The Achilles Tang, also known as the Red-tailed Surgeon, or Achilles Surgeonfish, is very dark brown to purple. It has bright highlights of white and orange around the dorsal, caudal, and anal fins. A white marking is also present on the gill covers and a striking orange teardrop is found near the caudal fin. The juveniles of this species have an orange marking by the tail in the shape of a streak instead of being teardrop in shape. A 100 gallon aquarium or larger is necessary to provide plenty of swimming room. It is aggressive towards other Tangs and Surgeonfish, but peaceful with other fish. Although Tangs will eat meaty foods along with the other fish in the aquarium, it is important that they are offered plenty of marine based seaweed and algae. This will strengthen their immune system, reduce aggression and improve their overall health. Offer dried seaweed tied to a rock or use a veggie clip, and feed at least 3 times per week. Sea Veggies, Seaweed Salad and Ocean Nutrition are all ideal products and are very easy to use.