Euglena has a stiff cell membrane known as a pellicle, which can be seen easily in these two photos. Euglena’a pellicle is composed of protein strips that wrap around the cell. Towards the left side of the cell in the featured photo is a single red eyespot. Around the middle of the cell is an elongated ring-like structure called a paramylon. The paramylon was briefly mentioned in an earlier post regarding Phacus.
Trachelomonas is a genus within Euglenaceae, a family including Euglena. Trachelomonas differs from most other Euglenids as it possesses a shell-like structure called a lorica. This lorica contains ferric hydroxide, which gives it a redish coloring. At one end of the lorica is a small aperture from which the cell’s flagellum may emerge. Small spines are also present outside the lorica.
A relatively long flagellum can be seen extended from the green cell (left).
Here we see Euglenoid cells in a dormant stage of their life cycle known as palmella. Each green cell is contained within a gelatinous mucilage. A few cells can be seen dividing.
Rather than remaining solitary, some flagellates will form colonies. A classic example of this are the Synura Uvella featured in the photo above. The genus Synura is included among the Chrysophyta (Golden Algae). Clearly seen extending from one cell is a single flagellum.
Please be aware the the Chrysophyta are NOT an actual taxon; the genus Synura is included in the class Synurophyceae
- A recently-made slide of floating pond debris held a large number of organisms, such as the Euglena shown above and the ciliate from an earlier post.
Algae were plentiful in the sediment as well. Lised below are some of the findings…
Euglenids are flagellate algae. This particular species possessed a photoreceptive eyespot, composed of a stigma (pigment bodies) and a paraflagellar body which directs processes of phototaxis (the movement of an organism towards light). The eyespot apparatus can be seen as an orange mass toward the anterior of the cell (in the photo, the end on the right). Also visible at the anterior is one of two flagella.
Included on the slide with the ciliate feeding frenzy was this rather large flagellate. There weren’t a lot of these in the sample.
In the photo above, you may see a large, hyaline inclusion amid the body of Phacus. This is known as the paramylon, which is a storage space for carbohydrates. Phacus species typically have one of these bodies, but species of Euglena may have two. Other visible components of this cell is the red eyespot located on the anterior, and the bar-shaped body which I believe is a lipid (oil) inclusion.
As far as I could tell, this organism was from the genus Phacus, included in the phylum Euglenozoa, which also includes the model organism Euglena. Phacus is a flagellate that is included within Excavata.