Reef Aquarium Question. When a leather coral shedds how does it affect other corals?

Question

When sarcophyton and/or lobophytum, shed can the waxy mucus harm other corals? I know that the water flow needs to be good and this causes the shedded material to flow throughout the aquarium... Also, I have heard that leathers can have a negative impact on stony corals, is this true? Thanks so much!

Answer 1

I wasn't aware of any particularly toxic compounds produced just by the mucus of leathers, but did some checking to make sure before I answered.

None of my reference books for corals mention any compounds restricted to the mucus for the leathers. The only such reference I was able to find is this one, which mentions the presence of terpenes (a variety of toxin) in the mucus of Sarcophyton: http://www.aquarticles.com/articles/saltwater/Ziegler07.html

As you are probably aware, most corals participate in a form of chemical warfare to prevent other corals from growing too closely and imparing water circulation and food availability. The leathers also do this as a primary defense against other corals because their tentacles are so short, they lack and effective way to "sting" their neighbors. And the terpenes will affect stony corals.

This paper mentions the presence of terpenes in the water surrounding Sarcophyton (see subheading "Chemicals" about 1/2 of the way down): http://www.colostate.edu/Depts/Entomology/courses/en570/papers_1998/lindberg.htm

It's possible that the terpenes released into the water may be present in the mucous, but they're present in the water without the mucous as well.

Zooanthids also produce toxins that affect stony corals (see article by Julian Sprung): http://www.advancedaquarist.com/issues/feb2003/invert.htm

This doesn't mean these corals can't be kept with stonys or other corals - you'll just need to be aware of their potential effects. You can reduce the effects by placement of the corals (keeping leathers or other "toxic" corals "downstream" of others so any toxin produced is more "dilute", use of carbon to remove the compounds, good circulation, and use of a protein skimmer.

As previously mentioned, leathers will shed more in the presence of irritants, so do as much as you can to ensure good water quality.

A few more links to info about leathers and chemical warfare, coral placement:

Answer 2

Shedding itself doesn't really do much of anything but releave the coral of waste. Depending on the water conditions leathers kept in optimal water conditions will shed LESS. Leathers will shed more in poor water conditions.

Leathers should not be kept near your stony corals in a tank. There is always a possiablity of the toxic mucas harming other corals, however having a good skimmer and keeping quality water in the tank, you should not have a major problem.

Answer 3

Yes, that's actually true.