Feeding ecology of the critically endangered Valencia letourneuxi (Valenciidae)

Abstract

Valencia letourneuxi is a critically endangered freshwater fish in urgent need of targeted conservation. Little information is however available on its life history and feeding ecology; therefore, food resource utilization by V. letourneuxi was studied in its most abundant known Greek population of Chiliadou stream. The diet of this population appears to be dominated by microcrustaceans, Dipteran larvae, Acari, and Mollusca. Its feeding is highly dependent on seasonal prey availability and diversity, with niche overlap being low only between winter and the rest of the seasons, indicating that only during winter its diet differs significantly in relation to the other seasons. There are no significant sex-and sizerelated dietary shifts. This V. letourneuxi population is characterized by a generalist feeding strategy and appears to consist mostly of individuals with broad niches. Its generalist feeding pattern and dietary flexibility permits it to fully exploit this very diverse and rich habitat and may account for the high local abundance of this population.

Prey utilisation and trophic overlap between the non native mosquitofish and a native fish in two Mediterranean rivers

“…However, the wet season is actually characterized by lower macroinvertebrate and algae biomass Mar. Sci., 15/2, 2014, 287-301 297 availabilities (for the seasonality of macroinvertebrates in a typical V. letourneuxi habitat, see Kalogianni et al, 2010b); consequently, the intensity of the competitive interactions inferred here for the summer period could be even more enhanced in winter. Furthermore, the profound differences of the two study sites as regards macroinvertebrate fauna availability, enabled a comparative study of the ecological interactions of the two species under two very distinct abiotic and biotic conditions.…”

“…for the G. holbrooki population of Lake Hévíz, Hungary, Specziár, 2004), while low levels of plant consumption were also reported for the only V. letourneuxi population previously studied (Kalogianni et al, 2010b). The higher plant material consumption of the mosquitofish, especially in the Acheron habitat, however, denotes a shift of G. holbrooki to a suboptimal but easily accessible and readily available food resource, possibly as an efficient buffer strategy when animal resources are scarce (Magalhães, 1993;Ribeiro et al, 2007).…”

“…At the laboratory, only fish larger than 16 mm SL were included in the dietary analysis (a size range roughly corresponding to the adult stage of both species, see Barbieri et al, 2000;Pyke, 2005;Kalogianni et al, 2010b), in order to minimize ontogenetic variation in their diet. Specimens were weighed before and after being eviscerated (TW and NW, nearest 0.01 mg).…”

Reduced genetic variation and strong genetic population structure in the freshwater killifishValencia letourneuxi(Valenciidae) based on nuclear and mitochondrial markers

“…Drought events, however, do not appear to be the main explanation for V. letourneuxi , as the species occupies lowland spring‐fed habitats with stable riverine conditions. Furthermore, population studies in some of the V. letourneuxi habitats do not indicate dramatic seasonal or yearly fluctuations in the species’ abundance (Kalogianni et al ., and unpublished data).…”

“…Valencia toothcarp Valencia hispanica is found along the Mediterranean coast of eastern Spain, between Tortosa and Cape San Antonio (Kottelat & Freyhof, ). Valencia letourneuxi 's historical distribution included southern Albania, the Ionian Islands, western continental Greece and western Peloponnese (from Lake Butrint in Albania to the Alfios drainage in Peloponnese, Bianco & Miller, ; Barbieri et al ., ; Barbieri, Stoumboudi & Economou, ; Kottelat & Freyhof, ; Kalogianni et al ., , b).…”