| Gonionemus vertens
A. Agassiz, 1862 Phylum Cnidaria / Class Hydrozoa / Order Limnomedusae / Family Olindiasidae |
Here's
a jelly that doesn't like to swim. Using adhesive discs near the middle of
each tentacle (visible as light spots on the tentacles in the photo), Gonionemus
attaches to eelgrass, sea lettuce or various types of algae. They are
small (bell diameter to 25 mm) and hard to find when hanging on to swaying
seaweeds. Although typically attached to something, they are capable of
swimming when necessary. The bell is transparent, revealing the 4 orange
to yellowish-tan gonads that lie along most of the length of the 4 radial
canals. The pale yellow manubrium has 4 short frilly lips. Up to 80
tentacles line the bell margin, with about an equal number of statocysts.
Copepods are a favored prey. Whereas Pacific Northwest Gonionemus
vertens lacks a sting that is felt by people, the same species in the
Russian Far-East is known to be venomous. This nearshore limnomedusa
inhabits quiet waters of northern Japan and Kamchatka (Russia), and from
Alaska's Aleutian Islands to northern California.
All photographs © David Wrobel and may not be used or copied without permission!