The Trigonectes balzanii was first described by Perugia in 1891 as Haplochilus balzanii till Myers (1925) placed it in the, than new erected, genus Trigonectes.

The type locality is Rio Paraguay at Villa Maria (today called Caseres, Lagoa da Imbauva), Mato Grosso, Brasil.

It was named in honor to Prof. L.Balzan, director of the Genova Museum. It is not clear if Prof. Balzan was also the dicoverer of the species. Ribeiro (1920) saw it as synonyme to Trigonectes rondoni but it is widely accepted as valid species.

As all other members of the Trigonectes family they can be found in open landscape with low bushes and in temporary waterbodies. Normally only in deadly waterbodies that have no current. The bottom is mostly build up out of clay in wich the species dives to burry their eggs. This gives us the knowledge the species does not like low pH values lower as neutral and low watertemperatures lower as 25 C. If they do not have any choise Trigonectes lay their eggs not deep into the spawning medium but it is likely they prefer diving into the bottom more than on the bottom. So they need a high container filled with soft material that is not reacting acid and is deep enough for their large body to dive in.

Unlike most other annual species that are no good jumpers Trigonectes can jump occasionally out of the water but it is not likely they jump from pool to pool to find new habitats like rivulus does.

There incubation period can vary between 5 and 12 months, even within one species and an regulary check for development is also needed.

Remarks :

Be aware.... Trigonectes balzanii is fast growing and during this period a preditor on smaller fish, also the youngsters that are growing less rapid become food. Mostly those are the females so males only remain if no action is taken.

Max. size 16.0 cm.
Dorsal 10.2,
Anal 15.2,
D/A 9.5,
LL scale count (average)34.8
Pre- dorsal length to % SL – 77.2 %
Depth to % SL – 23.1 %