I know it's really tough without a picture, but...

[marinenewbie]

Last night I found something new in my tank while peeking again with the flashlight.

At first I thought it was a bit of leftover food floating around, and then realized it was actually swimming! It had the look of a tadpole, but was more or less transparent. It's little tail was moving from side to side, and when I shone the light on it, it swam away into hiding. It was all of 1/4" at best.

I went around to the side of the tank, to shine the light behind the rocks and saw several more (maybe 3-4??) which were smaller than the first one, and these were sort of hovering around together about 2" above the sand. From the side, their eyes reflected a silver colour off of the flashlight.

Any ideas what these might be? Why hasn't something eaten them yet, do you think? I guess the inverts wouldn't be able to catch them, and presumably the fish are sleeping, so maybe they're not being hunted just yet?

I wish I could've gotten a picture, but even if I had been fast enough I know my camera wouldn't have caught them, they were so small...

 

[bertoni]

You could try googling mysid shrimp.

 

[Scuba Oz]

Do they look anything like this

 

[marinenewbie]

No they didn't. They were more of a tadpole or "sperm" shape for lack of a better description. I didn't notice any antennae or legs or anything on them either...they appeared to be smooth.

I will google mysid shrimp, as bertoni suggested.

I guess they must have been hiding in my most recent rock addition?

 

[marinenewbie]

You know, they could have been mysid shrimp. The shape was right and they were so tiny I likely just didn't see any little legs or antennae, but I am sure the bigger one was swimming with its tail...just like a tadpole.

I'm going to have to look again tonight for sure and see if I can get a better peek at them.