The Mandarin dragonet (Synchiropus splendidus) is one of my favorite fish, and I know I’m not alone. Mandarins are a fan favorite when it comes to saltwater aquariums for their vibrant psychedelic patterns and friendly personalities. So when the team from Critter At Lembeh Resort suggested we go on a mandarin spawning dusk dive, our eye lit up and we couldn’t say no.
Every night around sunset mandarins venture out beneath branching coral rubble for some serious sexy time. A group of females scurries around the rubble while a large male guarding his territory, displays his colorful fins to attract a nearby mate.
The courtship lasts for an hour or more as the sun is setting. The male weaves in and out of the rubble circling above a group of females until suddenly you start to see an undulating dorsal fin. If the Mandarin is lucky a female will be receptive and join him jittering her fin until both fish are vibrating side by side in unison.
Suddenly the pair rises from the sea floor fluttering furiously toward the surface until poof, the magic is over and all that is left is a cloud of sperm and eggs. Hungry cardinals and damsels fish wait patiently to snatch up their nightly treat of freshly fertilized Mandarin eggs.
To avoid disturbing their natural behavior divers are given red flashlights, as white light would cause the mandarins to abort the mating ritual. We were able to capture some video of the event but without any lights, the footage is a little grainy and doesn’t quite do justice to how incredible it was to see this event in real life. The second half of the video is red, since we were only able to use red light not to disrupt their behavior.
If you want the opportunity to see this event in real life, nothing beats the experience in Sulawesi. The Mandarin here were exceptionally large and it’s almost guaranteed to catch them performing their nightly dance. We dove the Bianca dive site in Lembeh Straight to see the Mandarin spawning.
Should you find yourself in Sulawesi and want to see the Mandarin spawning it’s important to know that only a limited number of divers can visit the site each night and each dive centers have a set day for the drive. You will want to contact the dive center ahead of time to make sure they can accommodate the dive.