Yellow polyps parazoanthus gracilis Soft Coral We'll call it a soft coral along with everyone else. Although, it is not yet known. Phylum: Cnidaria Class: Anthozoa Subclass: Hexacorallia Superorder: Hexactiniida Order: Zoantharia Family: Parazoanthidae Common names: colonial polyps; sea mat Origin: Indo pacific Temperament: Mine have exhibited low to no aggressiveness. However, care needs to be taken regarding placement. These are members of the phylum cnidarians (they sting). These yellow polyps may also exhibit an aggressive nature at the rate of which they spread. Mine have done well living amongst a zoa rock. Water quality: As with all reef tanks the following are recommended parameters. Keep in mind that these are very hardy and can/will tolerate higher than preferred NO3 and PO4. Reef parameters and recommended/desired levels. Salinity/specific gravity-1.025ppm or 35ppt temp.-78-82 PH-8.1-8.3 Ammonia/NH3-0 Nitrite/NO2-0 Nitrate/NO3-0 Phosphate/PO4-0 Magnesium/Mg-1400-1500ppm Alk/dKH/KH-7-14. Calcium/Ca-380-500ppm Hardiness: These things are pretty resilient. I would recommend them as a great beginner coral. They have made it through some rough times in the last 2 years in my system. I have had them wither down to 2-3 polyps and come back to spreading #'s. Current/flow: Low to moderate flow. These corals are great for giving the appearance of the wind over a wheat field as the flow in the current. Foods/feeding: These corals are photosynthetic and rely on zooxanthellae/photosynthesis for a main source of food. They will accept small meaty feedings. I am just an underfeeder in general so, I hardly ever target feed mine. Lighting requirements: These corals require moderate lighting. Frag difficulty: Easy....... If you can break a rock then you can frag these. Larger colonies are done by using a hammer/chisel to break rocks and split them up. Rubble can also be placed near existing colonies for a more patient approach. They are also individual polyps that can be easliy removed and glued to frag plugs. Personal observations: I have only seen an incident once when my yellow polyps attached to an adjacent closed brain coral causing some damage. I also notice that they tend to end up in random areas of the tank. If either it is my cuc accidentally giving them a pluck, or, polyp bailout they end up starting a new gig somewhere else. Links:YouTube - fragging yellow polyps Zoanthids http://images.google.com/images?oe=...parazoanthus'&um=1&ie=UTF-8&sa=N&hl=en&tab=wi This was probably the hardest article I have written yet which has sparked some further curiosity into these "so called" soft corals. They aren't as simple as I have been giving them credit for. In fact they were just thrown towards zoanthids tentatively because of similarities. They are quite different though comparitively. They re-produce by budding. Polyps are different though as they are individual as opposed to zoanthids. I also found that some of the parazoanthus form symbiotic relationships with sponges from deeper waters. They offer protection from "sponge eating" fish with their sting. In return they perch atop the sponge collecting food living in nutrient rich areas. They are also ahematypic (require food). Thanks for reading...... Please share pics of your yellow polyps if you have them.