When discovered, the rainforest in which it occurs was unprotected and threatened by deforestation, but a private nature reserve has since been established.

The first species of the genus, T. longipinnis, was described in 1983 from a very local population discovered in a remnant rainforest between the major cities Rio de Janeiro and São Paulo.

[2] T. claviger was discovered in 2010 by biologists during an assessment for environmental licensing purposes in an remnant rainforest in Castelo, Espírito Santo, some 1200 km northeast of the T. longipinnis population.

The species description was published later in 2010 by the Brazilian ichthyologist Mário C. C. de Pinna and colleagues.

[4][5] The specific name claviger is Latin for 'club-bearing' and refers to the distinctive club-shaped hind part of the operculum seen in males.

Within its family, the Trichomycteridae (pencil catfishes), the genus Trichogenes is basal ("primitive") because of its many plesiomorphic (ancestral) features.

[8] The genus is most closely related to the Copionodontinae, which are endemic to the Chapada Diamantina plateau in northeastern Brazil.

[2] T. claviger is a small fish; 18 collected specimens were between 15.9 and 50.8 mm in standard length (measured from the snout to the end of the vertebral column).

[2] The mouth is terminal (facing forwards rather than being upturned or downturned), a trait also found in T. beagle but absent in all other members of their family.

The lateral line is short, consisting of a succession of four or five tubules that reaches from the back of the head up to the level of the rear margin of the pectoral fin.

[2] T. claviger is a local endemic of the Atlantic Forest, the second largest rainforest of the Americas, and one of the most biodiverse regions in the world.

[2] The conspicuous opercular process is short in females but elongated in males, and therefore sexually dimorphic – the only known secondary sex characteristic in the Trichomycteridae.

Visual perception appears to be important in Trichogenes species, and the related T. longipinnis has been demonstrated to rely solely on sight to detect prey.

Several other neotropical freshwater fishes also have a movable black-tipped structure somewhere along the body; this feature therefore evolved independently several times.

[8] T. claviger has been classified as Critically Endangered globally by the International Union for Conservation of Nature (IUCN) since 2018.

[1] The main threats are its extremely small range and the ongoing deforestation, as this species depends on forests.

[13] From 2011, the nonprofit organization SAVE Brasil pushed for a large public nature reserve in the Caetés forest.

In 2021, the Marcos Daniel Institute, supported by several nonprofits, acquired 6.67 km² of the Forno Grande farm to create a second private reserve, the Reserva Kaetés, this time including the type locality of T.

[6] The entire Caetés forest was also included in the Pedra Azul–Forno Grande ecological corridor, a priority area for conservation recognized by the state.