MBARI (Monterey Bay Aquarium Research Institute) | Weird and Wonderful: Don’t be fooled by the sun star’s sunny disposition @MBARIvideo | Uploaded February 2021 | Updated October 2024, 4 hours ago.
California sun stars have a voracious appetite and they are not picky about their next meal. They maneuver across mud or rocks on an army of tiny tube feet, drawn to the scent of a rotting feast. But these sea stars don’t solely dine on scavenged scraps—they are also cunning predators. Sun stars feast on crabs, amphipods, worms, and other small invertebrate animals by trapping them in their arms and swallowing them whole.
The upper surface of the star is covered in tiny spines surrounded by jagged pincers—or pedicellariae—that can retract or wave in the water like pom-poms. When something crawls too close, the pincers grab tight. A hungry sun star can even raise an arm or two to snag a swimming snack from the waters overhead. Remarkably, MBARI’s remotely operated vehicles (or ROVs) have observed this species capture fast-moving prey, such as krill or even fish.
Like other sea stars, California sun stars can shed an arm when threatened. While the released appendage distracts the predator, the star can creep away to safety and later regenerate lost limbs. Luckily, with 8–22 arms, they have a few to spare.
The scientific name Rathbunaster californicus translates to Rathbun’s California star and honors Smithsonian scientist Richard Rathbun.
Scientific name: Rathbunaster californicus (Fisher 1906)
Size: up to 45 centimeters (18 inches)
Depth: 60–1,000 meters (200–3,300 feet)
Learn more about this and other iconic deep-sea animals at MBARI's Creature feature page: mbari.org/products/creature-feature
Editor: Ted Blanco
Writer: Raúl Nava
Production team: Kyra Schlining, Susan von Thun, Nancy Jacobsen Stout
Follow MBARI on social media:
Facebook: facebook.com/MBARInews/
Twitter: twitter.com/MBARI_News
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Tumblr: https://mbari-blog.tumblr.com
LinkdIn: linkedin.com/company/monterey-bay-aquarium-research-institute-mbari-/mycompany
References:
Lewis, L.M. (1992). Habitat use, diet, and parasitism of the seastar Rathbunaster californicus (Fisher) from the Monterey Submarine Canyon, California. Moss Landing Marine Laboratories Master’s thesis. 336. https://scholarworks.sjsu.edu/etd_theses/336
Warén, A. and L.M. Lewis (1994) Two new species of eulimid gastropods endoparasitic in asteroids. The Veliger, 37(4): 325-335.
Lauerman, L.M.L. (1998). Diet and feeding behavior of the deep-water sea star Rathbunaster californicus (Fisher) in the Monterey Submarine Canyon. Bulletin of Marine Science, 63 (3): 523-530.
California sun stars have a voracious appetite and they are not picky about their next meal. They maneuver across mud or rocks on an army of tiny tube feet, drawn to the scent of a rotting feast. But these sea stars don’t solely dine on scavenged scraps—they are also cunning predators. Sun stars feast on crabs, amphipods, worms, and other small invertebrate animals by trapping them in their arms and swallowing them whole.
The upper surface of the star is covered in tiny spines surrounded by jagged pincers—or pedicellariae—that can retract or wave in the water like pom-poms. When something crawls too close, the pincers grab tight. A hungry sun star can even raise an arm or two to snag a swimming snack from the waters overhead. Remarkably, MBARI’s remotely operated vehicles (or ROVs) have observed this species capture fast-moving prey, such as krill or even fish.
Like other sea stars, California sun stars can shed an arm when threatened. While the released appendage distracts the predator, the star can creep away to safety and later regenerate lost limbs. Luckily, with 8–22 arms, they have a few to spare.
The scientific name Rathbunaster californicus translates to Rathbun’s California star and honors Smithsonian scientist Richard Rathbun.
Scientific name: Rathbunaster californicus (Fisher 1906)
Size: up to 45 centimeters (18 inches)
Depth: 60–1,000 meters (200–3,300 feet)
Learn more about this and other iconic deep-sea animals at MBARI's Creature feature page: mbari.org/products/creature-feature
Editor: Ted Blanco
Writer: Raúl Nava
Production team: Kyra Schlining, Susan von Thun, Nancy Jacobsen Stout
Follow MBARI on social media:
Facebook: facebook.com/MBARInews/
Twitter: twitter.com/MBARI_News
Instagram: instagram.com/mbari_news/
Tumblr: https://mbari-blog.tumblr.com
LinkdIn: linkedin.com/company/monterey-bay-aquarium-research-institute-mbari-/mycompany
References:
Lewis, L.M. (1992). Habitat use, diet, and parasitism of the seastar Rathbunaster californicus (Fisher) from the Monterey Submarine Canyon, California. Moss Landing Marine Laboratories Master’s thesis. 336. https://scholarworks.sjsu.edu/etd_theses/336
Warén, A. and L.M. Lewis (1994) Two new species of eulimid gastropods endoparasitic in asteroids. The Veliger, 37(4): 325-335.
Lauerman, L.M.L. (1998). Diet and feeding behavior of the deep-water sea star Rathbunaster californicus (Fisher) in the Monterey Submarine Canyon. Bulletin of Marine Science, 63 (3): 523-530.
