Attack of the Hydra!

Today, I had the misfortune to discover a new creature in one of my fry tanks. Quite a few Hydra are present in this tank, presumably introduced by feeding incredibly small fry foods, such as newly hatched brine shrimp. It’s also possible that they’ve been present all along, but couldn’t survive until I provided high-quality micron-sized protein powder for them (and the fry) to feed on.

Hydra are bad to have because just like their marine cousins (jellyfish, corals, and sea anemones), they feed off of small organisms, capturing them using their stingers. If they just stuck to water fleas or infusoria, I wouldn’t mind, but they will also attack newly hatched fry. That’s unacceptable. Now, I have shrimp in this tank, which some folks report will keep them under control, but nevertheless the Hydras are still present. Supposedly, they can be killed by using Fluke tabs, raising the temperature significantly, or by breaking down the whole tank, and sterilizing it.

I’m not going to break down the whole tank because feeding fry will just continue to promote their presence in the future. For the next couple of hours, I’m just going to watch them, since they really are neat looking creatures. But, then, I’ll start my assault on their lives. Suggestions welcome!