Tenuisentidae is a family of parasitic spiny-headed (or thorny-headed) worms. The family contains two genera, each with one species.
Paratenuisentis Bullock and Samuel, 1975
Tenuisentis Van Cleave, 1936
T. niloticus Was found infecting the small intestine of the African arowana (Heterotis niloticus). The species name niloticus derives from the species name of the host fish, also niloticus. It has also been found in the Egyptian Nile and River Sourou at Di, Sourou Province, Burkina Faso, Sudan and Mali. It has also been found in the electric catﬁsh Malapterurus electricus Lekki Lagoon, Lagos, Nigeria. The proboscis contains 16 (rarely 15) rows of hooks, each with 30–33 hooks with the average hook length per row being 1,105 um in the female and 993 um in the male. The hooks are not symmetrical in robustness dorso-ventrally but does contain similar length angles of curvature. The ventral hooks were considerably larger and more recurved than the dorsal hooks. The males have cement glands between 6.62 and 6.92 mm long. There are 86–146 nuclei.
Worms of the Tenuisentidae family exclusively parasitize fish.
The European eel is a hosta of P. ambiguus
The African arowana is a host of T. niloticus