Dragonets
Dragonets are often mis-categorized as gobies or blennies by fish sellers. They are bottom-dwelling fish that constantly hunt tiny invertebrates for food. Most starve to death in a marine aquarium unless you provide a refugium or place for the invertebrates to reproduce safely without any fish being able to reach them.
Synchiropus ocellatus (Scooter Dragonet) is a species of tropical marine fish in the Dragonet (Callionymidae) family. It is native to the southwest Pacific Ocean.
The Scooter Dragonet is often referred to as the Ocellated Dragonet and, in the aquarium trade, as the Scooter Blenny. This often causes confusion because many then believe that the species is a member of the Blenny family when it is actually not. The same species is also occasionally listed under the scientific name Neosynchiropus ocellatus, and many mistakenly believe they are separate species.
The Scooter Dragonet grows to approximately 8 cm long. Viewed from above, it is distinctly diamond-shaped with the horizontal pectoral fins located at its widest point. It is brown and tan with a striped or spotted pattern- males are usually more colorful and have a large sail-like dorsal fin that is bright orange at the base.
The Scooter Dragonet is a reef-associated bottom dwelling fish that inhabits shallow, tropical waters, usually sandy lagoons or rocky reefs. They tend to form loose congregations of several individuals, but do not exhibit schooling behavior or other forms of social cooperation. Scooter Dragonets' diet consists almost entirely of Copepods: small zooplankton living in the water column.
Synchiropus picturatus is a Dragonet from the Indo-West Pacific. It occasionally makes its way into the aquarium trade. It grows to a size of 7cm in length.
The mandarinfish or mandarin dragonet (Synchiropus splendidus), is a small, brightly-colored member of the dragonet family, which is popular in the saltwater aquarium trade. The mandarinfish is native to the Pacific, ranging approximately from the Ryukyu Islands south to Australia. It is also somewhat misleadingly known as the mandarin goby, due to its resemblance to blennies and gobies. Other trade names include "green mandarinfish", "striped mandarinfish", or "psychedelic fish". The name psychedelic mandarin is also used for a closely related species, the picturesque dragonet, Synchiropus picturatus.
Mandarinfish are reef dwellers, preferring sheltered lagoons and inshore reefs. While they are slow-moving and fairly common within their range, they are not easily seen due to their bottom-feeding habit and their small size (reaching only about 6 cm). They feed primarily on small crustaceans and other invertebrates. The name of the mandarinfish comes from its extremely vivid coloration, evoking the robes of an Imperial Chinese mandarin.
Despite their popularity in the aquarium trade, mandarinfish are considered difficult to keep, as their feeding habits are very specific. Some fish never adapt to aquarium life, refusing to eat anything but live amphipods and copepods (as in the wild), though individuals that do acclimatize to aquarium food are considered to be quite hardy and highly resistant to diseases such as ich. They cannot contract the disease Ichthyophthirius because they do not have the skin type that this common aquarium disease affects.
They are one of only two species known to have blue colouring because of cellular pigment rather than blue due to nanostructure (Goda and Fujii, 1995), the other being the closely related picturesque dragonet, Synchiropus picturatus..
The similarly named mandarin fish, Siniperca chuatsi, properly known as the Chinese perch, is only distantly related.