Concepts of island biogeography, Australasian Copelatinae

Ever since Darwin and Wallace, island biodiversity and evolution of faunal diversity on islands have intrigued biologists. In the present project, we are going to test some theories of island biogeography using diving beetles of the subfamily Copelatinae in Australasia. This region is attractive for scientific research not only because it is one of 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. No data on water beetles from many parts of the region were available until scientists of ZSM and NHMW initiated a study on diving beetles (Dytiscidae) in 1995. Copelatinae is the second largest subfamily of Dytiscidae and one of its most taxonomically and phylogenetically enigmatic groups. In Australasia, the subfamily is represented by its speciose genera: Copelatus Erichson, 1832 and Exocelina Broun, 1886. While the latter has been well studied in our previous project, Copelatus remains poorly examined being the most species-rich and taxonomically challenging genus of Dytiscidae. The main project goal is to investigate the evolution of the species diversity of Copelatinae in the complex geological and ecological environment of Australasia using the obtained relationship hypotheses. We will 1) carry out a taxonomic study of Copelatus, 2) describe new species based on morphological and molecular data, 3) analyze relationships within the genus based on molecular data, 4) investigate the character evolution of the genus, 5) continue to study Exocelina: new species descriptions, biogeographical analyses, 6) study biogeographical and ecological aspects of the subfamily. The project will be carried out at the Naturhistorisches Museum Wien by Dr H. Shaverdo, and is planned as an international cooperation with Dr M. Balke and Dr L. Hendrich, Zoologische Staatssammlung München, Germany and Dr J. Hjek, Nrodn Museum Praha, Prague, Czechia. We believe that our project is of great importance since it will bring new data in two aspects. First, its results will test several general concepts in island biogeography, which explain how species colonize islands and develop on them, how new species appear and old species disappear, why there are many endemics on islands, how island geological history affects all these processes, as well as more than 80 species new to science will be described. The second aspect is important for the group: a) for the first time, the genus Copelatus will be studied using molecular and morphological data to reconstruct the biogeographical evolution of this group; b) a new preliminary classification of Copelatus will be proposed; c) first identification tables, 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 entomologists.

Island biogeography was one of the themes of our previous project "Systematics, phylogeny, and biogeography of New Guinean Exocelina". In the present project, we focused further on it and test some of its postulates using Copelatinae diving beetles to explain their species richness on the actual islands of Australasia. Australasian Realm has a highly complex geological history and extraordinary biological diversity with many unique plants and animals. It is limited to the eastern part of Indonesian Archipelago, New Guinea, several Pacific island groups, Australia, and New Zealand. Insects are tremendously diverse in the region and play vital roles in ecosystems, but remain poorly known, especially beetles. Predacious diving beetles (Dytiscidae) are carnivorous insects which are found in almost all aquatic habitats and count over 4700 species worldwide. With its Australasian genera Exocelina and Copelatus, Copelatinae is the second largest subfamily of Dytiscidae and is considered one of the most taxonomically and phylogenetically enigmatic diving beetle groups. In our previous project, we described 80 new Exocelina species from New Guinea and discovered that there was still a huge hidden species diversity in this genus as well as in genus Copelatus. Therefore, our present research focused on these insect groups. In the present project, we described 41 more new Exocelina species and created species-group structure of the genus that includes 26 species groups. We revealed that representatives of Copelatus are very diverse and, based on our morphological study and molecular analyses, we delimited the new genus Austrelatus, for which 81 new species from New Guinea, Solomon Islands, and Oriental Region were described. Also, one new species of Copelatus was described from Australia and New Guinea. An important part of our work was creating identification keys for genera and species providing them with high quality morphological character illustrations, distribution maps and habitat photos. We studied genus and species phylogenetic relationships and evolution and tested some general biogeographical hypotheses. We found out that genera Exocelina and Austrelatus originated in Australia and from there colonised New Guinea, some Pacific islands, Indonesian Archipelago and even Oriental Region. Some colonisations were very successful resulting, e.g., in a radiation of more than 150 Exocelina species and 80 Austrelatus species in New Guinea. We also showed that the main reason for this species diversity is geological evolution of the islands. Our results influenced the general fields of science. They are essential for any scientific discipline, which deals with biological objects and uses species names as labels for organisms. Our identification tables and distributional maps can be widely used in ecological research and nature conservation. For that, we increased availability of our data not only by publishing them in scientific papers, but also by dissemination them through the cybersources.