Circled Dragonet (Synchiropus circularis) Care Guide
Synchiropus circularis is a small Western Pacific dragonet of sand-rubble bottoms on seaward reefs, a benthic invertebrate feeder.
Compiled by Aquairi from published sources · Published · Updated
Overview
Synchiropus circularis, the circled dragonet, was described by Fricke in 1984. It is a small dragonet of the family Callionymidae from the Western Pacific. FishBase records a maximum standard length of about 2.3 cm.
Taxonomy
- Family: Callionymidae
- Genus: Synchiropus
- Scientific name: Synchiropus circularis Fricke, 1984
- Common names: Circled dragonet, circular dragonet
Habitat
According to FishBase, the species occurs in the Western Pacific, including Malaysia, Indonesia, the Philippines, Papua New Guinea, Guam, the Northern Marianas and the Chesterfield Islands. It inhabits sand-rubble bottoms on seaward reefs at depths of 2-35 m in tropical waters.
Tank requirements
- Minimum tank volume: 80 L (21 gal)
- Temperature: 24-26 °C (75-79 °F)
- pH: 8.1-8.4
- Carbonate hardness: 8-12 °dGH
- Maximum size: about 2.3 cm SL (FishBase)
- Lifespan: 4-10 years
- Requires a mature system with abundant live copepods
Diet
FishBase gives a trophic level of about 3.1, consistent with a small carnivore feeding on microscopic benthic prey. In aquaria dragonets graze continuously on copepods and other micro-fauna and depend on a mature, established system.
Compatibility
This is a peaceful, bottom-dwelling species. It is best kept with calm tankmates that do not compete for live food, and away from aggressive fishes and predators.
Conservation status
IUCN Red List: Least Concern (assessed 2022).
Synchiropus circularis Breeding Guide
Overview
Synchiropus circularis, the circled dragonet, is a small reef-associated dragonet of the family Callionymidae reaching about 2.3 cm standard length. It occurs in the western Pacific from Malaysia, Indonesia and the Philippines to Papua New Guinea, Guam, the Northern Marianas and the Chesterfield Islands, over sand-rubble bottoms at depths of 2 to 35 m in warm water around 28 to 29 °C. Like other dragonets it forages for small benthic invertebrates.
Sexing
Dragonets are sexually dimorphic, with males larger and bearing longer, more elaborate fins; display males flare these fins prominently. This is the practical basis for distinguishing the sexes, since no species-specific colour key is published for Synchiropus circularis.
Conditioning
As a benthic-invertebrate feeder this species relies on live copepods to reach breeding condition. A mature reef or refugium with self-sustaining pod populations is the practical means of conditioning a pair.
Spawning Behavior & Trigger
Dragonet spawning occurs in the late afternoon just before sunset. Following a courtship display in which both fish fan their pectoral and caudal fins and the male flares his dorsal fins, the pair ascends roughly 0.7 to 1.2 m up the water column, moving semicircularly with the pectoral fins, and releases eggs and milt near the top of the ascent.
Egg & Fry Care
The eggs are buoyant and pelagic, intermingling with plankton, and the parents give no care after spawning. In aquaria the eggs must be captured as they rise and the resulting planktonic larvae require extremely small first foods, so rearing has only been accomplished in specialist setups.
Common Challenges
Collecting floating eggs before filtration removes them and feeding the minute larvae are the central obstacles, together with sustaining the copepod density needed for broodstock and fry. Reproduction is therefore seldom documented beyond egg release for this species.