How do soft corals grow?

[eag]

I've read papers and articles that describe in great detail how SPS grow. If I recall correctly, they talk about a thin fluid layer between the skeleton and the tissue, in which calcification occurs. They talk about the reactions that drive the calcification, etc. One thing I don't remember them talking about is the growth of the tissue and polyps... But in that case, it was easy to wave away due to the relatively low mass ... Probably coming from nutrients in the water?

But what about soft corals? I've seen no such information about their growth, and googling doesn't turn up much either. Photosynthesis can provide energy but not mass ... And soft corals can grow large! I suppose some LPS are similarly questionable.

Folks talk about nutrient export via xenia. They will grow even without feeding. What exactly are they pulling out of the water and how do they use it?

 

[Goaway]

I would like to know this too. I don't know if they really dove into softies like they do with the sps. Something about sps gets too much attention.

 

[Broke2Broke]

Most people will just say use any light and dirty water meaning somewhat higher nutrients. I have yet to find anything like what you see for SPS. I understand they are easier to keep and all but would still like to know the scientific approach. Right now it's kinda trial an error. I have an all softie tank. Some corals seem to thrive faster than others and some just melt away for unknown reasons.

 

[eag]

Photosynthesis can provide energy but not mass

I realized after posting this that photosynthesis does eventually produce mass when considering the respiration component (CO2 -> O2) .. so I think that probably accounts for the majority of soft coral mass? They definitely seem to absorb nutrients from the waters, and I'm still curious to know more about that.

 

[a.t.t.r]

The exact same way hardcorals grown their tissue just no skeleton. They eat stuff they get energy (sugars iirc) from the algae inside them and they have cells that divide like all cells do.

Remember most of a tree is also made from photosynthesis very little of a trees mass comes from soil Carbon and nitrogen are big two.

heck look at the human body.

Element	Symbol	percent mass	percent atoms
Oxygen	O	65.0	24.0
Carbon	C	18.5	12.0
Hydrogen	H	9.5	62.0
Nitrogen	N	3.2	1.1
Calcium	Ca	1.5	0.22
Phosphorus	P	1.0	0.22
Potassium	K	0.4	0.03
Sulfur	S	0.3	0.038
Sodium	Na	0.2	0.037
Chlorine	Cl	0.2	0.024
Magnesium	Mg	0.1	0.015
All others		< 0.1	< 0.3

Well over half the list is found in co2 and h20

 

[rhostam]

As others have pointed out, same way SPS grow just with larger polyps and different patterns (solo, colonies, etc):

 

[sfin52]

I have watched my softies react when I add fine food into the tank. Its definitely a feeding response. Especially Reef roids. I get a great feeding response. They definitely are eating. The algea in the tissues will use the same stuff that plants and other algea uses for food. The reason when its deficient the coral looks dual. The algea is struggling and the coral also suffers.