The Smallest Giant Sea Bass

Meet the smallest giant sea bass you have ever seen.

This little one is a local celebrity here at the Aquarium. What makes this baby so special? Well, this fish happens to be the first baby giant sea bass hatched in any public aquarium and raised past the three month mark!

Aquarist Nicole Leier has spent years researching how to successfully breed this species. After collecting more than 1,000 eggs, she successfully hatched the Aquarium’s first healthy giant sea bass. Nicky explains the challenges she faced along the way and what this may mean for this critically endangered species.

When I took over caring for our Honda Blue Cavern exhibit, I had one goal in mind: I wanted to breed our giant sea bass. See, the giant sea bass is listed as a critically endangered animal, and raising a baby here at the Aquarium could help with their conservation.

Since 1998 we’ve had an adult pair in the exhibit, but have only been successful in raising the babies to forty-three days. It’s been a mystery, but I was determined to figure it out.

Since we knew the pair was capable of producing fertilized eggs, I decided to adjust various factors within the exhibit. I thought if the eggs were fertilized under different conditions, maybe it could increase their survival rate after they hatched.

I read numerous articles while doing research. Some scientists speculated that successful spawning was based on lunar cycles, while others believed that a certain water temperature yielded the best results. For more than two years I ran tests, including manually fluctuating the water temperature to coincide with the current ocean temperatures and monitoring the natural moonlight entering the exhibit.

After hundreds of unsuccessful hatchings, a healthy fertilized egg emerged!

You can identify giant sea bass eggs by their size. Most fish will lay eggs that typically measure about 1 millimeter in size, but giant sea bass eggs are closer to 1.5 to 2 millimeters. After two days (or what felt like a lifetime for me) our first healthy giant sea bass baby was hatched!

You can see how unbelievably tiny he is at just twenty-three days old in the photo above.

At this point, we don’t know if the baby is male or female. In fact, we are unable to identify the sex of a giant sea bass until they begin mating at about fifteen years old.

It’s now been 130 days, and I’m happy to report that this little fish is doing great! It recently graduated from eating smaller crustaceans like copepods to a hearty diet of mysid shrimp.

There is still a long road ahead; I hope to help breed more giant sea bass so we may one day be able to help further our understanding of the species.

In the meantime, this baby should be making his public debut in our Southern California/Baja gallery in the very near future. The next time you’re at the Aquarium, please be sure to stop by and say hello!