MicrobeHunter.com Microscopy Forum

About 4 weeks ago I found a small Hydra , being the first one I've ever found it instantly captivated my attention, and I haven't been able to take my eyes and my camera off of it
Every so often I move it from one petri dish to another, where there are different sources of food, from small Crustaceans to mosquito larvae. To my surprise while recording it I came across this flat worm, surprisingly the tables were turned and the Hunter became the prey.....Im not too worried since Frank The Hydra ( yes I named it ) will grow the tentacles back in less than a week.

The flat worm ended up regurgitating one of the tentacles and the Chlorella inside of it. My question is, has anyone seen or read about similar behavior? My understanding is that Hydras contain enough venom to kill small fish, even bigger mosquito larvae succumb to the poison, as seen on the second video.

Exciting presentation. Enjoyed and learned from it. Thanks.

Thank you Don.

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Excellent action video. Do hope Frank recovers soon!

Impressive videos, thanks you for sharing Plasmid.

Great videos!

Some flatworms are known to feed on hydras. They even integrate the cnidoblast of the hydras and use them - probably - as a defense for themselves.
The flatworm may be Stenostomum unicolor, but it is not possible to be sure with a video in darkfield only.

Thanks for sharing.

Michael Müller wrote: ↑

Sun Apr 11, 2021 7:58 am

Great videos!

Some flatworms are known to feed on hydras. They even integrate the cnidoblast of the hydras and use them - probably - as a defense for themselves.
The flatworm may be Stenostomum unicolor, but it is not possible to be sure with a video in darkfield only.

Thanks for sharing.

Thank you for that info... I ended up transplanting the Hydra to another petri dish with clean water, two days later I noticed that it was missing a lot more tentacles, to my surprise I found a fully grown worm, that had been plucking away.... Very difficult to get rid of those guys.

Way cool vid Plasmid-I started to feel a bit ill by the end of it! Was that with a stereo scope? If so what type?-never had one but it’s calling louder each day to be explored-hydras are definitely up there in my “haven't seen yet but really want to” list! Don’t they regrow from tiny bits left?
Keep it up-Frank is in my prayers tonight...

Yes it was using a stereo similar to this one https://www.amscope.com/8x-50x-track-st ... ights.html which works out perfect for larger samples like Hydras, but any little vibration will cause the water sample to vibrate. For the longest time I disliked the idea of owning a stereo...now I find myself using it a lot more than my compounds. This is the first hydra I've encountered, and haven't been able to find anymore, my understanding is that they can regenerate from small pieces.