The genus Thayeria is used to group several species of tetra

Tetra

thumb|right|250px|Pristella tetra — [[Pristella maxillaris]].thumb|right|250px|Golden Pristella tetra, a [[morph |morph]] of [[Pristella maxillaris]].thumb|right|250px|[[Silvertip tetra]] — Hasemania nana....

s, including the blackline penguinfish, Thayeria boehlkei. These fish, among other characteristics, are small, have one lateral black stripe, and have a vesica piscis

Vesica piscis

The vesica piscis is a shape that is the intersection of two circles with the same radius, intersecting in such a way that the center of each circle lies on the circumference of the other. The name literally means the "bladder of a fish" in Latin...

 shape. Penguin Tetra are peaceful creatures.

Species

• Blackline penguinfish, Thayeria boehlkei
  Thayeria boehlkei
  Thayeria boehlkei is a species of characin fish endemic to the Amazon river basin and Araguaia river, in Peru and Brazil respectively. The species is popular with aquarium hobbyists where it is traded under a variety of common names including blackline penguinfish, blackline Thayeria, hockey-stick...
  
  (Weitzman, 1957).
• Thayeria ifati (Géry, 1959).
• Penguinfish, Thayeria obliqua (Eigenmann
  Carl H. Eigenmann
  Carl H. Eigenmann was an ichthyologist who, along with his wife Rosa Smith Eigenmann, described many of the fishes of North America and South America for the first time....
  
  , 1908).

Location and habitat

Thayeria

Thayeria

The genus Thayeria is used to group several species of tetras, including the blackline penguinfish, Thayeria boehlkei. These fish, among other characteristics, are small, have one lateral black stripe, and have a vesica piscis shape...

inhabits small streams and the margins of smaller rivers in the Amazon Basin

Amazon Basin

The Amazon Basin is the part of South America drained by the Amazon River and its tributaries that drains an area of about , or roughly 40 percent of South America. The basin is located in the countries of Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, and Venezuela...

 of lowland Amazonia, where its is part of the highly diverse Neotropical fish

Neotropical fishes

The freshwater fishes of tropical South and Central America represent one of the most diverse aquatic ecosystems on Earth, with more than 5,600 species, representing about 10% all living vertebrate species...

fauna.