Got a hitchhiker or unknown critter?? Check here for an ID

AKTank · Jul 2, 2015

Thanks all. I'll toss in a crab pot and see if I can get it out. I watched this crab kill another crab that looked similar but was not harry. This will be the third dime sized crab I've pulled out in the last few months after loosing three acros to RTN. I wonder if these had anything to do with their demise?

Vpham · Jul 4, 2015

What is this thing? Good or bad for mixreef tank...
Thanks.

Reflective · Jul 4, 2015

Vpham said:
What is this thing? Good or bad for mixreef tank...
Thanks.

Looks like a Glass Anemone/Aiptasia. Bad.

Vpham · Jul 4, 2015

Umhhh.i never seen one with green ring on tenacles and it's in a buddy tank...just wanna give him a heads up...

Reflective · Jul 4, 2015

Vpham said:
Umhhh.i never seen one with green ring on tenacles and it's in a buddy tank...just wanna give him a heads up...

Ah, thought it was the lighting making the rings green, but it looks a lot like the one on this page: http://www.tranquilmarine.com.au/staticpages/index.php/marine-pests and http://atj.net.au/marineaquaria/organismstoavoid.html
I've seen ones that look like that with black/grey stripes too. But not green so maybe it's something else.

Vpham · Jul 4, 2015

I think it's morph by light...thanks a lot for more infos.

S3ASQU1RT · Jul 13, 2015

Is this a Bristle Worm??

kbourque · Jul 14, 2015

S3ASQU1RT said:
Is this a Bristle Worm??

Can't see the pics

Nanoreef523 · Jul 16, 2015

Could you ID this?

SeahorseKeeper said:
This thread is to list some of the more common hitchhikers that we come across.

Asterina Starfish:

R2R member:Jurg

Asterina starfish are a common hitchhiker that are seen in many aquariums. These starfish are pretty small and typically get no larger than a centimeter. Asterina starfish are scavengers that usually eat algae, but there have been many reports that these starfish eat corals and coraline algae. The most common corals that these starfish will are zoanthids, soft corals and acropora. The asterina starfish that are colored seem to be more likely to eat corals as opposed the white ones.

These hitchhikers reproduce by splitting their bodies into two. This is one the reasons why you will see asterina starfish with irregular shaped legs. It is also why the asterina population can explode in our aquariums. The populations also explode in tanks that are high in nutrients since the starfish have an abundant food source.

It can be difficult to eradicate a system of asterina starfish. One way to rid a system of them is to remove them manually. This can be quite time consuming and it is impossible to remove them all manually because they can hide deep in the nooks and crevices of the live rock. If you opt for the manual extraction method, it is a good idea to reduce feedings and reduce the nutrients in the tank. This can help to limit the food supply of the starfish. Another option would be to add harlequin shrimp to the tank. Harlequin shrimp feed exclusively on starfish and will quickly eradicate the tank of the starfish. Once the starfish are gone, the harlequin will have to be fed starfish.

Mini Brittle Starfish:

R2R Member: fasiczka

Brittle starfish are a welcome addition to most hobbyists' tanks. They are beneficial detritivores and eat waste. They also multiply rapidly in tanks with excess nutrients. However, they are not known to eat corals and are seen as a desirable hitchhiker. These starfish can look like small brittle or serpent starfish.