At least two species originally termed "H. robusta" are present at the same locality, the Sacramento River at the Sacramento Fairgrounds Bely, AE and Weisblat, DA (2006).
At least two species originally termed "H. robusta" are present at the same locality, the Sacramento River at the Sacramento Fairgrounds. Another closely related leech is now called "Helobdella sp. (Austin)" Bely, AE and Weisblat, DA (2006).