tank comes alive at night

[l3fty999]

I'm not real sure how they got in there, but I have a larval crustacean of some sort, it's either some kind of mysis or maybe a krill. I first noticed them when the main lights turned off and the moon lights turned on. At first, it appeared as though something stirred up a little debris, but upon closer examination, I could see that these "particles" were moving on their own. Anyway, I know that a picture is worth a thousand words, so here you go. The first shot is my tank at night, the other two were taken with my microscope, two different lighting options.

 

[charlesr1958]

Do you have any shrimp in the aquarium? Because those sure do look like larval shrimp.

Chuck

 

[redsea reefer]

That looks like Mysid shrimp

 

[l3fty999]

That looks like Mysid shrimp

I have one fire shrimp and one pistol shrimp that I know of. I say "that I know of" because the pistol shrimp was a hitchhiker. I've been to several sites dedicated to plankton and I narrowed it down to some kind of mysid, but some of the krill larvae also looked similar. I would really like to know how they got in there, because I haven't added anything in months. I have used frozen mysis shrimp to feed my tank's inhabitants, but I'm sure if any eggs were in there they wouldn't be any good since they were frozen. At any rate, it's nice to see food show up naturally in my tank.

Aaron

 

[redsea reefer]

They most likely came in with the live rock.

 

[Frankie]

Great pictures! I sent a pm to Boomer for a more accurate ID. I am guessing some type of shrimp myself.

 

[l3fty999]

Great pictures! I sent a pm to Boomer for a more accurate ID. I am guessing some type of shrimp myself.

Thank you, a positive ID would be cool. As far as the pics go, the first one was taken with an Olympus SP500UZ. Because of the low light and the fact that they didn't want to cooperate, I had to monkey with some of the manual settings (very nice set of features to have) and take several pics before I got one that I felt was good enough. The other two were taken using the DR Instruments Reefer's Digi-Microscope I bought from Live Aquaria. I started wearing gloves right after I began using it.

Aaron

 

[Boomer]

Eddie has it correct they are Mysid shrimp

 

[l3fty999]

Eddie has it correct they are Mysid shrimp

That's kinda what I was thinking now that they're getting bigger. Now to figure out where they came from. I haven't added any major amounts of live rock in several months, although I did score some free rubble from the lfs about a month and a half ago. However, that tank is well established, doesn't get any new live rock and doesn't appear to have any kind of shrimp in it. I have also used "reef bugs", which supposedly will add live planktonic critters to the tank. Is it possible that eggs could have made it in that way? I didn't think so myself, considering that I've been using that for quite a while and didn't see any kind of shrimp larvae before. Well, enough rambling for now, and Boomer, thanks for your input!

Aaron

 

[Reefmack]

Probably came in with the rock or the rubble. Mysids are a very tiny shrimp and you probably just didn't see them till they multiplied. I have them too and figure they must have come in with the rock or some chaeto I added.

 

[l3fty999]

Probably came in with the rock or the rubble. Mysids are a very tiny shrimp and you probably just didn't see them till they multiplied. I have them too and figure they must have come in with the rock or some chaeto I added.

You know, I got to thinking, at one time I had more fish in there and they were probably keeping the population down to levels that wouldn't be noticeable unless I was looking for them. By the way, they are now big enough to be seen at a few feet from the tank without any magnification.

Aaron