• Researchers collect gametes from spawning Sunflower star.
    Mark Yun (Birch Aquarium), Riah Evin (California Academy of Sciences), and Jenifer Burney (Aquarium of the Pacific) work together to carefully administer a spawn-inducing hormone to a male Sunflower star. (© Birch Aquarium at Scripps)
  • Sea stars are broadcast spawners and females release eggs into the water via the gonads located on each arm.
    Sunflower stars are broadcast spawners and females release eggs into the water via the gonads located on each arm. (© Birch Aquarium at Scripps)
  • Academy biologist Riah Evin prepares pot-stirrers to house fertile embryos.
    Academy biologist Riah Evin prepares basic kitchen pot-stirrers to house the young sea stars over the next three months. (Gayle Laird © California Academy of Sciences)
  • Academy biologist Kylie Lev inspects the barely visible embryos in a glass jar.
    Academy biologist Kylie Lev inspects the day-old Sunflower star embryos at Steinhart Aquarium. (Gayle Laird © California Academy of Sciences)

SAN FRANCISCO, CA (February 26, 2024) – Love is in the water and hope is in the air for the critically endangered Sunflower star (Pycnopodia helianthoides) as a multi-institution collaborative team from the California Academy of Sciences, Aquarium of the Pacific, Birch Aquarium, San Diego Zoo Wildlife Alliance, and Sunflower Star Laboratory successfully spawned and cross-fertilized sperm and eggs from a male and a female, resulting in fertile embryos that will be raised to bolster populations in human care. This success marks another step forward in an ongoing collaborative effort between organizations across the state to save the species from extinction.

The resulting embryos from the spawning event—which took place on Valentine’s Day at Birch Aquarium at Scripps Institution of Oceanography at UC San Diego—were transported to the Academy’s Steinhart Aquarium where biologists will employ their larval rearing expertise to raise the young sea stars to adulthood. The goal is to learn the best rearing practices for this particular species so that future generations of lab-spawned Sunflower stars can be outplanted back to their native kelp forests along the California coast.

“In order for future outplanting efforts to be successful, we need to develop protocols for rearing them in high numbers in an aquarium setting,” says Steinhart Aquarium Curator Kylie Lev. “While this is the first time Steinhart Aquarium has housed Sunflower star larvae, we’ve raised a number of animals through our larval rearing program, from corals to bat stars to sea urchins. By replicating the aquaculture techniques we’ve developed and adjusting them to fit the specific needs of Sunflower stars, we can increase their population numbers and bolster their genetic diversity.”

The embryos rapidly developed into free-swimming larvae within their first two days of life and will settle into the familiar five-legged star shape in about three months. Until then, they need to be kept in moving water. To support such a large quantity of larvae, the Steinhart team piloted novel rearing techniques using more common sea star species, namely bat stars and ochre stars. They found that the most effective tool to raise large quantities of larvae in the smallest amount of space is a budget-friendly kitchen appliance: an automated pot-stirrer.

Unlike other species within Steinhart’s larval rearing program, Sunflower stars are cannibalistic, meaning they could decimate their own population before they reach adulthood. After their three-month pot-stirrer swirl, the baby sea stars will be moved to an underwater nursery specially designed to isolate individuals. The team will also introduce foods with varying nutritional profiles to determine a diet plan that keeps the baby sea stars happy and healthy—without resorting to cannibalism.

While the spawning and subsequent larval rearing were made possible by the ongoing collaboration across five California institutions, it also marks a partnership within the Academy between the Steinhart animal husbandry team and the Institute for Biodiversity Science and Sustainability (IBSS), the Academy’s research arm. Academy researchers will genetically sequence sea stars at both larval and settlement stages to identify genetic markers that may contribute to the species’ survival.

For Center for Biodiversity and Community Science Co-Director Alison Young, this collaboration is a vital step in regenerating coastal California ecosystems:

“Sunflower stars play a critical role in balancing coastal kelp forest ecosystems, but sea star wasting disease has slashed their population numbers by more than 90% in just a decade. These predatory sea stars help keep sea urchin populations in check, so without Sunflower stars, these voracious marine herbivores are decimating California’s kelp forests. By leveraging our in-house expertise and partnering with other aquariums to hone techniques to successfully raise Sunflower stars in human care, we can bring back this iconic, threatened species and preserve the opportunity to see this magnificent animal in our waters again. Mobilizing our collective expertise to take action for nature in our home state is a cornerstone of the Academy’s Thriving California initiative.”

This collaboration is part of the Association of Zoos and Aquariums (AZA) SAFE Sunflower Sea Star Program, co-led by the Aquarium of the Pacific and Omaha’s Henry Doorly Zoo & Aquarium. It also contributes to a comprehensive multi-faceted, multi-partner “Roadmap to Recovery,” led by The Nature Conservancy, to help accelerate the recovery of this species along the West Coast.


Media Contacts:

  • Steinhart Aquarium at California Academy of Sciences | Megan Ely, mely@calacademy.org
  • Aquarium of the Pacific | Marilyn Padilla, mpadilla@lbaop.org, 562-951-1684 \ Andreas Miguel, amiguel@lbaop.org, 562-951-1678
  • Birch Aquarium at Scripps | Alex Feltes, afeltes@ucsd.edu \ Joanna Volavka, jcvolavka@ucsd.edu
  • San Diego Zoo Wildlife Alliance | Andrew James, ajames@sdzwa.org
  • Sunflower Star Laboratory | Ashley Kidd, ashley@sunflowerstarlab.org
About the California Academy of Sciences

The California Academy of Sciences is a renowned scientific and educational institution with a mission to regenerate the natural world through science, learning, and collaboration. Based in San Francisco’s Golden Gate Park, it is home to a world-class aquarium, planetarium, and natural history museum, as well as innovative programs in biodiversity science, environmental learning, and collaborative engagement—all under one living roof. Museum hours are 9:30 am – 5:00 pm Monday – Saturday, and 11:00 am – 5:00 pm on Sunday. Admission includes all exhibits, programs, and shows. For daily ticket prices, please visit www.calacademy.org or call (415) 379-8000 for more information.

About Aquarium of the Pacific

The nonprofit Aquarium of the Pacific is a community gathering place where diversity and the arts are celebrated and where important challenges facing our planet are explored. Home to more than 12,000 animals, Aquarium exhibits include the Southern California Gallery, Babies!, Coral Reefs: Nature’s Underwater Cities, Pacific Visions, and Shark Lagoon. Beyond its animal exhibits, the Aquarium offers educational programs for people of all ages, including First Wednesdays featuring guest speakers. The Aquarium offers memberships with unlimited FREE admission for 12 months and other special benefits. To make a donation to help support the Aquarium, please visit Pacific.to/donate. To visit, reservations are required for everyone and can be made at aquariumofpacific.org or by calling (562) 590-3100. The Aquarium of the Pacific is located at 100 Aquarium Way, Long Beach, CA 90802.

About Birch Aquarium at Scripps

Birch Aquarium at Scripps is the public exploration center for Scripps Institution of Oceanography at UC San Diego. Perched on a bluff overlooking the Pacific Ocean, Birch Aquarium features the groundbreaking work of Scripps Oceanography and UC San Diego scientists as well as conservation breeding programs and interactive exhibits. Birch Aquarium’s mission is to connect understanding to protecting our ocean planet, which it achieves through engaging hands-on learning opportunities for more than 500,000 guests and 40,000-plus pre-K-12 students each year. Visit aquarium.ucsd.edu for more information.

About San Diego Zoo Wildlife Alliance

San Diego Zoo Wildlife Alliance, a nonprofit conservation leader, inspires passion for nature and collaboration for a healthier world. The Alliance supports innovative conservation science through global partnerships. Through wildlife care, science expertise and collaboration, more than 44 endangered species have been reintroduced to native habitats. Annually, the Alliance reaches over 1 billion people, in person at the San Diego Zoo and San Diego Zoo Safari Park, and virtually in 150 countries through media channels, including San Diego Zoo Wildlife Explorers television programming in children’s hospitals in 13 countries. Wildlife Allies—members, donors and guests—make success possible.

About Sunflower Star Laboratory

Sunflower Star Laboratory is a Monterey-based non-profit committed to researching and developing reliable and scalable aquaculture methods for sunflower star (Pycnopodia helianthoides) conservation and reintroduction. Since 2021, the mission of the Sunflower Star Laboratory is to protect the diversity of coastal ecosystems by supporting research and developing scalable aquaculture methods to restore sunflower stars to their historic range in California. We are part of the Pycnopodia Recovery Working Group, a consortium of diverse researchers who are developing recovery management strategies. Since our inception, we have engaged in outreach and education opportunities with our local and online communities, sharing the fascinating life and importance of sunflower stars as they relate to kelp forest ecosystems, supporting hands-on learning through volunteer and internship opportunities. Our team is composed of an experienced, interdisciplinary group of researchers, marine conservation professionals, project managers and environmental educators passionate about the restoration of sunflower stars. To make a donation to directly support our culture lab, collaborations and outreach at SSL, please visit www.sunflowerstarlab.org.

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