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Giant sea bass (Stereolepis gigas) - General biological information

gianat sea bass in ocean

The American Fisheries Society has determined the common name of Stereolepis gigas to be giant sea bass. Despite the ruling, this species is most frequently referred to as black sea bass in California. 

General Description and Distinguishing Characteristics


Giant sea bass start out life as a brightly colored orange juvenile with large black spots.  As the fish grows it loses the orange coloration and takes on a bronzy purple hue. The spots slowly fade as the fish gets larger and darker, with large adults appearing solid black to gray with a white underside. As with its close relatives, the groupers, giant sea bass are capable of rapid and dramatic color changes. Large fish retain the ability to display large black spots, and can take on a bicolor appearance (light below, dark above), assume white mottling, or simply change from jet black to light gray. As implied by the name, the single most dramatic feature of giant sea bass is their large size. The International Game Fish Association all-tackle world record for this species is 563 pounds 8 ounces, caught at Anacapa Island in 1968. 


Despite the conspicuous size and protected status of giant sea bass, the species remains poorly studied and much of its biology remains a mystery to scientists.  In the eastern Pacific giant sea bass range from Humboldt Bay to the tip of Baja California, and occur in the northern half of the Gulf of California. Within California this species is rarely found north of Point Conception. Adult giant sea bass seem to prefer the edges of near shore rocky reefs(10-40 m) and are often associated with kelp beds.  At certain times of the year adults can be found well away from the reef, foraging over sandy bottom and routinely associated with spawning squid (Loligo opalescens).

Age and growth:

Unfortunately a comprehensive study of age and growth was never conducted when the species was plentiful in California and Mexico. A study of this type requires examination of a very large number of individuals; given the depressed population and protected status it is unlikely an aging study of giant sea bass will be completed in the near future. 

Feeding behavior:

The most important prey items of the giant sea bass are sting rays, skates, lobster, crabs, various flatfish, small sharks, mantis shrimp, blacksmith, ocean whitefish, red crab, sargo, sheephead, octopus, squid and an occasional kelp bass or barred sand bass.  Giant sea bass are not built for sustained speed, and the vast majority of their prey are organisms that live on the bottom. These organisms, located crawling across the substrate or buried just below the surface, are drawn into the mouth of a giant sea bass by the vacuum produced when the huge mouth is rapidly opened. Certainly some mid-water fish are ambushed and sucked in by giant sea bass lurking in the shadows of the kelp.

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