Catalaphyllia jardinei hardiness - Adult vs. Juvenile stages? 07/20/2008
Dear WWM Crew,
<Trent>
I've read somewhere (not sure where, I've tried and failed to find the reference) that it's thought that this species of coral has at least two nearly indistinguishable life stages: a cone-shaped juvenile stage where it lives detached from the reef in deeper waters (20m) and an adult stage where it's brought by currents to grow attached to the reef in shallower waters.
<Mmm, actually, the morphology is a function of two principal different collection types... a more shallow, mucky population being distinctly more wedge-shaped, the deeper water ones (same species) less so... among other differences... importantly here/to hobbyists; relative survivability of specimens... the shallow water being much more hardy>
This source pretty much agrees with the husbandry of the coral suggested in Bob Fenner's article 'Catalaphyllia; What’s Wrong With Your Elegance Coral, Family Caryophylliidae' (low-moderate diffuse light, higher nutrient levels, low-moderate water flow, horizontal placement, etc). However, the source claims that the 'adult' form is hardier than the 'juvenile' form and the two forms can be easily distinguished because the adult's calcareous skeleton will have obvious damage incurred during its breaking from the rest of the reef by the harvester.
<Mmm... better to seek out specimens that are entire/whole... not sections that have been broken from a larger/parent>
Evidence suggesting that this may contain some truth can be found at www.liveaquaria.com. On this site they offer this coral from 'eastern Asia' and 'Australia.' The skeleton of the form off Asia is undamaged because it lived detached from the reef, but the form found off Australia has damage to its skeleton because it had to be broken from the reef.
<Really... want to emphasize to hobbyists that the "free" phaceloid specimens of this species are MUCH more suitable for their use, purchase than pieces of attached colonies that have been broken off... Is this clear?>
They claim that the 'Aussie' coral is hardier than the other (which is reflected in its price) and that the damage to the skeleton will not be detrimental to the living animals.
<Mmmm>
What's your take on this juvenile v. adult theory?
<Is bunk... not an age difference at all, but habitat, developmental. Attached colonies (similar to Goniopora... stokesi if you will) may be "older" but not necessarily... they are less appropriate (survival wise) likely due to damage in collection mostly>
It seems to me that this would agree with the history of success of these animals being kept in aquariums. About a decade ago this coral was generally considered very hardy, but as time went on (and the depth at which these animals were harvested grew deeper due to limited supply) hobbyists tended to think the coral was becoming more difficult to maintain. It would seem that the hardier 'adults' were all harvested at the shallower depths and the harvesters were now going for the more delicate 'juveniles' at greater depths.
<The historical data is such...>
Last questions: I'm planning a species-specific aquarium for this coral and I was wondering, would a 70W MH be too strong/concentrated for these animals if the tank's depth is only 17in? Would a couple of PCLs be better?
<Mmm, either could be made to work... adaptation of the specimen to either is encouraged... with shading...>
How much (lbs/gallon) live rock would you recommend?
<As much as is reasonable, looks nice to you... Again, I would not be fastidious re nutrient levels per se, would use a good deal of very fine material, mud...>
The tank I have is, for some reason, called a 95 wide at 48inX24inX17in, but its actual volume is closer to 85 gallons.
Trent W.
P.S. - I just ordered the new edition of the 'Conscientious Marine Aquarist' and I can't wait to read it.
<I do hope/trust you will enjoy this second ed.. Bob Fenner>