Reef Discussion

[Haggibear]

Hi I need help identifying this!
Is it good or bad?
there are 4 now but they are never in the same spot the next day and you need a magnifying glass to spot them, and i have only seen them on the glass but i am afraid they might be juvenile aptasia so i always do several checks on my live rock everyday (call it paranoia).
There is nothing in the tank except live rock, sand and water.and there wont be anything in there for aleast 5 more months.

 

[Ian G]

Looks like a hydroid to me. How old is your tank?

They can be a nuisance but are more often found in new-ish tanks and often die out as the tank matures. I can't be sure from this photo but that's my best guess.

"Hydroids are colonies of tiny stinging jellies, best described as hundreds of inverted jellyfish attached to a feather- or seaweed-like base, known as the organism's polyp phase. Reproduction is achieved by releasing these fertile medusae into the plankton to feed and spawn. They are abundant on most submerged surfaces including seaweeds but are very small and easily overlooked. Powerful stinging cells are a primary cause of skin irritation when swimmers contact the reef, seaweed, pilings, floating docks, lines, or debris. Symptoms may be delayed a day or more, appearing as intensely itchy welts and blisters. Many species have been unintentionally spread around the world as adults on ship hulls or larvae in ballast water. Hydroids are eaten by some species of sea slugs, filefishes, puffers, and the Moorish Idol. Fire Corals are reef-building, photosynthetic hydroids."

 

[Priscacara]

+1 on the hydroid, I used to have loads of them initially but as mentioned they die off and only see them for a few days when I get anew piece of coral or rock. Shouldn't cause any problems.

 

[chimaera]

+another on hydroid, and yeah no need to worry about them.