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MISSION DISPATCH 8 • 09/03/01 Today's Weather - images courtesy of NOAA & RSMAS Dispatch by Rebecca Johnson - HARBOR BRANCH Oceanographic Institution Latitude: 48°16'2"N • Longitude: 68°6'9"W Someone on board this vessel must be very lucky. We've steamed back to Oceanographer Canyon and are enjoying weather that's unexpectedly serene for this time of year in the Gulf of Maine. Not wanting to waste one precious moment, we're pretty much working around the clock to collect, observe, and conduct experiments on Nanomia and several of its gelatinous cousins. 
Yesterday, two yet-to-be-described species of ctenophore were brought up from about 600 meters.
Both are simply stunning creatures, one with a vivid crimson body and brilliant orange tentacles,
and the other with a ruby-red body and sunflower yellow tentacles. These dazzling jewels of the
deep are breathtaking to behold - and a reminder that we really are only just beginning to
explore and understand the diversity of life in the ocean, especially the deep sea. This rarely
accessible environment remains an unparalleled source of wonder, full of secrets, surprises, and
extraordinary organisms.
Of all the gelatinous zooplankton, ctenophores must be among the loveliest. They are commonly
called "comb jellies" because of the eight rows of cilia-studded plates known as combs - or
ctenes, to be scientifically precise - that extend the length of their pleasingly plump,
spherical or ovoid bodies. The ctenes beat rhythmically, moving the animal through the water
mouth-end first, but at the same time providing a spectacular show of iridescence as light
refracts countless tiny cilia. Interestingly, comb jellies are the largest animals that use
cilia for locomotion.
Like Nanomia, these extraordinary ctenophores are planktonic predators that trail deadly tentacles in the water like fishermen casting lethal lines. And speaking of Nanomia, the specimens we're bringing up from the depths in Oceanographer Canyon differ morphologically from those we collected a few days ago in Wilkinson Basin. These deeper-living Nanomia are larger and more robust, and their tentillae (tentacle branches) harbor large day-glow-orange batteries of nematocysts. 
These siphonophores behave differently, too. For example, very few colonies appear to perform daily migrations to surface waters. And only a few of those we've collected are eating copepods. Most prefer larger, shrimp-like members of the zooplankton called euphausiids (also known as krill). A euphausiid meal takes twice as long to digest as copepod cuisine. Euphausiids fed to several captive Nanomia were still alive and kicking inside the gastrozooids after an hour and a half! Do you have a question for the researchers on this ocean expedition? Just ask a scientist @Sea in our MISSION FORUM!  | |
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