Present research and collaborations

Group leaders: Michel Sartori and Jean-Luc Gattolliat

Biogeography

• Large-scale DNA sequencing in taxonomy and conservation: a case study with the mayfly family Heptageniidae (Ephemeroptera) in the Alps and Madagascar
• Biogeography and evolutionary patterns between and within Madagascar and continental Africa
• Biogeography and origin of Macaronesian mayflies inferred from morphological and DNA analyses

Phylogeny

• Phylogeny of the Ephemeroptera
• Phylogeny of the Baetidae

Ecology

• Ecology of some mayfly species in a glacial environment
• Response of macroinvertebrates, especially mayflies, to the deforestation on the Eastern Coast of Madagascar
  

Systematics

• A global assessment of animal diversity in continental waters: Ephemeroptera
• Systematics of the mayflies from Madagascar
• Systematics of the mayfly fauna from Borneo (East Kalimantan, Indonesia)
• The mayflies of the Arabian Peninsula
• Systematics of the mayflies from West Africa
• Catalogue of F.-J. Pictet’s mayfly collection in the Museums of Geneva and Vienna
• Contribution to the systematics of the Swiss mayfly fauna
  

Large-scale DNA sequencing in taxonomy and conservation: a case study with the mayfly family Heptageniidae (Ephemeroptera) in the Alps and Madagascar
A research conducted by Laurent Vuataz, Michel Sartori, Olivier Glaizot and Jean-Luc Gattolliat, in collaboration with Luca Fumagalli, Lausanne University and Michael Monaghan, Natural History Museum, London, UK
Project granted by the Swiss National Science Foundation (3100A0-116049)

Advances in high-throughput DNA sequencing and analysis are transforming most aspects of organismal biology, but their potential for the study of biodiversity, taxonomy, and evolution has yet to be fully realized. Applied to whole communities and entire faunas, large-scale sequencing could provide rapid species inventories and a means to characterize biodiversity where an existing taxonomy is incomplete or absent. The need for such advances is critical; only 10-20% of Earth’s species have been formally described and the rate of conventional species description would require a 1000-fold increase to meet the existing taxonomic needs of the global community.

The "A" stream, in "A" Valley (VS) in the Alps.

Here we develop novel, DNA-based methods to provide a reliable, accurate, and stable taxonomy of species using mitochondrial and nuclear gene sequence data from ca. 1750 individuals of ca. 50 species of mayflies (Ephemeroptera, Heptageniidae). We then apply the data to a comprehensive study of their macroecology, population genetics, and speciation to identify key species and habitats for conservation. We study two different biogeographical regions, the European Alps (with a special emphasis on the genus Rhithrogena) and the rainforests of Madagascar, to compare faunas with different evolutionary histories. By delimiting putative species from the data and then corroborating these using other criteria (e.g. geography, morphology), we propose an alternative to ‘barcoding’ in which a priori (and potentially incorrect) entities are databased and compared to unknowns based on phenetic similarity.

We expect sequence variation to be partitioned into clearly recognisable groups or “clusters” of sequences detectable with a variety of parsimony-based statistical methods and newly developed likelihood analysis of branching (cladogenesis) rates. A lack of groups in the Alps and clearly defined groups in the tropics, or vice versa, would suggest incipient or recent speciation in one group that is not easily detected by our genetic methods. The magnitude of variation among Alpine and tropical taxa is likely to be different; greater divergence between tropical congeners may be the result of extinction within ancient lineages. Alternatively, a recent arrival to Madagascar and recent speciation could result in closely related species. Regardless, we predict that DNA sequences will accurately and consistently recover diagnosable species. We suggest that novel, DNA-based methods will provide both a reliable, accurate taxonomy of all species and a rapid means to quantify the genetic diversity and evolutionary history of an entire fauna. Phylogenetic and population-genetic analyses using the growing genetic data sets will drastically improve our understanding of the evolution, community structure, and conservation status of freshwater invertebrates in the very near future.

River on Lakato road, Est Madagascar

Biogeography and evolutionary patterns between and within Madagascar and continental Africa
A research conducted by Jean-Luc Gattolliat and Michel Sartori, in collaboration with Michael Monaghan, Natural History Museum, London, UK

In 2003, we conducted a field expedition in South Africa and Madagascar in order to collect fresh material suitable for genetic analyses. This project was based on the following statement: Madagascar is isolated from continental Africa since more than 100 millions years and should exhibit a very distinct mayfly fauna, due to the poor dispersal capacities of these insects. Although the endemism rate in Madagascar is about 99% at the specific level, numerous genera are shared between both landmasses, especially concerning the Baetidae (Gattolliat and Sartori 2003). Our results were recently published (Monaghan et al. 2005) and show that the Malagasy Baetidae found nowadays are the results of old vicariance processes followed by radiation, and also of more recent, unexpected dispersal events that took place mainly in species inhabiting lentic habitats.
		Team working in the field, South Africa, 2003. Photo Jean-Luc Gattolliat

In the future, we want to investigate other mayfly families (Tricorythidae) as well as others aquatic insect groups (Diptera, Simuliidae) to compare the relative importance of vicariance and dispersal events in different taxonomic groups. Using widespread taxa such as Dicentroptilum merina, we try to show if gene flow still exists between populations or if they are isolated. In the last case, what are the reasons for? Recent events such as the deforestation or old isolation due, for example, to geological barrier (mountains)? Recent phylogenetic analysis has shown that the Madagascar owns a completely endemic well diversified lineage. We want to see if the species and genera we have established using morphological characters can be genetically confirmed.

Dicentroptilum sp. from Madagascar Dicentroptilum sp. from South Africa

Relevant literature
Gattolliat, J.-L., and M. Sartori. 2003. An overview of the Baetidae of Madagascar, Pages 135-144 in E. Gaino, ed. Research Update on Ephemeroptera and Plecoptera. Perugia, University of Perugia, Italy.
Gattolliat, J.-L., Monaghan, M. T., M. Sartori, H.M. Barber-James, J.-M. Elouard, P. Derleth, O. Glaizot, F.C. De Moor and A. Vogler. 2008. A molecular analysis of the Afrotropical Baetidae. In: F. R. Hauer, J. A. Stanford and R. L. Newell (eds). International Advances in the Ecology, Zoogeography and Systematics of Mayflies and Stoneflies. pp. 219-232, University of California Press. Berkeley, California, USA
Monaghan, M. T., J. L. Gattolliat, M. Sartori, J. M. Elouard, H. James, P. Derleth, O. Glaizot et al. 2005. Trans-oceanic and endemic origins of the small minnow mayflies (Ephemeroptera, Baetidae) of Madagascar. Proceedings of The Royal Society B-Biological Sciences 272:1829-1836.

Biogeography and origin of Macaronesian mayflies inferred from morphological and DNA analyses
A research conducted by Michel Sartori and Jean-Luc Gattolliat, in collaboration with Michael T. Monaghan, Natural History Museum & Imperial College, London (UK) and Samantha J. Hughes, Centre for Macaronesian studies, University of Madeira, Funchal (Portugal)

Phylogeny of the Ephemeroptera
A research conducted by Michel Sartori and Jean-Luc Gattolliat, in collaboration with Heath Ogden, Arizona State University, USA; Arnold Staniczek, Museum für Naturkunde, Stuttgart, Germany and Tomas Soldán, Czech Academy of Sciences, Ceske Budejovice, Czech Republic.

In 2004, a first attempt of a global reconstruction of the phylogeny of the Ephemeroptera based only on morphological characters was presented during the XIth Mayfly conference in Montana.The matrix included 100 larval and imaginal characters for about 100 taxa representing all the different families. On another side, a phylogeny of the mayflies based on molecular sequencing was recently proposed (Ogden and Whiting 2005). The two reconstructions are mainly congruent and offer a new approach of some problematic groups. The project is now to reconstruct a phylogeny based on both morphological and genetic characters. Relevant literature Ogden, T. H., and M. F. Whiting. 2005. Phylogeny of Ephemeroptera (mayflies) based on molecular evidence. Molecular Phylogenetics And Evolution 37:625-643.
		From left to right: A. Staniczek, J.-L. Gattolliat, T. Soldán, M. Sartori

Phylogeny of the Baetidae
A research conducted by Jean-Luc Gattolliat and Michel Sartori, in collaboration with Carolina Nieto, Tucuman, Argentina and Heath Ogden, Arizona State University, USA

		With 100 genera and more than 800 species, the Baetidae is the second most diversified family of Ephemeroptera in the world. This family exhibits a worldwide distribution (except New Zealand and a few isolated islands) and is mostly diversified in southern hemisphere especially in Africa where it represents half of the known species of mayflies. Some attempts were made to divide the Baetidae in two or three subfamilies or to gather some apparently related genera in complexes (Gattolliat 2002).
Dabulamanzia concolorata.

There is no agreement in the suprageneric systematics of Baetidae and the different classifications were mainly intuitive based on presence/absence of a restricted number of characters (Gillies 1991; Lugo-Ortiz and McCafferty 1999). Genes of the available genera were also sequenced to constitute a database. We want to perform the first global and formal analysis of the Baetidae, using both molecular and morphological characters.

Relevant literature
Gattolliat, J.-L. 2002. Etude systématique, cladistique et biogéographique des Baetidae (Ephemeroptera) de Madagascar, Université de Lausanne.
Gillies, M. T. 1991. A diphyletic origin for the two-tailed baetid nymphs occurring in East African stony streams with a description of the new genus and species Tanzaniella spinosa gen. sp. nov., Pages 175-187 in J. Alba-Tercedor, and A. Sanchez-Ortega, eds. Overview and strategies of Ephemeroptera and Plecoptera. Gainesville, Sandhill Crane Press., Inc.
Lugo-Ortiz, C. R., and W. P. McCafferty. 1999. Global biodiversity of the mayfly family Baetidae (Ephemeroptera): a generic perspective. Trends in Entomology 2:45-54.

Ecology of some mayfly species in a glacial environment
A research conducted by Sandra Knispel and Michel Sartori, in collaboration with Emmanuel Castella, Laboratory of Aquatic Ecology, Geneva and John Brittain, Museum of Natural History, Oslo, Norway

This work is based on Sandra’s Ph.D. (Knispel 2004). In a first part, the functioning, spatial and temporal heterogeneity of the Rhone River proglacial flood plain, including the incidence of a tributary (the Mutt river) are studied in collaboration with Emmanuel Castella (Knispel and Castella 2003; in prep.). In a second part, field and laboratory studies have been conducted in order to decipher the life history of some mayfly species in this harsh environment. The first experiment has been devoted to the egg development, with special emphasis on the influence of temperature and spatial heterogeneity. This work is now completed and should be publish soon (Knispel et al., 2006).
		Braided section of the Rhone river below the glacier
		The second experiment links the previous results with the field experiment on the life history of the most common species found in Gletsch, Baetis alpinus. Our results show that some habitats of the flood plain play the role of tank for this metapopulation, whereas others are subsidized part of the year by migrating nymphs. This study will be completed within the next months. Relevant literature Knispel, S. 2004. Temporal and spatial dynamics of benthic invertebrate communities in an alpine glacier-fed alluvial system. Ph.D. thesis, Université de Lausanne. Knispel, S., and E. Castella 2003. Disruption of a longitudinal pattern in environmental factors and benthic fauna by a glacial tributary. Freshwater Biology 48:604-618.
Nymph of Ecdyonurus picteti

Response of macroinvertebrates, especially mayflies, to the deforestation on the Eastern Coast of Madagascar
A research conducted by Ranalison Oliarinony, Michel Sartori and Jean-Luc Gattolliat, in collaboration with Jean-Marc Elouard, IRD, Montpellier, France

This project is the Ph.D. thesis of Ranalison Oliarinony. Deforestation is one of the major threads Madagascar has to deal with. Some obvious consequences of the clear-cut of the forest are well known, but the incidences on the macroinvertebrate communities, especially under tropical climate, are still in great need of data (Benstead et al. 2003a; Benstead et al. 2003b; Benstead and Pringle 2004). Ten localities have been chosen in an area of the East Coast of Madagascar, half of them in intact tropical rainforest, the other half in degraded area with “savoka” (secondary savannah) and paddies.

Beforona area (East coast), savoka after deforestation, photo Jean-Luc Gattolliat

The work has two main purposes: • Consequences of the deforestation on the macroinvertebrate biodiversity: the 10 localities have been sampled three times in a year and the macroinvertebrates have been collected. Environmental data have also been recorded. The identification of taxonomic units has been done and analysis of their distribution with regard to their environment has been performed with multivariate analyses • Effect of the deforestation on the life cycle: six localities have been chosen and sampled each month during more than one year. Mayfly nymphs were identified to the species level when possible, and the life cycle of the more abundant species have been studied using mathematical models for asynchronous life cycles.
		Xyrodromeus namarona

Relevant litterature
Benstead, J. P., P. H. De Rham, J. L. Gattolliat, F. M. Gibon, P. V. Loiselle, M. Sartori, J. S. Sparks et al. 2003a. Conserving Madagascar's freshwater biodiversity. Bioscience 53:1101-1111.
Benstead, J. P., M. M. Douglas, and C. M. Pringle. 2003b. Relationships of stream invertebrate communities to deforestation in Eastern Madagascar. Ecological Applications 13:1473-1490.
Benstead, J. P., and C. M. Pringle. 2004. Deforestation alters the resource base and biomass of endemic stream insects in eastern Madagascar. Freshwater Biology 49:490-501.

A global assessment of animal diversity in continental waters: Ephemeroptera
A research conducted by Michel Sartori and Jean-Luc Gattolliat, in collaboration with Helen Barber James, Albany Museum, Grahamstown, South Africa and Michael Hubbard, A & M. University, Tallahassee, Florida, USA.

In October 2005, a workshop took place in Belgium, gathering a team of taxonomic specialists for each animal group living in freshwater. The aim of this project was to provide an assessment of animal diversity in the freshwaters of the world with an emphasis on the biogeographical distribution, the main areas of endemism and the phylogeny. The total estimate of animals living in freshwaters is above 100’000 species (Leveque et al. 2005). A chapter was dedicated to each zoological group: we are involved in this project for the chapter on Ephemeroptera. The broad results of our compilation work indicates that existant described Ephemeroptera belong to 42 families, ca 400 genera and a little bit more than 3’000 species. The results of the workshop will be published in the course of 2006 in a special issue of the journal Hydrobiologia.
		Ephemeroptera diversity: number of species / number of genera per realm. Dark colour indicates well known fauna, medium colour indicates data available, pale indicates paucity of data. NT: Neotropical, NA: Nearctic, PA: Palaearctic, AT: Afrotropical Au: Australasian (including the Pacific realm.

Relevant literature
Barber-James H.M. , J.-L. Gattolliat, M. Sartori & M.D. Hubbard. 2008. Global diversity of mayflies (Ephemeroptera, Insecta) in freshwater. Hydrobiologia 595:339-350
Leveque, C., E. V. Balian, and K. Martens. 2005. An assessment of animal species diversity in continental waters. Hydrobiologia 542:39-67.

		Since the mid 90ies, we mainly work on the mayflies of Madagascar with some major results: more than 30 publications and the description of 70 species and genera (Elouard et al. 2001, 2003). A lot of species are still waiting for description or are in need of revision. The huge collection gathered by Jean-Marc Elouard and his team (Laboratoire de recherche sur les systèmes aquatiques et leur environnement, Antananarivo) from 1991 until 1999 is now deposited in Lausanne.
Proboscidoplocia sp.
We are presently working on: • The Heptageniidae, in collaboration with Jeff Webb • The Prosopistomatidae in collaboration with Helen Barber-James and Michael Hubbard • The Caenidae, in collaboration with Peter Malzacher • Further studies on the Baetidae, conducted by Jean-Luc Gattolliat, mainly in the Afroptilum complexes of species. The final aim is to publish a fauna of the Malagasy Baetidae.
		slide preparation of Afroptilum sp.

Relevant literature
Elouard, J.-M., J. L. Gattolliat, and M. Sartori. 2003. Ephemeroptera, mayflies, Pages 639-645 in S. M. Goodman, and J. P. Benstead, eds. The Natural History of Madagascar. Chicago, University of Chicago Press.
Elouard, J.-M., M. Sartori, J.-L. Gattolliat, and R. Oliarinony. 2001. Ordre des Ephéméroptères, Pages 77-112 in J. M. Elouard, and F. M. Gibon, 2001 eds. Biodiversité et biotypologie des eaux continentales de Madagascar. Paris, IRD.

Systematics of the mayfly fauna from Borneo (East Kalimantan, Indonesia)
A research conducted by Michel Sartori, Jean-Luc Gattolliat and Pascale Derleth, in collaboration with Michael Hubbard & Jan Peters, A & M. University, Tallahassee, Florida, USA and Luke Jacobus, Purdue University, West Lafayette, Indiana, USA.

This project is a by-product of Pascale Derleth Ph.D. Thesis on the macroinvertebrate composition in a low land tropical forest subject to logging activities in North East of Borneo (Derleth 2003). The Ephemeroptera have been the subject of a preliminary broad study that revealed an incredible diversity both at the generic and species level (Sartori et al. 2003). We begun detailed studies on the genera Prosopistoma (Sartori and Gattolliat 2003) and Hyrtanella (Jacobus and Sartori 2004).		Natural unlogged stream, photo Michel Sartori
Prosopistoma olympus, drawing by Olivier Besse

The following studies are in progress and will be published in a near future:
• The genus Atopopus (Heptageniidae)
• The Teloganodidae, with emphasize on the Oriental realm (in collaboration with M. Hubbard & J. Peters)
• The Baetidae, with description of new genera and species
• The description of unknown stages among several families

Relevant literature
Derleth, P. 2003. Benthic macroinvertebrates and logging activities: a case study in a lowland tropical forest in East Kalimantan (Indonesian Borneo). Ph.D. thesis, Swiss Federal Institute of Technology, Lausanne.
Jacobus, L. M., and M. Sartori. 2004. Review of the genus Hyrtanella (Ephemeroptera: Ephemerellidae). Zootaxa 785:1-12.
Sartori M., P. Derleth & J.M. Webb. 2007. The nymph of Atopopus tarsalis Eaton, 1881 (Ephemeroptera: Heptageniidae): first description, ecology and behaviour. Zootaxa 1586: 25-32
Sartori, M., P. Derleth, and J. L. Gattolliat. 2003. New data about the mayflies (Ephemeroptera) from Borneo, Pages 403-406 in E. Gaino, ed. Research Update on Ephemeroptera and Plecoptera. Perugia, University of Perugia, Italy.
Sartori, M., and J. L. Gattolliat. 2003. First record and new species of the genus Prosopistoma Latreille, 1833 (Ephemeroptera, Prosopistomatidae) from Borneo (East Kalimantan, Indonesia). Mitteilungen der Schweizerischen Entomologischen Gesellschaft 76:301-305.

The mayflies of the Arabian Peninsula
A research conducted by Michel Sartori and Jean-Luc Gattolliat

Light-trap photo T. Van Harten

Mayflies of the Arabian Peninsula are poorly diversified but interesting because they may exhibit a lot of endemism and affinities with different bioregions. We have been involved in the pioneer studies in this region during the 1990ies (Sartori 1991; Sartori and Gillies 1990; Thomas and Sartori 1989). Recently, thanks to the courtesy of Tony van Harten, new material from Yemen, United Arab Emirates, as well as Oman was made available to us. Most of the specimens belong to the families Baetidae, Caenidae and Leptophlebiidae. Specimens from United Arab Emirates will be the subject of a special publication (T. van Harten editor) devoted to the insect fauna of this country.

Relevant literature Gattolliat, J.-L. & M. Sartori. 2008. Order Ephemeroptera. In: A. van Harten (ed). Arthropod fauna of the United Arab Emirates, volume 1: 47-83, Dar Al Ummah Publishing, Abu Dhabi. Sartori, M. 1991. The Mayfly fauna (Insecta; Ephemeroptera) of the Arabian peninsula (Part 3). Fauna of Saudi Arabia 12:242-245. Sartori, M., and M. T. Gillies. 1990. Further Records of Mayflies (Insecta: Ephemeroptera) from the Arabian Peninsula. Leptophlebiidae and Baetidae. Fauna of Saudi Arabia 11:10-17. Thomas, A. G. B., and M. Sartori. 1989. Mayflies (Insecta, Ephemeroptera) of Saudi Arabia. Fauna of Saudi Arabia 10:87-94.

Cloeon sp.

Systematics of the mayflies from West Africa
A research conducted by Michel Sartori and Jean-Luc Gattolliat, in collaboration with Peter Malzacher, Ludwisgburg, Germany.

Thanks to Jean-Marc Elouard (IRD, former ORSTOM), most of the mayfly collected in West Africa during the oncocercosis (river blindness) program between 1974 and 1990 are now housed in the Museum of zoology in Lausanne. This rich material will be studied step by step in the next years. Besides this, we received recently a small but interesting collection of mayflies sampled in the 1960ies by the famous entomologist S.Endrödy-Younga during his stay in Ghana. This material has also brought some interesting new records and possibly new species to science. The main works at the moment are concentrated on: • The Ephemeroptera of Ghana • The Ephemeroptera of Ivory Coast • The Baetidae of West Africa, with special emphasis on the Bugilliesia complex • The Caenidae of West Africa, in collaboration with Peter Malzacher
		Genitalia of a new species of Bugilliesia

		François-Jules Pictet (1809-1872) was a Swiss scientist and the pioneer in the study of what was called at that time the “Neuropteroid” insects, including Trichoptera, Plecoptera and Ephemeroptera. He published in 1843 and in 1845 a textbook that is the first modern synthesis of what was known at that time on mayflies (Pictet 1843-1845). Pictet’s monograph was based on the material he collected around Geneva, as well as the one kept in the Museum of Natural History in Geneva. Besides this, he received a couple of years before the publication of his book a manuscript and a collection of Ephemeroptera sent by Mr. Kollar from Vienna. Pictet’s collection was kept for a while by his family in Genthod. It was given to the Museum of Natural History in Geneva only in 1887 and a catalogue was established in 1892.
Baetis alpinus, species described by F.-J. Pictet

Nowadays, this collection has lost most of its value due to posterior rearrangement and mistakes to a such extent that only few original specimens are still kept. Fortunately, Kollar’s collection was sent back by Pictet after the monograph was published. It is housed in the Museum of Natural History in Vienna and has been adequately curated.
Based on these two collections, and with the help of Ernst Bauernfeind, a catalogue of Pictet’s collection is on the way to be completed and will be published in the next months.

Relevant literature
Pictet, F.-J. 1843-1845, Histoire naturelle des Insectes Névroptères. Famille des Ephémérines. Genève.

Contribution to the systematics of the Swiss mayfly fauna
A research conducted by André Wagner and Michel Sartori in collaboration with Ernst Bauernfeind, Museum of Natural History, Vienna, Austria and Arne Haybach, Essen, Germany.

The mayfly fauna of Switzerland encompasses 85 species at the moment. These insects have been the subject of an identification book (Studemann et al. 1992) as well as a distribution atlas (Sartori and Landolt 1999). Despite these recent progresses, some taxonomic uncertainties remain, especially in the family Heptageniidae. Within the genera Rhithrogena and Ecdyonurus, a lot of problems in the delineation of specific variability and/or population plasticity are still to be solved. Based on the collections housed in our Museum, as well as on recent material collected throughout Switzerland and adjacent regions, we are investigating in peculiar the following problems: • The delineation between some species of the Ecdyonurus helveticus group is uncertain, especially with regard to the species Ecdyonurus alpinus, E. austriacus and E. parahelveticus. Some new morphological characters on the nymphs are now tested
		La Lionne stream in the Jura mountain, winter 2005, photo André Wagner

		• The same problem arose with several Rhithrogena species group; in peculiar, delineation between Rhithrogena hybrida, Rh. austriaca as well as between Rh. colmarsensis and Rh. dorieri is quite problematic. New material coming from the type localities will help to find some new characters to distinguish them. Relevant literature Sartori, M., and P. Landolt. 1999, Atlas de distribution des Ephémères de Suisse (Insecta, Ephemeroptera): Fauna Helvetica, v. 3. Neuchâtel, SEG-CSCF. Studemann, D., P. Landolt, M. Sartori, D. Hefti, and I. Tomka. 1992, Ephemeroptera: Insecta Helvetica Fauna, v. 9. Neuchâtel, Société entomologique suisse.
SEM photography of Rhithrogena sp. egg