This widely distributed estuarine species is common and abundant in parts of its range. Estuarine degradation is not suspected to be causing a global decline approaching 30% at this time; therefore, it is listed as Least Concern.

This species is distributed from Rivers Inlet in British Columbia, Canada south to Bahía Magdalena in southern Baja California, Mexico (Love et al. 2021). Records from the Gulf of California are likely erroneous (Love et al. 2021). The depth range is 0-45 m (Love et al. 2021).

This species is abundant in estuarine mud flats along the west coast of North America (Johnson and Lema 2017) and is common and abundant throughout its range (L. Tornabene pers. comm. 2024). It is known from at least 464 museum lots, with the largest lot containing at least 1,008 individuals (FishNet2 online database accessed August 2023).

This demersal species inhabits estuaries, lagoons, and sloughs with soft bottoms, taking refuge within the burrows of the ghost shrimp Neotrypaea californiensis, the mud shrimp Upogebia pugettensis, and the fat innkeeper worm Urechis caupo (Prasad 1958a, Kells et al. 2016). It lives free and commensally within these burrows, and does not migrate from one locality to another (Prasad 1958a). It can be found at depths of less than three cm in the late spring and summer, lower intertidally in spring, higher in the summer, and not found intertidally in the fall or winter (Dawson et al. 2002). It prefers a salinity of between 15-35 ppt, but can tolerate ranges from 0-55 ppt (Dawson et al. 2002). This species reaches maturity at one year of age, and lives for a maximum of two to three years (Matarese et al. 1989). The maximum total length is 6.7 cm (Love et al. 2021).

23 percent of females begin maturing at a standard length of 29.0 mm (Prasad 1959). This percentage increases gradually, with all females 34.0 mm and above reaching maturity (Prasad 1959). The spawning season extends over a period of nine months with the heaviest spawning taking place from March to June (Prasad 1959). It lays about 750 to 1,000 eggs, but actual counts of ripe ovarian ova vary from 800 to 1,200 according to the size of the fish (Prasad 1959). In California, spawning occurs from December to August, with peaks from March through June (Hart 1973). The non-adhesive eggs are 0.7-0.8 mm diameter, and are laid in groups of up to 1,100 over a considerable area, either singly or in small groups (Prasad 1959, Hart 1973). This species does not exhibit parental care of young (Hart 1973). The eggs hatch in 10-12 days in 15.5 degree C water (Hart 1973). The larvae are pelagic, initially measuring 2.7-3.8 mm, and mature at 34 mm standard length (Hart 1973). It not known if its eggs are laid outside burrows, where they sink into the sediment, or if they are deposited in Neotrypaea californiensis shrimp burrows (Hoffman 1981) Data on the association between this species and the shrimp is lacking (Hoffman 1981).

Larvae of this species feed on the floating eggs of marine animals, copepods, nauplii and barnacle larvae (Hart 1973). Adults feed on diatoms, green algae, tintinnids eggs and young of their hosts (Hart 1973). Individuals are known to place large pieces of food near crabs, which tear up the pieces to feed, allowing this species to feed on the smaller pieces (Hart 1973). Analyses conducted on the stomach contents of specimens of varying sizes collected over a period of twelve months show that there are changes in the diet with age and with season, although copepods form the mainstay of food at all ages and at all seasons (Prasad 1958b). During the periods when copepod abundance is low, this species appears to eat more of ova, nauplii, and nematodes annelids (Prasad 1958b). Individuals begin eating larger organisms with increasing size, and gradually decrease their consumption of smaller items such as diatoms and tintinnids (Prasad 1958b). There seems to be a gradual change from plankton consumption to bottom feeding with advancing age (Prasad 1958b).

Estuarine degradation may impact this species on a local level.

This species is utilized as bait by bottom-fishing anglers (Lamb and Edgell 1986).

There are no species-specific conservation measures. This species' distribution overlaps with several MPAs, including the Scott Islands Marine National Wildlife Area in Canada, the Olympic Coast and Monterey Bay National Marine Sanctuaries in the United States, and the Islas del Pacífico de la Península de Baja California MPA in Mexico (World Database on Protected Areas accessed August 2023).