FACT: Coral tissue necrosis (RTN and STN) and Coral Bleaching are caused by an infection due to microscopic parasites.

Coral Tissue Necrosis

Tissue necrosis is when a coral loses its skin/flesh which results in exposed coral skeleton or coral melting. Coral bleaching is when the coral loses its zooxanthellae causing the coral skin to turn white. There are two kinds of tissue necrosis, Rapid Tissue Necrosis (RTN) and Slow Tissue Necrosis (STN). Rapid Tissue Necrosis can occur in the matter of hours, usually within 24 hours. Slow Tissue Necrosis can take days to  months. 

Both coral RTN and STN are caused by an infection of the coral tissue and skeleton by microscopic protozoans. These protozoans are a family of single cell microscopic organisms with cilia that are found both in the water column and within the coral tissue and skeleton. In 2018, Dr. Ara Deukmedjian performed a series of tests at Prime Coral Labs proving these protozoans are the cause of coral dieases RTN and STN by culturing and infecting coral samples with the protozoans. Because colonization of a healthy coral by the protozoans ultimately and ALWAYS leads to coral disease (RTN, STN and bleaching) and death, we must classify these protozoans as parasites. The parasites do not benefit the coral in any way and always cause coral tissue necrosis by consuming the coral tissue along with its zooxanthellae. These parasites cannot be seen with the naked eye or a magnifying glass. They can only been seen under a light microscope.

Prime Coral STOP RTN coral dip and Prime Coral Prevent RTN in-tank treatment are currently the ONLY products that are effective against RTN and STN parasites. The treatments are highly effective, yet gentle on corals and invertebrates. Made from all natural flora extracts, these products do not contain hazardous materials. They are organic and non-toxic.

Prime Coral Stop RTN is a complete coral dip used to treat common coral parasites. It is the only treatment effective against RTN, STN, and Coral Bleaching parasites. It is also effective against acropora eating flatworms, montipora eating nudibranchs, polyclad worms, black bugs, common flatworms, and eggs.

Prime Coral Prevent RTN is the ONLY in-tank treatment available to effectively treat saltwater systems infected with coral parasites that cause RTN, STN, and Coral Bleaching. It is added directly to your saltwater system to treat parasites that live within corals and free swimming parasites in the water column. Reef SafeNOT FISH SAFE.

It is strongly recommended to combine use of Prime Coral STOP RTN coral dip in conjunction with Prime Coral Prevent RTN in-tank treatment for maximum effect on RTN and STN parasites and better coral health.

Check out the Prime Coral Prevent RTN and Prime Coral STOP RTN page to learn more about our products.

RTN (Rapid Tissue Necrosis) occurs when a coral colony or portion of the colony loses its tissue rapidly. Typically coral loses its tissue within 24 hours.

FACT: The number one cause of RTN are the Philaster Lucinda and Philaster Guamense parasites. 

These two types of microscopic RTN Parasites are always found when a coral rtn’s. 

If you suspect a coral is starting to RTN, follow these steps.

STN (Slow Tissue Necrosis) occurs when a coral starts to lose its tissue over a longer period of time.

Euplotes, Cryptocaryon, and Dysteria parasites causes coral STN.

If you suspect a coral is starting to STN, follow these steps.

The combination of having both RTN and STN parasites causes coral bleaching. If you suspect a coral is starting to bleach, follow these steps.