Pseudosphromenus cupanus

The spiketail paradise fish lives in shallow, likely murky waters in Sri Lanka, southern India, Bangladesh, Myanmar and Malaysia. Like many anabantoids, it can absord oxygen from air through its labyrinth organ, so is able to live in oxygen-depleted waters like marshes, rice paddies and ditches.

IUCN lists it as 'least concern'.

If you have information about or footage of this fish in the wild, please reach out to us.

When I saw this fish for sale, I did not hesitate. I have a weak spot for labyrinth fish, and though I do not have the soft water the often require, I wanted to give it a try. I acquired five and homed them in a small tank of 30*30 cm with about 20 cm of water in it (18 liter). Overnight, one fish jumped and died, so I lowered the water level. The other four were very, very shy at first and hard to feed (or hard to catch eating anyway). About a month later, they eat everything and know to come to the glass in a specific corner of the tank when I get nearby, in an effort to beg.

In November 2022, two of the fish paired off and the male built a bubble nest below a floating oak leaf. They mated and spawned exactly like bettas: embrace, release of eggs, collection of eggs, putting eggs in bubbles, warding off other fish, etc. Footage here.

In January 2023, I undertook a more considered breeding attempt. I did this the exact same way I breed Betta spendens, minus the separation of the sexes. Needed: small tank or plastic container with a lid (5 liters of so suffices); small heater; some Indian almond leaves or a domestic alternative like oak; frozen or live food to condition.

Like many fish, P. cupanus seems to be triggered by a water change. I did a tank change, to much the same effect: from the main tank, which contains two pairs, I collected, with some luck, one pair. These were transfered to a plastic 40 x 20 container with about 8 cm of water in it. The water was a mix of their original tank water and water from the reservoir of my dehumidifier, which is less hard. It also was one of two degrees warmer. After about one day, the male started to build his bubble nest. Most online sources of information list this fish as a 'secretive bubblenester'. I have not found it to be one, or not necessarily so, anyway. In my container it had this choice of real estate: sunken oak leaves, floating catappa leaves, live water plants. It chose none and just bubbled in the rounded corner of the container. The next morning I noticed a handful of eggs in it, and in the afternoon a few dozen.