Giant Pill-Millipedes and Fire-Millipedes from Madagascar, taking stock of a hidden diversity

2009 REU Intern Ioulia Bespalova

IOULIA BESPALOVA

Sophomore Biology major at Mount Holyoke College

REU Mentors: Dr. Petra Sierwald (Associate curator, Zoology/Insects) and Dr. Thomas Wesener (Postdoctoral Fellow, Zoology/Insects)

Symposium Presentation Title: Discovery of Six New Species of Giant Pill-Millipede from Madagascar(Arthropoda: Diplopoda: Sphaerotheriida)

Symposium Presentation Abstract: Madagascarhouses a very unique mix of dry to rain forest climates and high mountain range habitats, which provide ecosystems for a wide array of millipede species. These ecosystems are rapidly being destroyed by deforestation. Description of newly discovered species at least ensures that they will not disappear unnoticed. This project focuses on the descriptions of new species of the enigmatic Malagasy giant pill-millipedes. The Malagasy giant pill-millipedes are all endemic and belong to the order Sphaerotheriida which is distributed all over the Southern hemisphere. Its members superficially resemble pill bugs, and possess the unique ability to roll into a fully closed ball. Six new species of the genus Zoosphaerium as well as the females of two other Zoosphaerium species, Z. pseudoplatylabum and Z. xerophilum, are described. Four of the newly described species belong to pre-existing species-groups, while two show surprising characteristics – one species from Torotorofotsy possesses male sexual organs that have not yet been seen in any other giant pill-millipede, and one new species from the montane rainforest of Andringitra which shows a linkage to two species which live in a different ecosystem, the southwestern sub-humid forest. This study focused on producing images (both hand drawn with camera lucida and ink, as well as Scanning Electron Microscopy) and descriptions of the specimens, detailing morphological characters discovered in earlier studies which can be later used in a larger phylogenetic analysis of Zoosphaerium. These characters include various features of the male and female sexual organs, features of the leg, anal shield, endotergum, and antenna. In general the identification and phylogenetic analysis of organisms has been a project that has been worked on since the early 18th century, and in this endeavor Myriapoda have been vastly ignored. This project is another incremental step forward towards that goal.


Original Project Description: The giant pill-millipedes reaching the size of a baseball and blood-red/pitchblack colored giant Fire-Millipedes belong to Madagascar's most conspicuous invertebrates. Nevertheless, they are poorly known. Recent inventory programs already lead to the discovery and description of one new genus and 36 new species of giant pill-millipedes as well as 12 new genera and 48 new species of classical millipedes. All the newly discovered species only occur on Madagascar. Describing the new species and genera, as well as assessing their interrelationships is an ongoing process.

Research methods and techniques: REU participants in this project will receive training in general millipede morphology, and will handle and sort specimens from our and other museums' collections, image important morphological characters using light and scanning electron microscopy, collect data on the morphological differences of various species, as well as prepare descriptions of these species.