-
Entomoneis (ent-owe-moan-aye-is) is a pennate diatom in which the frustule has a spiral twist. This image shows an empty siliceous frustule. Some say this genus cannot be distinguished from Amphiprora. This may be E. alata. Differential interference microscopy.
data on this strain.
-
Diatom with strongly developed internal intrusions of the frustule, girdle view.
-
Empty frustules by phase contrast microscopy. Generic identity needs to be confirmed.
-
Its the thing on the left (the thing on the right is a sand grain). A rather asymmetrical and often twisted pennate diatom, which in this case has valves that are a bit dish-like and are very often twisted. Frustule only, differential interference contrast optics.
-
A rather asymmetrical and often twisted pennate diatom, which in this case has valves that are a bit dish-like. This species is common in Alkaline Lake. Frustule and residue of cytoplasm, differential interference contrast optics.
-
A rather asymmetrical and often twisted pennate diatom, which in this case has valves that are a bit dish-like. This species is common in Alkaline Lake. Frustule and fragments of cytoplasm, phase contrast optics.
-
A rather asymmetrical and often twisted pennate diatom, which in this case has valves that are a bit dish-like. Girdle bands are splitting away from the frustule. This species is common in Alkaline Lake. Frustule only, phase contrast optics.
-
Diatoms are algae which live in little glass boxes or frustules - rather like little petri dishes. Pennate diatoms are motile, and rely on, we believe, the excretion of mucus through a slit in the wall - the slit is the raphe and runs down the flat faces of the petri dishes (frustules in diatom terminology). The frustule is perforated with tiny holes to allow the diatom to excrete waste products, and pick up nutrients, dissolved gases etc. from the surrounding water. The one is seriously asymmetric. Phase contrast.
-
Amphiprora (am-fee-pro-ra). Pennate diatoms are usually regarded as boat shaped, although some of the boats have very odd shapes. They can usually glide. This particular form is very common in sediments - the form apparently allowing the cell to penetrate through the pores of the sediments. Although enclosed in a siliceous shell, the shell of these rather delicate diatoms is flexible. The plastids contain chlorophylls a and c which gives the yellowy-brown colour. Phase contrast.
-
Pennate diatom seen in girdle view. The cells are enclosed in siliceous valves. There are typically two valves - a top one and a lower one, and they are joined together with fine bands or girdle strips. This image is a view from the side and shows the girdle strips. Differential interference contrast.
-
Pennate diatoms. The cells are enclosed in siliceous valves. There are typically two valves - a top one and a lower one, and they are joined together with fine bands or girdle strips. With plastids containing chlorophylls a and c (they are stramenopiles after all). Genera and species distinguished largely by the shape of the organism and the pattern of pores and sculptings of the siliceous shell or frustule. Pennate diatoms are important in intertidal and illuminated subtidal sediments in marine ecosystems and primary producers. Pennate diatoms are capable of movement, relying on the raphe to produce thrust. Movement benefits diatoms which may move towards the light, recover their location after disturbances by overlying water currents, wave actions, animal burial and so on. Several species illustrated. Phase contrast.
-
-
Cylindrotheca (sill-inn-dro-thee-ka) fusiformis, an elongate and slightly twisted pennate diatom (stramenopile), tends to move in a spiral motion, frustule not heavily silicifed and and can be deformed. Differential interference microscopy.
data on this strain.
-
-
Material from the Netherlands.
-
Formerly Brebissonia boeckii, material from the Netherlands.
-
Filamentous diatom commonly found near the Tvarminne Zoological Station. Previously known as Achnantes taeniata.
-
Detail showing plastids inside several cells at the end of a filament. Same filament as included in another picture in this collection.
-
Valves are rectangular in girdle view and elliptical in valve view. Each cell has four ribbon like and folded chloroplasts, two along each side of the girdle.
