unarmored three spine stickleback

Arundo Impact Score: 8
Status: Endangered
Range: Previously widespread in Southern California , now restricted to only four river/creek systems 
Average size: 2-3 inches
​Primary food: insects, crustaceans and snails.

Three spine sticklebacks prefer small clean pools in streams with constant water flow, well shaded by stream-side vegetation. Arundo uses high quantities of water to grow, depleting water supply in the pools that the fish need. Heavily invaded stretches of stream become chocked with arundo, changing the hydrology of the stream itself. 

Channelization has also impacted these small fish, increasing water speed during flood events and introducing pollution that affects their health and cause deformities.