Marine Betta

Looks how to spot one

Deep-bodied fish with very large, flowing fins

A dark brownish-black fish covered in tiny pale blue to white dots, with huge, rounded fins that flow like a cape. A blue-ringed black eyespot sits near the back of the dorsal fin, and there are yellowish spots at the top of the tail base.13

Personality what they are like

Calm, patient and peaceful toward fish too large to eat. It is a stalking predator by nature, so small fish and shrimp are best kept elsewhere.32

Daily activity how busy a day looks

Nocturnal. It rests in caves and under ledges by day and becomes more active around dusk and at night.123

Grooming and care the hands-on bits

Provide shaded caves and hiding places away from bright light. Live foods may help a newcomer start eating; once settled it usually takes meaty frozen foods 2 to 4 times a week.32

Home where they are happiest

Minimum about 50 US gallons (189 L) with caves and dim hiding spots. Saltwater at about 22 to 26 °C (72 to 78 °F), pH 8.1 to 8.4, dKH 8 to 12, specific gravity 1.020 to 1.025.3

Food basics what goes in the bowl

Carnivore. Wild fish hunt small fish and crustaceans; in the aquarium offer meaty and frozen preparations.23

Company who they like around

Usually kept singly with peaceful tankmates that are too big to be eaten and not so fast that they outcompete it at feeding time.32

The story where it all began

Franz Steindachner described the species in 1903 as Plesiops altivelis. J.L.B. Smith later described the same fish as Barrosia barrosi in 1952, a name now treated as a synonym. It has been bred successfully in captivity.2

Recognised by the official bits

IUCN Red List

Least Concern (assessed 2019)1