| Eutonina indicans
(Romanes, 1876) : Umbrella Jelly Phylum Cnidaria / Class Hydrozoa / Order Leptomedusae / Family Eirenidae |
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This inconspicuous hydromedusa is easily overlooked. With a
transparent bell and relatively small size (25 to 35 mm maximum bell diameter), only a
careful search will reveal its presence. The most conspicuous part of the body are
the four radial canals, each with attached gonads, which form a distinctive pattern.
The mouth has four frilly lips and extends below the bell margin on a conical
peduncle. Up to 200 fine, short tentacles line the margin of the bell. A
variety of small prey include invertebrate eggs and larvae, copepods and other small
hydromedusae. In Monterey Bay this jelly is relatively uncommon. In other
locations, such as the San Juan Islands and Vancouver Island, it can occur in dense
aggregations in nearshore surface waters, mainly during spring and summer months.
Eutonina can be found from southern California to the Aleutian Islands and areas off
Russia and northern Japan. It is relatively easy to establish hydroid
colonies and culture umbrella jellies in captivity. When provided appropriate
aquarium conditions, such as a pseudokreisel or even a rectangular tank with a
screen on one end, the medusae do well under captive conditions.
All photographs © David Wrobel and may not be used or copied without permission!