Sarsia tubulosa (M. Sars, 1835)

Common name(s): Clapper hydroid, clapper medusa, clapper hydromedusa, thimble jellyfish

Synonyms: Syncoryne mirabilis Sarsia sp
Phylum Cnidaria 
Order Hydroida 
Suborder Athecata (Anthomedusae) 
Family Corynidae 
Sarsia tubulosa. 8 mm long, captured at night at Sharpe Cove dock by Jamie Anderson Fields. Note the 4 tentacles, each connected to its own tentacular bulb which also has a black ocellus.
(Photo by:  Dave Cowles, August 2025)

Description:  This hydromedusa has four tentacles originating at the margin of the bell, each of which arises from a separate tentacle bulb. Each bulb also contains an ocellus. The height of the bell is only slightly greater than the diameter, and it has no marginal vesicles. The apex of the bell is rounded not pointed (photo). The tentacles have swollen batteries of nematocysts all along their length (photo). It has a highly extensible manubrium which can extend out to at least the height of the bell beyond the bell margin. The gonad of this species is a thick, bumpy growth wrapped around most of the manubrium, but it does not extend clear to the top of the manubrium (photo  photo). Mostly colorless but may have blue, red, green, or orange on the manubriumtentacles, or tentacle bulbs. Bell up to 4 cm tall. This species may be introduced. 

How to Distinguish from Similar Species:Sarsia princeps is rare, conical, and has height up to 2x the diameter. Sarsia viridis has iridescent green on its manubrium and tentacle bulbs.

Geographical Range:  Bering Sea to central CA

Depth Range:  Epipelagic (near the surface)

Habitat:  Pelagic

Biology/Natural History: Sarsia eat mainly crustaceans. 



 

References:

Dichotomous Keys:
  Carlton, 2007
  Kozloff, 1987, 1996

General References:
  Lamb and Hanby, 2005
  Wrobel and Mills, 1998

Scientific Articles:
 

Web sites:


General Notes and Observations: Locations, abundances, unusual behaviors:

nematocyst batteries on tentacles

The tentacles are covered with batteries of nematocysts. Photo by Dave Cowles, August 2025
Manubrium
The distal end of the manubrium is covered with bumps, which apparently are the gonads. Photo by Dave Cowles, August 2025

apex
The apex of the subumbrella, where the manubrium connects, has a small, orange projecting cone. Such a conelike stomach is found in S. tubulosa. Also, notice that the bumpy gonad completely wraps around the manubrium except for a short space just under the subumbrella. This is also characteristic of S. tubulosa. The four radial canals are also visible. The exumbrella is out of sight to the right but the conelike stomach does not project out to the exumbrella.  Photo by Dave Cowles, August 2025

Exumbrella
This view, zoomed out a bit from the view above, shows the exumbrella out beyond the orange stomach. Note also that the exumbrella apex is rounded as in S. tubulosa, not pointed.

Whole view
This whole view shows the animal attatched to a substrate by its 4 tentacles. The tentacles are extremely sticky, likely due to discharge of nematocysts. Note the orange on the tentacle bulbs. Photo by Dave Cowles, August 2025


Authors and Editors of Page:
Dave Cowles (2025):  Created original page
CSS coding for page developed by Jonathan Cowles

Salish Sea Invertebrates web site provided courtesy of Walla Walla University