The worms, known as C. elegans, were found in debris in Texas several weeks ago. Technicians sorting through the debris at Kennedy Space Center in Florida didn't open the containers of worms and dead moss cells until this week.
All seven astronauts were killed when the shuttle disintegrated over Texas on Feb. 1. Columbia contained almost 60 scientific investigations.
"To my knowledge, these are the only live experiments that have been located and identified," said Bruce Buckingham, a NASA spokesman at the Kennedy Space Center.
The worms and moss were in the same nine-pound locker located in the mid-deck of the space shuttle. The worms were placed in six canisters, each holding eight petri dishes.
The worms, which are about the size of the tip of a pencil, were part of an experiment testing a new synthetic nutrient solution. The worms, which have a life cycle of between seven and 10 days, were four or five generations removed from the original worms placed on Columbia in January.
The C. elegans are primitive organisms that share many biological characteristics of humans. In 1999, C. elegans became the first multicellular organism to have the sequencing of its genome completed.
C. elegans have two sexes: males and hermaphrodites, which are females that produce sperm. A hermaphrodite worm can self-fertilize for the first 300 or so eggs but later usually prefers to accept sperm from males to produce a larger number of offspring.
The experiment was put together by researchers at the NASA Ames Research Center in California.
The moss, known as Ceratodon, was used to study how gravity affects cell organization. During Columbia's flight, shuttle commander Rick Husband sprayed the moss with a chemical that destroyed protein fiber. He also sprayed the moss with formaldehyde to preserve it. Seven of the eight aluminum canisters holding the moss were recovered.
The experiment was put together by an Ames Research Center researcher and Dr. Fred Sack at Ohio State University.
"The cells were surprisingly well-preserved, but we're analyzing how useful it's going to be," Sack said.
NASA officials said they don't know if the worms will still have any scientific value since they were supposed to have been examined and unloaded from Columbia within hours of landing
"It's pretty astonishing to get the possibility of data after all that has happened," Sack said. "We never expected it. We expected a molten mass."
By Mike Schneider