Species Name: Polynemus paradiseus

Common Name: Paradise Threadfin

Size: Around 30 cm in nature; possibly smaller in captivity.

pH: 8-8.5

Minimum Recommended Tank Size: As long and wide as possible. I would say a minimum of 75 gallon for 1 or 2 individuals.

Native Location: Brackish and fresh waters of Indonesia and Thailand.

Temperature: Seems to tolerate a wide range but quite happy at 80-82 degrees F

Diet: The fish is quite a picky eater at first requesting only live foods like blackworms and live brine shrimp. After acclimated, they will accept most meaty foods like frozen krill, mysis, bloodworms, plankton and brine shrimp. Still, live blackworms seem to be a favortie food.

Breeding: Not reported in the home aquarium.

Gender Differences: None reported

Aggression: Very peaceful and shy species better suited for a species only tank.

Notes: A spectacular fish to keep although very hard and considered by many impossible to keep. It is a very poor shipper as most arrive DOA or die a few days after arrival. The slight percent that survive then face a long recovery.
Despite all the negatives, it is a fish I decided to deal with anyway and have not regretted it. I am still looking for more to add to the tank as I have a 125 gallon tank devoted to them. The tank is set up with sea salt added at 1 Tbsp per 5 gallons and no substrate. Filtration is via wet-dry filter and there is heavy aeration in the tank and in the filter. Water is always kept very hard by adding crushed coral to the sump and by adding calcium/mineral blocks to the tank as needed.
They have extremely long filaments which get damaged easily in cramped quarters. The fish also get extremely jumpy and anxious when unable to swim freely as they are ALWAYS on the move, never stopping once to rest or sleep like most other fishes.

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