Like the Turbinaria spp., they "sun" or "sunflower" polyps are asymbiotic; that is, they do not possess zooxanthellae. The polyps are large and extend mostly at night, although well fed and/or trained polyps may emerge during the day as well, especially if food is present. These corals have thick and sharply tapered tentacles, with the nematocyst buds and batteries visible as opaque spots on the translucent yellow to orange tentacles. A prominent central mouth is apparent, and completes an overall polyp one that truly typifies the "textbook" polyp formation. In terms of aquarium care, specimens should be positioned in areas of consistent water flow that will bring them available food when expanded. Aquariums employing strong foam fractionation that rapidly remove any "reef snow" planktonic elements should take note of the following: the key to success with Tubastrea is regular feeding. These corals will usually recede and waste away, cup by cup, unless provided with regular food sources. (Tubastrea by Eric Borneman July 1997 Aquarium.Net)