Help with Bug ID

[sg1838]

Saw this thing cruising around one of my rocks - took the best pictures that I could, which I know aren't very good. This thing moves pretty fast, is approximately 1/2" long x 1/8" wide, is greyish-white in color, and is living in one of my rocks (I saw it finally retreat in there).

If it isn't harmful, I'm perfectly OK leaving it in there. If it is harmful, I'll probably have to remove the whole rock that it is living in (and hope that it is in there at the time), as I have no idea how else I would catch it.

Thanks in advance for the help...

 

[shroutk3]

no worries, that's harmless fish food.

 

[museumguy]

no worries, that's harmless fish food.

Always nice to see folks from Chautauqua Co on here!!

Saw this thing cruising around one of my rocks - took the best pictures that I could, which I know aren't very good. This thing moves pretty fast, is approximately 1/2" long x 1/8" wide, is greyish-white in color, and is living in one of my rocks (I saw it finally retreat in there).

The pics are a little blurry, does the critter look like this?

If so it is a harmless (more like beneficial) amphipod. Where there is one there are probably 100s if not more, and this is a good thing. Corals and fish will eat them, sign of a healthy tank.

 

[tmz]

Can't make it out from the picture.

 

[Firefish76]

It is very hard to tell what it is based on the pic

 

[Gary Majchrzak]

Amphipod

http://reefkeeping.com/issues/2004-09/rs/index.php

commonly called a "pod"

 

[sg1838]

Well, I would GUESS it's an amphipod, as it looked almost exactly like that picture on the left side of Figure 4 in the article you posted Gary. But, the only thing that bugs me (ha ha - "bugs") is that in the article they state that in most cases they are not more than a few millimeters long. But, this guy was certainly in the 6mm - 12mm range. So, do I have just an extra large amphipod in my system?

If it wasn't for the reference to the length in that article, I'd probably be 99.9% sure it was an amphipod at this point...

 

[Gary Majchrzak]

adults get fairly large in my system

 

[tent boy]

I have heard that they can bother some corals when they get larger. Any truth to that?

 

[Gary Majchrzak]

the type of pod in my pic is a larger adult and eats algae and detritus. I've never heard of nor ever seen any of these pods bothering healthy corals.