Amoebae in the family Arcellidae make their shells from a self-produced organic substance, without incorporating any other building materials (diatoms, hard scales, bits of quartz etc.). Although described in older sources as “chitinous,” and in newer ones as “keratin-like”, the precise composition of this substance is still unknown. The stuff is not laid down as…
A couple of blog posts ago, I discussed some recent research suggesting that some testate amoebae use their shells for predation. Yesterday, I was looking at samples from Mer Bleue Bog, and came across some more specimens of the handsome amoeba I mentioned in that post, Netzelia corona. I took some time to look more…
A shelled amoeba I discovered nearly eleven years ago finally has a name! Meet Arcella prismatica Taylor, Strueder-Kypke & Siemensma, 2025. So far, this pretty morphotype has only been found at two sites, a brown-water lake in Ottawa’s Mer Bleue Bog, and a roadside mire in the Cree Nation of Chisasibi, on the Quebec coast…
Netzelia corona is a testate amoeba with “teeth” around the aperture of its shell. It also has some impressive spines jutting out from its posterior, which have obvious advantages as a defensive apparatus. But it’s the teeth that have always puzzled me. They’re very neatly made, featuring uniform lobes of organic cement from which tiny,…
Two wrongs don’t make a right. Fifty wrongs, however, can make a scientific consensus. All it takes is a large enough number of researchers drawing similar conclusions from a big enough pile of bad data. A confirmation cycle sets in, and tentative suggestions begin to solidify into confident assertions. A weird idea that might be…
On a recent trip to the eastern coast of James Bay, I collected large numbers of testate amoebae that, by morphological criteria, belong to various species in the genus Difflugia. I’ve spent some time making portraits of them, measuring them, and dropping live ones in little vials of guanidinium thiocyanate in the hope of eventually…
