Red-eye Medusa (Polyorchis penicillatus)

Description: Bell Medusa, Red-eye Jellyfish, Penicillate Jellyfish, or the Red-eye Medusa Jellyfish is a small hydromedusa jelly that only grows to about 4 cm in length. They have a transparent appearance with red eyespots around the bell and yellow to purple colored internal organs. The bell of the jelly is filled with over 100 tentacles that expand longer when drifting and can contract shorter into the bell when the jelly is swimming.

Habitat: This jellyfish species is found in waters from Alaska to Mexico, in bays or nearshore waters along the coast. They are found commonly along the bottom, around eelgrass.

Diet: During the day when the Red-eye Medusa is closer to the seafloor it feeds on benthic zooplankton by stirring up the seafloor and collecting the food in its tentacles. Aside from zooplankton, it also feeds on worms and crustaceans.

Reproduction: The polyp stage of this hydromedusa is unknown or may not even exist. It’s possible that the medusa stage we see develops straight from the larva, without having a polyp stage. Either way, they reproduce sexually by releasing gametes in the water that then fertilize to form the larvae.

Tide Pool Tidbits:

• The red spots on the jelly are used to help the jellyfish orient itself using light sensitivity - allowing it to move up and down in the water column.

• Unlike other jellyfish species, the Red-eye medusa is sadly on the decline as a result of ocean warming/acidification. There are some years when they are plentiful and others when they’re hardly seen at all.

Reference: Walla Walla University