Mandarinfish

Synchiropus splendidus

The mandarinfish or mandarin dragonet , 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.
Mandarin Fishes - Synchiropus splendidus Diver's Lodge Mandarin Reef, Lembeh.
Night dive. Female (smaller) and male engaging in mating ritual. Geotagged,Indonesia,Mandarinfish,Spring,Synchiropus splendidus

Appearance

To date, ''S. splendidus'' is one of only two vertebrate species known to have blue colouring because of cellular pigment, the other being the closely related psychedelic mandarin . The name "cyanophore" was proposed for the blue chromatophores, or pigment-containing and light-reflecting cells. In all other known cases, the colour blue comes from thin-film interference from piles of flat, thin and reflecting purine crystals.
Looking for dancing partner - Synchiropus splendidus Mandarin Reef Diver's Lodge, Lembeh>
Female in search for male for mating ritual. Geotagged,Indonesia,Mandarinfish,Spring,Synchiropus splendidus

Naming

The mandarinfish was first described as ''Callionymus splendidus'' in 1927 by Albert William
Herre, an American ichthyologist working in the Philippines. It was later placed in genus ''Synchiropus''. The generic name ''Synchiropus'' is from Ancient Greek ''syn-'', meaning "together", and ''-chiropus'' meaning "hand-foot". The specific epithet ''splendidus'' is from Latin for splendid.
The common name of the mandarinfish comes from its extremely vivid colouration, evoking the robes of an Imperial Chinese mandarin.
Other common names include mandarin goby, green mandarin, striped mandarinfish, striped dragonet, green dragonet and sometimes psychedelic mandarinfish.
The similarly named mandarin fish , properly known as the Chinese perch, is only distantly related.

The mandarinfish belongs to the perciform family Callionymidae, the dragonets, which counts 10 genera and more than 182 species. Genus ''Synchiropus'' counts 51 species, divided into 10 subgenera. The mandarinfish is in subgenus ''Synchiropus'' along with the Australian LSD-fish and the LSD- or psychedelic fish .
Male waiting for his dates - Synchiropus splendidus Mandarin Reef Diver's Lodge - This is the male that I saw courting and mating with a harem of females. This mushroom coral served him as his dancing platform to attract the females, just like John Travolta in Saturday Night Fever!  Geotagged,Indonesia,Mandarinfish,Spring,Synchiropus splendidus

Habitat

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 . They feed primarily on small crustaceans and other invertebrates.
Mandarin Fishes - Synchiropus splendidus Diver's Lodge Mandarin Reef, Lembeh.
I add a you tube video just to show how bizarre and pretty is their mating (wait until the end). One of these days when my husband works on his GoPro videos I may be able to add one from the same place where the pics were taken from.
https://www.youtube.com/watch?v=y3jAkDUJkyU
 Mandarinfish,Synchiropus splendidus

Food

Based on the gut analyses of 7 wild fish Sadovy ''et al.'' determined that the mandarinfish has a mixed diet that consists of harpacticoid copepods, polychaete worms, small gastropods, gammaridean amphipods, fish eggs and ostracods.
In the wild, feeding is continuous during daytime; the fish peck selectively at small prey trapped on coral substrate in a home range of many square meters.

References:

Some text fragments are auto parsed from Wikipedia.

Taxonomy
KingdomAnimalia
DivisionChordata
ClassActinopterygii
OrderPerciformes
FamilyCallionymidae
GenusSynchiropus
SpeciesS. splendidus