Trophic ecology of a nonnative population of suckermouth catfish (Hypostomus plecostomus) in a central Texas spring-fed stream

Abstract

Introduced suckermouth catfishes (Family Loricariidae) are now established in a number of spring-influenced streams in North America but their impacts on native biota are not well documented. Purposes of this study were to quantify gut contents of the loricariid Hypostomus plecostomus from the San Marcos River in central Texas and to evaluate the role of H. plecostomus in the San Marcos River food web using stable isotope analysis. Gut content analysis indicated that H. plecostomus (N=36) primarily consumed amorphous detritus (87% in biovolume), filamentous red algae (5.4%), and picoplankton (4.1%). Macrophytes, macroinvertebrates, and fish eggs were not found in gut contents. Stable isotopes demonstrate that H. plecostomus occupies a trophic position indicative of an herbivore and likely utilizes detritus of algal origin. The results from our study suggest that large populations of H. plecostomus in the San Marcos River may directly compete with several native herbivorous fishes and may be disrupting trophic flows and nutrient cycling in spring-influenced streams of central and west Texas.

Isotopic niches of sympatric native and exotic fish species in a Neotropical floodplain

“…Moreover, these studies have practical applications when assessing possible impacts of exotic species on native species (Clarke et al 2005, Pound et al 2011. Stable isotope analysis is becoming a very useful tool in studies that investigate the trophic ecology of native and exotic species (Cucherousset et al 2012, Jackson et al 2012.…”

High impact of low-trophic-position invaders: nonnative grazers alter the quality and quantity of basal food resources

“…High fish standing stocks and high per capita consumption rates of this food resource combined to yield a dramatic reduction in epilithon abundance. Loricariids frequently attain high population densities in invaded systems (Chavez et al 2006, Levin et al 2008, Mendoza et al 2009, Nico et al 2009, Pound et al 2011. Therefore, their effects may be especially profound in stream food webs that are supported by autochthonous production.…”

“…Loricariids may compete directly with native grazers and negatively affect their populations by altering the quality and quantity of epilithon in the Chacamax River (Gido and Franssen 2007, Mendoza-Carranza et al 2010, Pound et al 2011. Dominant native grazers typically have strong, negative effects on other benthic organisms via resource exploitation (Feminella and Hawkins 1995).…”

Parasites of two coexisting invasive sailfin catfishes (Siluriformes: Loricariidae) in a tropical region of Mexico

“…North America: Fuller et al, 1999;Capps, 2008;Gibbs et al, 2008;Pound et al, 2011;Puerto Rico: Bunkled-Williams et al, 1994;México: Guzmán & Barragán, 1997;Wakida-Kusunoki et al, 2007;Wakida-Kusunoki & Amador-del Ángel, 2011;Taiwan: Liang et al, 2005; Philippines: Chavez et al, 2006;Turkey: Özdilek, 2007; Poland: Keszka et al, 2008;Vietnam: Levin et al, 2008;Java and Australia: Capps, 2008;Bangladesh: Hossain et al, 2008;Italy: Piazzini et al, 2010;Serbia: Simonović et al, 2010 andTailand: Chaichana &Jongphadungkiet, 2012). It has been suggested that in most of those recipient areas recorded so far, aquarists were assigned responsibility for releasing the catfishes into natural ecosystems and the their subsequent establishment (Simonović et al, 2010).…”

“…The main problem caused by these species is the competition for space and food with native fish species, including those commercially important (Martínez-Palacios et al, 2009;Sandoval-Huerta et al, 2012). However, nowadays there is little information available about their parasitic fauna (Mendoza-Franco et al, 2012) and the role of these parasite species as potential pathogens to native fish species or humans (Pound et al, 2011).…”