Described from the Orinoco river basin, it was found solely to be hosted by individuals of the Characiform fish species Bryconops giacopinii.

Mature females are largely gill parasites, and males are planktonic and free-swimming, as well as the young.

[1] Ergasilus is a remarkably speciose genus with nearly 200 species named and accepted.

This is in reference to the unique brevity of the exopod associated with the fourth swimming leg.

[3] Ergasilids attach to a host by way of a specialized claw on the tip of their second pair of antennae, and members of Ergasilus specifically consume gill tissue, which includes blood, mucus, and gill epithelium.

[14] It can also make the fish in question overproduce gill mucus as an immune response, further interfering with proper oxygen intake.