Sea Walnut (Pleurobrachia pileus)
Sea Walnut (Pleurobrachia pileus)
Common name: sea gooseberry, sea walnut
Scientific name: Pleurobrachia pileus
Locations: tidal upwellings in open bays
Seasonality: early summer is best. we sometimes get them year round in plankton tows
Colors: translucent clear, white
Size: 1/2" average
Collected: by dip-net
Quantity: sold by the each
Tidepool Tim says, “Sea gooseberries arrive in great swarms each spring - there are literally tens of millions of them in our bay. We don't always find them though. Prevailing winds and tides can deliver them to opposite shores each day. Some summers there are lots and other summers we see none. Looking closely at a gooseberry will reveal two long whitish tentacles trailing out behind the jelly. These are used to fish for food. Along the oval-shaped body, there are 8-rows of cilia. These beat in waves and propel the little sphere along its way! They actually can swim along quite fast. Once their tentacles contact food, the catch is reeled in and put into its mouth. They catch planktonic animals, fish, shrimp, and worms. Amazing!”