[1] It can grow to up to around 14 centimeters, and is characterized by its grayish brown and white coloring, and black spots on its fins.

Some of the morphological characteristics separating L. hubbsi from other lamprey species include SO lamina 2 cusps; 4 inner laterals unicuspid; IO lamina 5 cusps; posterials about 10 (unicuspid); velar tentacles 3; reduced number of myomeres.

Species of the Entosphenus subgenus formed a tight-knit clade that was very distinct from the other two subgenera under the genus Lampetra.

Some of the threats that the Kern brook lamprey faces includes the loss of habitat and being degraded by dams, channelization, and diversions.

This has caused population fragmentation and these lamprey also face a narrowly restricted range, poisoning associated with fisheries management, and impacts of fish that are not native.