Threadfin Cardinalfish
These little Cardinalfish can have an almost transparent body. Whilst other individuals are silvery yellow with some bright blue on their eyes and blue and yellow stripes between the eyes and pectoral fins. They’re recommended to keep in a groups as they naturally school together.
The Threadfin Cardinal is a hardy fish and so is a great choice for a beginner. They are a very peaceful and social fish and so it is actually recommended that they kept in a peaceful reef tank in a group of 5 or more other Threadfin Cardinalfish.
These fish are only small growing up to a size of around 6.5 cm.
These Cardinalfish are both reef safe and coral safe and won’t harass any snails, Starfish or crabs in the tank. inverts present in the tank. They are slower swimmers which makes them slower eaters as well and it’s not good to keep them with fish that will outcompete them for food.
These fish originate from the Red Sea around Mozambique Island right over to the east around Samoa and Tonga, then north up to Ryukyu Islands and south to New Caledonia and Micronesia. They are usually found in sheltered bays and lagoons in the wild.
Tank Recommendations for Threadfin Cardinalfish
If you are keeping one of these on it's own then a 38 litre tank would be large enough. As these fish are usually kept in a group of 5 or more then we’d recommend keeping them in at least a 114 litre tank.
The Threadfin Cardinalfish is both reef and coral safe and will appreciate some branchy stoney corals to linger around.
Suitable Tank Buddies
The Threadfin Cardinalfish is a very peaceful species and so should be kept with other passive fish. The usual advice as with all small fish is don’t house them with any larger predatory fish that can fit them in their mouths as they’re likely to become lunch.
Usually Compatible
As these fish aren’t aggressive and are also slow swimmers it does make them some of the few fish that are compatible to keep as tank mates with Pipefish and Seahorses. You can also keep them with Blennys, Gobies, Dragonettes, Filefish, Clownfish, Boxfish, Butterflyfish and Dwarf Angelfish without any issues.
Sometime Compatible
Large Angelfish, Hogfish, Rays, Tangs, Damsels, Wrasses and Pufferfish can sometimes be a problem. When kept with these the Cardinalfish can struggle to eat by the more aggressive fish.Incompatible Tank BuddiesTanks mates that you can’t keep with your Threadfin Cardinals are the usual suspects that would be very likely to eat them and those are Groupers, Sharks, Scorpionfish, Lionfish, Eels and Snappers.
Feeding Your Threadfin Cardinalfish
These fish are carnivores and so their diet should include a variety of live or frozen mysis or brine shrimp and feeding should occur 2-3 times a day.
You can also feed them chopped crustaceans and shredded fish. They will also happily take live copepods, they will also take small pellet foods.