Nathan Everett Pearson was member of an major Expedition in Bolivia called the Mulford Expedition named after the sponsor.

The Mulford Expedition of 1921–1922 was organized by Henry Hurd Rusby to explore the Amazon Valley from the headwaters of the Quime River in Bolivia to the mouth of the Amazon in Brazil. The expedition arrived in Bolivia in July 1921 and began collecting high in the Andes, just south of La Paz. Using balsa-wood rafts, they moved down the Bopi River, stopping for weeks at a time to collect in Huacho and Rurrenabaque. The end of the expedition was 8 months later. They never reached the mouth of the Amazon.

During that scientific survey, that was mainly set up to learn more about botanic plant organisms, the Trigonectes rogoaguae was discovered.

The species was never seen alive after its original discovery.

As far as I know no new collecting was done afterwards and so the species is not available to hobbyists. 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.

The species was found around Lago rogoagua and named after that lake that makes it difficult for western people to pronounce its name without stottering.

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 :

Max. size 5.5 cm.
Dorsal 9.6,
Anal 15.3,
D/A 9.5,
LL scale count (average)34.0
Pre- dorsal length to % SL – 77.3 %
Depth to % SL – 19.6 %