Overview

Key Features:

Giant Sea bass have large black spots on their sides, the lower jaw protrudes slightly and the dorsal fin has 11 spines.

Primary Common Name:

Giant sea bass

General Grouping:

Bony fishes

Geographic Range:

Northern CA to southwestern Mexico.

The range of Giant Sea Bass extends along the west coast from Humboldt Bay (Northern
California) to Oaxaca (Southwestern Mexico). Within California, they are primarily seen around
and to the south of the Northern Channel Islands. In Mexico, they are mostly found on the
Pacific coast of Baja California and the Sea of Cortez.

Intertidal Height:

to feet ( to meters)

Subtidal Depth Range:

Minimum Depth: 5 meters or 16 feet
Maximum Depth: 46 meters or 150 feet

Notes:

Adults are believed to move deeper during the fall and winter. However, scientists and managers lack information about where they move to and what habitats they use during this time.

Habitats:

exposed rocky shore, kelp forest

Notes:

Giant Sea Bass occur in rocky waters and areas with kelp forests.  Juveniles are usually found in and around kelp beds as well as sandy bottom areas at depths 12–21 m (Crooke 1992), whereas adults are usually found deeper than 30 m and they tend to inhabit rocky bottoms where kelp beds are nearby (Eschmeyer et al. 1983).

Abundance:

Relative Abundance:

Rare.

Species Description:

General:

Conventional "bass" shape, slight countershading, dark gray-green on top, with large diameter black spots from gills to cuadal fin.  Entire surface with subdued speckling.  The largest bony fish you will see while diving!

Distinctive Features:

Giant sea bass (Stereolepis gigas), are the largest resident bony fishes in California. The
biggest giant sea bass ever recorded was 2.26 meters (7.4 feet) long and weighed 256
kilograms (563.5 pounds). Young juveniles, which are typically less than 20 centimeters (8
inches) long, are bright red or orange with dark spots. Adults are gray or brown with black spots.
Individuals can temporarily change (flash) the color and brightness of their skin and spots.

Size:

2.26 meters (7.4 feet) long and weighed 256 kilograms (563.5 pounds).

Natural History:

General:

Giant Sea Bass (Stereolepis gigas) spawns in the summer and doesnt mature until around 11-13 years of age. They are long lived and are known to live to at least 75 years. In the spring they are known to come in close to shore and fall they retreat offshore.

Giant Sea Bass were once a common and valuable species in fish markets. Commercial fishing for them began in the 1800s. Catch peaked in 1932 for commercial fisheries in both California and Mexico. Recreational fishing of Giant Sea Bass increased after the commercial peak, and recreational catches peaked in 1963 in California and 1973 in Mexico. The development of recreational fisheries that targeted Giant Sea Bass spawning aggregations contributed to a quick collapse of the population. Giant Sea Bass numbers continued to steadily decline until 1981. That year California passed a law restricting targeted recreational and commercial fishing of Giant Sea Bass, with the exception of one incidentally caught fish per fishing trip in the commercial gillnet and trammel net fisheries. Today, approximately 97 Giant Sea Bass are landed annually and sold in California in these commercial fisheries. Based on the severity of these declines, since 1996 Giant Sea Bass have been classified as a Critically Endangered species on the red list of the International Union for Conservation of Nature. Recent research suggests that Giant Sea Bass populations might be increasing, but their numbers have not recovered to levels anywhere near those recorded during the early 1900s.

Predator(s):

At juvenille stage they are consumed by larger fish species and some birds.  As adults they are illegaly taken by humans.

Prey:

Prey include fishes, crustaceans, squid, small sharks, and rays.

 

 

Feeding Behavior:

Carnivore

Notes:

Giant Sea Bass are apex predators in kelp forest ecosystems and feed on fishes, crustaceans,
squid, small sharks, and rays. Generally slow-moving, they suck prey into their mouths by
abruptly opening their jaws and creating a strong vacuum.

Seasonal Behavior

June - September

Reproduction:

Giant Sea Bass are long-lived, reaching at least 72-75 years, and are slow to mature.

The fish mature at 7 to 10 years (Domeier 2001). The maximum size of male/unsexed giant sea bass is 250 cm TL (IGFA 2001). Spawning aggregations are formed and remain together for one or two months over the period of June to September (Crooke 1992).

References

• Allen LG, Andrews AH (2012). Bomb radiocarbon dating and estimated longevity of Giant Sea
  Bass (Stereolepis gigas).
     Bulletin, Southern California Academy of Sciences 111:1-14. doi: 10.3160/0038-3872-111.1.1

  Domeier, ML (2001). Giant sea bass. California's living marine resources: a status report.
     Calif Fish Game, Sacramento, 209-211.

  Gaffney PM, Rupnow J, Domeier ML (2007). Genetic similarity of disjunct populations of the
  giant sea bass Stereolepis gigas.
     Journal of Fish Biology 70:111-124. doi: 10.1111/j.1095-8649.2007.01393.x

  House, Parker H., Brian LF Clark, and Larry G. Allen (2016). The return of the king of the kelp
  forest: distribution, abundance, and biomass of giant sea bass (Stereolepis gigas) off Santa
  Catalina Island, California, 2014-2015.
     Bulletin, Southern California Academy of Sciences 115.1: 1-14.

  Pondella DJ, Allen LG (2008). The decline and recovery of four predatory fishes from the
  Southern California Bight. Marine Biology 154:307-313.

  Gilbert, Carter Rowell., and James David. Williams. National Audubon Society Field Guide to Fishes. Alfred A. Knopf, 2002. p. 324

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