# Mandarinfish (*Synchiropus splendidus*)

The Mandarinfish is a tiny, colorful fish with bright blue and orange patterns. It is known to be very shy and prefers to hide among corals.

- **Category:** [Fish](https://www.snappit.app/explore/categories/fish)
- **Rarity:** Rare
- **Danger:** 2/5 · Low
- **Habitat:** Coral reefs
- **Also known as:** Mandarin Dragonet, Mandarin Fish

![Mandarinfish](https://media.snappit.app/site-media-v1/3e0909de8c64939d080d9941c7ddb984bc4a0dd18a81d16dca8c195d1a0d7528/image-560x560/w-560.webp)

## Appearance

The Mandarinfish has an electrifying pattern of wavy orange, blue, and green lines across its body, with large, bulbous eyes. Its fan-like dorsal and anal fins add to its flamboyant appearance, making it distinctly vibrant among reef fish.

## Taxonomy

- **Kingdom:** Animalia
- **Phylum:** Chordata
- **Class:** Actinopterygii
- **Order:** Perciformes
- **Family:** Callionymidae
- **Genus:** Synchiropus

## Mandarinfish, up close

The mandarinfish (Synchiropus splendidus), also called the mandarin dragonet, is a tiny, scaleless reef fish from the western Pacific, about as long as your little finger. Its orange body is covered in wavy blue-green bands, and the blue comes from special pigment cells that scientists first found in this fish and one close cousin. By day it pecks for tiny animals among coral rubble. Around sunset, pairs rise above the reef to release their eggs.

Also called: Mandarin dragonet, Mandarin goby, Green mandarin, Striped mandarinfish.

Blue made by real pigment cells, a bitter slime instead of scales, and a sunset dance that sends eggs drifting off. Spin it, tap it, then test yourself.

### Special abilities

- **True Blue** (1995 blue pigment cells described): The mandarinfish makes its blue with real blue pigment, held in special cells called cyanophores. Almost every other blue animal gets its colour from crystals that reflect light instead. [4][6][7][3]
  - In most blue fish, birds and butterflies, the blue is 'structural': stacks of tiny crystals reflect blue light, a bit like the colours on a soap bubble.
  - In 1995 two Japanese scientists, Makoto Goda and Ryozo Fujii, found branching cells full of blue pigment in the skin of the mandarinfish and the spotted mandarin. No such cells had been reported before.
  - Inside each cyanophore the blue sits in tiny packets the scientists called cyanosomes. The packets bunched up or spread out when the cells were stimulated, which may let the fish shift its shade of blue.
  - Blue pigment cells are still known from very few animals, which is one reason scientists sequenced the mandarinfish's whole genome.
- **Sunset Rise** (≈ 1 m rise above the reef): Around sunset, mandarinfish gather at spawning spots on the reef. A male and a female line up side by side and rise together about a metre into the water to release eggs and sperm. [2][8][10][11][13]
  - Spawning starts at dusk and carries on into the early night, all year round.
  - A female spawns once a night at most, and some nights not at all. A male can spawn with up to 8 different females in one night.
  - Females prefer big males: in one field study, females longer than 3 cm spawned with males over 4 cm 94% of the time.
  - The rise is risky: both fish and eggs are exposed in open water, away from the shelter of the coral.
- **Drifting Eggs** (12–205 eggs per spawn): At the top of the rise, the pair releases eggs and sperm into the open water. The tiny eggs float away on the current, and the parents never see them again. [2][9][10][11]
  - Scientists counted the eggs of 40 females: each spawn held between 12 and 205 eggs.
  - The eggs are clear, round and only 0.7–0.8 mm across. They float in the open water.
  - They hatch after about 12 hours. Neither parent looks after the eggs or the young.
  - A male releases roughly 50,000–230,000 sperm per spawn, and bigger males release more.
- **Bitter Slime** (0 scales; still debated): With no scales to protect it, the mandarinfish wears a thick coat of smelly, bitter slime. Scientists think it puts predators off, and its bright colours may be a warning. [2][3][12][1]
  - The skin is full of mucus cells, plus sacciform cells that release other substances. Among six dragonet species studied, sacciform cells turned up only in the mandarinfish and the spotted mandarin.
  - The study's authors linked these secretions to defence against predators and to living in close contact with the reef.
  - Some accounts call the secretions toxic, but how harmful they are to predators has not been measured. They are not known to harm people.
  - Bright colours that warn 'I taste bad' are called warning colours. That idea fits the mandarinfish, but it has not been tested.
- **Big Male Sail** (94% of spawns with males over 4 cm): Males are bigger than females and carry a tall first dorsal fin. Females choose big males, so size and a fine sail pay off at spawning time. [10][11][2][16]
  - In 67 spawning pairs watched in Palau, males were 3.1–5.8 cm long and females 2.3–3.8 cm. A female always picked a male bigger than herself.
  - In aquarium trials, females tried to pair only with the larger of two males.
  - Bigger males release more sperm, and more sperm meant more eggs fertilised.
  - Dragonet spawning runs in four stages: a courtship display, pairing up, rising together, then releasing eggs and sperm.
- **All-Day Picker** (All day pecking for tiny prey): A mandarinfish spends its day pecking tiny animals off coral and rubble, one bite at a time, across a home patch of many square metres. [3][9][2][15]
  - Wild mandarinfish eat copepods, ostracods and amphipods (tiny crustaceans), plus small worms, tiny snails and fish eggs.
  - Its small mouth limits it to very small food.
  - In aquariums many refuse anything but live copepods and amphipods, which makes them hard to keep.
  - Copepods matter from the very start: in a rearing study, adding copepods to the larvae's food raised survival at 12 days from 5.6% to 50%.
- **Coral Hideout** (1–18 m deep, in sheltered lagoons): By day the mandarinfish moves slowly among coral branches or tucks into cracks, which makes this bright fish surprisingly hard to spot. [1][2][3][14]
  - It lives in sheltered lagoons and inshore reefs, often on silty bottoms with coral and rubble.
  - Mandarinfish usually gather in small groups within a small area. Adults seem to stay in one area after settling; no adult migration has been recorded.
  - During the day it moves along coral branches or hides in cracks in the reef.
  - Its small size and bottom-hugging habits keep it out of sight, even though it is fairly common in its range.
- **Stripe ID** (400+ h of underwater surveys): No two mandarinfish have quite the same swirls. Scientists used each fish's markings like a name tag to follow the same individuals night after night, without catching them. [8][10][20]
  - In one field study, researchers spent more than 400 hours underwater watching mandarinfish.
  - They recognised individual fish from their body markings, a mix of stripes and spots.
  - That let them record who spawned with whom, and how often, without disturbing the fish.
  - Scientists now use markings like this to identify individuals of many other kinds of bony fish.

### Body parts

- **Blue bands** (1995 year its blue pigment cells were described) [4][6][7]
  - In most blue animals the blue is not a pigment: tiny crystals or structures bounce blue light back, like the shine on a soap bubble.
  - The mandarinfish is different. Its skin holds blue pigment cells, which the scientists who found them named cyanophores.
  - When they were described in 1995, nobody had reported blue pigment cells of this kind before. The only other fish they found them in was its close cousin, the spotted mandarin.
  - The blue sits in tiny packets inside each cell. The packets can bunch up or spread out, which may shift the shade of blue.
- **Striped face** (2 colours in one pigment cell type found in 2013) [3][5][6]
  - The face is green with bold blue stripes, and the eyes are usually red with black pupils.
  - In 2013 the same research team found a second new kind of colour cell in mandarinfish skin: one cell that holds both blue and red pigment.
  - Fish only have about a dozen known types of colour cell, and two of them were discovered in the mandarinfish.
- **First dorsal fin** (4 spines in the first dorsal fin) [1][2][3][14]
  - The first fin on the back has 4 spines. In males the first spine grows long, so a big male carries a tall orange-and-blue sail.
  - Females have a much lower first dorsal fin, which is one way to tell the sexes apart.
  - Collectors for the aquarium trade pick out big males, because their tall fin makes them the showiest fish.
- **Scaleless skin** (0 scales) [2][3][12][13]
  - Mandarinfish have no scales. Instead, a thick coat of slime covers the skin.
  - The slime smells bad and tastes bitter, which probably puts predators off.
  - The skin is packed with mucus-making cells, plus a second kind called sacciform cells that release other substances. These were found in mandarinfish and spotted mandarins, but not in four other dragonets studied.
  - The slime may also help keep out parasites and disease.
- **Tiny mouth** (6 kinds of prey found in wild guts) [2][3][9]
  - The mouth is small, so it can only eat very small food.
  - Scientists looked inside the guts of 7 wild mandarinfish and found tiny crustaceans called copepods, ostracods and amphipods, plus little worms, tiny snails and fish eggs.
  - It feeds all day, pecking one tiny animal at a time off coral and rubble.
- **Fan fins** (Slow hovering swimmer) [3][13]
  - Big, rounded pectoral fins stick out from behind the head like a pair of fans. Their edges are deep blue.
  - The mandarinfish is a slow mover. It hovers and creeps over the reef rather than racing about.
- **Pelvic fins** (Hand-foot rough meaning of the name Synchiropus) [2][3][16]
  - Under the chest sit wide pelvic fins. By day the fish moves slowly along coral branches and over rubble.
  - Dragonets push off the bottom with their pelvic fins when they need a quick burst of speed.
  - The genus name Synchiropus is built from Greek words meaning roughly 'together, hand, foot'.
- **Cheek spine** (1 per side spine on the gill cover) [16][1]
  - Dragonets have a spine on each gill cover, called the preopercular spine. It is a family trademark.
  - In some dragonet species this spine has been reported to be venomous. There is no report of that for the mandarinfish, which fish experts list as harmless to people.
- **Tail fin** (≈ 1 m rise above the reef when spawning) [2][13]
  - The tail fin is rounded and orange, with a deep blue edge.
  - Mandarinfish usually stay close to the bottom. The big exception is spawning, when a pair swims up about a metre into open water.

### Stats

| Stat | Value | Notes |
|---|---|---|
| Length | up to 7 cm | usually about 6 cm; males are larger than females; About as long as your little finger [1][2] |
| Depth | 1–18 m | sheltered lagoons and inshore reefs [1][2] |
| Water temperature | 24–26 °C | warm tropical water [2] |
| Eggs per spawn | 12–205 | counted from 40 females [9] |
| Egg size | 0.7–0.8 mm | clear, round and floating; Smaller than a grain of sugar [2] |
| Time to hatch | ≈ 12 hours | no parental care [2] |
| Drifting larva | ≈ 14 days | before settling on the reef (12–14 days at 24–26 °C) [2][9] |
| Spawns per male | up to 8 | in a single night; a female spawns once at most [8] |
| Sperm per spawn | 50,000–230,000 | bigger males release more [10][11] |
| First dorsal fin | 4 spines | the first spine is long in males [1][2] |

### Photos

- [Orange body, wavy blue-green bands and blue-edged fins, Lembeh, Indonesia.](https://commons.wikimedia.org/wiki/File:Mandarin_fish_(Synchiropus_splendidus)_(45103629692).jpg) (photo: Rickard Zerpe, CC BY 2.0)
- [A male in an aquarium in Liège, Belgium. Note the tall first dorsal fin that only males grow](https://commons.wikimedia.org/wiki/File:Synchiropus_splendidus_2_Luc_Viatour.jpg) (photo: Luc Viatour, CC BY-SA 3.0)
- [The green face with bold blue stripes and a red eye, Anilao, Philippines.](https://commons.wikimedia.org/wiki/File:Pez_mandar%C3%ADn_(Synchiropus_splendidus)%2C_Anilao%2C_Filipinas%2C_2023-08-24%2C_DD_236.jpg) (photo: Diego Delso, CC BY-SA 4.0)
- [A pair rising together above finger coral at dusk to spawn, Lembeh Strait, Indonesia.](https://commons.wikimedia.org/wiki/File:Mandarinfishes_(Synchiropus_splendidus)_mating_(8467394835).jpg) (photo: Bernard DUPONT from FRANCE, CC BY-SA 2.0)
- [A spawning pair, side by side and heading up, Anilao, Philippines.](https://commons.wikimedia.org/wiki/File:Peces_mandar%C3%ADn_(Synchiropus_splendidus)%2C_Anilao%2C_Filipinas%2C_2023-08-24%2C_DD_231.jpg) (photo: Diego Delso, CC BY-SA 4.0)
- [A male raises his tall first dorsal fin beside another mandarinfish in finger coral, Lembeh Strait, Indonesia.](https://commons.wikimedia.org/wiki/File:Mandarinfishes_(Synchiropus_splendidus)_(8468500620).jpg) (photo: Bernard DUPONT from FRANCE, CC BY-SA 2.0)
- [Several mandarinfish sharing one clump of finger coral, Lembeh Strait, Indonesia.](https://commons.wikimedia.org/wiki/File:Mandarinfishes_(Synchiropus_splendidus)_(6076583055).jpg) (photo: Bernard DUPONT from FRANCE, CC BY-SA 2.0)
- [Tiny on a big reef: a mandarinfish on coral rubble, Malapascua, Philippines.](https://commons.wikimedia.org/wiki/File:Malapascua_Mandarin_Fish_(Synchiropus_splendidus).jpg) (photo: Sodacan, CC BY-SA 4.0)
- [The look-alike spotted mandarin (Synchiropus picturatus), the only other fish known with blue pigment cells when they were discovered](https://commons.wikimedia.org/wiki/File:Picturesque_dragonet_(Synchiropus_picturatus).jpg) (photo: Rickard Zerpe, CC BY 2.0)

### Questions

- **Why is the mandarinfish so blue?** Its skin holds blue pigment cells called cyanophores, first described in 1995. Most other blue animals make blue with light-reflecting crystals instead of pigment. [4][6]
- **Is the mandarinfish poisonous?** It is harmless to people. It has no scales, and its skin is coated in a smelly, bitter slime that probably keeps predators away. How toxic the slime is has not been measured. [1][2][12]
- **Is the mandarinfish a goby?** No. It is sometimes sold as the 'mandarin goby', but it is a dragonet, from the family Callionymidae. [3][13]
- **When and how do mandarinfish mate?** Around sunset. A male and female line up side by side, rise about a metre above the reef and release eggs and sperm. The eggs float away and hatch in about 12 hours. [2][13]
- **What do mandarinfish eat?** Tiny animals they peck off coral and rubble all day: copepods, amphipods, ostracods, small worms, tiny snails and fish eggs. [3][9]
- **Where do mandarinfish live?** In sheltered lagoons and inshore reefs of the western Pacific, from Japan's Ryukyu Islands to Australia, 1–18 m deep, among coral and rubble. [1][2]
- **How can you tell a male mandarinfish from a female?** Males are bigger and have a tall, spiky first dorsal fin. Females are smaller, usually under 4 cm, with a low first dorsal fin. [2][3][10]
- **Is the mandarinfish endangered?** No. It is listed as Least Concern. But it is collected heavily for aquariums, mainly in the Philippines, and collectors take the big males first. [1][14][10]

### Mandarinfish myths and facts

Some of what you hear about this little fish is true. Some of it isn't.

- "The mandarinfish's blue comes from real blue pigment." **Fact!** Its skin has blue pigment cells called cyanophores. In most other blue animals, the blue is made by light bouncing off tiny crystals. [4][6]
- "The 'mandarin goby' is a goby." **Myth!** It is sold under that name, but it is a dragonet, from the family Callionymidae, not a goby. [3][13]
- "Mandarinfish have scales like most fish." **Myth!** They have no scales at all. A thick, bitter-tasting slime covers the skin instead. [2][3]
- "Mandarinfish are dangerous to people." **Myth!** Fish experts list it as harmless to people. Its smelly, bitter slime seems aimed at fish that might eat it. [1][2]
- "Its bright colours warn predators that it tastes bad." **Not proven!** It is a likely idea, since the slime is bitter, but nobody has tested whether predators really learn to avoid the colours. [2][3]
- "Mandarinfish parents guard their eggs." **Myth!** The eggs are released into open water and float away. The parents give no care at all. [2]
- "A female mandarinfish can spawn every night." **Fact!** She can spawn once a night, though some nights she skips. Males can spawn up to 8 times in one night with different females. [8]
- "The mandarinfish is a cousin of the Chinese 'mandarin fish'." **Myth!** The Chinese mandarin fish, or Chinese perch (Siniperca chuatsi), lives in fresh water and is only distantly related. They just share a name. [3]

### The life of a mandarinfish

From a floating egg to a dancer on the reef, in a couple of months.

- **Sunset**: The rise. A male and a female rise about a metre above the reef and release eggs and sperm into the water. [2][13]
- **12 hours**: Hatching. The tiny, clear eggs, under 1 mm across, hatch while drifting in open water. No parent is around. [2]
- **36 hours**: Eyes and mouth. The larva's eyes darken and its mouth forms, so it can start catching food. [2]
- **8–11 days**: Tail bends up. The tip of the backbone bends up to form the tail fin, a big step on the way to a fish shape. [2]
- **12–14 days**: Settling down. The larva leaves the open water and settles on the reef. That is one of the shortest drifting stages known for a fish with floating eggs. [2][9][14]
- **18–21 days**: Turning orange-brown. The young fish darkens to an orange-brown colour. [2]
- **Second month**: Adult colours. At just 1–1.5 cm long, it gets the blue and orange pattern of an adult. [2]
- **Adult**: Nightly spawner. Adults stay in their home area and spawn at sunset, all year round. [2][8][14]

### Mandarinfish record-breakers

A small fish with some big firsts.

- First blue pigment cells described: Mandarinfish and spotted mandarin, 1995 (Before then, no blue pigment cells had been reported in any animal.) [4][7]
- Busiest night: A male mandarinfish, 8 spawns (The most spawns seen for one male in a single night, each with a different female.) [8]
- Short childhood at sea: Mandarinfish larva, ≈ 14 days (One of the shortest drifting larval stages known among sea fish that release floating eggs.) [14][9]

### Mandarinfish vs spotted mandarin vs ocellated dragonet

Three small, colourful dragonets that people often mix up.

| | Mandarinfish | Spotted mandarin | Ocellated dragonet |
|---|---|---|---|
| Scientific name [1][17][18] | Synchiropus splendidus | Synchiropus picturatus | Synchiropus ocellatus |
| Longest [1][17][18] | 7 cm | 7 cm | 8.9 cm |
| Colour [3][18] | Orange with wavy blue-green bands, green face | Light grey-green with ringed dark spots | A starry pattern of small spots |
| Blue pigment cells [4] | Yes | Yes | Not studied |
| Depth [1][17][18] | 1–18 m | Usually 0–20 m | 1–30 m |
| Habitat [1][17][18] | Sheltered lagoons and inshore reefs with coral and rubble | Rubble below living coral on sheltered reefs | Sandy lagoons, rubble, algal turf and tide pools |
| Where [1][17][18] | Ryukyu Islands to Australia | Philippines, eastern Indonesia, NW Australia | Indonesia to the Pitcairn Islands, Japan to Australia |
| IUCN Red List [1][17][18] | Least Concern | Least Concern | Least Concern |

In dragonets the first dorsal fin often differs between males and females, so it is better for telling the sex than the species. Check the body pattern instead.

### Is the mandarinfish endangered?

No. It is listed as Least Concern, but it is caught in large numbers for home aquariums, and that fishing is not managed.

- **IUCN Red List:** Least Concern (LC). The mandarinfish is listed as Least Concern. It has a wide range in the western Pacific and is fairly common where it lives. [1][3][19]
- IUCN Red List, assessed 2018
- **Threat: Aquarium collecting**: It is collected heavily in Southeast Asia, mainly the Philippines, for the aquarium trade, and the fishery is not managed. Because adults stay in one area, heavy fishing focused on one spot could hit local fish hard. [14][9]
- **Threat: Big males taken first**: Collectors target big males for their tall fins. Females left behind may have to spawn with smaller males that release less sperm. [10][11][14]
- **Threat: Hard to keep**: Many refuse anything but live copepods and amphipods, which makes wild-caught mandarinfish hard to keep in home aquariums. [3][2]
- **Helping: Captive breeding**: Scientists have reared larvae in the lab and found that copepods as a first food greatly improve survival. Farmed fish could take pressure off wild reefs. [9][15]
- **Helping: Well-connected populations**: A genetic study found that mandarinfish at five sites in the Philippines were well mixed, probably thanks to eggs and larvae drifting between reefs. [14]
- **Helping: Field research**: Studies of who spawns with whom show why leaving big males on the reef matters for the next generation. [8][10]
- **Spotted mandarin (Synchiropus picturatus)** (LC): The look-alike cousin that also has blue pigment cells; assessed in 2022. [17]
- **Ocellated dragonet (Synchiropus ocellatus)** (LC): A widespread, starry-patterned dragonet; assessed in 2022. [18]

### Looks

- **Male**: Orange with wavy blue-green bands, a green face with blue stripes and a tall orange-and-blue first dorsal fin. Males are larger than females, up to about 6 cm. (Big males win the most spawns) [1][2][3][10]
- **Female**: Same colours as the male but smaller, usually under 4 cm, with a low first dorsal fin. Shown here at male size. (Spawns at most once a night) [2][8][10]
- **Red form**: A rare colour form with a bright red background where the usual form is orange. Same species, same blue bands. (Same species, different colour) [1][3]
- **Spotted mandarin (look-alike)**: A separate species, Synchiropus picturatus. Pale grey-green with dark spots ringed in orange and blue. It also has blue pigment cells. (Hides in rubble below living coral) [17][4][3]

### Mandarinfish quiz

1. What makes the mandarinfish's blue colour special? **It comes from real blue pigment cells.** Its skin has blue pigment cells called cyanophores. Most blue animals use light-reflecting crystals instead. [4]
2. What did scientists name the mandarinfish's blue pigment cells? **Cyanophores.** Goda and Fujii named them cyanophores in 1995, from the Greek for 'blue carrier'. [4]
3. What covers a mandarinfish's skin instead of scales? **Bitter, smelly slime.** It has no scales. A thick, bitter slime coats the skin and probably puts predators off. [2][3]
4. When do mandarinfish spawn? **Around sunset.** Pairs rise to spawn at dusk and into the early night, all year round. [2][13]
5. What does a spawning pair do? **Rise about a metre above the reef together.** The male and female line up and rise about a metre before releasing eggs and sperm. [2]
6. Who looks after mandarinfish eggs? **Nobody.** The eggs float away in the open water. The parents give no care. [2]
7. How many times can a male spawn in one night? **Up to 8 times.** Males can spawn up to 8 times a night, each time with a different female. Females spawn once at most. [8]
8. Which males do females prefer? **The biggest.** Females pick big males. In Palau, a female always chose a male bigger than herself. [10][11]
9. What do wild mandarinfish mainly eat? **Tiny crustaceans such as copepods.** Its small mouth picks off copepods, amphipods, ostracods, small worms and other tiny prey. [3][9]
10. What kind of fish is the mandarinfish? **A dragonet.** Despite the trade name 'mandarin goby', it belongs to the dragonet family, Callionymidae. [3]
11. How long do mandarinfish eggs take to hatch? **About 12 hours.** The tiny floating eggs hatch after about 12 hours. [2]
12. How did scientists in a field study tell individual mandarinfish apart? **By their unique body markings.** Each fish's stripes and spots are a little different, so they could be followed without being caught. [8][20]

### Sources (checked 2026-10-29)

1. [FishBase: Synchiropus splendidus, Mandarinfish (species summary).](https://www.fishbase.se/summary/Synchiropus-splendidus.html)
2. [Animal Diversity Web (University of Michigan): Synchiropus splendidus, mandarin-fish.](https://animaldiversity.org/accounts/Synchiropus_splendidus/)
3. [Wikipedia: Mandarinfish (Synchiropus splendidus).](https://en.wikipedia.org/wiki/Synchiropus_splendidus)
4. [Goda M, Fujii R (1995). Blue chromatophores in two species of callionymid fish. Zoological Science 12(6): 811–813.](https://doi.org/10.2108/zsj.12.811)
5. [Goda M, Fujiyoshi Y, Sugimoto M, Fujii R (2013). Novel dichromatic chromatophores in the integument of the mandarin fish Synchiropus splendidus. Biological Bulletin 224: 14–17.](https://doi.org/10.1086/BBLv224n1p14)
6. [Stervander M, Cresko WA (2021). A highly contiguous nuclear genome assembly of the mandarinfish Synchiropus splendidus (Syngnathiformes: Callionymidae). G3 11(12): jkab306.](https://pmc.ncbi.nlm.nih.gov/articles/PMC8664458/)
7. [KAKEN (Japan Society for the Promotion of Science): research project 06640888, Fujii R, chromatophores of poikilothermic vertebrates (1994–1995), project report.](https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06640888/)
8. [Sadovy de Mitcheson Y, Mitcheson G, Rasotto MB (2022). Mating system in a small pelagic spawner: field case study of the mandarinfish, Synchiropus splendidus. Environmental Biology of Fishes 105: 699–716.](https://doi.org/10.1007/s10641-022-01281-1)
9. [Sadovy Y, Mitcheson G, Rasotto MB (2001). Early development of the mandarinfish, Synchiropus splendidus (Callionymidae), with notes on its fishery and potential for culture. Aquarium Sciences and Conservation 3: 253–263.](https://doi.org/10.1023/A:1013168029479)
10. [Rasotto MB, Sadovy de Mitcheson Y, Mitcheson G (2010). Male body size predicts sperm number in the mandarinfish. Journal of Zoology 281: 161–167.](https://doi.org/10.1111/j.1469-7998.2009.00688.x)
11. [Practical Fishkeeping: Bigger mandarinfish produce more sperm (news report on Rasotto et al. 2010).](https://www.practicalfishkeeping.co.uk/fishkeeping-news/bigger-mandarinfish-produce-more-sperm/)
12. [Sadovy Y, Randall JE, Rasotto MB (2005). Skin structure in six dragonet species (Gobiesociformes; Callionymidae): interspecific differences in glandular cell types and mucus secretion. Journal of Fish Biology 66(5): 1411–1418.](https://doi.org/10.1111/j.0022-1112.2005.00692.x)
13. [Oregon Coast Aquarium: Mandarin goby.](https://aquarium.org/animals/mandarin-goby/)
14. [Leung PTY, Ma KY, Liu M, Planes S, Sadovy de Mitcheson Y (2020). Population genetic structure of a marine pelagic egg producer and popular marine aquarium species, the mandarinfish Synchiropus splendidus. Zoological Studies 59: e68.](https://pmc.ncbi.nlm.nih.gov/articles/PMC8181157/)
15. [Zeng C, Shao L, Ricketts A, Moorhead J (2018). The importance of copepods as live feed for larval rearing of the green mandarin fish Synchiropus splendidus. Aquaculture 491: 65–71.](https://researchonline.jcu.edu.au/53653/)
16. [Wikipedia: Callionymidae (dragonets).](https://en.wikipedia.org/wiki/Callionymidae)
17. [FishBase: Synchiropus picturatus, Picturesque dragonet (species summary).](https://www.fishbase.se/summary/Synchiropus-picturatus.html)
18. [FishBase: Synchiropus ocellatus, Ocellated dragonet (species summary).](https://www.fishbase.se/summary/Synchiropus-ocellatus.html)
19. [Wikidata: Synchiropus splendidus (Q77062), IUCN status Least Concern.](https://www.wikidata.org/wiki/Q77062)
20. [Dunkley K, Matchette SR, Hau CY, Drerup C, Holmes RB, Sadovy de Mitcheson Y, Herbert-Read JE (2025). Individual identification of bony fishes using unique body markings: implications and applications. Journal of Fish Biology.](https://pmc.ncbi.nlm.nih.gov/articles/PMC12861832/)

## Measurements & details

- **Length:** 6-8 cm
- **Weight:** 0.005-0.01 kg
- **Lifespan:** 2-4 years
- **Swim Speed:** 0.1 km/h
- **Maximum Depth:** 20 m
- **Water Type:** Saltwater

## Diet & Feeding

Mandarinfish are tiny hunters, mainly feasting on small worms and crustaceans found on the seabed.

- **Primary Foods:** Copepods, Amphipods, Small worms, Gastropod larvae
- **Foraging Method:** Foraging

## Ecological connections

- **Eaten by:** Red Lionfish (*Pterois volitans*) — Larger reef fish are opportunistic predators.
- **Shelter:** Staghorn Coral (*Acropora millepora*) — Hides among intricate coral branches.
- **Eats:** Japanese Rockpool Copepod (*Tigriopus japonicus*) — A primary food source for them.

## Traits

- [Wildlife](https://www.snappit.app/explore/traits/wildlife): Wildlife encompasses all undomesticated animal and plant life existing in their natural habitats.
- [Solitary](https://www.snappit.app/explore/traits/solitary): Solitary animals live alone for most of their lives, only interacting with others for mating or parental care.
- [Colorful](https://www.snappit.app/explore/traits/colorful): Colorful describes organisms or objects displaying a wide range of bright and distinct colors.
- [Piscivorous](https://www.snappit.app/explore/traits/piscivorous): Piscivorous organisms are animals that primarily subsist on a diet of fish.
- [Aquatic](https://www.snappit.app/explore/traits/aquatic): Aquatic habitats encompass environments where organisms live predominantly in water, including oceans, rivers, lakes, and wetlands.
- [Marine](https://www.snappit.app/explore/traits/marine): Marine habitats encompass all saltwater environments of the Earth's oceans, supporting an immense diversity of aquatic life.

## Collections

- [Fish](https://www.snappit.app/explore/collections/fish)

## Safety

**Danger:** 2/5 · Low

Watch quietly from a distance and never try to feed or chase wild animals.

## Frequently Asked Questions

### How to identify Mandarinfish?

Look at body shape, where the fins sit and their outline, mouth position, stripes and spots. Young fish and breeding adults can wear different patterns, and aquarium color varieties can look nothing like wild fish. Fish Identifier: upload a photo and compare the visible details.

### How long is Mandarinfish?

6-8 cm

### How much does Mandarinfish weigh?

0.005-0.01 kg

### How long does Mandarinfish live?

2-4 years

### What does Mandarinfish eat?

Mandarinfish are tiny hunters, mainly feasting on small worms and crustaceans found on the seabed.

### How fast can Mandarinfish swim?

0.1 km/h

### Where is Mandarinfish usually found?

Coral reefs

### How does Mandarinfish hunt?

Foraging

## More Fish

- [Rainbow Trout](https://www.snappit.app/explore/rainbow-trout) (*Oncorhynchus mykiss*)
- [Brown Trout](https://www.snappit.app/explore/brown-trout) (*Salmo trutta*)
- [Brook Trout](https://www.snappit.app/explore/brook-trout) (*Salvelinus fontinalis*)
- [Lake Trout](https://www.snappit.app/explore/lake-trout) (*Salvelinus namaycush*)

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Source: [Mandarinfish: Facts & Places to See — Snappit](https://www.snappit.app/explore/mandarinfish)