Hedruris spinigera is a parasite belong to phylum Nematoda, commonly found in the stomach of freshwater fish.

The female Hedruris spinigera attaches itself onto the epithelium of the fishes' stomach using a hook at the curved tail.

Although most fishes consume Paracorophium excavatum, Hedruris spinigera actually distribute in only a limited host range.

The infection site in the adult worm occurs at the stomach where the female attaches to, but parasite could also be free-living as found in rectum and intestine of fishes.

As for immature Hedruris spinigera, the site of infection occurs at hemocoelomic cavity, where the worms are coiled but not encysted.