Marine Life‎ > ‎California‎ > ‎Invertebrates‎ > ‎

Sea Urchins

Crowned Urchin

Centrostephanus coronatus

(1-3,8: Indian Rock, Santa Catalina Island / 4: Seal Cove, San Clemente Island / 5-6: Hen Rock, Santa Catalina island / 7: Sea Landing Cove, Santa Barbara Island)

Heart Urchin

Lovenia cordiformis

(1: San Carlos Beach, Monterey)

This is its test (skeleton):
(1: San Carlos Beach, Monterey)

Purple Sea Urchin

Strongylocentrotus purpuratus

(1: Monterey State Beach, Monterey / 2,5-6,8: San Carlos Beach, Monterey / 3: Whaler's Cove, Point Lobos / 4East Pescadero Pinnacle, Pebble Beach)

Young ones can be pale, but the short spines are still distinctive:
(1-2,4: San Carlos Beach, Monterey / 3: Whaler's Cove, Point Lobos)

Here's a close up of an urchin showing its tube feet:
(1: San Carlos Beach, Monterey)

These eat kelp:
(1: San Carlos Beach, Monterey / 2: Lovers Point, Monterey)

In turn, urchins are eaten by many species of sea star.  But with the wasting disease reducing many sea star populations the last few years, urchins have taken over at some Monterey dive sites and reduced kelp coverage.  This makes the sea otters sad:
(1: Monastery Beach, Carmel-by-the-Sea)

Red Sea Urchin

Strongylocentrotus franciscanus

(1: East Pescadero Pinnacle, Pebble Beach / 2: Whaler's Cove, Point Lobos / 3: Bluefish Cove, Point Lobos / 4-6: San Carlos Beach, Monterey / 7: Eel Point, San Clemente Island / 8: Monterey State Beach, Monterey)

Sand Dollar

Dendraster excentricus

(1,8: Monterey State Beach, Monterey / 2-3,6-7: San Carlos Beach, Monterey / 4-5 Lovers Point, Monterey)

Yes, these are actually sea urchins.  They have short, fuzz-like spines, longer on the bottom than the top.  They live in large beds on the sandy bottom in 10-20 feet of water.

What washes up on the beach with the leaf-like pattern is just the skeleton:
(1: Monterey State Beach, Monterey / 2: San Carlos Beach, Monterey)

Sand dollars sometimes slowly meander across the sand:
(1: San Carlos Beach, Monterey / 2: Monterey State Beach, Monterey)

White Sea Urchin

Strongylocentrotus pallidus

(1: Lovers Point, Monterey / 2: San Carlos Beach, Monterey)