Bipinnaria larva

Bipinnaria Larva

From the Latin words "bi" and "pinna," which mean "two" and "feather"

Parents: Sea stars

Food: Microscopic algae called phytoplankton

Size: About 900 microns long = 0.9 millimeters = 0.04 inches

adult sea star

Adult sea star. Photo by McKenna Hainey

Larval Form and Function

Watch this compilation video to learn more about the movement, anatomy, and feeding of a bipinnaria larva.

Life Cycle of a Sea Star

Lifecycle of a sea star

Drawn by Nadia Stoker

  • The bipinnaria larval form is only seen in some sea stars.
  • Adult sea stars are typically either male or female.
  • Eggs and sperm are spawning into the seawater where fertilization takes place and leads to the development of a Bipinnaria larva.
  • Sea stars can exist as larvae for about two months where they feed on microscopic algae called phytoplankton until they are large enough to metamorphose into their juvenile form on the seafloor.
  • Bipinnarias have complex nervous systems and some larvae can regenerate lost parts.

Larval Quest Activity

Developed by Nadia Stoker and Caitlin Plowman as outreach and education materials accompanying the Born in the Abyss film.

The Stephen Low Company
Oregon Institute of Marine Biology, University of Oregon
National Science Foundation