How do I breed Mandarins?


Dragonettes offer a great challenge for the marine fish breeder. Matt Pedersen has some advice to help you succeed.

Dragonettes of the genus Synchiropus are being spawned more frequently. I have spawned and attempted to rear the four most common species in the trade — S. splendidus, S. picturatus, S. ocellatus, and S. stellatus  — and all exhibit sexual dimorphism and/or dichromatism and the first dorsal fins vary in structure, size, shape and sometimes coloration.

Male S. splendidus and S. picturatus have an elongated first dorsal ray, provided it has not been damaged. Male S. ocellatus and S. stellatus have large, sail-like dorsal fins with scrawling and ocelli. Females have short black dorsal fins, sometimes edged in white.

Dragonettes pair easily. Select a male larger than the female and healthy, well fed pairs rarely quarrel. They require frequent daily feeds of quality frozen and prepared foods to attain spawning condition.

Those not trained on to prepared food, but left to fend for themselves are unlikely to ever come into spawning condition. All too often this simply leads to long-term starvation.

Taller tanks facilitate a rise in spawning and some breeders have cited short tanks as a possible cause of fertilisation problems. Synchiropus have been spawned in 45 l/10 gal tanks, but larger is recommended.

Pairs court and spawn around dusk, rising to the surface and releasing 50 to several hundred floating eggs. These can be skimmed from the surface, incubated separately and will hatch in 12 to 16 hours. Two to three days later larvae have developed eyes, mouths and gut, and start feeding.

Greenwater technique with rotifers has provided random successes as first foods, occasionally resulting in a couple of larvae per batch. Success improves when introducing copepod nauplii to the diet, as well as stringent enrichment protocols.  

Around two to three weeks, Synchiropus larvae settle to the bottom and start feeding on benthic fauna. Here too, copepods may play a vital role in early survival success. Brineshrimp nauplii are also taken. Over the next few weeks, the juveniles can be weaned onto prepared foods like crushed pellet foods.

It can take over a year for the juveniles to reach a marketable size.

This item was first published in the December 2009 issue of Practical Fishkeeping. It may not be reproduced without written permission.