Blue-green algae and Eubacterium

Blue-green algae noun - Predominantly photosynthetic prokaryotic organisms containing a blue pigment in addition to chlorophyll; occur singly or in colonies in diverse habitats; important as phytoplankton.

Eubacterium and blue-green algae are semantically related. In some cases you can use "Eubacterium" instead a noun phrase "Blue-green algae".

Eubacterium noun - A large group of bacteria having rigid cell walls; motile types have flagella.

Blue-green algae and eubacterium are semantically related. Sometimes you can replace phrase "Blue-green algae" with "Eubacterium", this terms are similar.