Note
Recent in situ observations of thecosome pteropods were made during five cruises in tropical,
temperate, and arctic waters of the North Atlantic Ocean, and during one astral summer season in
Antarctic waters. The long quiescent periods employed by thecosomes to fish their mucous feeding
webs and the apparent lack of a pumping mechanism to move water through the web suggests they
rely on contact trapping of large, motile prey. Species of Cavolinia and Diacria were estimated to remain
in one location for at least 35 min to fish sequential webs. The external spherical webs used
by euthecosomes and their ability to rapidly ingest them appear to be a unique feeding method among
plankton that utilize mucous feeding structures.