Apparently a specialized inhabitant of deep riverine environments, T. marauna may be endangered by extensive dam construction in the upper Paraná region, if not already extinct.

[1] The three known specimens of T. marauna, two male and one female, were collected from the upper Paraná River at the border between the Brazilian states of Mato Grosso do Sul and São Paulo in 1965, during the construction of the coffer dam for the Ilha Solteira reservoir.

The most distinctive feature of T. marauna is a prominent fleshy (possibly cartilaginous) extension at the tip of the upper jaw, in which approximately 15 slender teeth are loosely embedded.

These structures are found in both sexes, suggesting that they are not involved in reproductive behaviors as in other knifefishes with accessory teeth (e.g. Sternarchogiton nattereri).

[2] No new specimens of T. marauna have surfaced in the fifty-some years since its initial discovery, during which time its native habitat has been extensively altered by dam construction.