When the tides fall to their lowest, they briefly expose the rocky shore’s hidden wonders. The most wondrous of those, like the colorful starfishes and anemones, can draw us in (seasoned tidepoolers and first-timers alike) like almost nothing else. Still, it’s not strange at all to surrender to the pull of lesser treasures. For example, I’ve lost track of intertidal time more than once with the nereid worm, Nereis vexillosa. Nereids are polychaetes celebrated for their parapodia (fleshy leg-like appendages), among other impressive characteristics. The one shown below is a familiar resident on Oregon beaches. (Notice its parapodia?) I should caution that while I’m pretty sure it’s N. vexillosa, worms are worms—there are lots of them and lots of look-alikes. Unless you’re an expert, casual field identification is fraught with uncertainty.
When the tides are right in the spring and summer, it’s common to find lots of N. vexillosa on the shoulders of the mussel beds, where you can experience excellent wormwatching among the barnacles if you arrive by sunrise.
Morning finds the worms out and about, probing and exploring.
Spring and summer are the seasons, if you’re lucky, to see the ripe females’ blue anterior and red posterior body coloration. Enlarged parapodia too! Now that’s a treasure.