Science Stories

In May 2008, a team of researchers from the Florida Museum of Natural History traveled to Madagascar to search remaining patches of lowland forest for land snails and to document new snail species. Non-marine mollusks like land snails are the animal group with the highest number of recorded extinctions. The researchers emphasized determining areas of high species richness that could be the focus of future conservation efforts.

Isolated from other land masses for 80 million years, Madagascar harbors one of the most diverse land-based faunas on the planet. The island nation off the southeastern coast of Africa is home to a staggering 5 percent of the planet’s biodiversity. About 80 percent of Madagascar’s animals are found nowhere else, including this lemur.

Many people are familiar with Madagascar’s lemurs and chameleons. Less well-known are the island’s incredibly diverse snails. Madagascar has one of the richest land snail faunas in the world. The island is home to at least 1,500 species. About 1,000 have been discovered since 1992 -- the majority by Florida Museum research associate Kenneth Emberton. Researchers estimate many more snails have yet to be discovered.

Sadly, rapid deforestation from slash and burn agriculture and logging threatens many of Madagascar’s amazing species with extinction. Rainforest species are restricted to rapidly shrinking forest patches. Animal groups with poor travel ability, like land snails, are especially vulnerable to extinction because they cannot find new habitats fast enough. It is likely that many species will be lost before they are discovered. For this reason, it is important to document species to map out future conservation efforts.

Most easily accessible forests in Madagascar have already been cut, and poor roads over mountainous terrain make traveling to remaining forest fragments difficult. To reach a remnant patch of rainforest for snail collection, the research team drove eight hours from Antananarivo, the capital of Madagascar, to the eastern region of the country, followed by a one-day boat ride up the Rianila River and a half-day hike to Andriantantely Mountain.

All food and equipment for the expedition had to be floated upriver. The researchers’ campsite was located above several rapids and the experienced boatmen worked hard to pole the heavily loaded longboat and prevent it from tipping.

Florida Museum of Natural History collections manager John Slapcinsky and collections assistant Chelsey Campbell meet with the president of the Fokotany (local region) who lives in the village of Ambodikely. The researchers asked for permission to visit the forest, arranged for guides and porters and paid a small research fee. The community used the fee to plant seedlings to expand the rainforest.

To reach the forest, the team sloshed through muddy swamps, padded around rice fields and hiked steep mountains. Here the team passes houses and gardens that are encroaching on the rainforest.

At their destination at the base of a mountain in the rainforest, researchers John Slapcinsky, left, and Ken Emberton search for a GPS signal to accurately document their location. Snails were collected from sites at 100-meter intervals from the base of the mountain to its summit. This allowed comparison of the richness of snail species at different elevations. Snails in Madagascar forests are most diverse at low elevations, whereas other animal groups are more diverse at middle elevations. This discovery is especially important for conservation of Madagascar’s snails because few lowland forests remain.

Florida Museum researcher John Slapcinsky slides down a stream to reach one of the few remaining stands of protected low elevation forest in an isolated ravine. Team member Josephine Emberton looks on.

Team members measure one side of a collection site. To more accurately compare samples from different elevations, snails were collected in two-hour searches within 20-by-20 meter sites.

Timed searches for snails included visual inspection of all potential habitats. Most snails, even large species, are difficult to collect because they camouflage themselves well. Left: Florida Museum collections manager John Slapcinsky locates Helicophanta goudotiana snails under a fallen log. Right: Team member Josephine Emberton examines individual leaves in a basket fern while searching for small snails. Researchers focused on searching for small snails because they make up a large proportion of all snail species.

The research team lived and worked in tents for two weeks. This tent served as a portable field lab, as well as an escape from bloodsucking leeches and malaria-carrying mosquitoes.

Tiny snails that live and feed on dead leaves on the forest floor are not easily noticed. To find these species, which often make up the majority of snails in forest samples, team member Josephine Emberton collects eight liters of leaves, called a leaf litter sample, from the forest floor. The leaves were then sifted through screens to remove larger debris, making tiny snails easier to find.

Left: Team members sort leaf litter samples collected during the day. A typical day in the forest consisted of collecting snails from morning to late afternoon while there was enough light in the heavily shaded forest, then taking notes and sorting snails and leaf litter samples as the light faded in the evening. Right: Malagasy graduate student Tsitohaina Andriamiarison sieves dead leaves through multiple screen sizes. Andriamiarison is a Madagascar native who attends Universite d'Antananarivo and is advised by Florida Museum research associate Kenneth Emberton.

Madagascar’s unique fauna includes the world’s largest tree snail, Helicophanta souverbiana. This snail belongs to a group that lays bird-sized eggs and occurs in parts of the world that made up the southern supercontinent Gondwanaland 570 million years ago. Most of Madagascar’s animals spread from Africa over water, including the unique lemurs. Team member Chelsey Campbell hopes to use molecular genetic studies to determine if poorly dispersing snails arrived over water or if they were on Madagascar when it broke away from India and Africa.

Top: Team members Chelsey Campbell, left, and John Slapcinsky sift through leaves to find tiny snails. Daily heavy rains made camp life uncomfortable and dry sieving of small snails impossible. The researchers had to pour stream water through leaf sieves and search for snails in the resulting mud. Bottom: Researchers John Slapcinsky and Chelsey Campbell pause from working during a downpour.

After two weeks in the field the team returned to Antananarivo to sort samples and describe new species. To describe a species means to give it a scientific name and officially document its characteristics and appearance for the first time.

John Slapcinsky, bundled up for a late night on the microscope, sorts samples. With only one microscope, the team split into day and night shifts. Because Madagascar is located in the southern hemisphere, the team’s May trip occurred during the winter. Although only a few degrees south of the equator, Antananarivo’s high elevation results in cold winter nights.

Judicael Rakotondrazafy, a master’s degree student at Universite d’Antananarivo in Madagascar, photographs snail shells for a manuscript describing new species discovered during the expedition. Rakotondrazafy is advised by Florida Museum research associate Kenneth Emberton.

Researchers discovered more than 50 new species during the trip, some of which are pictured here. One quarter of the new snails were from one genus, Boucardicus and were found only in leaf samples. The new species descriptions will be submitted for publication in scientific journals. Florida Museum research associate Kenneth Emberton continues to live in Madagascar for another year, researching snails and discovering new species before they disappear.