Pond Life Viewed with a Microscope I

by Dr. Robert Berdan
October 12, 2018

Damsel Fly larvae - low magnification taken with a 2.5X microscope objective using Differential Interference microscopy. About 20X total magnification. The muscles are blue inside the legs. This organism is not really microscopic in size (about 1 cm) but a microscope can reveal the interior organization and polarized light reveals birefringence in the muscle due to the organization of the myosin and actin filaments inside.

Introduction

Since purchasing a new Zeiss microscope in February of this year I have been exploring creeks and ponds for microscopic life and finding a wide variety of micro-organisms to photograph. With the summer at and I am still collecting pond samples until the ponds are covered with ice.

The interesting thing about photographing pond life is the shear numbers of organisms and the wide variety of species that live there. This diversity makes it challenging to identify many of the organisms, but with some guide books and help on the Internet I have been able to make some progress.

A pond, even a small one is like a galaxy of different organisms that appear and disappear, many of them struggling to survive and one can watch the daily struggle between predator and prey. Many of them also reproduce by binary fission and populations of some organisms can explode in abundance then quietly die down as new ones take over in a period of a few days.

I am excited to share photos of some these animals, some resemble aliens seen in the movies, others take on the symmetrical shapes that resemble crystals and jewels. If you also find these pictures interesting I would encourage you to look at some of my other articles on pond life, such as diatoms, desmids, rotifers, hydra and those by other authors on this site.

Note the scale bar in the pictures indicates size in microns. A micron = 1\1000 of mm and when dealing with small organisms it is more convenient to work with this unit though I will sometimes described the organisms in mm and cm when they are large.

Cymatopleura solea diatom collected in pond water from Bowmount Park, Calgary Robert Berdan ©

Cymatopleura solea diatom collected in pond water from Bowmount Park, Calgary.

Diatoms

Diatoms are single-celled brown algae found in streams, ponds, lakes, oceans and soil. These beautiful shaped organisms create silica shells with various ornamentations. They are broken up into two major groups: pennate - rod shaped diatoms and centric diatoms. They are all microscopic and can be easily collected by scraping the "goo" from stones in streams and lakes or sampling the sediment. Diatoms are useful in oil exploration, forensic examinations, and as environmental indicators. They are used in filters, pest control, and there is growing interest in using them for nanofabrication techniques and as templates in the patterning of biomolecules.

Diatoms form the base of the food chain and produce a significant amount of the earth's oxygen.
From a microscopists point of view they are simply beautiful. Some microscopists collect, clean and then arrange diatoms - for instance see article by Steve Beats (Download PDF) and Klaus Kemp's web site. Those that arrange diatoms clean them first with acid and bleach and then use micromanipulators to arrange them on microscope slides. See example photo below. Diatoms that are living are filled with photosynthetic pigments which are usually brown. Some species move by gliding that is due to cytoplasmic streaming of protoplasm they exude though the mechanism of how they do this is not readily visible in the microscope.

Gyrosigma sp of Diatom has an "S" shape Robert Berdan ©

Gyrosigma sp of Diatom has an "S" shape. Some related species are used to test the resolution of the light microscope.

Cymbella sp Diatom DIC microscopy by Robert Berdan ©

Cymbella sp Diatom. There are a wide variety of Cymbella species - check out this web page to see 31 different varieties.

Fragilaria is common freshwater colonial diatom by Robert Berdan ©

Fragilaria is common freshwater colonial diatom. The individual diatoms are joined at their centers to form a ribbon. The brown colour is from their chromatophores which are involved in photosynthesis.

Asterionella is a pennate freshwater diatom  by Robert Berdan ©

Asterionella is a pennate freshwater diatom that forms colonies of 8 or more cells arranged in a star shape. This diatom is common - viewed here by DIC microscopy and focus stacked.

prepared diatoms from a purchased microscope slide by Robert Berdan ©

A variety of prepared diatoms from a purchased microscope slide showing the different shapes they may take - Darkfield microscopy about 400X

 

Desmids

Desmids are a group of green algae that also form a variety of interesting shapes but rather then silica they have cellulose walls. It is estimated their are about 5,000-6,000 species. They are found in ponds but seem to prefer acidic waters. Many species are found living in and among sphagnum moss. You can collect them by squeezing the water from the moss into a jar. Desmids form a wide variety of symmetrical shapes which provide the basis for their classification. Most secrete a translucent gelatinous mucilage from pores in their cell walls that helps protect them. Some have spines and crystals can be seen inside that are made up of Barium (ref A.J. Brook et. al. 2007 Barium accumulation by Desmids of the genus Closterium - download PDF).

Closterium sp of Desmid Focus Stack DIC microscopy by Robert Berdan ©

Closterium sp of Desmid Focus Stack DIC microscopy. Crystals often seen in their distal tips.

Closterium sp of Desmid Focus Stack DIC microscopy by Robert Berdan ©

Closterium sp of Desmid Focus Stack DIC microscopy.

Pleurotaenium sp Desmid DIC microscopy by Robert Berdan ©

Pleurotaenium sp Desmid DIC microscopy. Some of them can grow up to a millimeter in length.

Pleurotaenium sp Desmid autoflourescence by blue light excitation  by Robert Berdan ©

Pleurotaenium sp Desmid autoflourescence by blue light excitation fluorescence microscopy 200X

Spinocosmarium sp of desmid - DIC microscopy by Robert Berdan ©

Spinocosmarium sp of desmid - DIC microscopy.

Algae

Pandorina or Eudorina 32 cells DIC microscopy by Robert Berdan ©

Pandorina or Eudorina with 32 cells via DIC microscopy. Pandorina is a green algae that can contain 8, 16 or 32 cells. Each cell has 2 flagella. The colonies co-ordinate their flagellar motion to swim, and roll. I am not sure why the colour of the cells is yellow rather then green, but carotenoids are responsible for orange and yellow lipid soluble pigments found in their plastids (Othman et. al. 2018 - download PDF).

Eudorina with only 8 cells by Robert Berdan ©

This could be either Pandorina or Eudorina with only 8 cells, DIC microscopy.

Euglenoid sp - note the red eye and flagellum by Robert Berdan ©

Euglenoid sp - note the red eye and flagellum. These organisms are motile, have a red eye sensitive to light, can produce food by photosynthesis and can also feed on bacteria if there is insufficient light.

Pediastrum sp. is a genus of green algae. Phase contrast microscopy. by Robert Berdan ©

Pediastrum sp. is a genus of green algae. Phase contrast microscopy.

 

Volvox sp by brightfield microscopy by Robert Berdan ©

Volvox sp by brightfield microscopy. This genus of green algae can from spherical colonies that contain up to 50,000 cells. The spheres inside are daughter colonies. The cells are interconnected by thin strands of cytoplasm. They are common in freshwater ponds and shallow ditches.

Volvox sp by darkfield microscopy by Robert Berdan ©

Volvox sp by darkfield microscopy - to me it resembles the "Death Star" in Star Wars movie.

Volvox sp by Phase contrast microscopy by Robert Berdan ©

Volvox sp by Phase contrast microscopy.

Volvox sp by Darkfield by Robert Berdan ©

Volvox sp by Darkfield, each cell seems to have a red pigment inside - see enlargement below.

Volvox sp above showing the individaul cells by Robert Berdan ©

Higher magnification of the Volvox sp above showing the individual cells that make up the colony.

Gloeocapsa or Glaucocystis  by Robert Berdan ©

Gloeocapsa or Glaucocystis ? Algae coated in mucilage - blue green algae DIC microscopy

Appears to be a colonial form of algae with red pigment Robert Berdan ©

Appears to be a colonial form of algae with red pigment. Unidentified species.

 

Dinoflagellate

Dinoflagellates are single celled organisms living in both freshwater and marine environments. They can produce toxic compounds e.g. "red tides". Some species are bioluminescent. Most are free living flagellates - they often have two flagella. Their are about 2500 species.

Dinoflagellate DIC microscopy Gonyaulax sp by Robert Berdan ©

Focus stack of a Dinoflagellate DIC microscopy Gonyaulax sp.

Hydra

Hydra are small multicellular organisms 500 to 1,500 microns (1.5 mm) in size that are often found attached to plants in fresh water ponds. They do not appear to age and have incredible regenerative abilities. For more information about this fascinating organism see my previous article - Photomicrography of Hydra - a model for studying regeneration and aging.

Hydra - darkfield microscopy by Robert Berdan ©

Hydra - darkfield microscopy. The tentacles contain special cells called nematocyts that are used to sting and capture prey.

Hydra filled with symbiotic algae (Chlorella) Phase contrast microscopy about 100X by Robert Berdan ©

Hydra containing intracellular symbiotic algae (Chlorella). Phase contrast microscopy about 100X.

Hydra ingesting a Daphnia by Robert Berdan ©

Hydra ingesting a Daphnia - Darkfield microscopy about 100X. Their mouth can open to taken in food much wider then itself.

Water flea Daphnia sp Darkfield microscopy by Robert Berdan ©

Water flea Daphnia sp by Darkfield microscopy. These crustaceans provide food for fish, Hydra and other larger organisms living in freshwater.

Copepod (also called Cyclops because of the single anterior eye). Darkfield microscopy by Robert Berdan ©

Copepod (also called a Cyclops because of the single anterior eye). They are an important food source for fish an other organisms and are found in both fresh water and marine environments. At the posterior end are two yellow egg sacs.

Copepod larva called a nautilus - Phase contrast microscopy about 200X by Robert Berdan ©

Copepod larva called a nautilus they molt several times until they form an adult Cyclops - Phase contrast microscopy about 200X.

 

Snail Eggs & Embryos

Freshwater snails lay eggs in muscilagenous casings by Robert Berdan ©

Freshwater snails lay eggs in mucilaginous casings which are attached to plants or the side of an aquarium. Once can watch the entire development from a single cell to a young snail in a period of 10-14 days.

Freswater snail embryo - DIC microscopy by Robert Berdan ©

Freswater snail embryo - DIC microscopy. The development takes about 2 weeks depending on the temperature.

Young snail about to emerge from its egg by Robert Berdan ©

Young snail about to emerge from its egg - Darkfield microscopy

oung snail about to emerge from its egg - DIC microscopy by Robert Berdan ©

Young snail about to emerge from its egg - DIC microscopy.

Gammarus embryo? by Robert Berdan ©

Gammarus embryo? Gammarus is a freshwater amphipod which resembles tiny shrimp (1-5 mm) and are common in fresh water ponds.

 

References:

Wehr, J. D et. al. (2015) Freshwater Algae of North America, Academic Press, NY 1050 pg.

(2000) Illustrated guide to the Protozoa 2nd edition Society of Protozoologists. Allen Press, USA available on Amazon.com most recent Key to ciliates - check your library - excellent ref book.

Diatoms of North America web site - diatoms.org

W.C. Vinyard (1979) Diatoms of North America. Mad River Press, Eureka, California.

J.G. Needham and P.R. Needham (1962) A guide to the study of fresh-water biology. Holden Day Inc. San Francisco. Available at Amazon.ca

 

 

Authors Biography & Contact Information

Portrait of Robert Berdan

Robert Berdan is a professional nature photographer living in Calgary, AB specializing in nature, wildlife and science photography. Robert retired from Cell\Neurobiology research to take up photography full time years ago. Robert offers photo guiding and private instruction in all aspects of nature photography and Adobe Photoshop training - including photomicrography, macrophotography.

 

 

 

 

Related Microscopy Articles by Robert Berdan on this web site

1.   Photomicrography of Hydra - a model for studying regeneration and aging
2.   Photographing Daphnia 
3.   Photographing Gastrotrichs
4.   Photographing Rotifers 
5.   Photographing Ciliates
6.   Photographing Stentors - A Large Unicellular Protozoan (ciliate) living in Freshwater
7.   How to Collect and Photograph Water Bears (Tardigrades). 
8.   Tips on How to take Better pictures with a Microscope 
9.   Microscopic Pond Organisms from Silver Springs Calgary
10. Microscopic Life in Ponds and Rainwater - Pond Scum I 
11. Photographing Microscopic Plant and Animal Life - Pond Scum II 
12. Photomicrography and Video of Protozoa, Volvox and Rotifers 
13. Home Microscopy Laboratory for Photomicrography 
14. The Art & Science of Photomicrography with Polarized Light 
15. Photographing Through a Microscope Photomicrography - Inner Space 
16. Focus Stacking comparing Photoshop, Helicon Focus and Zerene
17. Rheinberg Filters for Photomicrography 
18. Scanning Electron Microscopy - Photography 
19. Photomicrographs of Diatoms from 1877 by John T. Redmayne

 

Email at: rberdan@scienceandart.org
Web site: www.canadiannaturephotographer.com
Phone: MST 9am -7 pm (403) 247-2457.