[Coral-List] Exotic vs. Invasive

Bruno, John jbruno at unc.edu
Fri Feb 15 12:13:26 EST 2013

Hi John

Exotic is any introduced species.  And there is a gigantic and never ending debate about what to call them, eg, exotic, introduced, alien, non-native, etc

The distinction with invasive is somewhat subjective and isn't set in stone, but in general, Invasive exotics are very common, probably to the point of being community dominants and potentially having negative effects on native species.  They are also considered to have become "naturalized" ie, established self-sustaining populations, which is a much lower bar than the dominance threshold and Tubastraea would certainly qualify.  In fact, in their microhabitat, I think Tubastraea can be quite common and Id be comfortable labeling them as "invasive".  And funny, but I just had a manuscript reviewer say lionfish were not invasive, so don't be surprised to hear disagreement about this stuff.



John F Bruno, PhD
Department of Biology
The University of North Carolina at Chapel Hill

species are exotics that

Dear List,

Ken Marks recent post concerning Tubastraea micranthus reminded me of an
incident that occurred on a recent trip to Bonaire.  A divemaster was
bemoaning the "invasion" of lionfish.  When I mentioned that the "poster
coral" for Bonaire (Tubastraea sp) was invasive, I was severely
chastised.  Lionfish were "invasive", Tubastraea was "exotic".

I noted that Ken Marks used both "exotic" and "invasion" in his e-mail.
I had never thought about the distinction before.

After Googling around a bit, I concluded that if the species under
consideration was sort of cute, it was "exotic".  If it was ugly, it was

While that is a vast oversimplification, I wonder if the coral-reef
community distinguishes "exotic" from "invasive" and, if so, is there a
precise definition of the difference?


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