# What are these creatures? Microfauna ID?



## Livyding (Feb 6, 2013)

So I was taking home some Fan shrimp from Pat yesterday, and while I was on the skytrain looking at the bag I noticed some stuff swimming around in the water. I'm a bit of a geek when it comes to tiny critters, so I got pretty excited, and when I'd put the shrimp in their tank, I emptied the water from the bag into a spare plant-growing tank so the whatever-they-are could get settled in.

Now it's the next day and they seem to be doing well... Thing is I've been scouring the web trying to ID these little guys and I'm completely mystified. My first thought was that they could be larvae from the shrimp, but a quick search told me that Ayatopsis shrimp larvae need salt water to survive, so this couldn't be that.

Here's what I know. There are LOTS of them... maybe a hundred. They move around in a shrimp-like way.. crawling around on the glass, cruising around in the water, sometimes doing that thing where they run into something that startles them and jumping backwards quickly.

They're small.. 1.5 -2.5 mm... They aren't any of these --> What is that bug in my Aquarium? .:. Various small creatures that can inhabit a Freshwater Invertebrate Aquarium as far as I can tell.

They don't seem to have any colour, but some of them might have a faint, pinkish/tan hue...

They're way too tiny to take a picture of.. (I REALLY wish I had a microscope at times like this!!) but I made a little drawing on paint of what they look like to my naked eye.










They swim around pointy end forward.... So, any ideas?


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## shaobo (Apr 21, 2010)

Most likely is Copepods you are seeing~


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## Livyding (Feb 6, 2013)

No, I actually have coepepods in the same tank and it's definitely not that. I know this is next to impossible to ID due to my terrible diagram and poor description, but any more ideas?


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## arash53 (Aug 13, 2011)

looks like they are daphnia


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## Livyding (Feb 6, 2013)

arash53 said:


> looks like they are daphnia


No I don't think so... They have a very distinct "broomstick" sort of a shape, not round.

The closest thing I could find pictures of that look like it are some kind of shrimp larvae... Which brings me back to the fan shrimp larvae idea, but it's been well over 24 h now, and they're all still alive and swimming and crawling around in freshwater so I don't think that's right.

Here I tried to make a better drawing of what they look like. I noticed today that they mostly only swim "broomstick handle" end forward, but when they crawl they go both "bristle" end forward or "handle" end forward.










So far I have no idea what to feed them, so I've just been culturing more coepepods in the tank hoping that they'll eat that, with a little bit of smushed peas in there and a single ramshorn snail to speed up the culturing. I've got a very mature air driven sponge filter in there, and once in a while I squeeze some water out of the sponge with a turkey baster and let the little particles go into the water.

They must be eating at least something out of those things I figure, since they seem to be growing/developing... Today I can clearly see body segments like in the diagram, and they are definitely all tan/peach coloured whereas yesterday they were mostly white/opaque.


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## Livyding (Feb 6, 2013)

Update... got my hands on a microscope and had a look at the critters. Here's a rough diagram I drew ..









Looks like it's definitely some kind of shrimp larvae... Could it be from the fan shrimp you think? The "brush" end of the broomstick shape I was talking about earlier look like some sort of mouth parts, but could they be the early developing "fans" maybe?


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## mrbob (Aug 9, 2012)

Looks like something off one of those sci-fi shows LOL


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## Foxtail (Mar 14, 2012)

I don't know for sure... But your Mario paint skills are killer 

Sent from my Galaxy Nexus using Tapatalk 2


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## Durogity (Jun 10, 2013)

Wouldn't it be easiest to just ask pat lol


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## Livyding (Feb 6, 2013)

Durogity said:


> Wouldn't it be easiest to just ask pat lol


That would be too easy!


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## Durogity (Jun 10, 2013)

Livyding said:


> That would be too easy!


I can see that, finding out on your own is half the fun lol


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## Livyding (Feb 6, 2013)

Update, they all died off after I did some water changes. In retrospect, and since I looked more closely at the anatomy of the adult fan shrimp I'm almost positive that they were shrimp larvae.

I think the reason they were staying alive in my fresh water is because I forgot that I'd been treating one of my Bettas for constipation in the same tank, and that *I'd added Epsom salt (3 tsp to 5 gallons ) to try to get him to "go", so the little tank I put them in had very hard water as a result.*

I wish I'd had the presence of mind to add some to the water I'd put in for the water changes, but too bad... It was fun while it lasted though!


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