Environmental Biology of Fishes 65: 387–400, 2002. © 2002 Kluwer Academic Publishers. Printed in the Netherlands. Life-history patterns of 25 species from European freshwater fish communities Anna Vila-Gispert & Ramon Moreno-Amich Institute of Aquatic Ecology and Department of Environmental Sciences, University of Girona, Campus de Montilivi, 17071 Girona, Spain (e-mail: anna.vila@udg.es) Received 21 March 2001 Accepted 15 February 2002 Key words: life-history styles, trilateral continuum model, life-history variables trade-offs, phylogenetic constraints Synopsis Fish life-history patterns were evaluated in relation to the trilateral continuum model by analyzing data from 25 species inhabiting European freshwaters. Multivariate tests identified a trend between later-maturing fishes with higher fecundity, larger size, and few spawning bouts per year and the opposite suite of traits with small fishes. A second trend contrasted fishes having parental care, smaller eggs, and longer breeding seasons against fishes with the opposite suite of traits. As a result, two extreme life-history patterns could be identified among European freshwater fish species: opportunistic and periodic. Nevertheless, intermediate patterns were also present. A true equilibrium life-history pattern was not represented among 25 fish species from European freshwaters. The high concordance of basic life-history patterns among distantly related taxa is probably caused by some universal trade- offs among life-history variables. As a consequence, only a limited life-history patterns may be recognizable among fish species, independently of the origin of fish communities. Introduction Balon (1975) proposed a comparative framework useful for predicting the response of fish populations to different kinds of environments and disturbances. Such framework contain few categories and it group simi- lar species irrespective of phylogenetic origin. Balon’s (1975, Balon et al. 1977) reproductive guild framework was based on the premise that environmental require- ments and adaptations of early life stages are likely to account for a large amount of the variance in densi- ties and geographical distributions of fish populations. Because it is qualitative and emphasizes the physio- logical ecology of early life stages, the reproductive guild concept is limited in its application because it does not easily yield quantitative predictions. Hence, a general comparative framework that could interface with both qualitative schemes, like reproductive guilds, and quantitative population models is desirable. Life-history theory deals with constraints among demographic variables and traits associated with reproduction and the manner in which these con- straints, or trade-offs, shape behaviors for dealing with different kinds of environments. Comparative life- history studies of fishes in very different environments have independently identified three similar life- history patterns as endpoints of a triangular con- tinuum (Kawasaki 1980, 1983, Baltz 1984, Mahon 1984, Wootton 1984, Winemiller 1989, Paine 1990, Winemiller & Rose 1992). Following Winemiller & Rose (1992), an ‘opportunistic strategy’ identifies small fishes with early maturation, small eggs, small clutches, and continuous spawning which are well equipped to repopulate habitats following disturbances. This suite of life-history traits permits efficient recol- onization of habitats over relatively small spatial scales. These small fishes frequently maintain dense populations in marginal habitats (e.g. ecotones, con- stantly changing habitats) and frequently experience high predation mortality during the adult interval (Winemiller & Rose 1992). A ‘periodic strategy’ iden- tifies fishes that delay maturation in order to attain