About Synchiropus splendidus (Herre, 1927)
Taxonomy and Blue Pigment Origin
Synchiropus splendidus (Herre, 1927), the mandarinfish, is one of only two vertebrate species known to get its blue colouring from cellular pigment; the other is its close relative, the psychedelic mandarin (S. picturatus). The term "cyanophore" was proposed for these blue chromatophores, which are the pigment-containing and light-reflecting cells that produce this blue colour. In all other known vertebrates, blue colour is structural, generated by thin-film interference from stacks of flat, thin, reflective purine crystals.
Body Shape Comparison
The mandarinfish shares only a goby-like body shape with gobies, with no other similarities between the two groups.
Base Coloration and Face Markings
Its vivid coloration has a bright blue base, with swirly orange stripes and a blue-green face marked by bold blue stripes.
Pelvic Fin Characteristics
Its large pelvic fins are used to "walk" across the seafloor, and are often mistaken for pectoral fins.
Pectoral Fin Characteristics
The true pectoral fins are located almost at the center of the body and are nearly transparent, with a slight tint.
Anal Fin and Body Striping
The anal fins, part of the tail, and the rest of the body are striped in vibrant orange and blue.
Male Dorsal Fin Features
The dorsal fin is exceptionally tall in males, and also has a striking orange-and-blue pattern.
Eye Appearance
The mandarinfish's eyes are usually red with black pupils.
Intraspecific Color Variation
Different varieties of the species have different markings and colours. The green mandarin morph matches the general colour description above. The red mandarin is the same species, but its pelvic fins and the regions that are orange in green mandarins are red.
Rare Color Morphs
In rare cases, entire individuals can be red with black stripes. The spotted mandarin morph is light gray-green with black, pink and blue spots.
Habitat Preference
Mandarinfish are reef-dwelling fish that prefer sheltered lagoons and inshore reefs.
Size and Observability
Though they are slow-moving and fairly common across their range, they are not easy to spot due to their bottom-feeding habits and small size, reaching only around 6 cm in length.
Diet
They feed primarily on small crustaceans and other invertebrates.
