SPOKANE, Wash. (AP) - The federal government said Tuesday that a petition to protect the giant Palouse earthworm as an endangered species does not contain enough scientific data to conclude that such protection is warranted.

The petition seeking threatened or endangered status for the rarely seen worm - which can grow as long as 3 feet and spit at attackers - was filed on August 30, 2006, by environmental groups.

"We share the petitioners' concern for the species," said Susan Martin, supervisor for the U.S. Fish and Wildlife Service Office in Spokane. "While we will not be initiating an in-depth status review at this time, we will continue to cooperate with others to monitor the species."

The decision upset conservationists, who blamed the Bush administration.

"Given that the earthworm has been seen only three times in the last 40 years despite considerable survey, the Fish and Wildlife Service's decision is utterly ridiculous and flies in the face of common sense," said Noah Greenwald, biologist with the Center for Biological Diversity.

"At the very least, the extreme rarity of the earthworm and substantial threats to its habitat warranted further study," he said.

The giant Palouse earthworm was first discovered in 1897 near Pullman, Wash. Although only a few specimens have been collected, it was thought to be abundant in the Palouse.

But the last confirmed sighting of the species was in 2005 by a University of Idaho researcher. Previously, the giant worm had not been seen since 1988.

There is little about the worm in the scientific record. Information regarding the range, distribution, population size and status of the worm is limited, preventing the assessment of population trends, the agency said.

The agency concluded that while the Palouse prairie has experienced a dramatic conversion of native habitat to agriculture, it was not clear if that hurt the worm.

The agency also found no information on predation or transmission of pathogens by other earthworms to the giant Palouse earthworm.

"The service could not determine if a lack of regulations may pose a threat to the species," the agency said.

The giant worm is the largest and longest-lived earthworm in North America. It is reported to have a peculiar flowery smell, and to be cream-colored or pinkish-white. It has been reported to spit at attackers and move quickly through the soil to escape predators.

The petition was filed by the Palouse Prairie Foundation, the Palouse Audubon Society, Friends of the Clearwater and three private citizens. ---