Larva

Very high resolution panoramic focus stack of the aqautic dwelling midge larva. Photographed in compensated polarised darkfield illumination.

Midge Larva

Very high resolution panoramic focus stack of the aqautic dwelling midge larva. Photographed in compensated polarised darkfield illumination. The image was made for the Olympus / Evident 2022 Calendar using the Olympus BX51 using the Olympus x10/0.4 X Line objective.

Midge Larva

Very high resolution panoramic focus stack of the aqautic dwelling midge larva. Photographed in compensated polarised darkfield illumination.

Diptera Midge Larva

Very high resolution panoramic focus stack of the aqautic dwelling midge larva. Photographed in compensated polarised darkfield illumination.

Diptera Midge Larva

Focus stack montage of a Diptera midge larva, photographed in compensated polarised darkfield illumination on the Olympus BX51 using the Olympus x10/0.4 X Line objective.

Diptera Midge Larva

Focus stack montage of a Diptera midge larva, photographed in compensated polarised darkfield illumination on the Olympus BX51 using the Olympus x10/0.4 X Line objective.

Aquatic Larvae

Midge Larva

A sample of algae was collected from the soft flowing Lugduff river that passes through Glendalough. Rummaging among the alage filaments was this larva.

Phantom Midge Larva

Here we see the larva of the species of phantom midge Chaoboridae. The image is a focus stack montage made in darkfield compensated polarised light microscopy.

Phantom Midge Larva

Here we see the larva of the species of phantom midge Chaoboridae. The image is a focus stack montage made in darkfield compensated polarised light microscopy.

Diptera Midge Larva

Focus stack montage of a Diptera midge larva, photographed in compensated polarised darkfield illumination on the Olympus BX51 using the Olympus x10/0.4 X Line objective.

Diptera Midge Larva

Muscle fibers within the body of a Diptera larva appear to glow yellow-orange in this compensated polarised light image.

Diptera Egg Mass

A gelatinous cocoon containing numerous embyro's.

Diptera Egg Mass

A gelatinous cocoon containing numerous embyro's.

Diptera Egg Mass

A gelatinous cocoon containing numerous embyro's.

Diptera Egg Mass

A gelatinous cocoon containing numerous embyro's.

Nematodes

Nematode

Magnified over 600 times, we can look into the head region of the nematode worm.

Nematode

Magnified over 600 times and captured in DIC, we can look into the head region of the nematode worm.

Water Fleas

Daphnia

Daphnia

Daphnia magna

Daphnia magna

Peritrich and Vorticella

Peritrich Colony in Darkfield (DF)

Large colony of the bell shaped ciliate - Peritrich. The entire colony is attached by a single long slender stalk to the organic debris below. Peritrich are holozoic ciliates. This means that they have a mouth and acquire nutrients by engulfing solid organic matter. Their mouth consists of an elaborate food-catching apparatus that secures food by means of ciliary currents. The anterior end of each peritrich body forms a bulging peristome. The peristome is the blue coloured path seen in each cell and is defined as a fringe of small projections around the mouth of a capsule. In this case, the fringe is composed of cilia, all of which beat in synchronised motion, like a Mexican-wave. The motion induces a water currents in the local environment in the form of a vortex that causes food particles to spiral down the funnel where they are then guided into the vestibule along the adornal zone.

Peritrich Colony in DIC+DF

Close-up of a large colony of the bell shaped ciliate - peritrich. The colony mirrors the structure of a tree in that it has a trunk called a stalk made up of myonemes. The stalk breaks up into a series of branches at the end of each is the bell-shaped peritrich capsule.

The blue coloured path is the peristome, the structure that generates the beautiful instability in the local watery environment, the vortex that funnels food into its mouth.

Peritrich Colony

Starting at a magnification of around 100 times, the movie shows the scene from the above photos - the overall tree-like structure of a colony of Peritrich microorganisms. The movie then progresses to a higher magnification at over 200 times to examine the finer details of the organisms. You can see the 'turbine' spinning at the anterior end of the vestibule. In fact, this is not a turbine but a row of hair-like structures called cilia. The cilia beat back and forth in a synchronised motion which gives the impression of rotation. Returning to x100 we see the spring like reflexes of the peritrich stalk that anchors the colony to a substrate composed of organic debris. Next we transition to over 400 times magnification switching from dark field to differential interference contrast microscopy that gives a 3D like effect.

Peritrich Colony in DIC

A small colony of Peritrich imaged in differential interference contrast..

Close up of several Peritrich in a Colony

Here we can see the details of the Peritrich as we peer inside of its translucent body as imaged in differential interference contrast microscopy and magnified over 600 times.

Vorticella Colony in DIC

Vorticella Colony and Rotifer

A rotifer hunts for food among a large colony of vorticella.

Flatworm (Typhloplana sp.)

Flatworm (Typhloplana sp.)

Flatworm (Typhloplana sp.)

The green dots seen inside are its endosymbioants, Zoochlorella. Zoochlorella are alga cells which contain chloroplasts. The chloroplasts provde the flatworm with energy and the flatworm provides the zoochlorella with a safe and secure home.

Typhloplana viridata

Photographed here swimming through its aquatic environment in the hunt for food, Typhloplana viridata is a species of flatworm that is found in fresh water habitats. The green cells living symbiotically inside the worm are the single-celled green algae - zoochlorellae. A nutritious meal is made up of carbon dioxide, organic matter rich in nitrogen and phosphorous, exuding oxygen and other minerals as waste products that the worm devours. Captured with Olympus X Line 40x objective on the Olympus BX51 Microscope.

Paramecium

Paramecium bursaria

The green dots seen inside are its endosymbioants, Zoochlorella. Zoochlorella are alga cells which contain chloroplasts. The chloroplasts provde the Paramecium with energy and the Parameciumreturns the favour by providing the zoochlorella with a safe and secure home.

Paramecium

Belonging to the kingdom Protista, Paramecium are agile creatures whose hydrodynamic propulsion in the low Reynolds number regime is achieved by rapid synchronised beating of the thousands of cilia carpeting its outer body.

Here, a Paramecium bursaria glides along a filament of alga hoovering bacteria that populate the encapsulating biofilm.

Paramecium

The intake of food is achieved by the beating cilia lining its oral groove, which induce a circular rotating vortex in the surrounding local environment and thereby funnel small debris into its mouth. The food particles are stored in membrane bound compartments called vacuoles which breakdown the food through chemical reactions catalysed by enzymes.

Paramecium feed on the biofilm encapsulating a strand of filamentous Spirogyra algae. The cell nuclei and cytoskeletal network are visible in the filamentous algal cells. The globular spots on the cytoskeletal filaments are motor proteins which ‘run’ along these microtubule ‘highways’. The green structures are the chloroplasts which are helically wound within the interior of the cells and produce sugary food and oxygen as a waste product through photosynthesis.

Bottom Feeders

Paramecium feeding on the biofilms on the pond bed.

Rootlet Ecosystem

A rootlet of pond weed provides the basis for a micro-ecosytem. Here we see Paramecium feeding on biofilms that encapsulate the rootlet.

Filamentous Algae

Unknown species of filamentous green algae collected from a fresh water habitat.

Photographed with the x40 X Line objective on the Olympus BX51 microscope.

Batrachospermum

Batrachospermum collected from the a fresh water bog habitat.

Magnified over 100 times with the Olympus X Line objective 10x/0.40 and photographed in DIC on the Olympus BX51 microscope.

Population Explosion of Flagellates

Configured for darkfield polarised light, here we image a population explosion of flagellated micro-organisms.

Rotifer

Just like the stream lines seen in vortex shedding from the wing tips of an airplane as it passes through moist air, in the second half of this movie clouds of flagellated protozoa make visible the twin vortex generated by a rotifers ciliated 'turbine'. By reducing the exposure time the tracks of the particles can be traced out, just like when one photographs the trailing lights of the traffic in a long exposure at night.

The movie shows a swarming population of dinoflagellates collected from a bloom in a fresh water habitat. The movie shows sequential magnification of approximately 150 to 250 times imaged in DIC.

Freshwater cyanobacteria magnified around 100 times.

Freshwater cyanobacteria magnified around 400 times.

A Springtail insect entangled in filamentous algae. Imaged in DIC at approximately 100x magnification.

Spirostomum

Spirostomum is a long worm-like ciliate protist which can contract its body by greater than 50% in a very short space of time and this moment catches that event. You can see the rows of cilia running longitudinally along its body which sweep the water past it during locomotion.

Blue-Green Algae

Timelapse movie show the movement of blue-green algae. The locomotion of this algae is thought to result from the secretion of mucus slime...