bbull 的最愛

Frontonia leucas Ehrenberg 1833 from the northernmost edge benthos (situated 250 meters from the edge of the Atlantic Ocean) of spring-fed freshwater coastal pond at Ocean Dunes Apartments in the Atlantic Double Dunes Reserve. The ciliate measures 300 um in length. There is a single ellipsoid macronucleus at the center of the cell. A single contractile vacuole with radiating collecting canals is present mid body on the right side. There is a long postoral suture and an indistinct preoral preoral suture. Imaged in Nomarski DIC on Olympus BH2 using SPlan 20x and 40x objectives plus variable camera phone cropping on Samsung Galaxy S0+. Per Foissner et al. 1994 "Identification made safe despite the enormous variability in size and shape with the following combination of features: contractile vacuole with long collecting ducts and 1 excretion pore, mouth opening very small in relation to body length (1:5 to 1:8)".

Description from Foissner W, Berger H, Kohmann F. T 1994: "Size depending on the population in vivo 120-600 x 60-250 pm, mostly 150-350 x 70-160 pm. Shape obovoid to ellipsoid or plantar. Approximately 2:1 flattened, body cross-section elliptical. Always broad in front, somewhat more narrowly rounded behind and sometimes slightly pointed. In some populations the anterior end clearly projects to the right. Macronucleus ellipsoid, roughly in the center of the cell, 2-9 spherical micronuclei are attached. Contractile vacuole on the right side at about midbody, with about 10 radial collecting canals that are noticeable even at medium magnification. 1 excretion pore. Resting extrusomes 6-10 pm long, spindle-shaped, clear seam under the pellicle. Cells often colored by ingested algae. 2O longitudinal rows of cilia terminating ventrally at a herringbone suture (pre- and postoral suture) that runs across the poles to the dorsal side. The postoral suture is very sensitive, which is why the cells here often burst when the coverslip is put on. No causdal cilia. Pellicle with square fields: the cilia in the center of the fields, the extrusomes in the horizontal ridges. Oral apparatus at the end of the first quarter of the body, oval and remarkably small (1/5 to 1/8 body length). On the left wall of the oral cavity 3 membrane cells (peniculi) each consisting of 4-5 long ciliated basal body rows. On the right edge of the mouth there is an undulating membrane and 3 rows of vestibular cilia made up of closely spaced pairs of basal bodies".

Serra et al 2021 (2) recently performed the "neotypification of F. leucas through the deposition of the neotype material in a museum collection, and the formal establishment of F. leucas as type species of the genus which was heretofore lacking" (2). This was because "Frontonia leucas (Ehrenberg, 1833) Ehrenberg, 1838, one of the first described Frontonia species which could be eligible to this role (as type species), actually consists of a set of different species, morphologically close to each other" (2).

1. Foissner W, Berger H, Kohmann F. Taxonomische und okologische Revision der Ciliaten des Saprobiensystems. Band III: Hymenostomata, Prostomatida, Nassulida. — Informationsberichte des Bayer. Landesamtes für Wasserwirtschaft. 1994;5/92:1–502.
2. The neotypification of Frontonia vernalis (Ehrenberg, 1833) Ehrenberg, 1838 and the description of Frontonia paravernalis sp. nov. trigger a critical revision of frontoniid systematics. Valentina Serra, Aldo D’Alessandro, Venkatamahesh Nitla, Leandro Gammuto, Letizia Modeo, Giulio Petroni & Sergei I. Fokin. BMC Zoology volume 6, Article number: 4 (2021)

Anisonema acinus Dujardin, 1841 from the northernmost pond edge benthos of the spring-fed freshwater coastal pond at Ocean Dunes in the Atlantic Double Dunes reserve situated 250 meters from the edge of the Atlantic Ocean. Measures 42.5 um in length. Imaged in Nomarski DIC using Olympus BH2 under SPlan 40x objective plus variable phone cropping on Samsung Galaxy S9+.

"Anisonema acinus Dujardin, 1841 Gliding euglenid with profile similar to a barley-grain, 25-47 µm long, mostly about 30 µm, dorso-ventrally flattened. With a wedge-shaped ingestion organelle which may be difficult to observe. With two flagella, the anterior flagellum about 1.5 times as long as the cell, and beating with an undulating and sweeping motion in front of the cell. The posterior flagellum is up to twice the length of the cell, very thickened at its base and follows an almost semi-circular loop as it leaves the flagellar pocket, emerging under a ventral fold of the cell surface. The posterior flagellum can cause occasional reversals of movement. With the flagellar pocket to left of cell and with an associated contractile vacuole. Nucleus with maculate texture and to right of the cell near mid-line. About 8-10 very delicate grooves on each side of body, grooves sometimes not seen. Sometimes contain algal materials, although no ingestion organelle was observed. Common and widespread" (1).

"The genus Anisonema contains slightly metabolic gliding euglenids with the capacity for reversal movements. The confirmation of an ingestion apparatus in this genus will require a review of the composition of this and adjacent genera" (1). "All are ovoid cells that maintain a constant shape most of the time (but are capable of some deformation), and glide on their thickened, hook-shaped posterior flagellum, whereas the anterior flagellum flails freely in front of the cell. Unlike Dinema, their pellicle is not thickened, and the feeding apparatus is difficult or impossible to observe. Many of our cells have ingested algal material" (2).

1. Free-living Heterotrophic Flagellates from Freshwater Sites in Tasmania (Australia), a Field Survey. Won J. LEE, Alastair G. B. SIMPSON and David J. PATTERSON. Acta Protozool. (2005) 44: 321 - 350

Climaciella brunnea. Cruickshank Trail, Merritt Island National Wildlife Refuge, Titusville, Brevard County, Florida, USA.

The most exciting encounter of my Florida trip. And there were hundreds of them sitting in the grass on the dike. I initially mistook them for paper wasps, but something was strange about them, even from a distance.

Found on the ground and apparently too cold to fly. Very small (< dime sized) bumble bee with very orange hair. Kept walking away on the ground so it ended up on my sleeve for the photo shoot where it warmed up and took off after a about 2 minutes. Never saw one quite like this before. Thank you John Ascher for the ID!

A male, so there was no danger of being stung. Found on some low growing Eupatorium and apparently out of energy., I placed it on a Clethra flower where it immediately began feeding. Not sure it helped this late in the season.

WOW!!! Flew up out of some ground cover and was surprisingly cooperative for the photo shoot. This individual really was that intensely colored and was still outside while I was editing some of these photos for comparison.