Download OCHRE SEA STAR

Grab & Go
NAME: Ochre Sea Star
CLASSIFICATION:
Pisaster ochraceous; phylum
Echinodermata
Main Messages: Over harvesting
and climate change are challenging the ecosystem’s stability and
productivity. Cold, nutrient-rich
water wells up seasonally from
the deep water along our
coast and fertilizes surface
waters; phytoplankton
bloom in profusion, forming
the base of food web.
Climate change may bring
changes to currents, water temperature, and
salinity that could disrupt upwelling
DISTRIBUTION AND HABITAT: With worldwide distribution, ochre sea stars are found
primarily in the intertidal zone and are very common along the California coast.
DESCRIPTION AND DIET: Like all echinoderms, sea stars have tube feet operated by
their internal water vascular system. Used for locomotion and feeding, as well for strong
attachment to the substrate, each tube foot has a sucker at the end. The sea star internal skeleton is made of interlocking plates, allowing flexing in any direction. At the end
of each arm are specialized tentacles sensitive to touch and chemicals, and eyespots
that detect light. Tiny pincers (pedicellariae) on the sea star surface can trap and remove parasites.
Important predators of the marine ecosystem, sea stars are voracious carnivores, feeding primarily on shellfish and barnacles. They can extrude their stomachs between
valves of prey (e.g. bivalves) and digest flesh externally.
PREDATORS: Sea stars have few natural predators, though they may be taken by wolf
eels, gulls and sea otters.
REPRODUCTION: Sexes are separate and sea stars reproduce sexually, broadcasting
gametes into the water. Larval stages are planktonic.
Grab & Go
LIFE SPAN AND CONSERVATION: Life span can be 20 years. Sea stars are potentially threatened, of course, by the same effects of climate change and ocean warming
as all other marine life.
INTERESTING FACTS: Sea stars are capable of regeneration. If an injured sea star
retains its central disk and at least one arm, the complete animal can regenerate.
Like most echinoderms, it can absorb nutrients from the water across its body surface.
The ochre sea star is considered a “keystone species” in the intertidal community. Because it eats so many kinds of intertidal animals and is often very common, it may play
the most important role in determining community structure.
WHERE IN THE ACADEMY? Sea stars are in the California Coast tank, but especially
in the Discovery Tide Pool.
C:\CAS GRAB N GO SPECIMENS–OCHER SEA STAR