Q. My husband and I have been maintaining a 75-gallon reef aquarium for about two years, and we read everything available on potential tank residents. I must add that your magazine has been most enjoyable and informative. One fish in particular which we fell head over heels for is the scooter blenny. We cannot seem to find out much about this adorable finned friend. Could you direct us to any back issues or could you please, please, please do an article on this fish? It would be greatly appreciated. Thank you.
A. The scooter dragonets are not blennies at all, but are members of the family Callionymidae, as are the striped (Synchiropus splendidus) and spotted (S. picturatus) mandarin dragonets. It is a relatively large family (the genus Synchiropus alone contains 26 species) whose members occur both in tropical and temperate regions around the globe. Unfortunately, some of the more outrageously colored species occur in colder seas and are never available to U.S. hobbyists.
Species are most easily separated by color pattern and the physical appearance of the large gill cover (“cheek”) spines. These spines are no doubt effective at dissuading smaller predators, and can easily become entangled in the mesh of a fish net. Therefore, when removing them from an aquarium it is best to herd them into a specimen container.
The dragonets are all sexually dimorphic, with males usually sporting more ornate colors and larger first dorsal fins. This fin is erected and spread wide when the male displays to females or rivals.
Unlike the mandarins, more than one male dragonet specimen can be kept in a medium-size aquarium. However, they should be introduced simultaneously. Scooters will display at each other and some chasing may occur, but they rarely inflict lethal damage like their cousins the mandarins will. If you want to keep more than one specimen, I would recommend keeping two or three females with a single male.
Dragonets feed on small crustaceans, shelled protozoans (foraminiferans) and annelid worms. I have seen adult specimens pull larger segmented worms out of live sand and suck them down like spaghetti, and on one occasion I observed a specimen ingest a small fireworm. These fish are easier to keep if you place them in a tank with live sand and live rock, which functions as the dragonets’ cafeteria. Do not be surprised if your dragonet buries under the sand when threatened, or at night.
If placed in a tank without living substrate, you will have to make sure that food gets to the bottom. In an aquarium with lots of aggressive feeders this can be difficult, because most food will be consumed before the more meticulous dragonet has a chance to ingest it. You can use a long pipette, rigid air line tubing or a turkey baster (that is used only for feeding your fish) to deposit food near the substrate where it has a better chance of becoming the dragonet’s supper.
These fish have been known to spawn in captivity, commencing their courtship behavior just before the lights go out. The male will display for and follow the female, and then suddenly they will dash up in the water column and shed eggs and sperm. Although I am not aware of anyone who has raised scooter larvae, there are reports of mandarin dragonets having been successfully reared.
The species most frequently seen in aquarium stores is Synchiropus ocellatus, which occurs in the west and central Pacific. It attains about 3 inches in length. The less common and more pricey (it usually costs around four times as much as its less colorful cousin) red scooter dragonet (S. stellatus) ranges from East Africa to Sri Lanka. It reaches about the same maximum length as S. ocellatus, but smaller individuals are more frequently imported.
The finger dragonet (Dactylopus dactylopus) is also occasionally seen at aquarium shops. This species is colored for camouflage, has a more elongate body, large pectoral fins and one to several very high (about half of the body length) dorsal spines at the front. It attains a maximum length of 7 inches. I have found this species to be less hardy than the other dragonets.