Symmetries and asymmetries in the topological roles of piscivorous fishes between occurrence networks and food webs.

Ecological networks represent the architecture over which diversity is assembled. The compartmentalization of trophic links and the spatial aggregation of species determine ecosystem dynamics and stability. Species traits such as body size or those related to dispersal ability or environmental and trophic niche may determine the role of a species in different ecological networks such as food webs and occurrence networks.

Ecological and phylogenetic determinants of life-history patterns among ten loricariid species.

We analysed the influence of ecological factors, phylogenetic history and trade-offs between traits on the life-history variation among 10 loricariid species of the middle Paraná River. We measured eight life-history variables and classified the life-history strategies following the equilibrium-periodic-opportunistic (EPO) model. Principal-component analysis of life-history traits segregated species along a gradient from small opportunistic (low fecundity, low parental investment) to large equilibrium (low-medium fecundity, high parental investment) species.