Nest guarding behavior has been observed, but it is unclear if males, females or both sexes guard eggs. Natural Mortality Estimates of natural mortality are not available. No information is available on diseases in monkeyface pricklebacks. The diet of monkeyface pricklebacks varies from carnivorous to omnivorous to herbivorous, depending on life history stage and time of year. As early juveniles, prey items are predominantly zooplankton.
Adults prefer annual red and green algal species.
Predators of monkeyface pricklebacks include piscivorous birds such as great egrets and red-breasted mergansers, and fishes such as cabezon and grass rockfish. Competition Other crevice dwelling fishes such as the black prickleback, high cockscomb and gunnels, such as the rockweed gunnel, may compete with the monkeyface prickleback for space and resources. Critical Habitat Typical habitat for monkeyface pricklebacks includes rocky areas with ample crevices, including high and low intertidal tide pools, jetties and breakwaters, and relatively shallow subtidal areas, particularly kelp beds. Juveniles are particularly adapted for the high intertidal area, and this species has air-breathing capabilities. No information is available on the status of stocks of monkeyface pricklebacks.