Favoritos de wleurs

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

• A water sample was taken on 09/13/2022 from the shore of Long Pond using a 10µ dip net to enrich for microbes. Air temp. 71°F. (Sample was stored at room temperature and assayed again on 9/29/2022.)

Mag. 400x

• A pond-side water sample was taken on 07/31/2023 using a 10µ dip net to enrich for microbes. Air temp. 75°F.

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

• A pond-side water sample was taken on 07/31/2023 using a 10µ dip net to enrich for microbes. Air temp. 75°F.

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

• A water sample was taken on 09/03/2023 from pond-edge using a 10µ dip net to enrich for microbes. Air temp. 80°F.

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

• A water sample was taken on 09/03/2023 from pond-edge using a 10µ dip net to enrich for microbes. Air temp. 80°F.

...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

• Water sample (with sediment) was taken from the shore of a small mill pond (on Billings Avery Brook) on 3/13/2024 using a jar tethered to an extension. pole. Air temp. 50F.

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.

Mag. 400x

• A pond-side water sample (retentate) was taken on 01/06/2024 using a 10µ dip net to enrich for microorganisms. (The shoreline had a layer of ice about 1/4" thick that needed to be breached in order to accommodate the dipnet. The retentate contained a lot of sediment due to the shallow depth and disturbance caused by the net.) Air temp 35F. (sample has been sitting on a cool, west-facing window ledge since 1/6/24)

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..