2 Freshwater Tank Fish To Add To Your Tropical Community – C to D
Two freshwater tank fish are described here; the Congo tetra and the Croaking tetra. Discover their behavioral patterns, colors and any unusual physical features, temperature and water requirements, feeding likes and dislikes and optimal breeding conditions.
Congo Tetra – Micralestes interruptus (Family: Characidae)
Behavior
The Congo tetra is not an aggressive species and may grow to about 7.5 cms, with the female slightly smaller. Its is a fast swimmer that spends most of its time near the topof the tank
Water and Tank Conditions
Also known as the Rainbow characin this fish is alright in a temperature range of 23 to 27 degrees centigrade.
Features and Colors
This fish has brighter and larger eyes than usual. And another unusual feature is the caudal fin. The end of the fin looks more like a feather and shows up more with the male. These sometimes get damaged but will grow back so do not worry.
Colorwise, you will quite often see a yellow band along the flanks and at other times it will be purple and gold. Its back is a blue color with the main body green with scales that will look a different color depending on the angle you view them at; milky colors like an opal. This is called opalescence. And the property that shows different colors at different viewing angles is caled iridescence.
Feeding
Has no particular requirements so treat as a normal occupant.See below for feeding the fry.
Breeding Conditions
Not that easy to get them to spawn. Put them both in a small tank, divides into two (glass partition?) to keep them apart and feed them live food. Set up a breeding tank at about 25 degrees centigrade and make sure it is well planted. Put the male in first and the female hours later, say after a night.
Eggs will be found at the bottom end of the plants and you need to remove the fish straight away after spawning has taken place. At the above temperature fry will emerge after about seven days. These fry will be larger than other tetras and have a greater appetite so you can feed them more or less immediately with micro-worms and sieved freshly hatched brine shrimp.
Croaking Tetra – Glandulocauda inaequalis (Family: Characidae)
Behavior
This fish gets its name from the noise it makes when gulped air is expelled through its gills. You should see fine bubbles at the same time. Like the Congo tetra this freshwater tank fish hangs around near the top of the tank, feeding there also. Great for the community aquarium as its small, peaceful and will get on well with others .
Water and Tank Conditions
The Croaking tetra is affected by too large a change in water temperatures. Its optimal preference is between 20 and 23 degrees centigrade.
Features and Colors
The body color is blue and the anal, caudal and dorsal fins have white ends. Now and agin you will see dark green to yellow colors on all of the fins. Its is fairly easy to tell the differences between the male and female as the dorsal fin is rounded in the female but sharp ended in the male.
Feeding
Feeds at the top the tank and will accept all the usual fish food. See below for feeding the fry.
Breeding Conditions
This fish is not a regular breeder and it does take some work to raise the fry. A really well planted large breeding tank with shallow water at 25 degrees centigrade is required. Remove both fish after spawning and wait for about three days for the eggs to hatch.
Infusoria should be fed to the fry that will be on the small side. Give it about ten to fourteen days before micro-worms are tried. It has been reported that using tubed foods normally given to egg laying fish has been successful.
This article is one of a series on freshwater tank fish for the benefit of aquarists who can then decide which ones they would perfer to have in their community tank or in certain cases a species specific aquarium.
