Expert: Walter Hintz - 6/14/2006

Question
if you answers to any of these questions,or anything else on the subject please email me back as quickly as possible. (this is for a science project)

what are barnacles (scietific explanation)?
how barnacles catch their food and absorb oxygen?
what is in seawater?
how much salt is in seawater?
what is sea water versus saltwater (water with added salt) ?
any other information on sea, seawater, saltwater, barnacles, etc.
thanks.

Answer
Hi Alexandria
Barnacles are arthropods that build a calcareous shell to live in.  They have jointed appendages that they stretch into the water and capture small organisms for food.  They take in O2 from the sea water by diffusion. They weree first classified by Charles Darwin.
Seawater contains just about every element in the periodic table (go to http://www.seafriends.org.nz/oceano/seawater.htm) The salinity of seawater is about 3.5% including all salts. Salt water is just water with NaCl added.
 Google the terms you ask about.