Zoanthids pests and problems

Only a few issues effect zoas outside of the normal issues that affect coral health. If you are sure that your tank has good water parameters and that nothing major has changed recently and your zoas are still not looking happy we need to look at what could be another cause.

Zoanthid eating beasties

The two most well known zoanthid eaters are the nudibranch and the pyramid snail but don't think they are the only ones, anything underfed with claws or a mouth could find that zoas don't taste as bad as they thought and start to include them in their diet. Records of starfish, copepods and other micro fauna plus some fish, snails and hermits have been witnessed causing zoas issues. If your tank is well fed and you have fish that pass waste often you should find the lesser risky tank mates mentioned above will not even consider touching your zoas.

Zoanthid eating nudibranch can enter your tank through hitch hiking in on rocks as adults or worse arriving as a ring of eggs on the side of a single zoa head. Eggs that make it into your tank will hatch one night if not spotted and leave you with an infestation of over 50 newly hatched zoas eaters!

Dealing with an infestation

The first point to make is if you are observant and use coral dip you should avoid most of these issues before they enter your tank, if you do find eggs simply manually remove them with a blade to avoid an outbreak. A sign of nudibranch activity is often seeing zoas closed up in the day when the lights are on or still open at night with the lights off, this is because they have a chemical in their tissue that zoas react to. The second common sign that you have an infestation is the missing or half sized lashes on your zoas, the slugs can eat a lot of lashes in 24 hours, the good news is that lashes grow back so as long as you remove the nudi’s your zoas will recover well.

The best way to deal with an infestation is, don’t panic and throw everything you can find at it, simply be ready for a little extra time for tank maintenance. Manual removal before they are old enough to lay eggs is the best method, you don't have to add chemicals and mess up your entire tank, you don't have to add a fish you would not have bought if it wasn’t for this outbreak.
You will need a torch and a pipette nothing more, check regularly and suck up any nudi's you can spot. The best time to hunt for nudi’s is just after lights out as they contain the florescent pigment of their host zoas, so a nudi that is feasting on orange zoas will have orange pigment in its tentacle. By looking for them after lights out you should find you zoas are all closed up and the things that still look like open zoas are our friends the nudibranch’s.


The Dreaded Zoa Pox

Coming soon