Rock Prickleback

Xiphister mucosus

The Rock Prickleback is a demersal fish found in the Eastern Pacific, ranging from southeastern Alaska to southern California, USA. It inhabits rocky areas, often in intertidal zones and down to depths of 18 meters. This species is notable for its greenish-black coloration with several dusky white bars on the posterior part of its body and two distinctive dark bands diverging back from each eye. These bands are double with a paler center, helping divers identify it among similar species. Rock Pricklebacks are facultative air-breathers, allowing them to survive out of water for extended periods, provided they remain moist. They primarily feed on algae, making them herbivorous. During breeding, females lay eggs in clusters under rocks, and males are known to guard these egg masses by wrapping their bodies around them, showcasing a unique parental behavior. Divers might encounter the Rock Prickleback in rocky coastal areas, where it may be seen grazing on algae. It is considered harmless to humans. According to the IUCN Red List, the Rock Prickleback is classified as Least Concern.