Tubastraea micrantha

[KeithM]

disregarding water quality - is it physically possible to over feed T. micrantha? or will they just reject the food?

[rich_tilbury]

Based on experience with sun corals I think it would be impossible to over feed! They seem to be ready to eat the next meal in minutes, even after a hearty feed! I've never tried to stuff until it could eat no more though.

T. micrantha is supposed to need more food than the other sun corals though.

[KeithM]

Has anyone witnessed physical damage to T. micrantha or any other Tubastraea sp. from overfeeding?

surely there is a limit to how much the skin can stretch?

[rich_tilbury]

What damage are you seeing? How far can the skin stretch; comfortably at least 2 times the normal polyp size when extended, if not a bit more.

[evilervin]

disregarding water quality - is it physically possible to over feed T. micrantha? or will they just reject the foodHas anyone witnessed physical damage to T. micrantha or any other Tubastraea sp. from overfeeding?
surely there is a limit to how much the skin can stretch?IMO it is NOT possible to over feed to the point of causing direct physical damage to the polyp, the coenosarc or any other part of the coral, but damage can be done indirectly;

If you feed a too large an amount of food in 'one sitting' the polyps will simply regurgitate the food, normaly as a tightly packed ball.

If the polyp/s do this everytime they fed, they run the risk of starvation and energy depleation. This occures because the food is not present within the gastric cavity long enough for the nutrients to be absorbed. When the polyps next recieve a trigger to expand, the polyp 'burns' stored energy to do so. If the polyp is then fed to the point of expulsion again, the polyp recieves no nutrients in return, thus stavation begins (if this happens many times).

Along the same lines;
If a whacking great big chunk of fish is offered, the polyps will 'over' expand and try to envelope the piece of food, and will have a dam good go at finishing the meal, but usualy the gut is over 'stuffed' and the polyp expells the food or contracts / deflates resulting in the food falling out of the polyp or washed away by the flow of water (if the piece of food hasn't already been stolen by fish or shrimps).

If feeding large food stuffs, try to offer pieces no bigger than the oral disc.
If the mouth is gaping following the ingestion of food, stop feeding.

damage caused by over expansion;
As Rich mentioned, Tubastraea sp. polyps can easily double their normal expended size, and then some.
If the water flow is strong enough, and turbulent enough, to 'fold' the polyp whilst over expanded, damage can be cause in the form of a tear to the tissue around the calyx edge.
It is not normal behavior for the polyps to expand to the point of causing damage within turbulent, strong flow; for this to happen the person feeding the coral offered the polyps to large a piece of food.

'throwing up' aside, can you over feed a sun coral?
No, but you can easily pollute the water column, resulting in damage to the coral.

HTH
Roger

[KeithM]

Roger, thanks for your fantastic explaination. exactly what I was looking for!