Black Widow Tetra (Gymnocorymbus ternetzi)

Also known as Black Tetra or Black-skirt Tetra, the Black Widow Tetra is a hardy, lively character, who can be nippy with smaller fish, so is best housed in a community aquarium with peaceful larger species.  They are less likely to fin-nip if kept in a larger group of their own species (they will be preoccupied with each other rather than bothering other tank-mates).  They are found wild in Paraguay and nearby, in South America, mostly in small, slow moving rivers, streams, and tributaries that are well shaded.  They sometimes breed in a home aquarium, and will scatter eggs among plants and undergrowth.  They are very tolerant of a range of water parameters  and will eat anything, making them a perfect beginners’ fish.

Size (fully grown):  5.5cm (2.2″)

Water temperature: 21 – 26C

Water pH: 5.8 – 8.5