Lemanea sp. from Eagleville Dam, Eagleville, CT |
close-up of a dissected filament of Lemanea sp. from Eagleville Dam, Eagleville, CT |
close-up of the surface of a Lemanea filament, showing corticating cells; Eagleville Dam, Eagleville, CT
Euglenoids
Euglenoids are an ancient lineage most closely related to Kinetoplastida (best known for the parasite Trypanosoma). They acquired photosynthetic abilities by engulfing a green alga - and therefore they may superficially resemble one. Among the commonly occurring genera are Euglena, Trachelomonas, and Phacus.
- Unlike green algae, which store energy in form of starch, euglenoids use a different carbohydrate, paramylon. The paramylon bodies are often large and of a white-ish, "shiny" appearance, like the one visible in the Phacus specimen below.
Phacus orbicularis from pond on Forest Rd., Mansfield, CT |
Phacus longicaudatus from River Park, Tolland, CT |
a large Euglena sp. from Breakneck Pond, Union, CT; video of another large Euglena species from Tift Pond can be found here |
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Trachelomonas armata var. steinii from Tift Pond, Storrs, CT |
Strombomonas sp. from Tift Pond, Storrs, CT
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Green algae: Chlorophyta
- Some algae grow on plants or on other algae - epiphytically. Aphanochaete from the order Chaetophorales, is an example of a green filamentous alga growing on another green filamentous alga, Oedogonium (order Oedogoniales).
- Other free-living filamentous algae are Microspora, the branching Chaetophora, the above mentioned Oedogonium, and Bulbochaete - a relative of Oedogonium with branched filaments ending in long projections.
- Green algae often produce swimming cells as part of their life cycles. As an example, a video of a swimming cell of Oedogonium can be found here.
Aphanochaete repens growing epiphytically on Oedogonium; from Walker Reservoir, Vernon, CT |
Chaetophora sp. from stream by the Willington Pizza restaurant, Willington, CT |
Microspora sp. from stream by the Willington Pizza restaurant, Willington, CT |
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Bulbochaete sp. from pond on Forest Rd., Mansfield, CT
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Palmodictyon varium, an unusual not-quite-filamentous green alga from Cedar Swamp/Rt. 195, Mansfield, CT |
Stigeoclonium flagelliferum, a branching filamentous green alga related to Chaetophora and Aphanochaete; from Cedar Swamp/Rt. 195, Mansfield, CT |
Characium sp., another epiphytic green alga, Cedar Swamp, Mansfield, CT |
Geminella ellipsoidea, Cedar Swamp, Mansfield, CT |
Selenastrum capricornutum, a colonial alga from Breakneck Pond, Union, CT
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Ankistrodesmus falcatus, a colonial alga from Breakneck Pond, Union, CT |
Kirchneriella lunaris, a colonial alga from Breakneck Pond, Union, CT |
Dictyosphaerium pulchellum, a colonial alga from wetland on Mansfield City Rd., Eagleville, CT |
Tetraedron regulare from wetland on Mansfield City Rd., Eagleville, CT |
Tetraedron enorme from wetland on Mansfield City Rd., Eagleville, CT
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- Some green algae form colonies with defined numbers of cells (4, 8, 16, etc.). Such colonies are called coenobia. Commonly found coenobial green algae are Pediastrum, Stauridium, Coelastrum, Desmodesmus, and Scenedesmus from the order Sphaeropleales. Their sister order Volvocales also contains several coenobial representatives, for example: Eudorina, Pleodorina, Pandorina, and Volvox.
Stauridium tetras from pond on Forest Rd., Mansfield, CT |
Desmodesmus denticulatus from pond on Forest Rd., Mansfield, CT |
Coelastrum microporum from pond on Forest Rd., Mansfield, CT |
Eudorina elegans, a coenobium of flagellates from Breakneck Pond, Union, CT |
Pandorina morum, a coenobium of tightly packed flagellates from Breakneck Pond, Union, CT
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Pediastrum angulosum, a coenobial alga related to Stauridium, from Halls Pond, Chaplin, CT |
Pediastrum duplex, a coenobial alga related to Stauridium, from Breakneck Pond, Union, CT |
Scenedesmus sp., a close relative of Desmodesmus, from Breakneck Pond, Union, CT |
Coelastrum cambricum, a colonial alga from Breakneck Pond, Union, CT |
Desmodesmus quadricauda, a coenobial alga from River Park, Tolland, CT
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Sorastrum americanum from wetland on Mansfield City Rd., Eagleville, CT
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Green algae: Streptophyta
- The order Desmidiales contains some of the most spectacular of algae. Many species of the crescent-shaped Closterium can be found in the Northeast, as well as Cosmarium, Staurastrum, Euastrum, Micrasterias, Xanthidium, and others.
Xanthidium antilopaeum from pond on Forest Rd., Mansfield, CT |
Cosmarium sp. from the EEB greenhouse, Storrs, CT |
Cosmarium granatum from pond on Forest Rd., Mansfield, CT |
Cosmarium contractum from pond on Forest Rd., Mansfield, CT |
Staurastrum cf. hirsutum from stream by the Willington Pizza restaurant, Willington, CT
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Tetmemorus brebissonii from a marsh at Bigelow Hollow, Union, CT |
Tetmemorus granulatus from a marsh at Bigelow Hollow, Union, CT |
Micrasterias mahabuleshwarensis var. ringens from Halls Pond, Chaplin, CT |
Onychonema laeve from Halls Pond, Chaplin, CT |
empty cell walls of Spondylosium luetkemuelleri from Halls Pond, Chaplin, CT
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Closterium navicula from pond on Forest Rd., Mansfield, CT |
Cosmarium denticulatum from pond on Forest Rd., Mansfield, CT |
Euastrum verrucosum from pond on Forest Rd., Mansfield, CT |
Euastrum cf. oblongum from pond on Forest Rd., Mansfield, CT |
Staurodesmus dejectus from pond on Forest Rd., Mansfield, CT
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Closterium cf. kuetzingii from pond on Forest Rd., Mansfield, CT |
Closterium sp. from pond on Forest Rd., Mansfield, CT |
Hyalotheca dissiliens, a filamentous desmid from Cedar Swamp/Rt. 195, Mansfield, CT |
Desmidium grevillei, a filamentous desmid from Cedar Swamp/Rt. 195, Mansfield, CT |
Desmidium swartzii, a filamentous desmid from Breakneck Pond, Union, CT |
Spondylosium cf. pulchrum, a filamentous desmid from Breakneck Pond, Union, CT |
Teilingia sp., a small filamentous desmid from Breakneck Pond, Union, CT
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Euastrum cf. pulchellum from pond on Forest Rd., Mansfield, CT |
Euastrum binale from Breakneck Pond, Union, CT |
Euastrum bidentatum from Breakneck Pond, Union, CT |
Euastrum affine from Breakneck Pond, Union, CT |
Euastrum denticulatum from Breakneck Pond, Union, CT
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Micrasterias radiosa, a large desmid from Breakneck Pond, Union, CT |
Micrasterias truncata from Breakneck Pond, Union, CT |
Micrasterias laticeps from Breakneck Pond, Union, CT
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Pleurotaenium nodosum from Breakneck Pond, Union, CT |
Staurastrum arctiscon from Breakneck Pond, Union, CT |
Bambusina brebissonii from Breakneck Pond, Union, CT |
Staurodesmus convergens from Breakneck Pond, Union, CT |
Staurastrum cf. ophiura from Breakneck Pond, Union, CT |
Cosmarium amoenum from Breakneck Pond, Union, CT
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Micrasterias denticulata from Bigelow Pond, Union, CT |
Micrasterias rotata from Breakneck Pond, Union, CT |
Micrasterias rotata var. japonica from Breakneck Pond, Union, CT |
Cosmarium subcucumis from Bigelow Pond, Union, CT
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Xanthidium cristatum from Pine Acres Lake, Chaplin, CT |
Micrasterias radiata from wetland on Mansfield City Rd., Eagleville, CT |
Gonatozygon aculeatum from wetland on Mansfield City Rd., Eagleville, Union, CT |
MIcrasterias pinnatifida from wetland on Mansfield City Rd., Eagleville, CT |
Euastrum evolutum from wetland on Mansfield City Rd., Eagleville, CT
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Cosmarium comminsurale from wetland on Mansfield City Rd., Eagleville, CT |
Staurastrum cf. teliferum from wetland on Mansfield City Rd., Eagleville, CT
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- The order Zygnematales contains commonly occurring ("weedy") filamentous taxa Zygnema, Mougeotia, and Spirogyra, but also several unicellular genera, for example Netrium or Spirotaenia.
Spirogyra sp. from stream by the Willington Pizza restaurant, Willington, CT |
Mougeotia sp. from Cedar Swamp/Rt 195, Mansfield, CT |
Netrium digitus from Breakneck Pond, Union, CT |
Spirotaenia condensata from Breakneck Pond, Union, CT
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- Klebsormidiales are a group of inconspicuous but commonly occurring filamentous algae.
- Coleochaetales are among the closest relatives of land plants. Some species retain and nourish the fertilized zygote (this is called matritrophy) and form disc-like thalli (bodies) that often grow attached to aquatic plants or other substrates.
Klebsormidium sp. from Halls Pond, Chaplin, CT |
Coleochaete scutata from Bigelow Pond, Union, CT
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- Not all algae are microscopic. Aside from the conspicuous marine seaweeds, several freshwater algae are also observable by the naked eye. The green algae of the class Charophyceae (stoneworts) can be found in many water bodies in the Northeast, but can be easily mistaken for aquatic plants.
Nitella flexilis from Walker Reservoir East, Vernon, CT |
Chara zeylanica from the EEB greenhouse, Storrs, CT, and a closeup of its reproductive structure (oospore)
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- And let's not forget the most famous lineage of Streptophyta - land plants!
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sundew - a carnivorous plant, growing on a stump |
Breakneck Pond, Union, CT
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