scientifically known as Pseudochromis diadema, is a small and colorful fish that is popular among saltwater aquarium enthusiasts. Belonging to the family Pseudochromidae, they are native to the Western Pacific Ocean, found in shallow reef environments from Indonesia to the Philippines.

Lyretail Dottybacks are relatively small, growing up to 4 inches in length. They have an elongated body shape and a pointed snout, which allows them to dart into small crevices in the reef for protection. The dorsal fin of the Lyretail Dottyback is divided into two parts, with the first section containing 11 spines, and the second section having 12-13 soft rays. The anal fin has three spines and 11-12 soft rays.

Lyretail Dottybacks have a vibrant and eye-catching body coloration. Their base color is a deep purple-blue, with a striking yellow or orange stripe running from the top of the head, down the back, and along the tail. The fins are translucent and have a hint of blue. Males tend to have brighter coloration than females.

In their natural habitat, Lyretail Dottybacks are solitary fish that prefer to hide in small crevices and caves within the reef. They are territorial and will defend their hiding spots from other fish, including those of their own species. Lyretail Dottybacks have a reputation for being aggressive and predatory, often preying on small fish and crustaceans in the reef. They can be kept in a reef tank, but it is important to ensure that they are not housed with fish that are too small to defend themselves.

In the aquarium hobby, Lyretail Dottybacks are a popular fish due to their striking coloration and small size. They are hardy and adaptable to various water conditions, making them a great choice for beginner to intermediate aquarium hobbyists. They require a well-established aquarium with plenty of hiding spots and live rock. Lyretail Dottybacks should be fed a varied diet that includes frozen or live foods, as well as high-quality pellets or flakes.

In conclusion, the Lyretail Dottyback is a striking and colorful fish that adds vibrancy to any reef aquarium. Although they are known to be aggressive, they can be kept in a well-stocked reef aquarium with caution. They are relatively hardy and easy to care for, making them a great choice for beginner to intermediate aquarists looking to add some color to their tanks.