Favoritos de ozalga

Video: https://youtu.be/9X78cstFh1c
Sampling location: The bark of a tree within the city limits.
Date and time of collection: 27 Aug 2023 at 10 AM
Date and time of observation: 27 Aug 2023 at 12 PM
The sample was stored at room temperature in a plastic container.

Planktonic, Blue Lake, Naree Budjong Djara National Park, North Stradbroke Island (Minjerribah)
Type locality published in Rott, E., Kling, H. & McGregor, G. (2006). Studies on the diatom Urosolenia Round & Crawford (Rhizosoleniophycideae). Part 1. New and re-classified species from subtropical and tropical freshwaters. Diatom Research 21(1): 105-124

Planktonic, Waranga Basin.

DESCRIPTION: Filaments planktonic, generally straight, and surrounded by a broad hyaline mucilage up to 6.5 µm wide; facultatively produce T-type true branching. Branching is homothallic, progressing from a lateral bulge in vegetative cells perpendicular to the main filament, and through subsequent cell divisions, continue to elongate; vegetative cells of branches generally similar to, or only slightly broader than the parent filament, apical cells barrel shaped and hyaline. Vegetative cells with aerotopes, ± vacuolate, longer than broad (L:W 1.9–6.3) ranging from short cylindrical to elongated club-shaped; 7.7–21.1 µm long × 2.8–5.2 µm broad. Apical cells ± hyaline, elongated and club-shaped (L:W 2.6–6.5); 10.8–47.8 µm long × 2.6–7.3 µm broad. Heterocytes spherical to slightly longer than broad; 5.4–11.2 µm long × 4.4–7.5 µm broad. Akinetes solitary or up to two in series, and remote from heterocytes; ovate to elongated cylindrical (L:W 1.2–4.2); rounded at the ends; 13.1–33.8 µm long × 6.3–10.9 µm broad.

Size: 191 µm x 72 µm.

Site of sample collection: A stream full of algae near the South Pond, Katsurashima Ryokuchi (a freshwater habitat), Sendai, Japan

Date of collection: August 27th, 2022

Weather: Cloudy

Water temp.: 25.4°C

pH 7.0

Date of observation: August 28th, 2022 (the collected sample in a plastic container was left near a window out of direct sunlight at room temperature until observation)

Bright-field observation using a Wraymer microscope (model BX-3500TL, Osaka, Japan) equipped with a Floyd-2 HDMI ethernet digital camera (Wraymer, Osaka, Japan). The accuracy of the scale bar was confirmed by using a stage micrometer glass slide (1 div. = 10 µm; Wraymer, Osaka, Japan) at each magnification.

Benthic, Edgbaston springs.

DESCRIPTION: Filaments densely arranged, radiating from the centre of spherical to discoid, blue-green to olive-green colonies, 5–25 mm in diameter. Filaments isopolar, uniseriate, cylindrical, straight or flexuous, 20–39 um in diameter, main filament generally wider than the lateral filaments which gradually taper to a bluntly conical end; with single or geminate false-branching. Sheath firm, lamellated, uncoloured to yellowish or yellow-brown, closed at the apex. Vegetative cells isodiametric to shorter than broad, slightly constricted at the cross walls, 3.3–8.2 um long 18.0–27 um wide in the main filament, 3.5–5.0 um long 4.2–12.0 um wide in lateral branches, with granular contents. Heterocytes basal and intercalary, solitary, spherical to compressed-ovoid, 6.3–9.5 um long 11.0–19.0 um wide. Akinetes absent.

Video: https://youtu.be/aRbMKqI5ak0

Sampling location: A water sample was collected from Istok Lake near the shore, where snags and aquatic vegetation were present.
Date and time of collection: 16 Jul 2023 at 3 PM
Date and time of observation: 17 Jul 2023 at 10 PM
The sample was stored at room temperature in a plastic container.
All images and videos are of the same colony.

Conochilus hippocrepis (Schrank, 1803)

Diagnosis of the organisms observed:
• A planktonic rotifer that forms colonies encased in a gelatinous matrix or sheath.
• The colony is comprised of approximately 30 individuals, with an approximate diameter of 1 mm.
• The length of adult individuals within a colony has been observed to reach up to 470 µm.
• The species exhibits two distinct lateral (ventral) antennae. It can be confirmed that the majority of the specimens observed from the colony exhibited unequal antennae lengths, with the left ones being shorter.
• The stomach has an asymmetrical median ridge used for dividing food mass into two sections.
• The species is round-vase shaped, tapering off to a long un-segmented retractile foot without a toe; the corona is horseshoe shaped with a double band of cilia.
• Malleoramate trophi.
• The bladder opening is strongly shifted forward to the level of the mastax.
• Two red eye spots under the corona.

References:
Rotifer fauna of the USSR (Rotatoria). Subclass Eurotatoria (Orders Ploimida, Monimotrochida, Paedotrochida) (652, Fig. 1072) by L.A. Kutikova (1970)

http://www.rotifera.hausdernatur.at/Species/Index/394?AddScansGrid-page=9

https://www.plingfactory.de/Science/Atlas/KennkartenTiere/Rotifers/01RotEng/source/Conochilus%20hippocrepis.html

https://www.nies.go.jp/chiiki1/protoz/morpho/rotifera/r-conoch.htm#Conochilus%20hippocrepis

https://cfb.unh.edu/cfbkey/html/Organisms/PRotifera/GConochilus/conochilus_hippocrepus/conochilushippocrepis.html

Coexistence of Conochilus unicornis with C. hippocrepis in Lake Geneva : and commensal organisms found in their gelatinous matrix by Gérard Balvay and Jean-Claude Druart (1995)
https://doi.org/10.5169/seals-740260

Size: 22 µm x 15 µm

Site of collection: Katsurashima Ryokuchi south pond (a freshwater habitat), Sendai, Japan

Date of collection: June 5th 2021

Weather: Sunny

Water temp.: 22.0°C

pH 6.7

Bright field observation using a Wraymer microscope (model BX-3500TL, Osaka, Japan) equipped with a Floyd-2 HDMI ethernet digital camera (Wraymer, Osaka, Japan).