| Polyorchis penicillatus
(Eschscholtz, 1829), top; P. haplus Skogsberg, 1948, bottom : Bell Jelly Phylum Cnidaria / Class Hydrozoa / Order Anthomedusae / Family Polyorchidae |
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Not all jellies
inhabit the boundless open ocean. Bell jellies feel more at home in quiet
bays and harbors, often near the bottom. Polyorchis penicillatus
has about 100 or
more thin, long tentacles, which are used to pick up benthic crustaceans. Captured food is
transferred to the mouth, which is attached to a long tubular stomach that extends
nearly the length of the bell. Distinctive light-sensitive ocelli, each with a ring
of red pigment, are situated at the bases of the tentacles. Bell jellies will
actually respond to bright lights at night (such as from a camera flash) and quickly swim
away. The rest of the jelly is basically colorless, with a transparent bell (4 to 6
cm high) and whitish manubrium, gonads and tentacles. Long tubular gonads hang from
each of the 4 branched radial canals. P. penicillatus can be found
in nearshore waters along the entire
coast of North America. This is one jelly you don't always need to get out
on the water to see - it can sometimes be found near the surface around docks in
harbors. A similar species, Polyorchis haplus (second photo), is confined to California
waters. It has fewer tentacles (up to 30) that are a bit stouter and may
have a more golden-brown color, and 4 radial canals that are usually
unbranched. The genus name (Polyorchis) is derived from the Greek, polys
(many) and orchis (testicle). Although they are not currently
cultured anywhere, bell jellies are a relatively popular display species at
public aquariums.
All photographs © David Wrobel and may not be used or copied without permission!