Morning sun star – State Wildlife Action Plan

Morning sun star

Photo is needed for this SGCN.

Morning sun stars are large sea stars with a wide central disc and 8 to 13 long tapering rays (arms) that reach a maximum span of about 40 cm. The upper (aboral) surface is smooth, and its external color is usually pale brown, tan, grey, reddish, or orange, sometimes mottled with pale patches. They generally inhabit rocky areas in subtidal areas, but have also been observed in unconsolidated (soft) sediment down to a depth of 420 m. Morning sun stars are cannibalistic predators that feed upon a diversity of asteroids, including other Morning sun stars, Solaster stimpsoni, Dermasterias imbricata, Leptasterias hexactis, Evasterias troschelii, Henricia leviuscula, Crossaster papposus, Pycnopodia helianthoides, and Mediaster aequalis. Morning sun stars also prey upon sea urchins (Strongylocentrotus purpuratus, Strongylocentrotus droebachiensis), sea cucumbers (Eupentacta quinquesemita, Psolus chitonoides, Cucumaria miniata, Parastichopus californicus, Apostichopus californicus), barnacles, and nudibranchs. Adults are broadcast spawners, and mature females spawn large yolky eggs that are buoyant and float upwards through the water column after release. The embryos develop into large, short-lived lecithotrophic larvae that subsist on yolk materials while they disperse in ocean currents for a period of about 8 to 10 days. As cannibals, morning sun stars are preyed upon by conspecific sea stars. Populations of morning sun stars (and many other species of asteroids) were decimated throughout their range by Sea Star Wasting Syndrome (SSWS) which is a contagious condition that results in body lesions, tissue decay, rapid disintegration and death. Sea stars along much of the North American Pacific Coast experienced massive mortality from 2013 to 2015 due to SSWS, and the die-off has persisted at low levels up to the present. Morning sun star largely disappeared from its normal habitats in marine waters off the coast of Oregon over 2016 to 2020, and individuals have not been reported from Oregon waters for several years. The biogeographic range extends from Japan, China, and Siberia along the West Coast of North America to California.

Overview

  • Species Common Name Morning sun star
  • Species Scientific Name Solaster dawsonii

Ecoregions

    Special needs

    Morning sun stars occur in lower intertidal and subtidal habitat. They are cannibalistic predators that feed primarily upon other sea stars which have been greatly reduced due to Sea Star Wasting Syndrome.

    Limiting factors

    Loss of primary food source due to Sea Star Wasting Syndrome. Larval supplies and episodic recruitment affect abundance and distribution. Prey availability and susceptibility to Sea Star Wasting Syndrome may be further limiting factors.

    Data gaps

    Determine the ecological role of morning sun stars in subtidal communities. Gather information on recruitment events. Assess population status. Evaluate ecological impacts of Sea Star Wasting Syndrome.

    Conservation actions

    Prevent disturbance, urban runoff, and sewage spills. Monitor status of populations at index sites. Gather scientific information to fill data gaps, and contribute to activities that facilitate recovery. Maintain prohibition of all non-scientific take of sea stars.

    Key reference or plan

    Nature Conservancy – Roadmap for Recovery of Sunflower Sea Stars along the West Coast of North America