Hitchhikers Guide to the Reef Tank

spanko

Active Member
What is this on my glass? What is this in my rocks? What is this on my coral? What is this growing in my sump? What are these bugs?We see these questions often. I thought I would put together a small thread with some of the more common hitchhikers we are fairly sure to see and question in our newly setup tanks. I thought I would list a few of the more common things we hear about.Feel free to add.
What are these stars on my glass?

These are tiny crawling hydromedusae, also known as hydroid jellyfish, and are generally not a problem. If they are bothering you or the view of your tank you can take them out with a siphon tube.

(Picture from Wet Web Media)
What are these thousand of white dots on my glass?

Here you have most likely an abundance of what will become food items. They also eat detritus, algae and things in the rock work. They are copepods and are a sign that the tank is indeed starting to mature. Beneficial stuff these are and something to be coveted down the road as you add fish that may require them as part of their subsistence.

(picture from kashville)
What are these shrimp like creatures crawling on my rocks?

These are probably amphipods, critters that will become food items down the road. As with copepods they do eat detritus, algae and things in the rock work. Another sign that your tank is indeed starting to mature.

(picture from Niles Biological)
I have centipedes in my tank!

These are bristle worms and as unconvinced as you are that anything so ugly and nasty could be good for your tank, I am sorry but these are. They are incredible detritus eaters. If something dies in your tank they will be all over it cleaning it up (read eating it). They did not kill it they are merely scavenging it. They can get huge though and are in my opinion are unsightly so you may want to get the larger ones out sometime. Their population will rise and fall with available food so if you see an overabundance of them you may want to investigate what is there food source and cut it down. Oh yeah, the bristles will get into your skin if you touch them and are painful. Best way to get rid of the bristles is to soak your hand in white vinegar as it will dissolve them.

(picture from Roescher's Reef)
What is this fuzzy stuff on my rocks?

Chance are a sponge or a tunicate. These are harmless filter feeders and will come and go over time. Come in many different colors.
Sponge hitchhiker on some Zoanthid sp.

(picture from swf thread)
Tunicate

(picture from fisheries research)
What are these cotton balls?

This is most likely Q-tip or Syconoid sponges. Another creature that will probably disappear from your tank over time although they may continue to live inside dark places where there is sufficient nutrient, like overflows etc.

(picture from reefs org)

I have red stuff growing on my rocks.

A couple of options here. Cyano bacteria, Forams, Coralline algae. Cyano will need to be dealt with as it is not something you want to have, forams will come and go and coralline algae is desired as it is the glue that binds the reef.
Cyano

(picture from steelheair)
Forminifera

(picture from helfrichchick)
Coralline

(picture from saltyzoo
 

meowzer

Moderator
This is a good idea...I see those questions come up a lot, and to tell you the truth, if I didn't read most of them I would probably be asking the same questions.
I am sure there are a lot of people here who could add to this site....If I had a pic available I would add the asterina star.
 
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