Frogspawn (Euphyllia divisa) is a large-polyped stony coral, which is typically characterized by the visibility of its polyps all day and night. It is generally green or brown in color and has a unique appearance, which combine to make it one of the most sought-after coral species for reef aquariums. Frogspawn Coral Facts Frogspawn derives its name from the fact that its polyps resemble the eggs of frog or fish to certain extent. It is also referred to as the grape coral or octopus coral. Its habitat spans the deep waters of the Red Sea, Samoa, Indo-Pacific, Solomon Islands, etc. It plays a crucial role in the formation of coral reefs, which, in turn, have an important role to play when it comes to biodiversity of the planet. It is one of the most aggressive species of coral in the world, and thrives best in stable or moderate flow water. In its natural habitat, frogspawn does not require direct feeding as it shares a symbiotic relationship with zooxanthellae―a photosynthetic algae. In what is considered one of the best examples of mutualism, frogspawn benefits from photosynthesis carried out by zooxanthellae, while zooxanthellae benefits from the nitrogen produced by the coral species. Its long tentacles are armed with Nematocysts, a type of venomous cell, which helps it capture food. This food can either be digested on-site itself, or brought to the coral's mouth for feeding. Frogspawn Coral Care It is classified as one of those species that are moderately difficult to care for, mainly owing to its requirements. It will only thrive if the conditions necessary to facilitate its growth are provided. It will grow well in water with pH level ranging between 8.1 - 8.4 and hardness of 8° - 12° dH. In order to facilitate proper growth, you will have to ensure that the temperature in its habitat ranges between 75°F - 82°F. You will also have to make sure that the aquarium, in which you house this coral, has moderate to high lighting and moderate flow of water. You need to take a note of the fact that frogspawn coral is quite aggressive when it comes to interaction with other coral species. It has the ability to extend its lengthy sweeper tentacles as far as six inches beyond its base and sting other species in the aquarium, which are within its reach. You have to take special precautions when it comes to the placement of this coral. Ideally, you should leave enough space between it and other species in order to make sure that they don't harm each other. The diet of this species includes small marine animals, like shrimp, krill, etc. If you house a frogspawn in your reef aquarium, you can feed it the same. Basically, its diet has a crucial role to play in its growth and color. Owing to its voracious feeding habit, you will have to give it some calcium and strontium supplements as well. It depends on photosynthesis facilitated by zooxanthellae in the wild, but in captivity, you will have to make sure that you provide it the necessary nutrients. If you don't pay attention to its diet and other requirements, you will notice that it will start fading―this is a sign of it dying. A healthy frogspawn coral has very bright vibrant colors. The simplest way to make sure that it stays healthy, is to follow all the measures of care discussed above religiously.