Hello everyone! I found this forum in my efforts to research a strange problem I'm having with my tank, and I hope some of you may be able to help. Before I go into details, it would probably help to explain that A) I don't own a "fish", it is in fact a crayfish, and B) the question is not about the fish but instead the small white pests that are inhabiting her tank. I hope that even with that in mind, this is the correct place to be asking this sort of question.
First, some details: I have been keeping various fish since I was 10 years old, starting with the classic goldfish and moving my way up to slightly (although still relatively un-advanced) more difficult to care for aquarium creatures. I have had my white crayfish, Tabetha, in the same 15 gallon tank ever since I bought her as a baby. It's just her in the tank, no other animals or plants, nor have there ever been (trying to research a plant that crayfish don't like to tear apart!). She has been living in this tank since January this year (2010). Filtration with a Tetra "whisper" 20i. 20% water changes every week or week and a half with de-chlorinated tap water. About 2.5 inches of gravel, a few plastic plants, and one large plastic "coliseum" decoration, lol. She is healthy and the water is 99% clear, if anything an incredibly slight yellowish/green color from natural algae.
That all being said, about two weeks ago I noticed what looked like small white specks in the tank. The first thing they reminded me of was baby triops right after they first hatch, swimming around erratically with tiny bursts of movement, affected by the slight current of the water. But, these guy's dont grow into triops, they stay almost the same size. They look like tiny white/ light brown seeds. From more than a foot away, they are completely invisible. Even with my nose against the glass, all I can make out are tiny tiny round white insects, with no visible eyes, antenna, flagella, legs, swimmerets, anything lol. Just tiny white bugs that swim around. They look like grains of sand suspended in water except they move on their own. There are literally thousands of them, on the substrate, in the water, and even a few on my crayfish (although she seems completely unphased by them). There are much higher densities of them in the corners of my tank just beneath the surface of the gravel, where they actually do look like someone just poured a pinch of sand in the corner.
My current research leads me to believe that they are either seed shrimp or daphnia, although daphnia have visible antenna, right? Also, I read that seed shrimp have clam-like shells (these guys are way too small to tell) that close up and freeze when a fish approaches, which is not something these critters seem to do. They never stop moving either swimming or being pushed around by the slight current from my filter. I've tried netting a few to get a closer look, but only the very largest of them (which are still very tiny) manage to actually get caught by the net (made of that very fine white cloth material).
My main concern is what exactly these guys are. I am pretty sure they are harmless, and from what I've read so far these critters (or at least lots of ones like them) are used as food for fish. Unfortunately, my crayfish doesn't really have the means to eat them because they are so tiny. My only other concern (which is not vital) is that when you get close to the tank, they really become noticeable, which is a tiny bit irritating, mostly because there are so many of them lol. If there were maybe half as many, I wouldn't mind as much.
Today, I bought two feeder guppies for a quick experiment, and they did start eating the little critters, one by one. They barely managed to put a dent in them though, and soon my crayfish snatched up one of the guppies. I don't mind keeping extra fish to control the population, but my cray will eventually eat them, and too much protein is not very good for her.
Anyways, sorry for the long explanation. I've seen so many similar posts on forums and people are always unable to determine what the critters might be because people don't give enough information. As a last attempt, I am going to include a video I took of them swimming around, but they look very non-descript. Might help though if someone has seen them before!
Here's the video. For comparison's sake, the gravel is no bigger than 1/24 of an inch. The opening on the "coliseum" decoration is 1" wide, and my lovely crayfish is approximately 3.5" long and 2" tall.
Video - TinyPic - Free Image Hosting, Photo Sharing & Video Hosting
Thanks so much for any information anyone might be able to give me!
First, some details: I have been keeping various fish since I was 10 years old, starting with the classic goldfish and moving my way up to slightly (although still relatively un-advanced) more difficult to care for aquarium creatures. I have had my white crayfish, Tabetha, in the same 15 gallon tank ever since I bought her as a baby. It's just her in the tank, no other animals or plants, nor have there ever been (trying to research a plant that crayfish don't like to tear apart!). She has been living in this tank since January this year (2010). Filtration with a Tetra "whisper" 20i. 20% water changes every week or week and a half with de-chlorinated tap water. About 2.5 inches of gravel, a few plastic plants, and one large plastic "coliseum" decoration, lol. She is healthy and the water is 99% clear, if anything an incredibly slight yellowish/green color from natural algae.
That all being said, about two weeks ago I noticed what looked like small white specks in the tank. The first thing they reminded me of was baby triops right after they first hatch, swimming around erratically with tiny bursts of movement, affected by the slight current of the water. But, these guy's dont grow into triops, they stay almost the same size. They look like tiny white/ light brown seeds. From more than a foot away, they are completely invisible. Even with my nose against the glass, all I can make out are tiny tiny round white insects, with no visible eyes, antenna, flagella, legs, swimmerets, anything lol. Just tiny white bugs that swim around. They look like grains of sand suspended in water except they move on their own. There are literally thousands of them, on the substrate, in the water, and even a few on my crayfish (although she seems completely unphased by them). There are much higher densities of them in the corners of my tank just beneath the surface of the gravel, where they actually do look like someone just poured a pinch of sand in the corner.
My current research leads me to believe that they are either seed shrimp or daphnia, although daphnia have visible antenna, right? Also, I read that seed shrimp have clam-like shells (these guys are way too small to tell) that close up and freeze when a fish approaches, which is not something these critters seem to do. They never stop moving either swimming or being pushed around by the slight current from my filter. I've tried netting a few to get a closer look, but only the very largest of them (which are still very tiny) manage to actually get caught by the net (made of that very fine white cloth material).
My main concern is what exactly these guys are. I am pretty sure they are harmless, and from what I've read so far these critters (or at least lots of ones like them) are used as food for fish. Unfortunately, my crayfish doesn't really have the means to eat them because they are so tiny. My only other concern (which is not vital) is that when you get close to the tank, they really become noticeable, which is a tiny bit irritating, mostly because there are so many of them lol. If there were maybe half as many, I wouldn't mind as much.
Today, I bought two feeder guppies for a quick experiment, and they did start eating the little critters, one by one. They barely managed to put a dent in them though, and soon my crayfish snatched up one of the guppies. I don't mind keeping extra fish to control the population, but my cray will eventually eat them, and too much protein is not very good for her.
Anyways, sorry for the long explanation. I've seen so many similar posts on forums and people are always unable to determine what the critters might be because people don't give enough information. As a last attempt, I am going to include a video I took of them swimming around, but they look very non-descript. Might help though if someone has seen them before!
Here's the video. For comparison's sake, the gravel is no bigger than 1/24 of an inch. The opening on the "coliseum" decoration is 1" wide, and my lovely crayfish is approximately 3.5" long and 2" tall.
Video - TinyPic - Free Image Hosting, Photo Sharing & Video Hosting
Thanks so much for any information anyone might be able to give me!
You will definitely need to keep fish in the tank to control the population of that.
