Fish, Tanks and Ponds


Fish, Tanks and Ponds
A comprehensive guide to fish

Dragonets

Family Callionymidae

Mandarin goby, Synchiropus splendidus
Mandarin goby, Synchiropus splendidus

Introduction:

Closely related to gobies and commonly erroneously called gobies, dragonets are a peaceful, reef friendly, playful, benthic fish that is a greatly prized and highly desired fish. Unfortunately their own unique beauty comes at a high price as they are very fussy eaters and often parish from starvation within the captive environment. Although physically hardy and disease resistant, the feeding requirements for members of the Dragonet family make them a poor choice for most aquariums, especially new or small tanks.

When choosing a dragonet for your tank, it’s extremely important to ensure that you pick only the healthiest specimens you can find. Often they are brought into the LFS with sunken stomachs, poor or excessively bright colouration or damaged fins, which should be avoided at all costs because the likelihood of recovering the specimen is very slim.

Habitat and Behaviour:

The skin of a dragonet is scale less, to compensate for that they have a think slimy coating. This slime coating is used as protection against parasites and has a foul taste, and is potentially poisonous to protect them from being eaten by other fish. In addition to this slime coating, most dragonets have a spine on the front of the operculum for additional protection.

Dragonets best kept in a mature reef tank type environment with plenty of live rock and a sandy bottom. Most dragonets prefer to spend most of their time on the sand and will often burry themselves when startled or at night. Provide plenty of places for the Dragonet to hide from other fish. They are reef friendly and will not pick on any corals or larger invertebrates.

Although Dragonets generally remain on the bottom of the tank, if startled they can jump out of the tank, make sure the tank is well covered.

Dragonets are benthic creatures that occupy a very small territorial range in the wild. They are very protective of their small territories against the invasion of another dragonet and will only venture outside their usual range for breeding purposes. Due to their territorial nature only one dragonet should be kept in a tank unless it’s a very large tank, in which case a pair consisting of one male and one female will be acceptable. Having two males in the same tank will result in aggressiveness and territorial disputes, possibly resulting in the death of one or both fish.

Feeding:

These slow fussy eaters are one of the hardest types of fish to feed within the trade. A disproportional number of dragonets perish due to slow starvation. They require a mature tank, at least one year old, with a self-sustaining population of small benthic crustaceans, mainly pods, and worms. There should be a minimum of 80 pounds of live rock per individual dragonet along with no other tank mates that will compete with them for the pods within the tank. A refugium should also be considered essential to insure a sustained population of pods for the dragonets to feed upon.

Occasionally there have been reports of some dragonets adapting to feeding on live baby brine shrimp or frozen and prepared foods, however this is very rare and the diet still wont provide enough nutrition to sustain the dragonet over the long term. Dragonets will also occasionally graze on algae off of the live rock, however algae alone wont sustain them.

Disease:

Dragonets have a thick slimy coating that helps protect them from external parasites. However should they become infected, they are extremely sensitive to copper, metal-based or formalin based meditations. The best way to treat a dragonet is through environmental controls such as temperature increases and salinity alterations.

Breeding:

Males can be told apart from females from their larger size and much longer dorsal fin. Captive raised dragonets have not yet been accomplished although there have been a lot of reported spawning. The difficult part of rearing dragonets is similar to that of all marine fish, the fry go through a planktonic stage that is nearly impossible to sustain in our current tanks.

Common Species:

Callionymus

C. lyra
This fairly drab looking dragonet is referred to as the Common dragonet. It's commonly found in sandy areas of the east Atlantic and Mediterranean. They grow to a maximum of 2 inches in length.

Dactylopus

D. dactylopus
Commonly called the Finger Dragonet, it is not often seen in the trade however is slowly becoming more popular. In the wild they are one of the few species of dragonets that are commonly found in the tall sea grasses and among coral reef areas. They grow to a maximum of 3 inches.

Synchiropus

Scooter Blenny S. ocellatus
Often referred to as a Scooter Blenny or scooter dragonet. They are fairly common in the trade. Blends in with the rockwork really well, don’t live long in captivity unless in a well established tank. They grow to 2.5 inches in length
Green Spotted Mandarin Goby This is the most difficult of the group, it needs a large mature reef tank so that it will have access to sufficient food.

S. picturatus
This is the second most popular Dragonet commonly referred to as the Green Spotted Mandarin Goby. Often seen in the hobby. Males have elongated dorsal fin. Only keep one male per tank.

Mandarin Goby S. splendidu
The most popular of all the Dragonets, commonly referred to as a Mandarin goby. They are most commonly exported from the Philippines. Occasionally red colour morphs are found as well. They grow to about 2.5 inches in length

Red Scooter Blenny, S. stellatus
Commonly referred to as the Red Scooter Blenny. Common name often causes confusion when it comes to the captive care of these bottom dwelling species. Requires live food. Often dies of starvation in a tank.

Glossary

 

References