One of the first things I learned when I moved to California in 1975 was that the garibaldi (Hypsypops rubicundus) was California’s official state fish. It was something I heard over and over again. The problem was that although widely believed, this information was not true. And to some degree there has been and still is some confusion about the status of this iconic fish. 

California Diving News
Today, the garibaldi is indeed officially recognized as California’s state marine fish. The golden trout (Salmo aguabonita, also written as Salmo agua-bonita) is designated as the state fish. 
Here’s the story of how the garibaldi became designated as our state marine fish, plus a few facts about this beloved species. 
The Path To Becoming Our State Marine Fish
In 1971 because of the garibaldi’s beauty, popularity, limited stock, and the realization that the fish was not widely sought after as a food source, the California Department of Fish and Game recommended to the State Legislature that the garibaldi be fully protected. This protection would mean garibaldi could not taken for sport or commercial reasons. However, despite what many people believed, this recommendation was not acted upon.
For the next twenty-two years commercial fish collectors targeted garibaldi because of its strong popularity with hobbyists and the fact that garibaldi are relatively easy to catch. In addition, a small number of spearfishers were known to pursue garibaldi.
In 1993 legislation was passed that was intended to protect garibaldi from being over harvested. Live captures were prohibited from February 1 through October 31. Even so it was widely believed that commercial collectors continued to greatly reduce the garibaldi population in many areas, and in 1994 Assembly Bill No. 77 was introduced with the intent of putting a collecting moratorium in place so the state’s garibaldi population would recover. The bill was enthusiastically backed by a grass roots campaign led by Jean-Michael Cousteau’s Ocean Futures Society. 
Not surprisingly, however, amendments slowed the bill’s passage. Finally, in September of 1995 the bill was passed (signed into law by then Governor Pete Wilson on October 16, 1995), and in it was a section that designated the garibaldi as California’s official state marine fish. As a result of this law, garibaldi are protected, and taking them requires a special permit, not just a valid fishing license. 
So, the garibaldi is our state marine fish. The golden trout is our state fish. I’d say “only in California” but frankly I think this kind of confusion exists all over the world when governments enact legislation. 
The garibaldi is a member of the damselfish family, Pomacentridae. Worldwide there are approximately 275 species described in approximately 30 genera in the damselfish family.
Damselfishes occur worldwide in tropical and temperate seas. The majority of species inhabit relatively shallow water, but there are exceptions with some species occurring as deep as 1,250 feet. Damselfishes typically remain close to the sea floor where they feed on bottom dwelling organisms such as algae, myriad invertebrates and fish eggs. However, members of the genus Chromis feed on planktonic organisms in mid-water.
Damselfishes are commonly described by divers as being feisty, pugnacious and irascible. These words seem fitting, as many species are well known for their vigorous defense of their territory and their willingness to physically confront intruders many times their size.
Although there are numerous exceptions, many damselfishes are characterized by their brilliant coloration, a characteristic that is especially evident in juveniles. While it is not a trait that stands out to laymen, a single nostril on each side of their snout is another feature that characterizes damselfishes. Most other species of bony fishes possess four nostril openings with a pair being located on each side of the head. The majority of damselfihses have bodies that are flattened from side to side, and generally disc-like. While bearing some resemblance to angelfishes and butterflyfishes, many damselfishes are easy to distinguish by noting that they look like “pug-nosed perches.” However, the species described in the genus Chromis are an exception. These damselfishes have longer bodies and distinctly forked tails.
The Garibaldi
The range of the garibaldi extends from central California’s Monterey Bay southward to Magdalena Bay, a well known birthing ground of California gray whales located roughly halfway down the Pacific coast of Mexico’s Baja peninsula. Within California waters, divers and snorkelers are more likely to encounter garibaldi the farther south we explore, and it is quite common for beachgoers to spot their brilliant reddish-orange bodies from the shoreline as garibaldi dart through the shallow waters of rocky reefs and tide pools that are close to nearby kelp beds.  
The common name, garibaldi, is believed to be a reference to the Italian military and a prominent political and military figure of the mid-1800s, Giuseppe Garibaldi, whose followers often showed their allegiance by wearing a bright reddish-orange shirt. 
As is the case with so many species of damselfishes, garibaldi are highly territorial. Adult males vigorously defend a staked-out patch of reef on the rocky sea floor. This section of reef typically covers several square yards, and the males do what they can to keep other garibaldi as well as other intruders out of their domain. 
Adults are very particular about the boundaries of their territories. Neighboring garibaldi may graze peacefully within a few inches of each other at the edges of their territories. But if neighbors come too close they will face each other head to head and rapidly wave their tail fins in an effort to establish clear boundaries. Competing males also produce popping sounds made by drumming their swim bladder. Easily heard by nearby divers, these low-frequency sounds are used to discourage intruders. 
In preparation for and during its breeding season an adult male garibaldi will build and maintain a nest by cultivating a patch of red algae that can be several feet in diameter. The males clear away all growth except for certain species of red algae. From approximately March to July mature males try to woo females and encourage them to lay their eggs in the males’ nests. In addition, they tirelessly groom and defend the nest against competing males and other intruders. 
Males keep the algae in their nests trimmed to a height of one to two inches by nipping at the tops of the algae. Once the males have cultivated the algae to their liking, they are faced with the age-old problem of attracting a mate. When a potential mate enters a male’s territory he will try to entice her to lay her eggs in his nest by making loud clicking noises and by making himself obvious as he rises away from the nest and zips around in a series of elaborate patterns in an effort to make himself seen.
Females are extremely picky and prefer to deposit their eggs into large nests that contain some eggs that have already been deposited by other females. If the male is dashing enough and the nest suits her, the female will deposit her eggs, and then she will swim away. If she lingers the male will quickly chase her away to prevent her from eating some of her own eggs. The chosen male then fertilizes the eggs and tends to them until they hatch some two to three weeks later.
Interestingly, several females are routinely persuaded to lay their eggs in the same nest during the same season. However, during the selection process females might avoid a nest that appears to be filled with eggs. Males are known to occasionally eat some already fertilized eggs to vacate space in a gamble that they might gain even more eggs in their nest. 
The brilliantly colored reddish-orange bodies of the juveniles are covered with iridescent blue spots. Though most fish lose the blue spots as they mature, some specimens retain a blue color along the border of their fins. The brilliant blue spots on juveniles serve to advertise that these fish are juveniles, thus preventing attacks by the territorial adults. 
Garibaldi mostly feed on a variety of sponges, worms and crabs. As is the case with many fishes, size correlates with age in garibaldi. A 6-inch long garibaldi is estimated to be in the neighborhood of three years old while a 12-inch long fish is thought to be at least ten years old. A length of 15 inches is about as big as garibaldi get. 
The Golden Trout 
The California golden trout, not the garibaldi, is California’s official state fish. It was so designated by the State Legislature in 1947. Once commonly known as the Volcano Creek golden trout, the brightly colored species is native to California where it originally occurred only in a limited number of cold freshwater streams at the headwaters of the Kern River system. Hatchery raised fish have been used to expand the golden trout’s range to numerous high elevation lakes and streams in the high Sierra Nevadas as well as to similar areas in other western states. 
According to statistics provided by the International Game Fish Association, the largest golden trout ever caught weighed in at a whopping 11 pounds! Most are considerably smaller. 
Today, the brown trout represents a threat to golden trout populations due to predation as well as competition for food and habitat. Another threat to the golden trout is the ability to maintain genetically pure populations as it has recently been learned that many fish once believed to be golden trout are hybridized with rainbow trout. 
California Diving News