Digital.CSIC > Recursos Naturales > Centro de Estudios Avanzados de Blanes (CEAB) > (CEAB) Artículos >





Closed Access item Predation by introduced fish constrains the thermal distribution of aquatic Coleoptera in mountain lakes

Authors:De Mendoza, Guillermo
Rico, Eugenio
Catalán, Jordi
Keywords:Population fragmentation, Salmonidae, Alien species, Climate warming, Dytiscidae
Issue Date:2012
Publisher:Blackwell Publishing
Citation:Freshwater Biology 57 : 803–814 (2012)
Abstract:1. Most high mountain lakes were free of fish until humans stocked them. This provides the opportunity to study the extent to which predation constrains the thermal distribution of large macroinvertebrates, among lakes of a suitable temperature for them. 2. We analysed the distribution of aquatic beetles (Coleoptera, Dytisicidae, including the genera Agabus, Platambus, Hydroporus and Boreonectes) in a set of 82 lakes in the Pyrenees. Temperature was the most important variable explaining the overall distribution of dytiscids (out of 29 environmental variables considered). The presence of fish (i.e. salmonids) and macrophyte cover (plants provide refuge from predators) was also important. Indeed, either salmonids or macrophytes as single factors explained more of the variance in dytiscid distribution than temperature. 3. Further analysis showed that the presence of salmonids was particularly important for the medium-sized dytiscid Agabus bipustulatus. This species is generally eurythermic, although in the Pyrenees it is found mainly in cold lakes. This is attributed to predation pressure from fish, since the latter are more likely to be present in warm lakes. As a consequence, salmonids increase fragmentation of A. bipustulatus with respect to populations occupying lowland habitats. 4. Predation can therefore constrain the distribution of species to a fraction of habitats that appear suitable based on simple thermal responses. As humans also facilitate the dispersal of non-native fish, the consequent modification of distribution patterns in fresh waters could make it difficult to predict how distributions might change in relation to climate warming.
Description:12 páginas, 5 figuras, 2 tablas.
Publisher version (URL):http://dx.doi.org/10.1111/j.1365-2427.2012.02746.x
Appears in Collections:(CEAB) Artículos

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.