If you've ever been tide pooling, you’ve probably come across brightly colored starfish. They look like they don’t move much, but they’re actually voracious predators. Most starfish have five arms. Scientists at San Francisco State University let me know they are studying a miniature starfish with six arms, aptly called a six-rayed sea star. Unlike other starfish, which reproduce by releasing sperm and eggs into the ocean, six-rayed sea star moms hold their developing offspring under their bodies to protect them during their first vulnerable months. Adults are hard to spot since they’re only about the size of a bottle cap and they’re extremely well-camouflaged. The best part of filming them was seeing how the baby starfish, about the size and shape of snowflakes, take after their mom when it comes to hunting prey. Check it out in our Deep Look episode and this week’s newsletter.
Josh Cassidy, Deep Look Lead Producer and Cinematographer
Watch This Starfish Protect Her Babies From Danger
Image: Josh Cassidy/KQED
To stay safe, developing six-rayed sea star embryos attach to their mother right underneath her, in front of her mouth. Eventually, the popcorn-shaped embryos hatch into larvae. Then the larvae grow arms, turning into tiny snowflake-shaped juveniles ready to swim off and hunt.
Photo: Josh Cassidy/KQED
These baby starfish might look like serene underwater snowflakes, but they’re really ruthless predators who have grown up under the care of their supermom!
This year marks the 12th anniversary of the Bright Award, Stanford’s highest environmental prize given to individuals all around the world who are dedicating their careers to increasing sustainability and conservation. Learn about this year’s Bright Award recipient Rodrigo Botero Garcia, environmental activist in Colombia, here.
DEEP FACTS
Six-Rayed Sea Star Wonders
Image: Josh Cassidy/KQED
🥚Six-rayed sea star moms have fewer offspring than most starfish and will sit on their embryos for two to three months.
👶This style of holding on to their young as they develop is called brooding, which increases the chances that offspring will survive.
💪Larvae hold onto the underside of their mom with three temporary limbs called brachiolar arms, which are reabsorbed into the sea star’s body as they develop.
🛑While six-rayed sea star moms are brooding, they stop feeding themselves for up to three months!
🐌They are ruthless carnivores and eat shellfish like mussels, clams and snails.
❄️Juveniles look like little snowflakes and have the same hunting skills as adults, going after baby barnacles and baby shellfish.
PLAY
Name That Critter
What animal starts its early life drifting in the ocean currents before it lands on the rocky ocean floor and grows into a spiny creature? Hint: Sea otters love to eat them! Find out the answer at the bottom of this newsletter.
KQED SCIENCE Landmark Bay Area Regional Plan to Combat Sea-Level Rise Unveiled For the first time in history, the Bay Area now has a regional sea-level rise plan, but it requires cities and counties to plan ahead — before the water laps over the top of the bay shoreline.
Explore the innovations that are helping protect our oceans. Join Deep Look Producer Rosa Tuirán in conversation with some of the world’s leading experts in ocean health and sustainability, including Julie Packard, executive director of the Monterey Bay Aquarium, and scientists from both the Stanford Doerr School of Sustainability and SRI. This FREE event is on Tuesday, Oct. 15, at 5 p.m. at SRI’s PARC Campus in Palo Alto, California. Registration is required.
Become a DEEP LOOK Patreon Member today to help us with our mission to give everyone a deeper understanding of science and nature - especially about the living organisms too small to easily see with the naked eye. Just like out in the wild, everyone has a role to play.
We hope you enjoyed this week’s newsletter. Thank you for your support! Until next week!
- The Deep Look Team
Deep Look is KQED’s award-winning wildlife video series that reveals the tiny dramas playing out in the natural world. We’re a member-supported YouTube series from KQED and PBS Digital Studios. Learn more.
Sea urchin! Each year hundreds of millions of tiny sea urchin larvae float around the ocean, preparing for one of the most dramatic transformations in the animal kingdom. But, only a handful make it back to the shoreline to grow into adults. Sea urchins can often live more than 100 years – if a sea otter does not eat them! The photo in the Name That Critter section is of a single sea urchin larva called a pluteus.
