One endangered parasitic variety, the Morrison Creek lamprey (Lampetra richardsoni var. marifuga), is unique to Morrison Creek, Vancouver Island, British Columbia. Which is larger in size (15 – 18 cm). The Morrison Creek lamprey is able to feed after it becomes an adult unlike the western brook lamprey which can only feed in its larval stage.
The western brook lamprey is Not at Risk (Yellow List) and does not have a Species at Risk Act.
It spawns in spring until mid-summer when the water temperature is over 10 degrees Celsius. They create nests made out of gravel, and after hatching they are swept downstream into quieter parts of the stream and burrow into the ground. They stay in these quiet areas for about four years until eventually turning into adults. When they become adults in late summer to late fall they do not eat. After the lamprey spawns it dies.
Additional field notes
Larvae and transformed western brook lampreys use different foods and parts of a stream.
Sources: Lampetra richardsoni species summary
A feeding larva and nonfeeding adult
The larval stage, called an ammocoete, occupies sandy or muddy backwaters and pools. FishBase records diatoms and other microscopic plant and animal material in its food. After transformation, the typical western brook lamprey stops feeding. Adults use gravel riffles and runs in clear, cool streams, so protecting adult spawning gravel alone would leave out the quiet sediment habitat used earlier in life.
Sources: Lampetra richardsoni species summary
Article text: Wikipedia contributors, Western brook lamprey (source revision). Licensed under CC BY-SA 4.0. Retrieved 2026-10-11.
