Observaciones de mnold1

Mag 200x

• A pond-side water sample taken on 02/24/2024 using a small sample bottled attached to an extension pole Air temp 42F (no ice at the shore).

Interestingly shaped ciliate, something like a solid question mark. A black arrow indicates what I think is its oral groove or cavity. Posterior projection seems like this critter was once stalked?
For a video, see https://youtu.be/IQ3wGbN_lQA.

Mag. 400x

• A pond-side water sample taken on 02/24/2024 using a small sample bottled attached to an extension pole Air temp 42F (no ice at the shore).

Moderately-sized ciliate with a short "proboscis". For a video, https://youtu.be/pFHxRFsq2ic.

Mag. 400x

• A pond-side water sample taken on 02/24/2024 using a small sample bottled attached to an extension pole Air temp 42F (no ice at the shore).

Unexpected movement inside the shell of a specimen of Arcella spectabilis (IDd by Bruce Taylor) revealed a highly metabolic, flagellated euglenoid. The Arcella shell appears intact, so the euglenoid must have entered through the shell's aperture... we just don't know why! Bruce Taylor suspects this is a species of the Astasia. For a long video of dubious quality, see https://youtu.be/_srdcoOyTaE.
ref: https://cfb.unh.edu/phycokey/Choices/Euglenophyceae/non_ps_euglenoids/ASTASIA/Astasia_key.html

Mag. 400x

• A pond-side water sample taken on 02/24/2024 using a small sample bottled attached to an extension pole Air temp 42F (no ice at the shore).

Very large specimen of A. conica. Siemensma notes a maximum dimension of ~100µ (for his and literature observations.) A large Arcella (up to 345µ wide) with a highly folded test is A. formosa , but its pie shape (highly folded and flattened) does not seem appropriate for the current specimen.

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.

Shell of an intermediate sized specimen of T. enchelys; F. Siemensma cites a size range of 30-100µ, https://arcella.nl/trinema-enchelys/. Denticulate scales ringing the aperture margin are apparent in these images. The last composite image shows the current specimen (53µ) beside 2 other Trinema specimens observed in this same water sample.

Mag. 400x

• A pond-side water sample taken on 02/24/2024 using a small sample bottled attached to an extension pole Air temp 42F (no ice at the shore).

Stalked, pennate diatom. Compare to a similar observation from a different, local waterbody, https://www.inaturalist.org/observations/86792792. It may be that the diatoms in the current observation are all presenting in girdle view... Diatoms from the earlier observation have distinctive profiles in girdle and valve views. The distinction can not be made for the current specimens.

Mag. 400x

• A pond-side water sample taken on 02/24/2024 using a small sample bottled attached to an extension pole Air temp 42F (no ice at the shore).

A larger specimen was previously observed, https://www.inaturalist.org/observations/158455990. Both appear similar to Eunotia mayamae as seen here https://phytokeys.pensoft.net/article/23806/zoom/fig/199/, an excerpt from https://phytokeys.pensoft.net/articles.php?id=23806.

Mag. 400x

• A pond-side water sample taken on 02/24/2024 using a small sample bottled attached to an extension pole Air temp 42F (no ice at the shore).

Stalked, loricate ciliate in the role of an epizoite; it is attached in the urosome/seta region of a copepod (tail area). The copepod was very active, whipping the Cothurnia sp., and its associated epizootic alga, in sweeping arcs... a testament to the strength of the attachments involved. The last image (replicated in composite image 2) may give a hint of the nature of the pellicle of the zooid; see the horizontal striations at the base of the zooid. I was unable to capture a good video of this critter and not thoughtful enough to photograph the entire copepod with its Cothurnia passenger.

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)

Small, smooth Arcella, partial ventral view (50µ wide, 13µ aperture). For the purpose of size comparison, the last composite image includes recently observed Arcella species from the same water sample, all normalized to the same 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)

Relatively large Centropyxis (230µ including its single spine) and 190µ excluding the spine. This is the first time I've been able to capture a lateral view of any Centropyxis (images 1 & 3). The flattened test in lateral view is ~70µ tall. Freshening the liquid under the coverslip caused the test to flip to a dorsal view (images 2 & 4), revealing a very round margin. Large and flat appear to be key features in identifying this species. For more information and images (especially the side-view image which shows internal structure that my images only suggest), see https://arcella.nl/centropyxis-discoides/.

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)

Large Stauroneis specimen (200µ L x 45µ W; L/W = 4.44). The stauros (clear, transverse band in the central area) is rectangular rather than bowtie-shaped. The striae are slightly radiate and densely packed at 12 striae per 10µ near the central region (see image 2). Proximal termini of the raphe are expanded (looking like the end of a Q-tip) and, to my wishful eye, the terminal portion of each proximal raphe is slightly deflected up, toward the top of the photos in image 1 (perpendicular to the long axis). These characteristics and the overall shape and size correspond well with the taxon, Stauroneis americana as seen here https://diatoms.org/species/stauroneis_americana.

This is a compilation of Difflugia gigantea specimens observed in the 1/6/2024 and 11/8/2022 samples from Lantern Hill Pond. All of the specimens are placed on the same scale for comparison purposes. Some additional species of Difflugia, all locally observed, have been added for comparison purposes. Only in this manner can I get a sense of how large the D. gigantea specimens truly are. Oh my!
(This compilation is patterned after those presented by F.J. Siemensma at his "Microworld, world of amoeboid organisms" - see https://arcella.nl/difflugia-gigantea-2/)

Mag. 100x (1), 200x (2)

• 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.

This taxon is a regular find at this sampling location, https://www.inaturalist.org/observations?place_id=any&preferred_place_id=1&taxon_id=1426238&user_id=mnold1&verifiable=any. The shells (tests) have ranged from 365 to 460µ (current specimen) in length, all with relatively the same shape and coarse texture. For more information, see https://arcella.nl/difflugia-gigantea-2/.

Mag. 100x

• 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.

This taxon is a regular find at this sampling location, https://www.inaturalist.org/observations?place_id=any&preferred_place_id=1&taxon_id=1426238&user_id=mnold1&verifiable=any. The shells (tests) have ranged from 365 to 450µ in length, all with relatively the same shape and coarse texture. For more information, see https://arcella.nl/difflugia-gigantea-2/.

Mag. 200x

• 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.

Large, coarse-grained test. Meets criteria for this taxon as recorded and pictured here https://arcella.nl/difflugia-gigantea-2/, although it is smaller than previously observed specimens from this sampling location https://www.inaturalist.org/observations?place_id=any&taxon_id=1426238&user_id=mnold1&verifiable=any.

Mag. 200x (1), 400x (2)

• 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.

The egg capsule (hatched) of a species of Rhabditophora, a subphylum of flatworms (formerly known as Turbellaria). This single specimen is larger than those previously observed from a different local waterbody, https://www.inaturalist.org/observations/159905180. Many thanks to @shanesmicrocope for helping to ID these earlier specimens. For more information and images see http://www.jaes.shimane-u.ac.jp/laguna/laguna28pdf/laguna28_15_35.pdf. From this paper, I've included as a 3rd image, Fig. 8 (left portion) which shows the anatomy of a Rhabditophora (formerly, Turbellaria) egg capsule.

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.

Possibly a rotifer resting egg.
A similar specimen (in size and configuration) was observed from the same location during Fall 2022 https://www.inaturalist.org/observations/188170793. @shanesmicrope shared an image from Plingfactory that that was very similar to the current and previous specimens. The similarity is with the resting egg of Polyarthra vulgaris https://www.plingfactory.de/Science/Atlas/KennkartenTiere/Rotifers/01RotEng/E-TL/Bdelloid/Rotifer%20reproduction.html. My suspicion is that my specimens are also rotifer eggs.

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.

Seen regularly at this location (https://www.inaturalist.org/observations?place_id=any&taxon_id=1468257&user_id=mnold1&verifiable=any). All images are of the same specimen, trying to visualize the valves independently; compare top an bottoms images images in the composite). For reference images and information see https://diatoms.org/species/pinnularia-undula-var-major.

L = 100µ
W = 20µ
Striae density = 7-8/10µ @ center,
9/10µ @ shoulder approaching apex

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.

Normally spherical shape is compressed here (perhaps my fault). Short spine-scales (blue arrow in image 1) are deeply bifurcated, while the long spine scales have a very shallow bifurcation (red arrow). The absence of green coloration means zoochlorellae are absent. For information and reference images see https://arcella.nl/acanthocystis-turfacea/

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.

Not sure, but it appears to be an exceptionally large Syura colony (160µ wide; ~20 cells across) that is disintegrating. The golden color and granules (bumps) on the cell surface is consistent with Synura. Unfortunately, I am unable to resolve any flagella, so my diagnosis is uncertain.

Mag. 200x

• 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.

Large (≥250µ long when near completely extended), colorless euglenoid. Long anterior flagellum. An amazing contortionist (metabolic motion), see 1-6 sequence image 2 (be sure to enlarge).

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.

Unfortunately, the fundus is buried in debris. I think I see one, hollow spine (marked in the images). The number of spines present in C. aculeata is variable. The size of the test, the offset of the large aperture, all seems consistent with this taxon... or complex.https://arcella.nl/centropyxis-aculeata/