First record of sympagic hydroids (Hydrozoa, Cnidaria) in Arctic coastal fast ice

We report on the first record of interstitial cnidarians in sea ice. Ice core samples were collected during eight Weld periods between February 2003 and June 2006 in the coastal fast ice off Barrow, Alaska (71 degrees N, 156 W) at four locations. A total of 194 solitary, small (0.2-1.1 mm) elongated...

Full description

Bibliographic Details
Published in:Polar Biology
Main Authors: BLUHM BA, GRADINGER R, PIRAINO, Stefano
Other Authors: Bluhm, Ba, Gradinger, R, Piraino, Stefano
Format: Article in Journal/Newspaper
Language:English
Published: 2007
Subjects:
Online Access:http://hdl.handle.net/11587/104793
https://doi.org/10.1007/s00300-007-0316-9
Description
Summary:We report on the first record of interstitial cnidarians in sea ice. Ice core samples were collected during eight Weld periods between February 2003 and June 2006 in the coastal fast ice off Barrow, Alaska (71 degrees N, 156 W) at four locations. A total of 194 solitary, small (0.2-1.1 mm) elongated specimens of a previously unknown interstitial hydroid taxon were found. By cnidome composition and the occurrence of a highly retractable pedal disc formed by epidermal tissue only, the specimens are tentatively assigned to representatives of the family Protohydridae, subclass Anthomedusae. The hydroids were found almost exclusively in the bottom 10 cm-layer (at the ice-water interface) of 118 ice cores, with abundances ranging from 0 to 27 individuals per core section (0 4,244 ind m(-2)) and a grand mean of 269 ind m(-2) in bottom 10 cm-layer sections. Abundances were lower in December and late May than in months in between with considerable site variability. A factor analysis using 12 variables showed that hydroid abundance correlated highest with abundances of copepod nauplii and polychaete juveniles suggesting a trophic relationship.