Giant Sea Bass, Stereolepis gigas
The Giant Sea Bass, Stereolepis gigas, whose common Spanish name is pescara, is a member of the family Polyprionidae, the Seabases or Wreckfishes, known as náufragos in Mexico. This fish is also known as the Black Sea Bass. Globally, there are only three species in the genus Stereolepis, of which just one, this species is found in Mexican waters of the Pacific.
The Giant Sea Basses have robust oblong bodies covered with small rough scales and have a depth that is 38 – 42% of standard length. Juveniles are brightly colored orange with large black spots. As the fish mature and get larger and darker, their orange coloration changes to a bronze-purple hue and their spots fade. Large adults are grayish black with a white underside. These fish have the ability to make rapid and dramatic color changes; large fish can display large black spots, take on a bicolor appearance (light below, dark above), assume white mottling, or simply change from jet black to light gray. Their anal, caudal, and dorsal fins are dark with clear margins, their pectoral fins are clear, and their pelvic fins are black. They have a large mouth with small teeth and a serrated gill cover with one or two spines. Their anal fins have three spines and eight to ten rays, their caudal fin is straight, their dorsal fin is divided and has eleven or twelve spines and nine to twelve rays, and their pelvic fins are larger than their pectoral fins. Their anal and dorsal fins are mirror images of each other.
The Giant Sea Basses are found at depths between 100 and 150 feet within rocky structures adjacent to kelp beds. They reach a maximum length of 224 cm (7 feet 4 inches) and can weigh up to 563 pounds 8 ounces based on a fish caught off the Southern California coast in 1968. They are a poorly studied species and little is known about their behavioral patterns as they are a deep-water fish found demersal in caves and within shipwrecks and in small schools. They prey on stingrays, skates, lobster, crabs, various flatfish, small sharks, mantis shrimp, blacksmith, ocean whitefish, red crab, sargo, sheephead, octopus, squid, kelp bass, and barred sand bass. They are not built for sustained speed, thus most of their prey is caught off the ocean bottom by the vacuum produced when their huge mouth rapidly opens. Each female can lay up to 60 million eggs per annum. In Mexican waters of the Pacific they are found along the entire west coast of Baja and in the northern half of the Sea of Cortez.
The Giant Sea Bass can be confused with the Atlantic Goliath Grouper, Epinephelus itajara (dorsal fin without notch; rounded caudal fin).
The Giant Sea Basses are currently classified as a critically endangered species. They have a very limited distribution and a large size, and they aggregate during spawning season making them very vulnerable to all types of fishing pressure including spear fishing. They were strongly overfished with landing rates in Mexican waters decreasing from 363 tons per year in 1932 to 12 tons per year in 1980. They are a slow maturing fish that require regeneration times of 7 to 10 years. Without pressure they have a minimum population doubling time of more than 14 years. California State Legislature banned both commercial and recreational fishing of the Giant Sea Bass in 1981 in response to the great decline in population. They also banned the inshore use of gill nets in California in 1990. It is currently believed that their population has now been stabilized.
Within the Baja they can be found for sale in the major food markets and are considered an excellent food fish. In contrast, the Fish and Game Department of the State of California has established a $1,000 fine and up to six months in jail for anyone in possession of a Giant Sea Bass.