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Bloom of life in my shrimp tank - including hydra!

14K views 20 replies 4 participants last post by  onemanswarm 
#1 ·
I have a semi-planted red cherry shrimp tank that has just bloomed with life recently. I introduced MTS into that tank and pond/bladder snails hitchhiked a ride on some plants I bought. The population of MTS don't bother me. I actually like them. The bladder snails are another story. The population has EXPLODED and I see egg sacks all over the place (little clear jelly like sacks with dots in them). The RCS population has also exploded and I see baby shrimps everywhere I look. The MTS population has grown but no where near the pond/blatter snail level.

While staring at this tank yesterday I noticed small little brown things on the filter and glass. These are semi fast moving when they do move and are very small dots. I also see what I think are just hatched snails crawling on the glass. These are almost clear dots. I also see a increasing number of nemotodes in the water whipping their way around.

I saw my first hydra in this tank yesterday too. I was kinda expecting them to show up and was excited when I saw it. Very small anchored on a piece of driftwood with his tentacles waving in the current. A few larger shrimp would venture by him and he would quickly either retract or kinda whip out at them. Cool.... I seem to have this huge ecosystem going in this 10 gallon. If I saw all this in my other fish populated tanks I would probably freak out. This tank is my 'lets see what happens' experiment.

For feeding I tend to drop a algae wafer in there daily which the shrimp and snails swarm to. I do weekly water changes but don't vac because I have sand and a lot of baby shrimp. The plants are a couple of large for a 10gal Wisteria plants, a java moss clump and two medium size java fern

I am wondering if I should do anything. I know the hydra can kill and eat baby shrimp. Do they also eat nemotodes? I am also wondering what are the other little critters that are swimming around?
 
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#3 ·
That's one of those questions that I see different answers to. In my research I have found where people lump all type of aquarium worms as 'planaria' and them some people separate them into two categories - planaria being the flatworm with the pointy head and two eyes which kinda glide over things in the tank and then the roundworm nemotodes which are much smaller, thinner and do "S" motions in the water.

In both cases they eat detritus so its a sign of too much decaying organics in the water. The bloom of pond/bladder snails point to that as well. I have yet to see planaria (the flatworm) in this tank. I am changing my feeding schedule from 1 daily algae wafer to every other day to cut down on the detritus. I can care less about the snails but I think the shrimp will be good from the naturally occurring algae in the tank for a while.

I'm really wondering what the effect of the hydra in the tank would be and if maybe the 'dots' I'm seeing now are their food source? I can only see one but I assume there are many more. I think they are interesting little creatures but if the primary purpose of the tank is RCS and they may harm them then I would need to kill them off without harming the RCS. The RCS are to small and numerous to move and gravel/sand vacs really are not a option.

I am hoping someone can chime in on the flatworm/roundworm question/debate and the effect of seeing hydra questions.
 
#4 ·
Yours sounds like a really fascinating tank! It really is an impressive ecosystem in a 10 gallon aquarium. I'm sorry to say that I don't have anything of substance to add to the discussion, but I'm going to chime in anyway so that it will be easy for me to keep track of this thread. I can't wait to see what the experts have to say! Good luck.
 
#5 ·
It is a very fascinating tank. My others seem boring to this one now with all the non-fish life swimming around. This is the only tank out of 4 without fish. I spend the most time looking it it now.

Yesterday I found a different type of snail. Its not a bladder or MTS. These are more of a circular type of shell instead of a bladder or cone spiral. I saw a few of them climbing around. I guess they reproduce slower and haven't really noticed them before now as they are big enough to spot... I guess they hitchhiked on some plants I bought.

I also found another small hydra. I'm going to get a magnifying glass today and see if I can see any shape to the brownish fast moving specs and search for other life. I wish I had a microscope.

Another question I have is could some of these smallish creatures and worms appear - as in not hitchhiked on a plant or fish but maybe naturally occurring in bodies of water or carried in on dust or something? IDK... just a thought.

To add more info about this tank - At one point I used to have guppies in this tank along with the RCS but moved them out a couple weeks ago. My thoughts are that they and their fry kept this worm and other glass crawling life in check. Now they are gone there are no predators and the population has exploded from that. The guppies where picking off the baby shrimp so they had to get moved. I used to take the guppy fry as snacks for another fish tank so I guess they (the guppies) were thinking a eye for a eye when it came to my RCS...
 
#6 ·
The new type of snail you're seeing: could it be ramshorn? Along with pond and MTS, Ramshorn would have a spot on the Mt Rushmore of most commonly introduced snails.

Most likely, I'd guess that all of these unexpected inhabitants arrived on plants or possibly in your substrate. In any event, it seems they appreciate your water parameters!

I did a little poking around and it seems the hydra could be a real threat to small RCS. What's more, they reproduce asexually when food is abundant, so if they do like the RCS (or any other forms of life your tank has to offer), it could get out of hand quickly. On the other hand, some people claimed to have had hydra and RCS simultaneously with seemingly no shrimplet predation.

Among the favorite sources of prey for wild hydra are cyclops and daphnia. I wonder if that might help ID your mystery guest?

Because you've established this as an experimental "see what happens" tank, I'd selfishly prefer if you did just that! I'd love to hear updates as this microcosmic ecosystem continues to unfurl before your eyes. Then again, I'm not the one who invested in RCS!

If you do decide to rid yourself of the hydra, nematodes, and other uninvited guests, check out the spixi snail. This might be a good advocate as they have an appetite for hydra, pond snail egg sacs, etc. but won't go after your shrimplets.

Whatever you do, DO NOT put anything with copper in there!
 
#7 ·
I was wondering if the brown specs where cyclops or daphnia. Those were my first thoughts but they are so small I cannot ID.

I also want to see "what happens" in this little ecosystem. I have read that hydra eat baby RCS but thier numbers are so numerous I think I would have to have hundreds of hydra to make a dent in that population.... Now watch for a post by me in a few months sayng "I have hundreds of hydra! help.":lol:

I think I will keep feedings to 1 wafer every other or 3 day and weekly PWC to keep the water quality good. I suspect with all of this life it could get out of hand. On the other hand if one organisms waste is another ones dinner it could keep itself in check as long as some balance is kept.

I am going to check out the spixi snail. Assuming the other critters are cyclops and dapnia I would expect the population of hydra to grow with no predators. I was also thinking a couple of assassin snails to prey on the pond, mts, and now ramshorn snails.. not to many as to clean it completely of these snails but enough to keep populations from exploding. Do you know of any other non-fish predators of hydra?

The initial cost of the shrimp were low so I don't mind loosing them for 'science.' I have been wanting a microscope for awhile - now I have a good reason.
 
#8 ·
I've been searching around for additional info on this and although most people regard hydra as a nuisance to be eradicated, I have to admit I'm more than a little envious of your crazy microcosm tank! A few thoughts:

1) As you said, the RCS are prolific breeders so the hydra probably won't decimate the population even if they do acquire a taste for shrimplets. Hopefully, a reliable supply of cyclops/daphnia will draw their focus elsewhere.

2) I never came across anyone complaining of a massive hydra infestation. Many people said that they vanished as quickly as they appeared without any intervention.

3) There are some chemical treatments that will wipe out the hydra or you could jack up your water temp to 100+ until they succomb, but obviously you'd need to quarantine anything you want to keep alive.

4) Any fish that will eat the hydra will probably also relish your shrimp.

5) I read up on the Spixi Snail and I think this is the ideal solution to have in your back pocket. They will eat hydra, they will eat pond snails and their eggs, and they will eat ramshorn snails and their eggs. They cannot eat Malaysian Trumpet Snails. This is ideal because I think you'll want to keep the MTS, especially if you have a sand substrate, and it doesn't sound as if they will completely wipe out the pond/ramshorn snails. Spixi snails also do not reproduce asexually so you can control the population from the start if you can figure out their gender. If not, they will cannibalize young spixis, thus keeping their own numbers in check. Assassin snails will eventually wipe out all of the snails including the MTS and I don't think they cannibalize, so you may end up with a massive population of hungry assassin snails.

6) Bottom line, unless someone with more experience comes along and explains why we're both fools for even considering it, I say let this thing sort itself out! You seem like the kind of person who will enjoy observing the process day to day rather than trying to assert control over it as quickly as possible. And if I'm wrong about you, do me a favor: bag up a bunch of them and ship them my way!
 
#9 ·
Today I found more Hydra. It appears some individuals now have buds growing off of them forming new hydra. They seem to stay in a small localized area still and have only colonized a small area of the simulated driftwood in the tank. It also looks as two individuals have climbed to the end of a strand of java moss and their foot(s) are now combined on it. They just sit at the end of the strand waving in the current.

I saw a smaller sized dead shrimp in the area of the hydra colony. I didn't remove him but the tank took care of his body within a hour or two. It appeared to be eaten by other shrimp and snails.

They are growing in number. I also have seen a huge decrease of the little brown swimming spots.
 
#11 · (Edited)
Today I found more Hydra. It appears some individuals now have buds growing off of them forming new hydra.
Yes, that is exactly how their asexual reproduction was described. In nature, this only occurs when resources are plentiful. When food supplies dwindle (typically as winter approaches), hydra begin to reproduce sexually resulting in fertilized eggs that can overwinter or otherwise weather the storm until conditions improve.

They seem to stay in a small localized area still and have only colonized a small area of the simulated driftwood in the tank. It also looks as two individuals have climbed to the end of a strand of java moss and their foot(s) are now combined on it. They just sit at the end of the strand waving in the current.
This is textbook as well. They can move by sort of inchworming their way across the substrate, or by drifting in current, but they prefer to conserve energy and catch prey in exactly the manner you described.

I saw a smaller sized dead shrimp in the area of the hydra colony. I didn't remove him but the tank took care of his body within a hour or two. It appeared to be eaten by other shrimp and snails.
It's possible it was killed by a hydra, but I'd be surprised if their method of capturing prey proved to be so inefficient (i.e., killing without feeding). If they do start eating shrimp, you ought to be able to tell. Digestion is said to take a couple days with indigestible portions of the prey being more or less regurgitated a few days after consumption. Because of the color of the RCS, I'm guessing they'll be visible while enclosed within the hydra.

They are growing in number. I also have seen a huge decrease of the little brown swimming spots.
More evidence suggesting that the little brown swimming spots are cyclops or daphnia. I would guess that their dwindling numbers could lead to a couple different outcomes:

1) The hydra feast until their preferred food runs out, stash some fertilized eggs around your tank and die off. This is probably what happened in the cases where people described the hydra outbreak as very quickly appearing and disappearing without intervention. If this proves to be the case, watch out for an ammonia spike if there's a mass die-off and they all start decomposing.

2) The hydra feast until their preferred food runs out, then acquire a taste for your shrimplets.

Either way, I continue to encourage you to stay the course and see what happens next. You've always got the Spixi in your back pocket if you decide to eradicate! Incidentally, you might want to start looking now. I did a quick search for Spixi snails and couldn't find any for sale from the usual suspects.
 
#10 ·
It sounds like you may be overfeeding a bit. I had hydra in my planted 20G last year, they can actually kill baby shrimp so you are probably going to want to control them. Mine disappeared shortly after I moved my Blue Rams to the tank. I'm not sure if the rams ate them, or I just stopped overfeeding at that time.
 
#12 ·
6 days after seeing my first hydra they have established a nice little colony. Not sure how much longer im going to keep this going as their population has exploded to the point where I have seen hydra floating thru the water column. I may throw a couple of bolivian rams in there to see if they can take care of the issue with out using chemicals. I have had no luck finding Spixi snails to control the issue.


I was able to image the hydra group... A pic is here: Hydra Colony | Flickr - Photo Sharing!
 
#13 ·
6 days after seeing my first hydra they have established a nice little colony. Not sure how much longer im going to keep this going as their population has exploded to the point where I have seen hydra floating thru the water column. I may throw a couple of bolivian rams in there to see if they can take care of the issue with out using chemicals. I have had no luck finding Spixi snails to control the issue.


I was able to image the hydra group... A pic is here: Hydra Colony | Flickr - Photo Sharing!
Okay I already wanted to hang out with you just because of your crazy shrimp tank. Then I saw your telescope. Your astrophotography is awesome dude! If you should find yourself shooting in northern Illinois in need of a caddy to haul some gear and act all giddy seeing Messier objects, PM me any time!

Revised list of things to do if my wife dies before me:
1) Become a falconer
2) Become an astrophotographer
 
#15 ·
I see dwindling numbers of the suspected daphnia/cyclops which is why I think they have taken to drifting on the currents. The ones I see drifting my guess are more mature and larger then most. The ones that are drifting I have been watching get sucked up in the filter where they are cut up into tiny pieces. I don't know they die or regenerate in the filter floss...

I am going to keep this going for a bit longer but I am concerned with how fast the hydra population has grown. The images on my page are blown up of course so u really can't get an idea of scale but they are starting to take over a small area of the driftwood.

I have seen no hydra related RCS deaths but if a shrimp was to die - it would be eaten pretty quickly by the hungry snail population.

Off topic - thanks for the comments on the astrophotography. It is a passion of mine that I don't do enough of these days. I moved recently to a much more light polluted area so its kinda taken a backburner. I have been thinking of going into microscopic photography to satisfy that passion. I like taking photographs of things that are there but we just cant see for whatever reason.
 
#16 ·
Careful for an ammonia spike if the hydra do start dying off en masse. You're probably right about them riding the current in search of greener pastures. Keep us posted on the progress whatever you choose to do. In the meantime, I'll keep an eye out for Spixi snails.

A couple years ago, I was doing some backyard binocular astronomy and found Andromeda for the first time. I was fundamentally changed by the realization that the light I was perceiving had traveled for 2.5 million years before implanting itself in my retinotopic map. It must feel good to track down those objects and capture their image in such impressive fashion!
 
#17 ·
Tank update:

Looks like there was a massive birth of the unidentified swimming dots recently. The visible hydra population continues to increase but the larger older members of that population seem to have moved elsewhere or detached themselves from the colony and were sucked into the HOB filter. The remaining members show budding so I expect another boom in visible hydra soon as they detach from their 'parent'

I did see a dead juvie shrimp yesterday. My daughter said she watched one drop dead the other day after being by the hydra colony. On a side note my daughters class is studying hydra. My daughter told her teacher and my pics are being used in the lesson now..

To observer individual hydra I use a Canon DSLR w/ a 200mm macro lens. The canon has "live view" so I can see these animals 'close up' in real time. Pretty cool. I wish I had the version of the Rebel that can do video.

On astronomy - I was hooked the first time I saw Saturn.
 
#18 ·
Your hydra pictures are amazing. Figured you must have had some pretty powerful glass at your disposal! I'm not at all surprised to hear that your images are being put to good use in your daughter's class. She'll certainly have a leg up on her classmates when she takes the hydra quiz. In the meantime, you should enter the shot of the hydra on the leaf of the sword in the photo of the month competition on this site. I'd vote for it! So hard to get a sharp shot of something so small, especially in an aquarium.
 
#19 ·
p.s. Are those Hydra eggs or maybe nymphs on the leaves adjacent to the adult hydra in the pic? Seriously, submit that photo for the contest! That's one of the coolest aquarium shots I've ever seen.

Any chance you'd be able to image the suspected daphnia/cyclops without a microscope? If not, maybe that's your excuse to get the microscope you've been thinking about!
 
#20 ·
Ill check the image when I get home. If its what I think then I wasn't able to blow up enough to tell. I did try to image the 'fast moving dots' but zoomed in it just looked like a white football.

Tank update - The hydra have pretty much populated the entire tank and on track to over take it. I see them on the glass, the plants, and other equipment in the tank. They are all over. Many that I see have buds growing on them.

I have decided to end the 'experiment' - I added a dewormer known to kill hydra late yesterday and within a couple of hours noticed the individual hydra starting to die. We will see if this kills them. The interesting thing tho is that after I added the dewormer the small worms in the tank started going crazy and started swimming thru the water column in large numbers.

I haven't looked at the tank since last night but I expect them to be dead when I get home.

I must admit I did enjoy observing this all taking place. I wish I could have found an invert predator of the hydra. That would have been interesting variable to add.

Ill add the image to the contest. Thanks for your comments!
 
#21 ·
I applaud you for conducting the experiment for as long as you did. I agree, the Spixi would have been the perfect addition at this point. Too bad they're so tough to come by. They're cool looking snails, too.

Thanks for the updates. This has been a fascinating thread to follow from afar!
 
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