American Oceans

White Sea Bass (Croaker)

The White Sea Bass, scientifically labeled Atractoscion nobilis, is the largest species of croaker fish on the west coast.

white sea bass atractoscion nobilis large croaker fish

The scientific name comes from the Latin stems atrax (spindle), skion (from sciaena, an old name for croakers), and the nobilis (noble). So the name essentially means the noble spindled croaker, which is a very accurate description.

The White Sea Bass has several other names, including ghost fish, grey ghost, king croaker, Catalina salmon, bull tomcod, weakfish, or seatrout.

In Mexico, they are referred to as corvina cabaicucho or corvina blanca because of their light coloring.

Characteristics & Appearance

The appearance of this fish doesn’t feature anything particularly unusual. The fish have long bodies with dorsal fins, anal fins, and pectoral fins.

white sea bass holographic appearance of scales appearance

The most impressive feature of the fish is the spiked fins on top and the holographic appearance of the scales that seem to change color as it swims. 

Weight & Length

The White Sea Bass is not only the largest croaker on the west coast, but it is the largest croaker fish in existence.

white sea bass species of largest croaker characteristics

These swimmers can grow as large as five feet long, but the average size is about three feet. While they typically weigh between 20 and 25 pounds, the largest recorded was a whopping 93 pounds, cementing its status as the largest species of croaker.

Physical Characteristics & Color

The fish are an attractive bluish-grey color on their sides and back and seem to glitter as they move through sunny water.

white sea bass bluish-grey color on sides

Many croakers have this appearance, and it can help them hide in the water. But it can also make them more visible depending on the environment. The majority of their body is typically silver with speckles of blue scales.

Their underbellies are a pure silver, almost white color. When the fish are young before they are sexually mature, they often have dark vertical stripes running along their back that eventually fade away.

They have elongated bodies that are relatively compact, so they are excellent, streamlined swimmers.

Their tapered head helps them cut through the water, and they have a wide mouth. Closed, their mouth looks small but can open rapidly to take in prey.

Their lower jaw is always slightly protruding from their body and drops significantly when they open their mouth to expose their teeth.

They have one long row of teeth on their upper and lower jaws. Their teeth are small but sharp, perfect for the kind of prey they hunt.

Lifespan & Reproduction

White Sea Bass typically lives for about 13 years, so maybe they’re a lucky fish! Some have been recorded to live as long as 20 years.

These fish move north in the springtime and south in the fall for their spawning patterns. Like most fish, the White Sea Bass practices external fertilization for reproduction.

The females will lay millions of eggs, usually near the shores in rocky habitats where the eggs will be safe from predators. Then, the males come along and expel sperm over the eggs to fertilize them.

White Sea Bass typically becomes sexually mature around the age of three or four, and almost all White Sea Bass have participated in at least one spawning season by the age of six.

The peak of the spawning season is between May and June, but they will spawn anytime between April and August.

Habitat

Adults reside in rocky reefs, kelp beds, offshore banks, and the open ocean. They have the best chance to find food and thrive in these locations.

But newly hatched juveniles like to live in safe bays where they can use eelgrass beds to hide from predators and feed.

Juveniles may also move to piers and jetties where there are kelp beds, just before sexually maturing and moving elsewhere.

Juveniles avoid areas where predators may lurk and focus on safety rather than food until they become sexually mature.

Where Do White Sea Bass Live?

White Sea Bass lives mainly in the Pacific ocean. They live off the coast of California; specifically, they are abundant in Magdalena Bay near Baja, California.

However, they can travel north as far as Canada, and people often see them along the shores of Juneau in Alaska.

White Sea Bass generally prefers cooler water, but sometimes they will travel farther south, reaching the shores of Mexico. But primarily, they return to the Baja area, and most of the population resides there.

Food & Diet

Because of the large size of these fish, they have a pretty broad diet that includes a lot of other, smaller fish.

But they’ll also snack on crustaceans and planktonic creatures if times are tough. However, it is unlikely they go very long without finding a substantial fish to consume.

What Does White Sea Bass Eat?

The diet of the white seabass shifts as it ages. When they first hatch and start swimming around, they mainly survive off of insects and small aquatic invertebrates like mussels, clams, shrimp, and snails.

These animals are typically slow-moving, except for the shrimp, making them easy targets for young bass.

Once the White Sea Bass grows to eight inches, they start eating other fish and honing their hunting skills.

The older juvenile fish usually eat smaller fish and sea creatures, such as anchovies, sardines, and squid. These are easy prey to catch and consume while the fish grow and mature.

Adult White Sea Bass enjoys more hardy meals. They mainly consume mackerel, anchovies, herring, sardines, squid, and ocean-dwelling red crabs.

The size the Sea Bass grows to will determine what kind of diet it has. The bigger the fish, the more likely it is to consume larger prey like the mackerels.

Some White Sea Bass that doesn’t grow to be very large will continue to practice juvenile hunting techniques like visiting protected bays and hiding in eelgrass to surprise prey.

Threats & Predators

While the White Sea Bass does have some natural predators and faces the threats of pollution and climate change, they are generally very resilient and flexible in their environments.

Human Threats

Unfortunately, humans pose a significant threat to the White Sea Bass population. However, humans have also contributed to the growth of the population, evening things out in a sense.

Overfishing, habitat destruction from humans and ocean pollution have resulted in a slow decline in the population over decades.

Humans have spawned White Sea Bass captivity, releasing large quantities of the fish back into the ocean, helping to supply the population and boost the species’ success.

Climate Change & Global Warming

The White Sea Bass is a coldwater fish, meaning it likes temperatures below 70 degrees Fahrenheit, ideally between 50 and 65 degrees.

As the oceans warm, the White Sea Bass seems to adapt to the changing temperature better than other coldwater fish. Climate change appears to have little to no effect on the White Sea Bass population.

Predators

White Sea Bass have few predators to worry about, given that they are large, densely populated fish.

But they are prey for other larger fish, sharks, and sea lions that they come into contact with. The way they travel in large schools acts as protection from predators.

Other Threats

The White Sea Bass faces the threat of elevated carbon dioxide concentrations in the oceans. Right now, the levels are not excessive, but they likely will be soon.

However, studies on White Sea Bass larvae and juvenile fish seem to show resilience to this acidification of the water. 

Conservation Status

The White Sea Bass is currently classified as Not Extinct. This classification is partly due to the efforts of humans to increase the population.

But the White Sea Bass display incredible resilience and adaptation to changing conditions in the ocean.

Fun Facts About White Sea Bass

  • In California, if you catch a White Sea Bass smaller than 28 inches, you are required by law to throw it back. This law is to help maintain the population.
  • White Sea Bass is a promiscuous fish, as both males and females will spawn with several different partners in one season. They can spawn up to six times per season.
  • It isn’t a sea bass at all! It is technically a croaker fish, as mentioned in the article.
  • In 1986, more than 2,000 juvenile White Sea Bass were released from captivity into Mission Bay to increase the species population, and it worked!

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