Planktonic, Yelko Waterhole
DIC x400 magnification (preserved specimen)
Benthic/metaphytic, Racecourse Swamp
DIC x400 magnification (preserved specimen)
Benthic, Boomerang Lakes, K'gari (Fraser Island), Great Sandy National Park
DIC x400 magnification (preserved specimen)
Benthic, Boomerang Lakes, K'gari (Fraser Island), Great Sandy National Park
DIC x400 magnification (preserved specimen)
Planktonic, Yelko Waterhole, Mitchell River
DIC x400 magnification (preserved specimen)
Planktonic, Yelko Waterhole, Mitchell River
DIC x400 magnification (preserved specimen)
Planktonic, Twelve Mile Lagoon, Mitchell River
DIC x400 magnification
Sample taken on 8/4/18. Image of specimens taken later from Lugol's preserved material.
Sample taken on 8/4/18. Image of specimens taken later from Lugol's preserved material.
A Tropical variety of Micrasterias torreyi
Mag. 400x (1,4,6); 200x (2,3,5)
Various forms of Hyalotheca dissiliens. The first 3 images show a mass of H. dissiliens zygospores. These masses are the largest I've encountered and were seen throughout the slide. The 4th image shows a segment of H. dissiliens with cells attached in filamentous form, surrounded by broad mucilaginous sheath. The last 2 images show H. dissiliens in single cell format. Both lateral views (barrel-shaped) and apical views (where the chloroplast has a stellate form) are visible.
Ref. https://www.outerhebridesalgae.uk/desmids/desmid-species.php?id=324
Mag. 200x (1-3), 400x (4)
Go here for a (mesmerizing!) video https://youtu.be/Ur60MbXHExU
Reference images:
Mag. 400x, 2 specimens photographed
Micrasterias ringens, according to AlgaeBase (https://www.algaebase.org/search/species/detail/?species_id=103503), is now considered a synonym of Micrasterias mahabuleshwarensis var. ringens
Mag. 400x
Previously observed in this same water sample, https://www.inaturalist.org/observations/160823260.
Mag. 400x
Found singly and in tandem pairs. (11 singletons and pairs in all.) All have a mucilaginous sheath. The size varied little: approx. 20µ L x 35µ W; 10µ isthmus. @karolina suggests this may be Staurastrum sublaevispinum.
Mag. 400x
Onychonema as seen here http://cfb.unh.edu/phycokey/Choices/Charophyceae/Desmids/desmid_filaments/ONYCHONEMA/Onychonema_Image_page.html.
Mag. 400x
Micrasterias laticepts. The second photo is a composite image assembled to highlight the pockmarked cell surface, especially visible along the apical axis.
For a reference photo, see
https://www.algaebase.org/search/images/detail/?img_id=35149
Mag. 400x
As seen here https://www.algaebase.org/search/images/detail/?img_id=19628.
L= 60µ
W = 60µ
Isthmus = 17µ
Mag. 400x
Large Cosmarium. A similar specimen (slightly smaller), from the same water sample, was identified by @geraldojpr, https://www.inaturalist.org/observations/176333296.
top left specimen
L = 150µ
W = 95µ
Isthmus = 35µ
Mag. 400x
This taxon was recently observed in a water sample from a nearby pond (Long Pond, which is much larger than the current sampling location, Sawmill Pond); observations from Long Pond, https://www.inaturalist.org/observations?d1=2023-07-01&d2=2023-07-31&place_id=any&taxon_id=1486895&user_id=mnold1&verifiable=any.
The current and previously observed specimens are very large and their cell wall surface appears entirely toothed except the apices.
L = 150µ
W = 95µ
Isthmus = 28µ
Mag. 400x
...rather than M. radiosa var. elegans, which would have narrower lobes, or M. radiosa var. ornata, which would have spines along the margins of the polar lobes. For reference images and descriptions, see https://www.researchgate.net/publication/328845266_Taxonomic_notes_on_the_species_of_the_genus_Micrasterias_Desmidiaceae_Conjugatophyceae_from_the_Metropolitan_Region_of_Salvador_Bahia_Brazil.
Mag. 400x
Mag. 400x
Mag. 400x
This spiny taxon has been observed 3 more times in local ponds (twice from the current sampling location and once from a nearby location), https://www.inaturalist.org/observations?place_id=any&taxon_id=996326&user_id=mnold1&verifiable=any
Reference
https://www.desmids.nl/maand/english/staurastrum_polytrichum.html
Mag. 400c
Medium-large (70µ x 25µ), asymmetric biraphid. Apiculate apices. Striae density: 7/10µ at the center, 9/10µ toward the apices. If you use your wishful-seeing vision on the first image, you might see the proximal end of the right raphe make an L-shaped dive into the central depression (aka, central nodule). All of these characteristics fit well with Cymbopleura apiculata as the ID. https://diatoms.org/species/cymbopleura_apiculata.
(However, it is also very similar to Cymbopleura americana https://fottea.czechphycology.cz/pdfs/fot/2011/02/01.pdf, but this taxon is not in algaebase.)
Mag. 400x
Small Trinema shell (from a testate, filose amoeboid). Though small, the 35µ length may push the ID to Trinema enchelys rather than Trinema lineare. According to F. Siemensma's data, the size range for T. lineare is 16-30µ and for T. enchelys, 30-100µ, https://arcella.nl/trinema/. Comparing the current images to others ID'd here on iNat as T. lineare, I lean toward T. lineare as the ID, https://arcella.nl/trinema-lineare/. For comparison purposes, the last composite image shows the current specimen compared with 2 other Trinema species observed in this same water sample. All 3 are on the same size scale.
A stream water sample (freshwater) was taken on 11/06/2021 using a 10 micron dip net to enrich for microorganisms.
About 14 microns long.
Mag. 400x
https://arcella.nl/arcella-gibbosa/
The final composite image includes recently observed Arcella species from the same water sample, all normalized to the same scale..