Systematics, phylogeny, and biogeography of New Guinean Exocelina

The project examines the taxonomic and phylogenetic structure and biogeography of the genus Exocelina Broun, 1886 in New Guinea. The island is attractive for scientific research not only because it is one of only three remaining major tropical wilderness areas with a very rich biodiversity, but also because of the complexity of its geological origin and colonization history in combination with the scarcity of information on all of them. Although numerous papers on different insect groups of New Guinea have been published to date, no data on water beetles of the island were available until a study on diving beetles (Dytiscidae) was initiated by Dr M. Balke in 1995. The genus Exocelina (91 described species) is a recently discovered water beetle group with high levels of diversification and endemism throughout the Australian and Pacific Regions. The genus was first described as subgenus Papuadytes Balke, 1998 of the genus Copelatus Erichson, 1832 for more than 30 New Guinean species. As a result of transferring the Australian Exocelina advena Broun, 1886 into Papuadytes, the latter name became a synonym of the older genus name. New Guinea is the core of diversity of the genus, but it remains least studied. There is no key to identify the already described species and extensive recent fieldwork in New Guinea revealed the existence of more than 100 additional new species. No morphological and taxonomic work was carried out since the genus had been described, except for descriptions of several new species, whereas a number of phylogenetic examinations on Exocelina were conducted by Dr M.Balke using molecular data (DNA sequences). However, only 24 species were used in his phylogenetic analyses and only eight of them carried valid scientific names, the others were only classified using voucher numbers. Absence of described and named species acts as a brake on further molecular study of the genus, as it is crucial now to delimit species based on morphology, to understand where DNA sequence data fail to reveal recently diverged morphospecies and how many species there are in total. Adding formal descriptions and morphological data will also allow more detailed studies of patterns and processes involved in the species delineation of the New Guinean Exocelina, to test the hypothesis of the monophyletic nature of the group and its clades, and to study the phylogeny and evolution of the genus with a complex approach. The main project goal is to investigate the evolution of Exocelina in the complex geological and ecological environment of New Guinea. To fulfill this goal we will 1) carry out a taxonomic revision of the genus, with descriptions of the new species; 2) test species limits based on morphological characters and molecular data; 3) analyze relationships within the genus based on morphological characters and on molecular data separately; 5) carry out combined phylogenetic analysis, based on morphological characters and molecular data, including biogeographical and ecological aspects. The project will be carried out at the Naturhistorisches Museum Wien and is planned as an international cooperation with Dr M. Balke, Zoologische Staatssammlung München. We believe that our project is of great importance since it will bring new data in two aspects. First, its results will test/support several general theoretical and methodological hypotheses in biogeography, e.g. a long-distance dispersal might play a prominent role in the formation of the Southern hemisphere distributional patterns, and in systematics, e.g. a) success of an integrate approach for species delimitation; b) more than 100 species new to science will be described. Here, the most innovative aspect is the creation of a cybertaxonomy infrastructure for scientific publications: descriptions, keys, and digital imaging linked to Wiki-online resources. The second aspect is important for the group: a) for the first time, phylogenetic analyses of Exocelina will be performed based on morphological and molecular data, combined to the largest dataset for this region and invertebrates available to date, to reconstruct the biogeographical evolution of this group; b) a new supraspecific classification of Exocelina will be proposed; c) a first key, illustrated with drawings and digital images, will be created. Results of our project will have an implication not only for other biological disciplines (e.g. ecology, and nature inventory and conservation) but also for popularization of nature study and conservation and training of local people as parataxonomists.

No additional funding sources recorded.