Solaster stimpsoni “Stimpson’s Sun Star” Asteroidea, with
Ulva lactuca “Sea Lettuce” Chlorophyta

Point Robinson, Vashon Island, WA
July 4, 2012
Robert Niese

Solaster sea stars tend to be a more subtidal echinoderm, so we only really get to enjoy them as beachgoers at especially low summer tides. This species is a voracious hunter of sea cucumbers which are common in rocky inter- and subtidal ecosystems. However, this individual was hunting in open sand before it was stranded by the tide, which suggests it might have been feeding on the plentiful sea pens which occur in these areas instead. This species of sea star is the host of a commensal scale worm which can be found hiding in the groove between the paired tube feet on the underside of each arm.

Strongylocentrotus droebachiensis “Green Urchin” Echinoidea

Olympic National Park, WA
June 2, 2013
Robert Niese

Strongylocentrotus droebachiensis has one of the longest binomial Latin names of any organism in the world. It is also one of the most abundant and widely distributed urchins on Earth. Here in Washington, S. droebachiensis is at the southernmost extent of its range.