AQUATIC MICROBIAL COMMUNITIES

Very small organisms (submillimeter size) not only form the foundation of most food webs, they are among the oldest life forms on the planet. Genetically conservative, some may have survived pretty much unchanged for more than a billion years.

Checklist of Microbiota for Southern Ontario

Getting Started

Micro-gallery

As such, microorganisms anticipate development of the plant and animal kingdoms: submillimeter life forms have their own photosynthetic and heterotrophic compartments. I have spent much of my life enjoying these creatures, making local collections and watching them under my microscope. In the process, I have become familiar with more than 300 species from groups as diverse as Eubacteria, Ciliophora, and Bacillariophyta.

GETTING STARTED

In 1990, anticipating my early retirement from the Computer Science Department, I decided to "get serious" about this erstwhile hobby. Having joined the EMAN (Ecological Monitoring and Coordinating Network, an initiative of Environment Canada) as a member of the Science Cooperative, I began a monitoring project of my own, a study to log changes in the shore and midstream benthic submillimeter organisms in a small creek known as the Logan Drain, near Kintore Ontario. I loaded up on new reference manuals and monographs, then began taking monthly samples from the Logan Drain through the eight warmest months of the year. I pursued this project for two years, adding a survey of a forest stream (Bradley's Creek) in the second year for purposes of comparison.

Shown below is a species abundance histogram for the Logan Drain, a summary of occurrences on slides of each of 222 microorganisms. For each integer k, the height of the bar indicates the number of species which occurred k times on the slides. In this particular case, abundance categories have been grouped as 1-2, 3-4, etc. I was somewhat surprised by the shape of this histogram. It resembled a hyperbola!

This led, indirectly, to the next strange experience. Thinking that intense interactions that characterize so much of the microbial community must lead to quite a different shape, I wrote a computer simulation program that would imitate such interactions (mutually predatory) only to discover, after the usual process of debugging and validation, the same hyperbolic shape staring at me from the computer screen! See Biodiversity Research.

Since that time, several years ago, I have probed other local waters, some systematically, others occasionally. I have summarised my observations in the following checklist, which I have used in workshops on aquatic microbial communities.

CHECKLIST OF MICROBIAL SPECIES IN FRESHWATER PONDS AND STREAMS OF SOUTHERN ONTARIO

The "microbiota" listed in this document have a simple, pragmatic definition: anything that will travel up a standard Pasteur pipette with its (slightly less than) one-millimeter inside diameter. The species in the list have been observed by the author in local waters, specifically as follows:

Logan Drain (LD), a tributary of the Middle Thames near Kintore

Bradley's Creek (BC) in Springwater Forest south of Aylmer

The Pinery Old Channel (OC) near Port Franks

A'Nowaghi Forest Ponds (FP), in London's new southern annex

North Thames River (TR) in UWO campus

Newport Forest (NF) on the Thames River near Wardsville

The Logan Drain was sampled intensively on a monthly basis from May to October in 1995 and again in 1996. In the second of those years, Bradley's Creek was sampled on the same basis and in parallel with the sampling effort at the Logan Drain. The Pinery Old Channel study was conducted on a more occasional basis during the warm seasons of 1997 and 1998 at each of seven transects. The A'Nowaghi Forest Ponds study was conducted on a more informal basis. In total observing hours, the Logan Drain required about 120, Bradley's Creek about 60, the Old Channel and A'Nowaghi Forest Ponds about 50 hours each. The Thames River species were added in preparation for a workshop, but with a total of no more than five observing hours. Finally, the Newport Forest survey has been conducted sporadically, not with a view to monitoring, but in the spirit of a microbial survey. The latter project is ongoing and as of this writing approximately 30 hours have been spent on observation.

Beside each species name below, sites where it was observed are indicated by the initials: LD; BC; OC; FP; TR, and NF, respectively. The fact that some sites seem richer than others reflects sampling intensity, rather than intrinsic richness. I have some very large databases that log sample abundances for some of these sites.

The 338 species have been organized into a taxonomic structure that reflects the Five (Six) Kingdoms approach of Lynn Margulis [Margulis and Schwartz 1988] down to the level of phylum and (occasionally) class. Within Kingdom Monera the taxonomy of cyanobacteria species follows the scheme used in [Prescott 1970], while the heterotrophic bacteria are grouped into morphospecies, a practice that will nevertheless enable one to distinguish a few species without actually identifying them.

Within Kingdom Protista the classification follows [Margulis, Corliss et al. 1990] exclusively except for Phylum Ciliophora in which we have retained the traditional classification as exemplified in [Jahn et al. 1979]. Although ultrastructural studies have made a thorough revision of the traditional taxonomy of the ciliates both possible and necessary, most organisms could not be placed in the new scheme as laid out in the Margulis-Corliss book.

The species of Animalia, all being aquatic, could be classified from [Thorpe and Kovich 1991]. Kingdom Fungi follows [Kendrick 1992].

In the use of scientific names I have made one departure from standard practice.  When a species or genus name appears in square brackets, it means that the organism in question most closely matches the organism so named among all the species (of the organism¹s family, say) that appear in my modest collection of about 20 books, monographs, papers and other reference materials on hand.  In some cases (possibly many) the identification is probably correct.

KINGDOM MONERA


CYANOBACTERIA

Chroococcales

Chroococcaceae
Anacystis sp. (syn. Aphanocapsa) FP OC BC
[Chroococcus sp.] OC
[Gloeothece] sp. OC
[Marssoniella elegans] FP OC BC TR
Merismopedia [convoluta] FP
M. [glauca] FP LD
Microcystis aeruginosa(syn. Polycystis) FP OC
M. flos-aquae FP
    

Chamaesiphonales

Pleurocapsaceae

[Pleurocapsa minor] OC

Oscillatoriales

Oscillatoriaceae

Lyngbya birgei FP LD
L. contorta FP LD
Oscillatoria spp. FP LD BC
O. [rubescens] FP
O. [minima] (pseudo sp.) OC LD BC
Phormidium sp. OC LD
Spirulina sp. FP OC

Nostocales

Nostocaceae

Anabaena [subcylindrica] FP OC LD BC
A. spiroides FP
Anabaena sp. A (not coiled) FP
Nodularia [spumigena] FP NF


unplaced

CGC (colourless/pale gliding) FP OC LD BC

EUBACTERIA (morphospecies) (not recorded for OC)        

(bending) filaments FP LD BC
vibrios FP LD BC
coccal filaments FP LD BC
motile cocci FP LD BC
colonial cocci BC
bacilli FP LD BC
bacillary chains LD
pseudomonads FP
spirilla LD BC



KINGDOM PROTISTA

OOMYCOTA

Saprolegniales

Saprolegnia sp. LD


BACILLARIOPHYTA

Centrales

Cyclotellaceae

Cyclotella spp. OC LD BC


Melosirales

Melosiraceae

Melosira [varians] OC LD BC NF


Fragilariales

Fragilariaceae           

Diatoma vulgare OC LD BC NF
Diatoma elongatum NF
Fragilaria [brevistriata] FP LD BC NF
F. [inflata] FP LD
F. [arcus] OC
Meridion circulare FP LD BC NF
[Opephora] sp. FP
Synedra pulchella FP
S. [tabellata] OC LD BC NF


Tabellariaceae

[Tabellaria fenestrata] OC


Eunotiales

Eunotiaceae

Eunotia pectinalis var minor FP OC BC
Rhoicosphenia curvata NF


Naviculales

Pinnulariaceae

Pinnularia sp. FP LD BC
Pinnularia [borealis] NF


Naviculaceae

Navicula [affinis] OC LD BC
N. canalis FP OC TR NF
N. [bacillum] FP OC LD BC
N. cuspidata FP OC BC NF
N. [elegans] OC LD
N. hungarica FP OC LD BC
N inflexa NF
N. [interrupta] FP OC LD BC NF
N. [nodosa] FP LD BC
N. peregrina OC LD BC TR
N. [parva] LD BC
N. [radiosa] FP
Navicula viridis NF
Stauroneis phoenicentron NF


Pleurosigmataceae

Gyrosigma [scalproides] FP OC LD BC NF
Gyrosigma Kutzingii NF


Cymbellales

Cymbellaceae

Cymbella [tumida] FP OC LD BC NF
C. [ventricosa] FP OC LD BC
C. [cistula] OC
Encyonema sp. BC TR
Amphiprora [ornata] OC BC
Caloneis amphisbaena FP OC LD BC TR NF
C. [bacillum] FP


Gomphonemataceae

Gomphonema acuminatum FP OC BC
G. constrictum FP OC LD BC
G. [olivaceum] FP OC BC NF


Acnanthales

Cocconeidaceae

Cocconeis sp. FP OC LD BC TR


Amphorales

Amphoraceae

Amphora sp. A (short) FP LD BC NF
Amphora sp. B (long) FP LD
A. [ovalis] OC LD


Bacillariales

Nitzschiaceae

Nitzschia acicularis FP OC LD BC NF
N [filiformis] LD BC NF
N. sigmoidea FP OC NF
N. [paradoxa] OC LD BC
Hantzschia amphioxys NF


Epithemiales

Epithemaceae

Rhopalodia gibba FP


Surirellales

Surirellaceae

Campylodiscus sp. OC LD BC
Cymatopleura elliptica OC LD
C. solea OC LD BC NF
Surirella splendida OC LD BC TR
S. [ovalis] LD
S. [ovata] LD
S. [elegans] LD


XANTHOPHYTA

Xanthophyceae

Tribonematales

Tribonemataceae

[Tribonema] sp. LD BC


Vaucheriales

Vaucheriaceae

Vaucheria sp. FP


Ochromonadales

Ochromonadaceae

[Ochromonas] sp. LD
[Monas] sp. LD
[Uroglena volvox] OC


Dinobryaceae

Dinobryon sp. OC BC NF


Synuraceae

Synura uvella FP BC NF


Chrysococcaceae

[Chrysococcus] sp. LD


CRYPTOPHYTA      

Cryptomonadaceae   

Chilomonas [paramecium] FP LD BC


unplaced

Goniomonas sp FP LD BC


CHLOROPHYTA     

Chlamydomonadales

Chlamydomonadaceae

[Chlamydomonas] sp. FP LD
Haematococcus lacustris NF
[Polytoma] sp. LD


Volvocales

Volvocaceae

Gonium sp. FP


Tetrasporales

Gloeocystaceae

[Gloeocystis] sp. FP OC LD BC


Chlorococcales

Coccomyxaceae

Ourococcus sp. FP


Chlorococcaceae

Bracteacoccus sp. NF
Chlorococcum aquaticum NF
[Chlorococcum] sp. LD


Characiaceae

[Characium] sp. FP LD NF


Hydrodictyaceae

Pediastrum biradiatum FP OC TR
P. boryanum FP OC BC TR
P. [obtusum] FP
P. simplex OC


Palmodictyaceae

Palmodictyon varium FP NF


Oocystaceae

Ankistrodesmus [braunii] FP OC
A. falcatus FP
[Chlorella] sp. LD
Tetraedron limnecticus FP TR
T. regulare FP
Selenastrum [gracile] FP OC LD BC
Kirchneriella lunaris FP
Oocystis [borgei] FP


Scenedesmaceae

[Lauterborniella] sp. FP
Scenedesmus bijuga FP
S. incrassatulus FP OC
S. quadricauda FP OC LD BC TR NF


Dictyosphaeriaceae

Dimorphococcus lunatus FP


Oedogoniales

Oedogoniaceae

Bulbochaete sp. FP NF
[Oedogonium] sp. FP NF


Chaetophorales

Chaetophoraceae

[Desmococcus viridis] OC
Stigeoclonium sp. FP


Ulvophyceae

Ulotrichales

Ulotrichaceae

[Geminella] sp. OC
Ulothrix spp. FP LD NF


Siphonocladales

Cladophoraceae

Cladophora/Rhizoclonium sp. FP OC LD BC TR NF


Charophyceae

Charales

Characeae

Chara sp. FP


CONJUGOPHYTA (syn. Gamophyta)

Zygnematales (no classes)

Zygnemataceae

[Debarya] sp. FP
[Entransia] sp. FP
Mougeotia spp. FP OC NF
Spirogyra ssp. FP OC LD BC NF
S. "gigantissima" FP
Zygnema sp FP
Zygnemopsis sp. NF


Desmidiales

Closteriaceae

[Arthrodesmus] sp. FP
Closterium [leibleinii] FP LD BC TR NF
C. kuetzingii FP OC
C. [loefgrenii] FP TR
C. [parvulum] LD
C. lunula NF
Cosmarium margaritatum FP OC LD
Cosmarium sp. A (no ornam.) FP LD TR NF
Euastrum sp. FP OC
Micrasterias [americanum] FP
Spinocosmarium sp. OC
Spondylosium sp. FP
Staurastrum spp. FP LD
S. [leptocladum] FP BC
S. [rotula] OC


DINOFLAGELLATA

Peridiniales (no classes)

Peridiniaceae 

Glenodinium monensis FP
Glenodinium cinctum NF


ZOOMASTIGINA

Kinetoplastida

Bodonida

Bodonidae

Bodo sp. LD BC


EUGLENOPHYTA

Eutreptiales (no families)

Distigma [proteus] LD
[Distigmopsis] sp. OC


Euglenales

Euglena acus FP
E. cyclopicola LD
E. deses LD BC NF
E. spirogyra FP LD
E. pisciformes NF
E. proxima FP
E. [Ehrenbergii] OC
E. rostifera NF
Astasia sp. FP LD BC NF
Lepocinclis [acuta] FP
L. glabra FP
Cyclidiopsis acus FP
Trachelomonas sp. FP OC LD BC NF
Phacus sp.A (subrectangular) OC
Phacus sp.B (short tail) FP
P. longicauda FP
P. triqueter FP OC LD
P. trimarginatus FP
P. curvicauda NF
Hyalophacus ocellus FP


Rhabdomonadales

[Rhabdospira spiralis] OC BC
Menoidium bibacillatum FP LD


Sphenomonadales

[Atraktomonas] sp* FP OC BC
Petalomonas bicarinata FP
P. tricarinata FP BC
P. alata FP
Petalomonas sp. (poss. above) LD BC
Notosolenus sp. FP OC LD BC
Anisonema sp. FP OC LD BC NF


Heteronematales      

Urcoelus sabulosus FP LD BC
Urceolus cyclostomus NF
U. [cyclostomus] LD
Peranema [trichophorum] FP LD BC NF
Heteronema [acus] FP OC LD BC
H. spirale FP
Entosiphon sulcatus BC

* This organism is quite rare, so ID is highly uncertain

CRYPTOPHYTA

Cryptophyceae (no orders or families!)

Chilomonas paramecium FP BC NF


KARYOBLASTEA  (essentially one species in the phylum!)   

Pelomyxa palustris FP


RHIZOPODA           

Lobosea

Gymnamoebia (sC)

Amoebida

Amoebidae

Amoeba proteus FP OC LD
Trichamoeba sp. FP OC BC


Hartmannellidae

Hartmanella [vermiformis] OC LD BC TR


Thecamoebidae

Thecamoeba striata FP OC LD BC NF
Vanella [simplex] LD BC


Striamoebidae

Striamoeba striatus NF


Paramoebidae

Mayorella sp. FP OF LD BC NF
M. penardi FP LD
M. bigemma LD
Saccamoeba  sp. NF


Testacealobosa (sC)

Arcellinidae

Arcellidae

Arcella vulgaris FP OC LD BC TR
[Hyalosphaenia] sp. OC BC


Centropyxidae

Centropyxis sp. FP


Difflugiidae

Difflugia corona FP LD TR
D. globulosa FP OC LD BC NF
D. oblonga FP OC LD BC TR NF
D. urceolata OC


Cyclopixidae

Cyclopyxis arcelloides FP OC LD


Filosea

Aconchulinida

Filamoeba nolandi FP OC
[Dactylamoeba stella] FP


Testaceafilosida

Euglyphidae

Euglypha alveolata FP OC BC
Cyphoderia [ampulla] OC LD BC


ACRASEA

Acrasidae (no classes or orders)

[Acrasis] sp. FP


ACTINOPODA         

Heliozoa

Cryptaxohelida

Actinophryidae

Actinophrys [sol] FP LD SC BC TR NF
[Actinosphaerum] sp. OC
Echinosphaerium [eichhornii] FP TR


Ciliophryidae

Multicilia [lacustris] LD BC


Phaneraxohelida

Acanthocystidae

Acanthocystis sp. OC LD BC BC TR


unplaced

[Myriophrys] sp FP OC LD


CILIOPHORA (61) [Jahn et al.]

Suctorea

Exogenida (order)

Podophryidae

Metacineta mystacina LD


Hypostomea

Synhymenida

[Nassulopsis] sp. LD


Nassulida

Nassula aurea OC LD NF


Cyrtophorida

Chilodonellidae

Chilodonella spp. FP LD BC NF


Gymnostomea/Pleurostomatida

Amphileptidae

[Litonotus] sp. (small) FP BC
L. [fasciola] FP OC LD BC TR NF


Trachelocercidae

Trachelocerca sp NF


Karyorelictida

Loxodes [vorax] LD BC


Haptorida

Enchelyidae

Lacrymaria olor OC
Lacrymaria sp. (not L. olor) FP


Tracheliidae

Dileptus anser FP LD BC NF
Dileptus sp. (not anser) TR


Actinobolinidae

Actinobolina [vorax] FP LD


Didiniidae

[Askenasia] sp. LD
Didinium sp. LD


Prorodontida

Prorodontidae

Prorodon sp FP LD


Colepidae      

Coleps hirtus FP OC BC NF


unplaced        

[Microregma] sp. LD


Vestibulifera

Colpodida

Colpodidae

Colpoda cucullus FP BC
Colpoda [steini] TR


Hymenostomea

Hymenostomatida

Tetrahymenidae

Tetrahymena [pyriformis] LD
T. [gyrans] BC
Glaucoma scintillans NF


Parameciidae

Paramecium aurelia-gp. LD BC
P. [bursaria] OC LD
P. caudatum-gp. FP TR


Frontoniidae

Frontonia [acuminata] FP
F. [altra] LD
F. leucas FP OC LD BC TR NF


Urocentridae

Urocentrum turbo FP LD BC TR


Lembadionidae

Lembadion [bullinum] FP LD BC NF


Cohnilembidae

Cohnilembus sp. OC BC

Pleuronematidae

Pleuronema sp. OC LD BC


Cyclidiidae

Cyclidium [glaucoma] FP OC LD BC TR NF


unplaced

Stokesia sp. LD


Peritrichea

Sessilida

Vaginicolidae

Vaginicola [ingenita] FP BC


Vorticellidae

Vorticella [campanula] FP OC TR NF
V. [convallaria] LD BC NF


Epistylidae

Epistylis chrysemidis FP
Zoothamnium sp. FP


unplaced

Ophrydium sp. OC


Hypotrichea

Stichotrichida

Holostichidae

[Uroleptus] sp. LD BC NF


Sporadotrichida

Oxytrichidae

Oxytricha [fallax] FP OC LD BC TR NF
Oxytricha saltigera NF
Stylonychia [mytilus] FP OC NF
S. [pustulata] LD BC
Urosoma sp. A (no caudal filam.) FP
Urosoma sp. B (with) OC LD BC


Aspidiscidae

Aspidisca [lynceus] FP OC LD BC NF
A. costata FP OC LD BC TR
Aspidisca sp. A FP


Euplotidae

Euplotes [patella] FP OC LD BC NF


unplaced

[Chaetospira] sp. LD


Spirotrichea

Heterotrichida

Spirostomidae

Spirostomum ambiguum FP OC LD BC
S. [minus] FP
Blepharisma [americanum] FP LD BC
Blepharisma steni NF


Metopidae

Metopus [es] FP OC LD


Stentoridae

Stentor coeruleus FP OC BC
Stentor sp. A (rosy, flared perist.) FP BC
S. [igneus]        (no nuclear chain) FP OC LD TR NF


Bursariidae

Bursaria truncatella FP


Caenomorphidae

Caenomorpha [sapropelica] FP OC BC


Odontostomatida

Epalxellidae

Saprodinium [putrinum] FP


unplaced

Brachonella spiralis FP


Oligotrichea

Oligotrichida

Strombidiidae

Strobilidium gyrans FP LD BC TR NF


KINGDOM ANIMALIA

CNIDARIA

Hydrozoa

Hydra viridis TR


PLATYHELMINTHES

Turbellaria     

Catenulida

Catenulidae

Catenula sp. FP


Stenostomidae

Stenostomum sp. OC LD BC

                                                        


Macrostomida

Macrostomidae

Macrostomum sp. FP BC


Tricladida

Planariidae

[Planaria] sp. OC


Dalyelloiida

Dalyelliidae

[Microdalyellia] sp. LD


GASTROTRICHA

Chaetonotida (no classes)      

Chaetonotidae

Polymerurus sp. FP OC
Chaetonotus spp. FP OC LD BC NF


Dasydytidae

Dasydytes sp. FP OC LD BC TR


ROTIFERA

Digononta

Bdelloidea     

Philodinidae

Dissotrocha sp. NF
[Philodena/Rotaria] sp. FP OC LD BC TR NF


Ploima

Branchionidae

Platyas patulus FP
P. quadricornis FP
Brachionus quadridentata NF

                                                             

Colurellidae

Colurella sp. FP NF
Lepadella sp. FP LD BC TR NF


Dicranophoridae

Dicranophorus sp. OC LD BC TR


Euchlanidae

Euchlanis sp. FP LD
[Beauchampiella] sp. FP

Lecanidae

Lecane (syn. Monostyla) sp. FP OC LD BC TR NF


Mytilinidae

Mytilina sp. FP


Notomatidae

Cephalodella sp. FP LD BC NF


Synchaetidae

Synchaeta [stylata] FP


Trichocercidae

Trichocera sp. FP OC LD BC TR NF


Trichotriidae

Trichotria tetractis FP BC


NEMATODA

nematode spp. FP OC LD BC TR


ANNELIDA

Oligochaeta (few-bristled worms) (no orders)

Naididae

Dero furcatus FP
Chaetogaster sp. FP OC LD


TARDIGRADA (water bears)

Eutardigrada

Parachela

Macrobiotidae

Macrobiotus sp. FP


ARTHROPODA

Malacostraca/Crustacea

Branchiopoda (water fleas/shrimp)      (also in OC)

[Chydorus bicornatus] FP
[Alonella] sp. FP
[Macrothrix] sp. FP


Ostracoda (ostracods)

Ostracod spp. FP OC BC TR


Copepoda (copepods)

Cyclopodea (sO)

Eucyclops sp. FP
other sp. OC LD BC


Harpacticoida (sO)

Atthyella sp. FP 
other sp. LD


Amphipoda

[Hyatella sp.] LD
other spp. FP OC


Insecta

Diptera

Chironomidae

Chironomus sp. OC LD BC TR


KINGDOM FUNGI

Eumycota (See also Oomycota)

Dothidiales

Alternaria sp. LD BC


unplaced - teleomorphs unknown

Clavatospora sp. BC
Alatospora sp. BC
Lemonniera sp. BC
Tetrachaetum sp. BC


Bibliography Used For Identification

Bick, Hartmut. 1972. Ciliated Protozoa. World Health Organization, Geneva.

Chengalath, R. et al. 1971. Planktonic Rotifers of Ontario, University of Waerloo Biology Series. N0. 2. Waterloo, Ontario.

Curds, Colin R. 1975. A Guide to the Species of the Genus Euplotes (Hypotrichida, Ciliatea). Bulletin of the British Museum (Natural History). Zoology, Vol. 28 No. 1. London.

Donner, Josef. 1966. Rotifers.(transl. H. G. S. Wright) Frederick Warne & Co. London.

Faure-Fremiet, E. 1921. Contribution a la Conaissance des Infusoires Planktonique. Supplements au Bulletin Biologique de France et de Belgique. Paris.

Jahn, Theodore L. et al..1979. How to Know the Protozoa [2nd ed] Wm. C. Brown Co,. Dubuque, IA.

Kendrick, Bryce, 1992. The Fifth Kingdom [2nd ed]. Focus Texts, Newburyport, MA.

Leedale, Gordon F. 1967. Euglenoid Flagellates. Prentice-Hall, Englewood Cliffs, NJ.

Mackie, G. L. 1988. Common Benthic Invertebrates, Zooplankton, Algae, and Macrophytes of the Speed River Watershed. Dept. of Zoology, University of Guelph. Guelph, Ontario.

Margulis, Lynn, Corliss, John O., Melkonian, Michael, Chapman, David J. [eds] 1990. Handbook of Protoctista . Jones & Bartlett, Boston.

Margulis, Lynn & Schwartz, Karlene V. 1982. Five Kingdoms: An Illustrated Guide to the Phyla of Life on Earth [2nd ed.] W. H. Freeman & Co., New York.

Needham, James G. & Needham, Paul R. 1963. A Guide to the Study of Fresh-water Biology. (Fifth ED.) Holde-Day, Inc. San Francisco.

Nuttall, P. N. & Fernasndo, C. H. 1971. Fresh Water Ostracoda of Ontario. University of Waterloo Biology Series. No. 1. Waterloo, Ontario.

Page, F. C. 1988. A New Key to Freshwater and Soil Gymnamoebae. Freshwater Biological Association, Ambleside, Cumbria.

Prescott, G. W. 1970. How to Know the Freshwater Algae [3rd ed.] Wm C. Brown Co., Dubuque, IA.

Prescott, G. W. 1962. Algae of the Great Lakes Area.William C. Brown Co., Dbuque, IA.

Thorpe, James H. & Kovich, Alan P. 1991. Ecology and Classification of North American Freshwater Invertebrates. Academic Press, San Diego, CA.

Smith, Kristin & Fernando, C. H. 1978. A Guide to the Freshwater Calanoid and Cyclopoid Copepod Crustacea of Ontario, Univrsity of Waterloo Biology Series. No. 18, Waterloo, Ontario.

Weber, Cornelius I. 1971. A Guide to the Common Diatoms at Water Pollution Surveillance System Stations. U. S. Environmental Protection Agency, National Environmental Research Center. Cincinnati, OH.

Wolle, Francis. 1894. Diatomaceae of North America. The Comenius Press, Bethlehem, PA.

publications by author

April 1996. Micro-ecology in a Small Stream. Environmental Science Program, U. of Western Ontario, London, Canada.

(To appear) The Structure and Distribution of Benthic Microbial Communities in the Old Ausable River Channel. (in) Response of an Aquatic Ecosystem to Human Perturbation: Hydroecology and Geochemistry of the Old Ausable Rive Channel. (M. A. Maun, ed.) National Research Council, NRC Books. Ottawa, Ontario.

MICRO-GALLERY

The organisms pictured below might be found in a local pond or stream. The bizarre, not to say "alien" appearance of many microorganisms is due primarily to the very different constraints faced by micro-scale evolution. For example, none of these life forms require an internal skeleton, since cohesion and forces of compression/tension are much stronger, relatively speaking, on a scale of microns than they are in the macro-world of our own everyday experience.

The organisms in Kingdom Animalia (the rotifer, the gastrotrich and the snail) have relatively simple nervous systems, but members of the other kingdoms have no nervous systems at all, even though some of them have rather complex behaviors. How do they get by without brains? The answer is that long stretches of DNA of the unicell do not carry genetic information, per se, but oversee the synthesis of various messenger molecules that control everything from swimming to digestion, including all reactive elements of behavior. Molecular control, at this scale of existence, appears to produce all the "cybernetic complexity" required by such organisms.

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