Out of sight from visitors and school field trips, Birch Aquarium in La Jolla is quietly raising more than 3,000 tiny octopus hatchlings, a big milestone for the Scripps-run facility and an unusual achievement for a species whose young typically drift out in the plankton. The nearly transparent paralarvae, each about the size of a grain of rice, are being kept behind the scenes while staff focus on feeding them and tracking their progress through a fragile early life stage.
Behind the Discovery
The brood turned up when staff noticed a female Red Octopus guarding strings of eggs tucked away in a back-of-house tank. The mother laid the clutch on June 7, and the eggs finished hatching on Oct. 16, producing more than 3,000 paralarvae, as reported by The San Diego Union‑Tribune. According to the aquarium, staff believe a male fertilized the eggs before the mother ever arrived in La Jolla, and many of the eggs ended up festooned along the smooth acrylic inside the tank.
What Birch Aquarium Says
Birch Aquarium at Scripps confirmed the hatch and says its husbandry team watched embryos develop until features like chromatophores and the species’ three hearts became visible, with each egg described as slightly smaller than a grain of rice, according to Birch Aquarium at Scripps. The aquarium says the babies will stay off exhibit for now while they grow, and notes that adults of this red octopus species can reach roughly 20 inches.
Why Rearing Paralarvae Is Hard
For octopus species that produce lots of tiny eggs, the young hatch into free-floating, planktonic paralarvae that drift with currents and feed on microscopic prey. That phase can last from weeks to months, and it is notoriously hard to copy in a controlled setting. A review in Frontiers in Marine Science notes that this planktonic stage, along with the paralarvae’s strict feeding needs, are the main hurdles aquarists run into when they attempt to rear these early life stages.
What the Team Is Doing Now
Senior aquarist Maddy Tracewell told the San Diego Union‑Tribune that staff are carefully regulating water temperature and fine-tuning the behind-the-scenes setup to boost hatch success and support the mother’s condition. Tracewell said that successfully rearing red octopus paralarvae would be a first for the species as far as she knows, and the team expects the paralarvae to complete settlement into bottom-dwelling juveniles in about one to two months, the Union‑Tribune reported.
Why It Matters
Beyond the novelty of thousands of baby octopuses swirling in off-exhibit tanks, Birch Aquarium is framing the work as a research and husbandry milestone that could help scientists better understand local cephalopod development and guide conservation efforts and exhibit care, according to the aquarium’s newsroom. For now, the tiny octopuses will stay out of public view while staff refine feeding protocols and monitor their growth, and Birch Aquarium says it plans to share updates as the animals reach settlement and move toward their juvenile stages.
