Mandarin fish have got to be one of the most colourful and truly ornate looking fish that we see in the Indo-Pacific. During the day time, whilst we do have occasional sightings, these little critters lay low and hide within the branches of staghorn corals. During sunset however, they leave the reef and perform one of nature’s most magnificent and flamboyant of mating rituals. We run dedicated mandarin fish dives at Two Fish Lembeh and Two Fish Bunaken, timed for sunset. Here are some Mandarin fish facts which you may not know, followed by our hotspots for sightings.
Fun facts about mandarin fish
- Mandarin fish (Pterosynchiropus splendidus) are also known by several other common names, including the Mandarin Dragonet, Mandarin Goby, Green Mandarin fish, Striped Mandarin fish and the Psychedelic fish.
- These little beauties are a small species only reaching about 3 inches in length.
- This species is best known for its ritual reproduction mating “dance” which only occurs during sunset hours. Females will group together at the reef and seek a male mate. The males then begin to court the females, the bigger and stronger males are more likely to be chosen. Males also can reproduce with multiple females in a night. The male and female pair attach at the pelvic fin and swim to the top of the reef where they release the eggs and sperm in a cloud (about 200 eggs). Once the egg and sperm clouds have been released the pair part ways and the courtship ends. The fertilized eggs take only 18-24 hours to hatch into larvae, then after two weeks of drifting, they settle into the reef.
- Mandarin fish they are very picky eaters. They eat mainly small worms, protozoans, and small crustaceans. The majority of our mandarin fish dive sites have areas of sand and patches of staghorn (branching corals). These sites are ideal as they provide protective corals and food for the fish.
- Scorpionfish are one of their most known predators.
- One of the biggest threats to mandarin fish comes from mankind and the tropical fish tank industry in which they are highly prized. Individual fish can sell for up to USD $150 – it has also recently been proven that, like many fish, they live up to 4 times longer in the wild than they do in captivity.
- Did you know that these fish do not have scales? Instead, they secrete mucus from their skin, which helps repel predators and keep them clean from parasites. Also, their bright coloration is not for attracting a mate, instead, it is to mislead predators into believing that they may be toxic to consume.
- Bold Colours but not bold characters: Mandarin fish are actually very skittish and shy, so they prefer to avoid other fish. This makes our mandarin dive site in Lembeh quite unique as they are often spotted living quite harmoniously in the staghorn corals with pajama cardinalfish and the endemic Banggai cardinalfish.
Mandarin fish in Lembeh
The best dive site is at Police Pier (aka Bianca) which is directly across the Lembeh Strait from Two Fish Divers Lembeh Resort and just 5 minutes by boat. We use this site as it is very reliable and we often see the fish mating.
The dive boat leaves at 16:30 and the dive is 60 minutes, with most of the time being spent in front of a large patch of staghorn coral waiting for the fish to come out and mate. There are also sightings of pipefish, octopus and plenty of nudibranch to keep you entertained while you wait for the mating ritual.
If Police Pier is busy there are also a couple of other dive sites where we dive, but did you know that at Two Fish Lembeh we also have a few mandarin fish on our house reef so you can go also searching for them any evening in your free time!
Mandarin fish in Bunaken
At Two Fish Divers on Bunaken Island we see Mandarin fish at our Subsea dive site. It is a shallow dive in a lagoon where we often stay at 6m for 45-60 minutes. At the right time of the month, usually around the new moon, we see 10-15 mandarin fish mating or fighting and this usually happens around dusk so we depart at 16:30 and dive between 17:00 and 18:00. If you haven’t seen Mandarin fish before, or love this critter, it is a great opportunity to spend a whole hour with a “bucket list” species.
Want to see the mandarin fish mating ritual for yourself?
We run these dives at sunset from Two Fish Lembeh and Two Fish Bunaken. Tell us when you are travelling and we will build it into your trip — and check our current offers before you book.
