| Mimagoniates | |
|---|---|
 | |
| Blue tetra (Mimagoniates microlepis) | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Characiformes |
| Family: | Stevardiidae |
| Subfamily: | Glandulocaudinae |
| Genus: | Mimagoniates Regan, 1907 |
| Type species | |
| Mimagoniates barberi Regan, 1907 | |
| Synonyms [1] | |
| |
Mimagoniates is a genus of freshwater ray-finned fishes belonging to the family Stevardiidae. This species is found in rivers and streams in southeastern, southern and central-western Brazil, northeastern Argentina, and Paraguay. [2] [3] The individual species generally have relatively small ranges and two, M. lateralis and M. sylvicola, are considered threatened by Brazil's Ministry of the Environment. [4]
Commonly known as croaking tetra or chirping tetra because they can produce sounds, [5] some of these fish were historically included in Glandulocauda and together with Lophiobrycon they form the tribe Glandulocaudini. [3] Mimagoniates have a supplementary breathing organ located above the gills which makes a faint chirping sound when these fish come to the surface to gulp air. It also plays a role in courtship as the male chases and hovers near the female while taking gulps of air and expelling it to make a rhythmic noise. [5] Croaking behavior may have evolved from a behavior called "surface nipping", which occurs when the fish is searching for food. This gulping of air has no useful respiratory function. [6] They are small fish, up to 3–6.1 cm (1.2–2.4 in) in standard length depending on the exact species. [2]