I love walking the beach at low tide. At this time, the ocean delivers its twice daily deposit of flotsam and jetsam when it begins to rise. The line of seaweed, shells, driftwood and detritus often provides a window into what lies below the lowest reaches of the low tide. Sometimes the dropping tide deposits strange jellyfish like the Red Eye Medusa (Polyorchis penicillatus) on the sandy beach.

Jellyfish in the Strand Line

I was exploring the beach at Radar Hill in Pacific Rim National Park Reserve earlier this week and noticed several small jellyfish at the edge of the ocean. The jellyfish mixed with what looked like eelgrass or surf grass in the strand line. I had already seen plenty of moon jellies on the longer sandy beaches in the national park this summer. These were something different. 

Red Eye Medusa

These denizens of the subtidal zone were Red Eye Medusa (Polyorchis penicillatus), commonly found in shallow bays with eelgrass beds. It’s a small jellyfish with a distinctive red spot at the base of each short tentacle. Apparently each red spot shades a simple eye that is able to detect light. This enables the Red Eye Medusa to position itself in the water column as it searches for plankton to feed on.

I wasn’t able to find much else about this little jelly in my intertidal guides (maybe because it’s subtidal) or online as well but was able to identify it using Lamb and Hanby’s Marine Life of the Pacific Northwest. With the onshore wind and heavy seas there wasn’t any hope of returning these beautiful jellies to the ocean. Once a jellyfish spends some time on the beach they are often too damaged to survive rescue.

Further Reading

Beware the Blobs is an older Wavelength magazine article that is a good overview of ten species commonly encountered in British Columbia.