Are these Obelia hydroids? The mini-tank has saltwater, algae, and sand from the Black Sea. I suspect the algae-like thing on bottom left might have been an Obelia colony that spawned these.

Are these Obelia hydroids? The mini-tank has saltwater, algae, and sand from the Black Sea. I suspect the algae-like thing on bottom left might have been an Obelia colony that spawned these.

by Detonatress