Following its initial description in 1849, additional details were provided based on specimens from French Guiana in 1899, after which the species was largely forgotten for over 70 years.

One of these leeches, dubbed Grandma Moses, founded a successful breeding colony at UC Berkeley.

[4] Unlike jawed leeches who use rows of teeth to puncture skin, Haementeria ghilianii uses a 10 centimetres (3.9 in) hypodermic needle-like proboscis to feed.

[2][5] Blood is moved into the digestive system through a series of undulation movements, and leeches can go months without feeding.

[4] Haementeria ghilianii is endemic to the northern portions of the Amazon river, ranging from Venezuela and the Guianas.