Images: A Torrent of Crabs Running to the Sea
Joanna Gyory lowers a water filter into a coastal bay in Panama. Interested in marine ecology from her childhood, she took on a natural history project for her Ph.D. work. "The coasts of Central and South America have not been studied nearly as well as temperate ecosystems in the northern hemisphere," she said. (Photo courtesy of Joanna Gyory, Woods Hole Oceanographic Institution)
The Liquid Jungle Lab, a private research laboratory built by philanthropist Jean Pigozzi, sits on an island off Panama's Pacific coast. The undeveloped island presents wide-ranging research opportunities because it encompasses pristine tropical forest, mangrove, and coastal ocean environments, and is also near deep ocean and settled mainland environments. (Google maps)
Alert and ready! Brilliantly colored land crabs are abundant near the Liquid Jungle Lab in Panama. But no one knew what their larval forms were or how they completed their full life cycle, from eggs laid in the sea to adults that live on land, until MIT/WHOI Joint Program student Joanna Gyory studied them. (Photo courtesy of Joanna Gyory, Woods Hole Oceanographic Institution)
After a six-month dry season in coastal Panama, the first rains bring masses of bright red land crabs boiling out of their burrows in the forest and migrating to the shore. There, females lay fertilized eggs in the water. WHOI student Joanna Gyory discovered previously unknown parts of this species's life cycle. (Photo courtesy of Joanna Gyory, Woods Hole Oceanographic Institution)
Adult Panamanian land crabs
Gecarcinus quadratus are important to the forest ecology. During the dry season the red land crabs stay below ground in burrows to avoid drying out. They come out at night to gather leaf litter that they bring back to the burrows to eat, adding organic carbon to the forest soil and increasing its fertility. (Photo courtesy of Joanna Gyory, Woods Hole Oceanographic Institution)
Joanna Gyory (right), doctoral student at WHOI, and assistant Hazel Levine did field work in Panama with Gyory's adviser, WHOI biologist Jesús Pineda. Using kayaks, they explored the area's mangroves. (Photo courtesy of Joanna Gyory, Woods Hole Oceanographic Institution)
The behavior of her research subjects turned night into day for Gyory (right). She and research assistant Hazel Levine collected plankton in the bay between 9 p.m. and 3 a.m. every night for weeks—and then examined their catch under microscopes.
(Photo courtesy of Joanna Gyory, Woods Hole Oceanographic Institution)
Tracing the circle:
Gecarcinus quadratus eggs hatch into zoea when females deposit them in seawater. To identify developmental stages, Joanna Gyory collected new-hatched zoea from the bay and reared them in the lab. After 21 days they had passed through several zoea stages and one metamorphosed into a megalopa. She observed the next stage in the field—the first juveniles came ashore 30 days after the first eggs were deposited—and deduced a 9-day development time from megalopa to juveniles. The time it takes for juveniles to become full adults is still an open question.
Sunrise over the bay marks the end of another long night of sampling for Joanna Gyory. (Photo courtesy of Joanna Gyory, Woods Hole Oceanographic Institution)