Photos of Giant Sea Bass Courtship, Mating and Spawning Groups at Catalina Island

By July 25, 2023July 28th, 2023Catalina, Fish, Underwater Photography

Giant sea bass (Stereolepis gigas) are an enormous species of wreckfish (not a true bass) found in the kelp forests of California. Once known as “jewfish” and later as “black sea bass”, giant sea bass are one of the most thrilling fish species divers will encounter in California. ¬†They are huge, exceeding 8 feet (2.5 m) in length and 500 pounds (225 kg). Once hunted nearly to extinction by overfishing, giant sea bass are now considered endangered and enjoy considerable protections which seem to be supporting a rebound in the population numbers. Giant sea bass are one of the apex predators of the kelp forest, feeding on many other fish species as well as rays and small sharks. Each summer, they gather in mating aggregations to court and spawn. (Spawning is assumed to occur at night since it has not yet documented in the daytime when the fish can be observed.) Some summers I stay in Avalon for a few days to do some diving, hoping to make a few new images of giant sea bass, especially of multiple animals as they are engaged in their courtship behaviors. This year I enjoyed nice conditions and had the dive area largely to myself by diving at times and on days when the usual crowds were not in the water. I’m looking forward to a return next year. Here are some of my favorite images of pairs and groups of giant sea bass as they court one another in anticipation of spawning. In a few images, one of the fish can be seen nudging another. According to what I have read in species descriptions, it is presumed in these situations that a male is nudging a female in the belly, perhaps as a encouragement to release eggs. Cheers, and thanks for looking!

Be sure to watch the video below in 4K.

Two Giant Black Sea Bass in a Courtship Posture, in Kelp at Catalina Island. In summer months, black seabass gather in kelp forests in California to form mating aggregations.  Courtship behaviors include circling of pairs of giant sea bass, production of booming sounds by presumed males, and nudging of females by males in what is though to be an effort to encourage spawning, Stereolepis gigas

Two Giant Black Sea Bass in a Courtship Posture, in Kelp at Catalina Island. In summer months, black seabass gather in kelp forests in California to form mating aggregations. Courtship behaviors include circling of pairs of giant sea bass, production of booming sounds by presumed males, and nudging of females by males in what is though to be an effort to encourage spawning.
Image ID: 39432
Species: Giant black sea bass, Stereolepis gigas
Location: Catalina Island, California

Three giant black sea bass, gathering in a mating/courtship aggregation amid kelp forest at Catalina Island. In summer months, black seabass gather in kelp forests in California to form mating aggregations.  Courtship behaviors include circling of pairs of giant sea bass, production of booming sounds by presumed males, and nudging of females by males in what is though to be an effort to encourage spawning, Stereolepis gigas

Three giant black sea bass, gathering in a mating/courtship aggregation amid kelp forest at Catalina Island. In summer months, black seabass gather in kelp forests in California to form mating aggregations. Courtship behaviors include circling of pairs of giant sea bass, production of booming sounds by presumed males, and nudging of females by males in what is though to be an effort to encourage spawning.
Image ID: 33355
Species: Giant black sea bass, Stereolepis gigas
Location: Catalina Island, California

Three Giant Black Sea Bass in a Courtship Posture, Hovering One Above the Other in Kelp at Catalina Island. In summer months, black seabass gather in kelp forests in California to form mating aggregations.  Courtship behaviors include circling of pairs of giant sea bass, production of booming sounds by presumed males, and nudging of females by males in what is though to be an effort to encourage spawning, Stereolepis gigas

Three Giant Black Sea Bass in a Courtship Posture, Hovering One Above the Other in Kelp at Catalina Island. In summer months, black seabass gather in kelp forests in California to form mating aggregations. Courtship behaviors include circling of pairs of giant sea bass, production of booming sounds by presumed males, and nudging of females by males in what is though to be an effort to encourage spawning.
Image ID: 39434
Species: Giant black sea bass, Stereolepis gigas
Location: Catalina Island, California

A male giant sea bass nudges a female giant sea bass to encourage spawning as they swim in a tight circle. This courting pair of giant sea bass is deep in the kelp forest at Catalina Island. In summer months, giant sea bass gather in kelp forests in California to form courtship and mating aggregations, eventually leading to spawning, Stereolepis gigas

A male giant sea bass nudges a female giant sea bass to encourage spawning as they swim in a tight circle. This courting pair of giant sea bass is deep in the kelp forest at Catalina Island. In summer months, giant sea bass gather in kelp forests in California to form courtship and mating aggregations, eventually leading to spawning.
Image ID: 39435
Species: Giant black sea bass, Stereolepis gigas
Location: Catalina Island, California

Two giant black sea bass swim in a courtship circle, part of a larger gathering of a mating aggregation amid kelp forest, Catalina Island. In summer months, black seabass gather in kelp forests in California to form mating aggregations.  Courtship behaviors include circling of pairs of giant sea bass, production of booming sounds by presumed males, and nudging of females by males in what is though to be an effort to encourage spawning, Stereolepis gigas

Two giant black sea bass swim in a courtship circle, part of a larger gathering of a mating aggregation amid kelp forest, Catalina Island. In summer months, black seabass gather in kelp forests in California to form mating aggregations. Courtship behaviors include circling of pairs of giant sea bass, production of booming sounds by presumed males, and nudging of females by males in what is though to be an effort to encourage spawning.
Image ID: 33357
Species: Giant black sea bass, Stereolepis gigas
Location: Catalina Island, California

Giant black sea bass, gathering in a mating - courtship aggregation amid kelp forest, Catalina Island, Stereolepis gigas

Giant black sea bass, gathering in a mating - courtship aggregation amid kelp forest, Catalina Island.
Image ID: 33359
Species: Giant black sea bass, Stereolepis gigas
Location: Catalina Island, California

Two Giant black sea bass hover in the kelp forest as a courting pair, part of a larger mating aggregation at Catalina Island. In summer months, giant black seabass gather in kelp forests in California to form mating aggregations leading to spawning.  Courtship behaviors include circling of pairs of giant sea bass, production of booming sounds by presumed males, and nudging of females by males in what is though to be an effort to encourage spawning, Stereolepis gigas

Two Giant black sea bass hover in the kelp forest as a courting pair, part of a larger mating aggregation at Catalina Island. In summer months, giant black seabass gather in kelp forests in California to form mating aggregations leading to spawning. Courtship behaviors include circling of pairs of giant sea bass, production of booming sounds by presumed males, and nudging of females by males in what is though to be an effort to encourage spawning.
Image ID: 33360
Species: Giant black sea bass, Stereolepis gigas
Location: Catalina Island, California

Five giant black sea bass in a mating and courtship aggregation in the kelp forest at Catalina Island. In summer months, black seabass gather in kelp forests in California to form mating aggregations leading to spawning.  Courtship behaviors include circling of pairs of giant sea bass, production of booming sounds by presumed males, and nudging of females by males in what is though to be an effort to encourage spawning, Stereolepis gigas

Five giant black sea bass in a mating and courtship aggregation in the kelp forest at Catalina Island. In summer months, black seabass gather in kelp forests in California to form mating aggregations leading to spawning. Courtship behaviors include circling of pairs of giant sea bass, production of booming sounds by presumed males, and nudging of females by males in what is though to be an effort to encourage spawning.
Image ID: 33361
Species: Giant black sea bass, Stereolepis gigas
Location: Catalina Island, California

Two Giant sea bass comprise a courting pair as part of a larger mating aggregation amid the kelp forest at Catalina Island. In summer months, giant seabass gather in kelp forests in California to form mating aggregations leading to spawning.  Courtship behaviors include circling of pairs of giant sea bass, production of booming sounds by presumed males, and nudging of females by males in what is though to be an effort to encourage spawning, Stereolepis gigas

Two Giant sea bass comprise a courting pair as part of a larger mating aggregation amid the kelp forest at Catalina Island. In summer months, giant seabass gather in kelp forests in California to form mating aggregations leading to spawning. Courtship behaviors include circling of pairs of giant sea bass, production of booming sounds by presumed males, and nudging of females by males in what is though to be an effort to encourage spawning.
Image ID: 33362
Species: Giant black sea bass, Stereolepis gigas
Location: Catalina Island, California

A male giant sea bass nudges a female giant sea bass to encourage spawning as they swim in a tight circle. This courting pair of giant sea bass is deep in the kelp forest at Catalina Island. In summer months, giant sea bass gather in kelp forests in California to form courtship and mating aggregations, eventually leading to spawning, Stereolepis gigas

A male giant sea bass nudges a female giant sea bass to encourage spawning as they swim in a tight circle. This courting pair of giant sea bass is deep in the kelp forest at Catalina Island. In summer months, giant sea bass gather in kelp forests in California to form courtship and mating aggregations, eventually leading to spawning.
Image ID: 33364
Species: Giant black sea bass, Stereolepis gigas
Location: Catalina Island, California

Two Giant Black Sea Bass in a Courtship Posture, in Kelp at Catalina Island. In summer months, black seabass gather in kelp forests in California and form courtship and mating aggregations, Stereolepis gigas

Two Giant Black Sea Bass in a Courtship Posture, in Kelp at Catalina Island. In summer months, black seabass gather in kelp forests in California and form courtship and mating aggregations.
Image ID: 39444
Species: Giant black sea bass, Stereolepis gigas
Location: Catalina Island, California

Giant black sea bass, gathering in a mating - courtship aggregation amid kelp forest, Catalina Island, Stereolepis gigas

Giant black sea bass, gathering in a mating - courtship aggregation amid kelp forest, Catalina Island.
Image ID: 33368
Species: Giant black sea bass, Stereolepis gigas
Location: Catalina Island, California

About Phil Colla

I am a natural history photographer. I enjoy making compelling images in the ocean, on land, and in the air. I have maintained the Natural History Photography blog since 2005 and my searchable Natural History Photography Library since 1997. Here are some tear sheets and behind the scenes views. Thanks for looking!