Gorgonians are just gorgeous, such as this purple one above. Gorgonians rely on food for survival, and some don't even benefit from light (referred to as non-photo synthetic corals) whatsoever. I can't add much more since I don't have personal experience with this coral. Do your research before making a purchase. Reef-safe
Originally identified as a ricordea, this is in fact a Hairy Mushroom. They tend to grow quite large (as much as 12") rather than splitting as most mushrooms do. Hairy mushrooms are known by their split tentacles, in comparison to their "frilly" counterparts. They can eat a fish under the right conditions, as they will close up around it quietly and slowly. They contain a powerful sting and can harm neighboring corals. This would be a good choice for a soft coral tank. Reef-safe-ish. :)
Kenya Tree is a fast growing soft coral that resembles, well, a tree. The trunk supports the many branches that are seemingly covered with 'leaves'. Expect this coral to take up a good amount of space as it grows. Don't let this little frag fool you. It will be quite the bush when mature, and drop babies continuously.
This is a very common beginner's coral.
I bought three Red Mushrooms, and a year later I had hundreds, with more every day. I gave them away, I shipped them away, I did all I could to control them and they continued to propagate like Tribbles! All who've received them tell me how well these did even under very intense lighting. From tiny to 5" in diameter, they do add color to the tank, but they can sting other corals as they seek to gain new territory. At night they shrink in size when the lights are off. They spread via pedal laceration, or spin off and drift to a new location to attach elsewhere.
These appear to be Star Polyps - Briareum - and depending on the lighting look either pink or faintly green. In strong current its base will spread across nearby rockwork, and extended thousands of individual polyps when the tank lights are on. At night they are fully receded into its mat. Some consider these to be a weed-like nuisance, so isolation may be in order. Great beginner coral for new coral keepers, but after a while you may want to replace it with something nicer.
This nudibranch is very likely a creature that feeds on soft corals, such as leathers. Nudibranches in general are pretty to look at, so it comes down to maintaining their food source if you hope to keep it long term. Most reef keepers would prefer to focus on the corals rather than such predators. I'd remove it if I were you.
Photos by Todd Preisler
This colorful corals are called Ricordea - Ricordea florida - and they are beauties. Keeping them in a reef tank, they will spread across the rockwork without any assistance on your part. For some reefkeepers, rics are easy to keep but for me they've always been challenging.
I spotted these during a dive trip in October 2016 to the Dominican Republic. They blended into the reef so I was really excited to spot them at 30' deep, and even more excited to get a good picture of them myself.
This Gorgonian - Pseudoplexaura sp. - was acquired from the 20,000g reef in Long Island back in 2012, and has been growing steadily for years. Occasionally I'll frag a small piece to share with a special hobbyist. This species is easy to keep; it's photo-synthetic meaning it does need light to feed, but I never target feed it any foods directly. Clearly it captures what it needs on its own, since it is doing so well in my system.