Stranded 2 – Red Eye Medusa

Red Eye Medusa (Polyorchis penicillatus)
Red Eye Medusa (Polyorchis penicillatus) washed up on the shore at Radar Hill Beach in Pacific Rim National Park.

There’s a reason it’s called the strand line. I love walking the beach at low tide when the ocean is delivering its twice daily deposit of flotsam and jetsam as 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.

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, mixed with what looked like eelgrass or surf grass. I’d already seen plenty of moon jellies on the longer sandy beaches in the national park this summer and knew that these were something different.

Red Eye Medusa (Polyorchis penicillatus)
Red Eye Medusa (Polyorchis penicillatus) has a distinctive ring of red eye "shades" at the base of its tentacles.

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, enabling 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 has spent some time on the beach they’re often too damaged to survive rescue.

If you’re interested in further reading about jellyfish I found an older Wavelength magazine article that provides a good overview of ten species that are commonly encountered in British Columbia called Beware the Blobs.

1 comment

  1. Pingback: Dave Ingram's Natural History Blog :: Stranded 3 – Scourge of the Surf-line

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