Pattern and process in the ecological biogeography of European freshwater fish

Abstract

Summary Species lists for regions of Europe defined by Illies (1978, Limnofauna Europaea , 2nd edn. Gustav Fischer Verlag, Stuttgart), and augmented by information from Maitland (2000, Guide to Freshwater Fish of Britain and Europe . Hamlyn, London), are used to describe patterns in freshwater fish species richness and to examine the contribution of habitat preference, migration, body size and glacial history to these patterns. 2. The number of non-endemic species declines to the north and west, with increasing distance from the Ponto-Caspian region, the main source area, whereas endemic species richness declines only with latitude. 3. Habitat generalists tend to be migratory while riverine specialists are usually resident. Similar numbers of riverine species and generalists occur in Europe as a whole but generalists dominate in regional faunas and, to an increasing extent, in more isolated, formerly glaciated areas. Very few lacustrine specialists were found, reflecting the geologically ephemeral nature of lakes. Only 8% of riverine species have colonized glaciated areas, compared with more than half the generalist species, and the number declines rapidly with increasing distance from the source area. 4. Diadromous species show no geographical variation in species richness but potamodromous and resident species are affected by glaciation and by mountain and marine barriers. 5. The mean body size of regional faunas increases with latitude because there are relatively fewer small species in more distant, glaciated areas. 6. About half the species occurring in Europe are restricted to one region and the majority of these endemics occur in barrier regions with Mediterranean climates. Species in glaciated regions have much larger range sizes. Habitat preference and migration type, not body size, are the main determinants of range size. 7. Freshwater habitat availability varies across Europe with glaciated areas having more lakes of a given size than unglaciated areas. Catchment size is greatest at mid-latitudes. For a given catchment size rivers in glaciated areas are shorter. 8. The results support the notion that habitat variability, on both short and long time scales, favours colonization ability, which requires large body size. 9. As a result of their limited vagility northern fish faunas are depauperate, show high levels of plasticity and polymorphism and may show elevated speciation rates. The isolated southern faunas of the Iberian and Italian peninsulas and the Balkans are rich in endemic species but may be subject to extinctions because of the spread of the highly seasonal Mediterranean climate.

Past, present and future of the fish community of Lake Orta (Italy), one of the world’s largest acidified lakes

“…Indeed, although Alpine barriers and glaciation events likely determined species richness, species that overcame such factors faced various abiotic and biotic constraints and opportunities that modulated the fish assemblage (Griffiths, 2006;Gandolfi et al, 1991). Beginning in the 19 th century the fish communities of alpine Italian lakes faced significantly more human interventions.…”

Size diversity and species diversity relationships in fish assemblages of Western Palearctic lakes

“…The different patterns for the size-species relationship along latitude will be potentially driven by biogeographical and ecological processes (Micheli and Halpern 2005, Guillemot et al 2011, Stuart-Smith et al 2013, Arran et al 2017. Glaciations in central and northern Europe have caused an impoverished fish fauna (Dynesius and Jansson 2000, Griffiths 2006, Lévêque et al 2008, with dominance of large-…”

“…All rights reserved.' bodied ecological generalist species capable of exploiting a variety of ecological niches and with increased levels of intraspecific variability (Robinson and Schluter 2000, Griffiths 2006, Blanchet et al 2010. Since body size is a good proxy of niche separation, we may expect a higher size overlap in fish species of these regions and, as a consequence, a weaker coupling between size diversity and species diversity.…”

“…In contrast, fish communities in southern lakes (e.g. Mediterranean region) have had longer time for speciation due to the lack of widespread major glaciations (Griffiths 2006). These different biogeographical histories may have resulted in different relationships between size and species diversity.…”

Fish-based groups for ecological assessment in rivers: the importance of environmental drivers on taxonomic and functional traits of fish assemblages

“…Due to zoogeographical traits, Iberian fish fauna is very rich in endemisms, many restricted to particular basins. Native species richness per site is generally low (Griffiths, 2006;Reyjold et al, 2007) and had undergone a steep decline during the last decades (Doadrio, 2002;Cabral et al, 2005;Smith and Darwall, 2006;Ribeiro et al, 2009). Moreover fish assemblages from Iberain Peninsula may present a high variability both at seasonal and inter-annual scale determined by the influence of Mediterranean climate (Gasith and Resh, 1999;Bernardo et al, 2003;Ilhéu, 2004).…”