Eukaryotes aren’t really my bag but I’ve heard that the pretty ones are diatoms. Can anyone confirm or deny the identity of my friend in center field here?
Oh my! There’s a good chance Damhnait has inadvertently crashed a diatom party. Diatoms are possibly the most abundant eukaryotic aquatic organisms, so they make frequent appearance in water samples. When I took phycology in college, I could pretty much count on finding at least a few diatoms mingling with other regulars like Spirogyra and their ancient prokaryotic friend Spirulina on days when we were asked to collect samples for class.
Diatoms are usually divided into two broad groups: pennate and centric. Our little friend is clearly not in the latter group, whose members are typified by radial symmetry (I’ve previously posted a few examples of centric diatoms). Particularly in the larger version of the above image, there appear to be parallel riblike costae running the length of the cell, a feature commonly seen in the frustules of pennate diatoms (costae can be clearly seen in several of the diatoms here).
Unfortunately, I lack the expertise to make a more precise classification, which in diatoms is generally done by closely examining the details of their frustules. Moreover, there’s some possibility that I’m completely mistaken, and this is actually something that belongs in Raynor’s wunderkammer.
