COTM July '09-Hydnophora Rigida-Horn Coral

Bad Pictures


Some of the latest frags growing out. I have seen these put on 1/4"+ in a week, no joke.

Latin Name: hydnophora rigida
AKA: Horn Coral, Knob Coral, Velvet Horn Coral or Branch Coral
Phylum: Cnidaria
Family: Merulinidae

Origin: The Indo-Pacific ocean, Eastern Africa, Fiji/Tonga, Solomon Islands and the Great Barrier Reef

Reef Safe: Despite the look it is NOT a true SPS and is extremely agressive. Hydnophora has a VERY potent sting and will kill any corals it comes in contact with. Give it plenty of room to grow.

Lighting: Needs high lighting. Should be kept under at least T5's if not metal halide relatively high in the tank.

Water Conditions: SG of 1.023-1.024, pH of 8.4. Needs good(440-480ppm) calcium levels and very low nitrate levels to thrive.

Flow: High intermittent flow is preferred. Should not be constantly buffeted.

Feeding: Gathers most of its need from zooxanthellae but will filter feed and consume zooplankton.

Appearance: Flat clustering branches. Tends to grow very densely with many knobby protrusions. Usually shades of green or yellow, with brown specimens tending to be unhealthy. Some of the green specimens will fluoresce brightly under bluer lighting and actinics. Nice specimens are breathtaking under the right spectrum.
It should be noted that despite the look this is NOT a "true" SPS, it is actually falls in the LPS category.

Growth: Hydnophora is a VERY quick grower under good conditions. Be prepared to frag it often. I have fragged off large sections only to see it growing over the cut areas and starting to rebranch in less then a week.

Personal Observations: Very neat, realtively hardy coral. Great for people who want to take a first dive into SPS corals without many of the headaches that come with Acropora. As I mentioned they grow EXTREMELY fast, plan accordingly or be prepared to loose corals. I have noticed it completely grow over fragged areas in less then a week.
When adding to your tank make sure it is well secured and can't fall on any neighboring corals, I learned that lesson the hard way.
The difference between my two tanks lighting(one is 14k halide, the other 20k) is night and day. Under the bluer lighting it glows a bright vivid neon green.

 

This is not a bad thing necessarily. I've used Hydno's to control invasive species.

Great write up BTW.

 

Yep. I've used them to control GSP

 

thnx for introducing me to this coral larkin.

 

I have 2 of them...they are banished to the sides of the tank by themself!!! LOL....
I thought I had them spaced out enough and got up one day and saw this threads shooting out across an entire rock...at least a couple inches onto my large acan colony!

They are very cool corals. Excellent write up!

 

I have mine placed to limit GSP growth, but honestly it is almost as bad as the GSP I am trying to control. I need to make a run to my LFS, I just cut another 8 frags off the mother colony bringing the total up to 17.

Anybody who is considering picking up Hydno should thing long and hard about placement.

 

k+ one of my favorites

 

Updated with a couple pictures