| Haliscera conica
Vanhoffen, 1902, top; H. bigelowi Kramp, 1947, bottom Phylum Cnidaria / Class Hydrozoa / Order Trachymedusae / Family Halicreatidae |
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Both
of these deep-water species are commonly collected in mid-water trawls.
They are characterized by a bell width no more than 2.5 cm, and a rounded to
conical apical projection (more pronounced in Haliscera conica).
The mouth and stomach are circular, and connect to 8 broad radial canals.
The canals are typically swollen in their midsection by flat. oval gonads.
The velum is quite broad. About 160 tentacles (lost in these trawl
collected specimens) line the bell margin. They have nematocysts
concentrated in the distal (farthest) ends, and are about 1 to 3 times as long
as the bell width. Both species are transparent and colorless, but may
have an orange tinge to the canals and gonads, or rose-pink stomach and mouth
(as seen in the photo of H. bigelowi). They inhabit mid-water zones
in both the Atlantic and Pacific Oceans.
All photographs © David Wrobel and may not be used or copied without permission!