Hydra eating grindal worms ID video

These hydra came originally from off the coast of Florida. They proceeded to eat all of my hippocampus zosterae babies, laugh when I tried to kill them with levamisole hydrochloride and it also killed the seahorses, and then cackle maniacally as it turns out they had invaded a second saltwater tank without me ever touching anything (no net, nothing) in between tanks. I drained the second tank, filled it with freshwater, and surprise! They are capable of surviving freshwater. They are also fine with water at 95 F for a few hours.

I captured this video as a test to see if they really were eating my fry (the idea being that if they would eat the grindal worms that they would also be a threat to the fry) before treating the tank with fenbendazole, which finally killed them.

Here is the video of the response of hydras to grindal worms. This should serve as a good identification video for people in the future and definitive proof that yes, they are carnivorous.

youtube.com/watch?v=o8I9p9woyU8

Cool vid ! I've also fought with hydra, in my case they came in on crayfish....don't remember what I used during combat operations though !

Rich

Ps, pretty amazing how those skinny little arms can grab and hold that "big" worm !

I have used Panacur to successfully eliminate them. This was in a tank with a healthy breeding population of both snails and cherry shrimp, neither of which suffered any ill effects. I didn't measure it precisely, but a "pinch" in a ten gallon did the trick (after it dissolved, which took about a day)

I have used Panacur to successfully eliminate them. This was in a tank with a healthy breeding population of both snails and cherry shrimp, neither of which suffered any ill effects. I didn't measure it precisely, but a "pinch" in a ten gallon did the trick (after it dissolved, which took about a day)

I used two one gram packets in my 75 gallon tank, one day after the other. Fenbendazole is the active ingredient in Panacur. The levamisole hydrochloride also killed them in the first of the two 75 gallon tanks, but it killed my seahorses and copepods, too. I've heard that Panacur doesn't kill seahorses. If I saw hydras in my tanks again in the future I'd use fenbendazole again instead of levamisole hydrochloride. The female mandarin dragonette died within a month of the levamisole hcl and I can't rule that out as the cause of death.

I didnt know there were Hydra species that could survive in both seawater and fresh water.

I didnt know there were Hydra species that could survive in both seawater and fresh water.

I didn't either. I'm glad they didn't spread to any of my other tanks.

This is the first of my aquatic denizens that my husband has found cute in the past several years. Of course he likes the hydras, one of the few things I absolutely can't keep because they eat fry. >.< Maybe if we put them in a separate room, and if he'd told me he liked them just a few hours before I added the fenbendazole instead of a few hours after... *shrugs* They are kinda cute, the way their little arms grab for the worm. I found out they eat, digest, and vomit out of the same hole instead of pooing, though, which does make them slightly less cute. :/

Wow...and I thought aiptasia were bad... O.o

I found out they eat, digest, and vomit out of the same hole instead of pooing, though

Kinda makes you wonder how they...
Never mind.