Synchiropus splendidusMandarin-fish

Geographic Range

Synchiropus splendidus is found in much of the western Pacific including the Philippines, Indonesia, Hong Kong, Australia, and New Guinea (Delbeek, 1989). These fish are also found in the Ryukyu Islands (Randall et al. 1990). Outside of its native range, S. splendidus is primarly a marine aquarium fish (Sandovy et al. 2001). (Delbeek, 1989; Randall, et al., 1990; Sadovy, et al., 2001)


Mandarin fish are tropical, marine fish found in waters with a temperature range of 24 to 26ºC. They are bottom dwelling, found at depths up to 18 m (Randall et al. 1990). During spawning they are pelagic and are seen in the open ocean (Sadovy et al, 2001). Mandarin fish are found on coral reefs and shallow lagoons hidden under foliose and dead coral (Randall et al. 1990). It is difficult to maintain mandarin fish in captivity because of their dietary requirements (Sadovy et al, 2001). (Randall, et al., 1990; Sadovy, et al., 2001)

  • Aquatic Biomes
  • reef
  • Range depth
    1 to 18 m
    3.28 to 59.06 ft

Physical Description

Mandarin fish are distinctive due to their unusual shape and intense coloration. They have a broad, depressed head and are primarily blue with orange, red, and yellow wavy lines (Delbeek 1989). Mandarin fish are small, reaching a maximum length of 6 cm. Males are notably larger than females (Sadovy et al. 2001). Mandarin fish lack scales and instead have a thick mucus coating that has an unpleasant smell (Sandovy et al. 2005). They have 4 dorsal spines, 8 dorsal soft rays, and no anal spines. In males, the first dorsal spine is greatly elongated, sometimes long enough to reach the caudal peduncle (Delbeek 1989). (Delbeek, 1989; Sadovy, et al., 2001; Sadovy, et al., 2004)

  • Sexual Dimorphism
  • male larger
  • Range length
    .02 to 6 cm
    0.01 to 2.36 in


Mandarin fish have a short incubation time and larvae that are small and develop quickly. Clutch sizes range from 12 to 205. Eggs measure from 0.7 to 0.8 mm in diameter, are colorless, spherical, and pelagic. The eggs at first are clumped together and then slowly break up into smaller units. The eyes become pigmented and the mouth becomes well developed 36 hours after fertilization. During the flexion stage, which occurs after 8 to 11 days, the caudal fins become distinctive, the pelvic fin rays move distally and the body becomes robust. The larvae are active and feeding at this stage. After 12 to 14 days, which is the settlement stage, juveniles look like the adults with a large head,and a triangular shaped body. In 18 to 21 days, the body darkens to an orange brown color with greenish banding and the dorsal spines are observed. The adult color pattern does not develop until the second month when lengths are from 10 to 15 mm. The swim bladder is retained in adults (Sadovy et al. 2001). (Sadovy, et al., 2004)


Spawning occurs on areas of the reef where small groups of males and females gather during the night. Mating occurs when the male and the female release sperm and eggs after they align themselves and rise about a meter above the reef. Each female spawns only once each night and may go without spawning for a few days. Since there are few active females, there is much competition amoung the males. The larger and stronger males tend to mate more frequently because there seems to be a sexual preference by the females for larger males (Sadovy, 2001). (Sadovy, 2001)

Mandarin fish are pelagic spawners. External fertilization occurs when a male and female are in close contact and swimming upward. Spawning occurs at about weekly intervals where up to 200 eggs are released. This occurs for several months (Delbreek, 1989) Mandarin fish breed year round. The population doubling time is less than 15 months (Randall, 1990). (Delbeek, 1989; Randall, et al., 1990)

  • Breeding interval
    Breeding can occur weekly throughout the year.
  • Breeding season
    Breeding occurs year round.
  • Range number of offspring
    200 (high)
  • Average time to hatching
    12 hours

Mandarin fish have no parental involvement after release and fertilization of eggs.

  • Parental Investment
  • no parental involvement
  • pre-fertilization
    • provisioning


In the wild mandarin fish are expected to live between 10 to 15 years (Sale, 2002). In captivity, however the lifespan is greatly reduced due to dietary requirements. On average, mandarin fish live between 2 to 4 years in captivity (Delbeek, 1989). (Delbeek, 1989; Sale, 2002)

  • Typical lifespan
    Status: wild
    10 to 15 years
  • Typical lifespan
    Status: captivity
    2 to 4 years


Mandarin fish are slow, shy, and mostly passive. They have large fan-like pelvic fins which are used often to walk along the bottom. Mandarin fish are found usually in groups or in pairs on reefs. In captivity, mandarin fish are rather intolerant of conspecifics. Two males will not survive together in an aquarium due to their agressive behavior towards each other (Delbeek 1989). During daylight hours, mandarin fish move along coral branches or hide in their home crevices (Sadovy et al. 2004). (Delbeek, 1989; Sadovy, et al., 2004)

Home Range

There was no information found pertaining to the home range of mandarin fish.

Communication and Perception

Mandarin fish secrete mucous that has an unpleasant smell and a bitter taste. They also have a layer of sacciform cells on the skin which produce and release substances with some toxins. It is suggested that this secretion is used as a repellent from predators and other competitive fish. The significance of the vibrant display of colors of the species is not known. However, it probably makes them highly conspicuous when feeding and mating and may be an aposematic warning (Sadovy et al. 2005). (Sadovy, et al., 2004)

Food Habits

Mandarin fish feed on the bottom. They eat small crustaceans such as amphipods and isopods, small worms and protozoans. Much of its food intake is found living in the reefs and other live rock. If there is a substantial amount of live rock, mandarin fish do not need any other outside source for food. In captivity, the fish usually do not eat prepared food, therefore it becomes difficult to maintain them. They need a great supply of live rock to feed. Mandarin fish have a relatively small mouth, therefore they eat only small food items (Delbeek 1989). (Delbeek, 1989)

  • Animal Foods
  • aquatic or marine worms
  • Other Foods
  • microbes


Mandarin fish secrete mucous which might act to repel predators. The intense coloration also might play a role in avoiding predation by signalling to potential predators that they are toxic (Sadovy et al. 2005). Early development could possibly be an adaptive strategy to reduce the risk of predation (Sadovy et al, 2001). There is no available information on specific predators of the species. (Sadovy, et al., 2001; Sadovy, et al., 2004)

Ecosystem Roles

Mandarin fish eat small invertebrates (Sadovy et al. 2004). Beyond this, little is known of the role of mandarin fish in the ecosystem. (Sadovy, et al., 2004)

Economic Importance for Humans: Positive

The vibrant display colors of mandarin fish make them valuable fish for the aquarium trade (Sadovy, 2001). The aquarium trade of mandarin fish plays a part in the local economies of the Phillipines and Hong Kong. These fish are also used as food in many Asian countries (Sadovy, 2001). (Sadovy, 2001; Sadovy, et al., 2001)

Economic Importance for Humans: Negative

There are no known adverse effects of S. splendidus on humans.

Conservation Status

Mandarin fish do not have any special conservation status currently (Randall, 1990). (Randall, et al., 1990)


Tanya Dewey (editor), Animal Diversity Web.

Komal Patel (author), University of Michigan-Ann Arbor, Kevin Wehrly (editor, instructor), University of Michigan-Ann Arbor.



Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

World Map

Pacific Ocean

body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


an animal that mainly eats meat


uses smells or other chemicals to communicate

  1. active during the day, 2. lasting for one day.

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

external fertilization

fertilization takes place outside the female's body


union of egg and spermatozoan


A substance that provides both nutrients and energy to a living thing.


having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.


offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).


A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.


having the capacity to move from one place to another.


specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.


an animal that mainly eats all kinds of things, including plants and animals


found in the oriental region of the world. In other words, India and southeast Asia.

World Map


reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

pet trade

the business of buying and selling animals for people to keep in their homes as pets.


the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.


structure produced by the calcium carbonate skeletons of coral polyps (Class Anthozoa). Coral reefs are found in warm, shallow oceans with low nutrient availability. They form the basis for rich communities of other invertebrates, plants, fish, and protists. The polyps live only on the reef surface. Because they depend on symbiotic photosynthetic algae, zooxanthellae, they cannot live where light does not penetrate.

saltwater or marine

mainly lives in oceans, seas, or other bodies of salt water.


remains in the same area


reproduction that includes combining the genetic contribution of two individuals, a male and a female


associates with others of its species; forms social groups.


lives alone


uses touch to communicate


defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement


the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.


uses sight to communicate

year-round breeding

breeding takes place throughout the year


Delbeek, C. 1989. The Mandarin Fish: Synchiropus splendidus. Seascope.

Randall, J., A. G.R, S. R.C. 1990. "Fishbase" (On-line). Accessed October 11, 2005 at

Sadovy, Y., J. Randall, M. Raotto. 2004. Skin structure in six dragonet species (Gobiesociformes; Callionymidae): interspecific differences in glandular cell types and mucus secretion.. Journal of Fish Biology, 66: 1411-1418. Accessed October 11, 2005 at

Sadovy, Y. 2001. When being female is better. Porcupine, 23. Accessed October 16, 2005 at

Sadovy, Y., G. Mitcheson, M. Rasotto. 2001. Early development of the mandarinfish, Synchiropus splendidu (Callionymidae), with notes on its fishery and potential for culture.. Aquarium Sciences and Conservation, 3: 253-263.

Sale, P. 2002. Coral Reef Fishes : dynamics and diversity in a complex ecosystem. San Diego, CA: Academic Press.