Meet Eudorina compacta!

Nozaki et al. 2020 Fig. 2A & B

Fig 2A & B from Nozaki et al. 2020. Light microscopy of Eudorina compacta Nozaki sp. nov. originating from Lake Victoria. (A) Surface view of 32-celled vegetative colony showing compactly arranged cells. (B) Optical section of 32-celled vegetative colony showing a hollow structure.

Hisayoshi Nozaki and colleagues have described another new species of volvocine algae, a member of the genus Eudorina from Lake Victoria in Tanzania. Unlike most species in this genus, the cells of Eudorina compacta are tightly packed around the surface of the colony, which is ellipsoidal. They coexist in Lake Victoria with Colemanosphaera charkowiensis, another species that Dr. Nozaki and colleagues described in 2014.

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Volvox videos by Shigeru Gougi

Shigeru Gougi (@sgougi on Twitter) has a YouTube channel of video microscopy, including several videos of Volvox:

There’s a good mix of developmental stages here: juveniles (smaller spheroids with nothing visible inside), reproductive age asexual colonies (larger spheroids with small green dots, which are asexual reproductive cells called gonidia), mature asexual colonies (with small spheroids inside that will eventually “hatch” out to become juveniles), and pregnant females (containing yellowish zygotes that will mature into desiccation-resistant spores). I’m not sure about the species ID, but with such a large number of cells, they’re probably in the section Volvox (sometimes known as Euvolvox): [Read more…]