Corals to Avoid
Adam Blundell M.S.
The coral family
Nephtheidae contains several species commonly found in the aquarium trade.
Some of these corals are very well suited for home aquaria, but unfortunately
some are not. This article is a synopsis of the experience of hobbyists
with the genera Dendronephthya and Scleronephthya (please note that this is the
correct spelling, as it commonly misspelled in publications and journals).
two genera have been difficult if not impossible to keep in captivity.
Often alluring with vibrant colors, one cannot blame hobbyists for wanting to
give a try at these corals. In fact the author would love to solve their
husbandry issues as these rank high on my list of personal favorite corals.
(for in depth information please see Borneman 2001 and Sprung 1999)
Dendronephthya/Scleronephthya are filter feeding corals. Voracious filter
feeding corals that is. These corals completely lack the symbiotic
zooxanthellae found in most corals. The pro to that is that these corals
are presumably more tolerant (and hardier) than most other corals. For
example these corals can withstand environmental changes without the possibility
of coral bleaching (Kaufman 2004). These corals continuously reproduce and
rapidly populate areas with favorable conditions (Siegel 2002).
Unfortunately the pros of these corals are dwarfed by their cons. Without
the aid of photosynthetic zooxanthellae these animals are dependent on large
amounts of plankton. That is beginning (and the end) of their captive
demise. Simply put, for now these corals are impossible to keep in
Dendronephthya/Scleronephthya are easily found and identified (in a general
manor) on reefs. Their vibrant colors and large sclerites are quick to
catch the eye. The sclerites serve to hold shape, and also contribute to
the defense mechanisms of this coral (which includes a high concentration of
toxins). It is possible that sclerites aid in gas exchange but that has
yet to be well studied.
These corals are
found in waters (doing best) with flow rates between 5 cm/sec and 25 cm/sec (2
in/sec and 10 in/sec). The feed heavily throughout the day and in
captivity always require heavy feeding. This continuous feeding cycle may
correlate to their ongoing reproductive mode.
Before you think
that you can keep these corals let me say this; it’s been tried before.
That isn’t to say that hobbyists won’t be successful with these corals in the
future, but for now it would highly irresponsible of me to encourage people to
experiment with the husbandry of these corals.
The most advanced efforts to captively keep these animals have been performed by
the Waikiki Aquarium and the Long Beach Aquarium of the Pacific. This
information is well documented and can be found in the online article in the
references below (Delbeek 2003). These two well maintained aquariums used
a slurry of phytoplankton foods, supplemented with zooplankton. Great
efforts have been made to create laminar flow recreating tide patterns along
reef drop offs (Delbeek 2002). Coral attachment was also explored and
anecdotally showed that hanging the corals upside down so that the branches do
not touch substrate improved coral health and growth.
However, long term success has still yet to occur. With an incredible
amount of feeding an aquarist needs to provide an incredible amount of
filtration. Public aquaria have the option of using flow-through systems
which so far seem to be the only filtration method able to keep up with the high
At this time while
enticing to purchase Dendronephthya/Scleronephthya are still not a coral to be
purchased. The extreme feeding techniques of these animals is not
practical (or maybe even possible) in the home aquarium. Future husbandry
advancements may help, but for now these organisms are to be avoided.
Adam Blundell is
the president of the Wasatch Marine Aquarium Society. Comments and
questions are always appreciated and welcomed at
email@example.com. You can find Adam at
www.UtahReefs.com. This article was sponsored by the Aquatic &
Terrestrial Research Team.
(2001) “Aquarium Corals selection, husbandry, and natural history”, T.F.H.
Publications, Neptune City, NJ. USA.
(2002) "Non-photosynthetic Corals: They really are hard!”,
http://advancedaquarist.com/issues/jan2002/feature.htm , Advanced Aquarist
Online Magazine, USA.
Kaufman, L., (2004)
“Fiji’s Rainbow Reefs”. National Geographic, USA.
Siegel, T., (2002)
“Struggling with Alveopora and Dendronephthea”,
http://advancedaquarist.com/issues/oct2002/Editorial.htm , Advanced Aquarist
Online Magazine, USA.
Sprung, J., (1999)
“Corals a quick reference guide”, Ricordea Publishing, Miami, Fl. USA.