Scientists aren’t sure how the 12 species spend weeks underwater without breaking the surface. They don’t have gills and they don’t hold their breath.
Moths of the Hawaiian genus Hyposmocoma are an oddball crowd: One of the species’ caterpillars attacks and eats tree snails. Now researchers have described at least a dozen different species that live underwater for several weeks at a time.
"I couldn’t believe it," said study coauthor Daniel Rubinoff, an evolutionary biologist at the University of Hawaii at Honolulu, of the first time he spotted a submerged caterpillar. "I assumed initially they were terrestrial caterpillars . . . how were they holding their breath?"