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Rodolphe E. Gozlan - One of the best experts on this subject based on the ideXlab platform.
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chemically mediated sexual display postures in pre ovulatory female topmouth gudgeon Pseudorasbora parva
Behaviour, 2012Co-Authors: Demetra Andreou, Dean Burnard, Peter C Hubbard, Carsten Theodor Muller, Sian Wyn Griffiths, M D Osselton, Adelino V M Canario, Rodolphe E. GozlanAbstract:While mating systems vary considerably throughout the animal kingdom, smell is increasingly recognised as a common factor in successful copulation. However, the full range of olfactory- induced mating behaviours among animals is undoubtedly underestimated in comparison to visual or contact stimuli, and this underestimation suggests that our understanding of courtship rituals may be incomplete. Here, we use the highly invasive topmouth gudgeon, Pseudorasbora parva as a biological model to separate and validate the induction of headstands as courtship behaviour in many fish species. Conspecific odour was isolated using solid phase extraction (SPE) and fractionated using high-performance liquid chromatography (HPLC). Active fractions were characterised using nuclear magnetic resonance (NMR). Electrophysiological responses of pre-ovulatory females to conspecific odour were also tested via the electro-olfactogram (EOG). Results revealed that pre-ovulatory females adopted headstand body postures during exposure to nest guarding male odour (4/12) and SPE extract (5/12) but did not display during exposure to any other odour. Fractions from HPLC yielded 1 active fraction that induced headstand body postures in pre-ovulatory females (4/12). The active fraction eluted at 30–35 min and showed no response in the UV. NMR imaging revealed low intensity levels of aliphatic protons: methylene protons (CH2) at around 2 parts per million (ppm) and methin (CH) at around 3 ppm. EOG response amplitudes were approximately double in response to pre-ovulatory female odour than to odour derived from post-ovulatory females (Mann–Whitney U-test, p < 0 . 01 , N = 6 ). This study provides evidence of sex-specific chemical cues and responsive, adaptive sexual behaviour in P. parva and demonstrates that female display postures may be induced by chemical stimuli alone.
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pan continental invasion of Pseudorasbora parva towards a better understanding of freshwater fish invasions
Fish and Fisheries, 2010Co-Authors: Rodolphe E. Gozlan, Nuno Caiola, P. Cakic, Kathleen Beyer, Demetra Andreou, Takashi Asaeda, Rachid Bouhadad, Dean Burnard, Vesna Djikanovic, Hamid Reza EsmaeiliAbstract:In recent years, policy-makers have sought the development of appropriate tools to prevent and manage introductions of invasive species. However, these tools are not well suited for introductions of non-target species that are unknowingly released alongside intentionally-introduced species. The most compelling example of such invasion is arguably the topmouth gudgeon Pseudorasbora parva, a small cyprinid species originating from East Asia. A combination of sociological, economical and biological factors has fuelled their rapid invasion since the 1960s; 32 countries (from Central Asia to North Africa) have been invaded in less than 50 years. Based on a combination of monitoring surveys (2535 populations sampled) and literature reviews, this paper aims to quantify and characterise important invasion parameters, such as pathways of introduction, time between introduction and detection, lag phase and plasticity of life history traits. Every decade, five new countries have reported P. parva introduction, mainly resulting from the movement of Chinese carps for fish farming. The mean detection period after first introduction was 4 years, a duration insufficient to prevent their pan-continental invasion. High phenotypic plasticity in fitness related traits such as growth, early maturity, fecundity, reproductive behaviour and the ability to cope with novel pathogens has predisposed P. parva to being a strong invader. The Pseudorasbora parva invasion has provided quantitative data for the development of 1) early warning systems across different spatial scales; 2) rapid eradication programmes prior to natural spread in open systems and 3) sound risk assessments with emphasis on plasticity of life history traits.
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Pan‐continental invasion of Pseudorasbora parva: towards a better understanding of freshwater fish invasions
Fish and Fisheries, 2010Co-Authors: Rodolphe E. Gozlan, Nuno Caiola, P. Cakic, Kathleen Beyer, Demetra Andreou, Takashi Asaeda, Rachid Bouhadad, Dean Burnard, Vesna Djikanovic, Hamid Reza EsmaeiliAbstract:In recent years, policy-makers have sought the development of appropriate tools to prevent and manage introductions of invasive species. However, these tools are not well suited for introductions of non-target species that are unknowingly released alongside intentionally-introduced species. The most compelling example of such invasion is arguably the topmouth gudgeon Pseudorasbora parva, a small cyprinid species originating from East Asia. A combination of sociological, economical and biological factors has fuelled their rapid invasion since the 1960s; 32 countries (from Central Asia to North Africa) have been invaded in less than 50 years. Based on a combination of monitoring surveys (2535 populations sampled) and literature reviews, this paper aims to quantify and characterise important invasion parameters, such as pathways of introduction, time between introduction and detection, lag phase and plasticity of life history traits. Every decade, five new countries have reported P. parva introduction, mainly resulting from the movement of Chinese carps for fish farming. The mean detection period after first introduction was 4 years, a duration insufficient to prevent their pan-continental invasion. High phenotypic plasticity in fitness related traits such as growth, early maturity, fecundity, reproductive behaviour and the ability to cope with novel pathogens has predisposed P. parva to being a strong invader. The Pseudorasbora parva invasion has provided quantitative data for the development of 1) early warning systems across different spatial scales; 2) rapid eradication programmes prior to natural spread in open systems and 3) sound risk assessments with emphasis on plasticity of life history traits.
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Morphological variability of the Asiatic cyprinid, topmouth gudgeon Pseudorasbora parva, in its introduced European range
Journal of fish biology, 2009Co-Authors: Eva Záhorská, Gordon H. Copp, Kathleen Beyer, Vladimír Kováč, I. Falka, Stanislav Katina, Rodolphe E. GozlanAbstract:To assess the spatial variability in external morphology of non-native populations of topmouth gudgeon Pseudorasbora parva within an ontogenetic context, triple regression analysis (distance-based measurements) was applied to data from eight European populations (two Slovak, four Romanian, one English and one French). The data from Slovakia were also subjected to geometrical analysis (co-ordinates-based measurements) to obtain a more complex picture of the species' overall morphology. Great phenotypic variability was observed, being expressed not only in the formation of different definite phenotypes but also in the manner by which the phenotypes are achieved. Thus, both the definite phenotype and the patterns of development in invasive P. parva may be highly influenced by environmental conditions. Such great morphological (phenotypic) variability is likely to be one of the attributes that make this species such a successful invader.
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Is topmouth gudgeon Pseudorasbora parva responsible for the decline in sunbleak Leucaspius delineatus populations
Journal of Fish Biology, 2007Co-Authors: Alexandre Carpentier, Rodolphe E. Gozlan, Julien Cucherousset, Jean-marc Paillisson, Loïc MarionAbstract:In England, a severe decline of introduced sunbleak Leucaspius delineatus populations has been attributed to the introduction of the invasive topmouth gudgeon Pseudorasbora parva. In France, however, after 4 years of P. parva colonization in a large natural lake, no demonstrated impacts on the native L. delineatus populations have been observed. This suggests that the original impacts observed in England, such as spawning inhibition and high mortality, were the result of an emerging pathogen, the rosette-like agent, hosted by L. delineatus rather than P. parva.
Kathleen Beyer - One of the best experts on this subject based on the ideXlab platform.
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pan continental invasion of Pseudorasbora parva towards a better understanding of freshwater fish invasions
Fish and Fisheries, 2010Co-Authors: Rodolphe E. Gozlan, Nuno Caiola, P. Cakic, Kathleen Beyer, Demetra Andreou, Takashi Asaeda, Rachid Bouhadad, Dean Burnard, Vesna Djikanovic, Hamid Reza EsmaeiliAbstract:In recent years, policy-makers have sought the development of appropriate tools to prevent and manage introductions of invasive species. However, these tools are not well suited for introductions of non-target species that are unknowingly released alongside intentionally-introduced species. The most compelling example of such invasion is arguably the topmouth gudgeon Pseudorasbora parva, a small cyprinid species originating from East Asia. A combination of sociological, economical and biological factors has fuelled their rapid invasion since the 1960s; 32 countries (from Central Asia to North Africa) have been invaded in less than 50 years. Based on a combination of monitoring surveys (2535 populations sampled) and literature reviews, this paper aims to quantify and characterise important invasion parameters, such as pathways of introduction, time between introduction and detection, lag phase and plasticity of life history traits. Every decade, five new countries have reported P. parva introduction, mainly resulting from the movement of Chinese carps for fish farming. The mean detection period after first introduction was 4 years, a duration insufficient to prevent their pan-continental invasion. High phenotypic plasticity in fitness related traits such as growth, early maturity, fecundity, reproductive behaviour and the ability to cope with novel pathogens has predisposed P. parva to being a strong invader. The Pseudorasbora parva invasion has provided quantitative data for the development of 1) early warning systems across different spatial scales; 2) rapid eradication programmes prior to natural spread in open systems and 3) sound risk assessments with emphasis on plasticity of life history traits.
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Pan‐continental invasion of Pseudorasbora parva: towards a better understanding of freshwater fish invasions
Fish and Fisheries, 2010Co-Authors: Rodolphe E. Gozlan, Nuno Caiola, P. Cakic, Kathleen Beyer, Demetra Andreou, Takashi Asaeda, Rachid Bouhadad, Dean Burnard, Vesna Djikanovic, Hamid Reza EsmaeiliAbstract:In recent years, policy-makers have sought the development of appropriate tools to prevent and manage introductions of invasive species. However, these tools are not well suited for introductions of non-target species that are unknowingly released alongside intentionally-introduced species. The most compelling example of such invasion is arguably the topmouth gudgeon Pseudorasbora parva, a small cyprinid species originating from East Asia. A combination of sociological, economical and biological factors has fuelled their rapid invasion since the 1960s; 32 countries (from Central Asia to North Africa) have been invaded in less than 50 years. Based on a combination of monitoring surveys (2535 populations sampled) and literature reviews, this paper aims to quantify and characterise important invasion parameters, such as pathways of introduction, time between introduction and detection, lag phase and plasticity of life history traits. Every decade, five new countries have reported P. parva introduction, mainly resulting from the movement of Chinese carps for fish farming. The mean detection period after first introduction was 4 years, a duration insufficient to prevent their pan-continental invasion. High phenotypic plasticity in fitness related traits such as growth, early maturity, fecundity, reproductive behaviour and the ability to cope with novel pathogens has predisposed P. parva to being a strong invader. The Pseudorasbora parva invasion has provided quantitative data for the development of 1) early warning systems across different spatial scales; 2) rapid eradication programmes prior to natural spread in open systems and 3) sound risk assessments with emphasis on plasticity of life history traits.
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Morphological variability of the Asiatic cyprinid, topmouth gudgeon Pseudorasbora parva, in its introduced European range
Journal of fish biology, 2009Co-Authors: Eva Záhorská, Gordon H. Copp, Kathleen Beyer, Vladimír Kováč, I. Falka, Stanislav Katina, Rodolphe E. GozlanAbstract:To assess the spatial variability in external morphology of non-native populations of topmouth gudgeon Pseudorasbora parva within an ontogenetic context, triple regression analysis (distance-based measurements) was applied to data from eight European populations (two Slovak, four Romanian, one English and one French). The data from Slovakia were also subjected to geometrical analysis (co-ordinates-based measurements) to obtain a more complex picture of the species' overall morphology. Great phenotypic variability was observed, being expressed not only in the formation of different definite phenotypes but also in the manner by which the phenotypes are achieved. Thus, both the definite phenotype and the patterns of development in invasive P. parva may be highly influenced by environmental conditions. Such great morphological (phenotypic) variability is likely to be one of the attributes that make this species such a successful invader.
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Hybridisation between Pseudorasbora parva and Leucaspius delineatus
Folia Zoologica, 2006Co-Authors: Rodolphe E. Gozlan, Kathleen BeyerAbstract:Hybridisation between introduced and native species is an increasingly important issue concerning environmental stakeholders because it decreases genetic integrity of native stocks. However, hybridisation could also happen between non-native species even if these species belong to different genera. Our study illustrates this particular aspect of alien species invasion with the attempt of artificial hybridisation between sunbleak Leucaspius delineatus and topmouth gudgeon Pseudorasbora parva, both recent additions to the freshwater fish fauna of England. The crossed fertilisation of L. delineatus ova with P. parva sperm lead to viable eggs with a very high hatching rate of 86% although hybrids failed to develop beyond the 1st larval step. Early morphological development of these hybrids was quantified and compared to the early development of the pure bred species.
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Biometric data and bone identification of topmouth gudgeon, Pseudorasbora parva and sunbleak, Leucaspius delineatus
Folia Zoologica, 2006Co-Authors: Kathleen Beyer, Gordon H. Copp, Rafael Miranda, Rodolphe E. GozlanAbstract:a b s t r a c t. Biometric relationships between bone dimensions and body size are presented for topmouth gudgeon Pseudorasbora parva and sunbleak Leucaspius delineatus, two invasive fish species in the UK. This study also provides a tool for identification of these species using key bones. Such information facilitates the assessment of the potential role of these invaders in the diet of piscivorous fauna.
Takashi Asaeda - One of the best experts on this subject based on the ideXlab platform.
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pan continental invasion of Pseudorasbora parva towards a better understanding of freshwater fish invasions
Fish and Fisheries, 2010Co-Authors: Rodolphe E. Gozlan, Nuno Caiola, P. Cakic, Kathleen Beyer, Demetra Andreou, Takashi Asaeda, Rachid Bouhadad, Dean Burnard, Vesna Djikanovic, Hamid Reza EsmaeiliAbstract:In recent years, policy-makers have sought the development of appropriate tools to prevent and manage introductions of invasive species. However, these tools are not well suited for introductions of non-target species that are unknowingly released alongside intentionally-introduced species. The most compelling example of such invasion is arguably the topmouth gudgeon Pseudorasbora parva, a small cyprinid species originating from East Asia. A combination of sociological, economical and biological factors has fuelled their rapid invasion since the 1960s; 32 countries (from Central Asia to North Africa) have been invaded in less than 50 years. Based on a combination of monitoring surveys (2535 populations sampled) and literature reviews, this paper aims to quantify and characterise important invasion parameters, such as pathways of introduction, time between introduction and detection, lag phase and plasticity of life history traits. Every decade, five new countries have reported P. parva introduction, mainly resulting from the movement of Chinese carps for fish farming. The mean detection period after first introduction was 4 years, a duration insufficient to prevent their pan-continental invasion. High phenotypic plasticity in fitness related traits such as growth, early maturity, fecundity, reproductive behaviour and the ability to cope with novel pathogens has predisposed P. parva to being a strong invader. The Pseudorasbora parva invasion has provided quantitative data for the development of 1) early warning systems across different spatial scales; 2) rapid eradication programmes prior to natural spread in open systems and 3) sound risk assessments with emphasis on plasticity of life history traits.
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Pan‐continental invasion of Pseudorasbora parva: towards a better understanding of freshwater fish invasions
Fish and Fisheries, 2010Co-Authors: Rodolphe E. Gozlan, Nuno Caiola, P. Cakic, Kathleen Beyer, Demetra Andreou, Takashi Asaeda, Rachid Bouhadad, Dean Burnard, Vesna Djikanovic, Hamid Reza EsmaeiliAbstract:In recent years, policy-makers have sought the development of appropriate tools to prevent and manage introductions of invasive species. However, these tools are not well suited for introductions of non-target species that are unknowingly released alongside intentionally-introduced species. The most compelling example of such invasion is arguably the topmouth gudgeon Pseudorasbora parva, a small cyprinid species originating from East Asia. A combination of sociological, economical and biological factors has fuelled their rapid invasion since the 1960s; 32 countries (from Central Asia to North Africa) have been invaded in less than 50 years. Based on a combination of monitoring surveys (2535 populations sampled) and literature reviews, this paper aims to quantify and characterise important invasion parameters, such as pathways of introduction, time between introduction and detection, lag phase and plasticity of life history traits. Every decade, five new countries have reported P. parva introduction, mainly resulting from the movement of Chinese carps for fish farming. The mean detection period after first introduction was 4 years, a duration insufficient to prevent their pan-continental invasion. High phenotypic plasticity in fitness related traits such as growth, early maturity, fecundity, reproductive behaviour and the ability to cope with novel pathogens has predisposed P. parva to being a strong invader. The Pseudorasbora parva invasion has provided quantitative data for the development of 1) early warning systems across different spatial scales; 2) rapid eradication programmes prior to natural spread in open systems and 3) sound risk assessments with emphasis on plasticity of life history traits.
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Swimming restricted foraging behavior of two zooplanktivorous fishes Pseudorasbora parva and Rasbora daniconius (Cyprinidae) in a simulated structured environment
Environmental Biology of Fishes, 2006Co-Authors: Tilak Priyadarshana, Takashi AsaedaAbstract:In littoral zones of aquatic systems, submerged macrophytes have marked structural variation that can modify the foraging activity of planktivores. Swimming and feeding behavior of Pseudorasbora parva and Rasbora daniconius (Cyprinidae) on their prey Daphnia pulex and Artemia salina, respectively, was studied in a series of laboratory experiments with varying stem densities. A range of stem densities was tested for each of the two species to compare the effect of simulated macrophytes on prey attack rates and swimming speed, average stem distance (D) was measured in fish body lengths for each of the two fish species. We found that, with reducing average stem distance, the attack rate decreased in the similar trend and this trend was similar for both fish species. However, the species differed in the degree to which swimming activity was hindered at increased stem densities, and this was due to species-specific differences in the distance moved with one tail beat. Therefore, we conclude that the reductions in swimming speed with reduced average stem distance are due to the differences in fish movement per tail beat.
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Hunger-induced foraging behavior of two cyprinid fish : Pseudorasbora parva and Rasbora daniconius
Hydrobiologia, 2006Co-Authors: Tilak Priyadarshana, Takashi Asaeda, Jagath ManatungeAbstract:The feeding and swimming behaviors of Pseudorasbora parva and Rasbora daniconius (Cyprinidae) with two different prey types (Daphnia pulex and Artemia salina) at different densities (0.5, 1, 2, 5, 10, or 25 per l) were studied after 36 h of food deprivation. Full satiation was defined as the cumulative number of attacks performed until fish attain a constant attack rate which for P. parva was 425 and R. daniconius was 390 attacks. Initial feeding rates showed marked variation with prey availability. Feeding rates of fish in high prey concentrations were higher at the beginning of the experiment and decreased faster than in low prey densities. Decreases in the feeding rate at high prey densities were due to faster attainment of satiation. Feeding rates of fish across high prey densities reached a steady level after satiation. Swimming speeds of fish were inversely proportional to prey density. Moreover, the change in swimming speeds was directly related to the level of satiation. The ratios of the attack rate and the encounter rate against prey density of both fish reveal that the search for prey triggered swimming and thereby feeding during the transition from hungry to satiation. The findings of this study demonstrate that satiation plays an important role in fish foraging that should be considered a significant factor in foraging analysis.
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The effects of predation risk and current velocity stress on growth, condition and swimming energetics of Japanese minnow (Pseudorasbora parva)
Ecological Research, 2006Co-Authors: Sunardi, Takashi Asaeda, Jagath Manatunge, Takeshi FujinoAbstract:A Japanese minnow, Pseudorasbora parva, was exposed simultaneously to multiple dangers in experimental tanks. The study aimed to quantify to what extent the risk of predation coinciding with an adverse environmental factor, high flow velocity, affects prey in terms of growth and energy expenditure. In this experiment, two measures of growth (i.e., body weight and length), condition, feeding, swimming cost and behavioral responses were analyzed. The results showed that in such an environment, prey showed lowered growth and were in a poorer condition. As the prey shifted to the shallow area with high flow velocity, the prey consumed a lower ration and incurred multiple costs for swimming locomotion that might reduce the allocation of energy to biomass and energy storage. Reduction in activity might decrease the cost of locomotion, but it did not have a considerable effect on overall swimming energy expenditure. In stream ecosystems, the high swimming energy expenditure appears to magnify the effects of predation risk by causing lowered growth and a poorer condition and, hence, fitness. The present study shows that high flow velocity is one of the environmental factors that determine the energetic responses of a potential prey to the presence of predators.
Gareth D. Davies - One of the best experts on this subject based on the ideXlab platform.
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Towards the successful control of the invasive Pseudorasbora parva in the UK
Biological Invasions, 2009Co-Authors: John Robert Britton, Gareth D. Davies, M. BrazierAbstract:The aim of this paper is to detail a control programme of the invasive Asian cyprinid fish Pseudorasbora parva in the UK that was initiated in March 2005. Described as Europe’s most invasive fish, P. parva presents a risk to native fishes through the transmission of a novel pathogen and undesirable impacts arising from processes including increased inter-specific competition. Populations have been recorded in 32 UK waters since their first recording outside of aquaculture in 1996; the majority are lakes 99%. To date, the total direct cost of this programme of sustained and on-going P. parva control is approximately £190,000.
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Eradication of the invasive Pseudorasbora parva results in increased growth and production of native fishes
Ecology of Freshwater Fish, 2009Co-Authors: John Robert Britton, Gareth D. Davies, M. BrazierAbstract:Abstract – The topmouth gudgeon, Pseudorasbora parva, has been described as Europe’s most invasive fish. To control their UK invasion, some lentic populations at risk of causing fluvial dispersal have been eradicated. The first of these operations was from a lake in north-west UK in March 2005 using rotenone application; prior to eradication, their mean density was estimated as 6.1 m−2 whereas since eradication, no P. parva have been recorded. Prior to rotenone application, the majority of native fishes were removed, held off-site and reintroduced following degradation of rotenone to safe levels. In the three growth seasons since their reintroduction and P. parva eradication, the abundance, somatic growth rate and production of roach Rutilus rutilus and common bream Abramis brama have increased significantly; production is now driven by a lower number of comparatively larger, faster growing individuals. These data suggest that the eradication of this P. parva population has been highly beneficial for the growth, recruitment and production of these native species.
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Contrasting life history traits of invasive topmouth gudgeon (Pseudorasbora parva) in adjacent ponds in England
Journal of Applied Ichthyology, 2008Co-Authors: John Robert Britton, Gareth D. Davies, M. BrazierAbstract:Summary Two topmouth gudgeon Pseudorasbora parva populations were studied in adjacent ponds in Northwest England to determine the influence of density on the expression of their life history traits. Initial introduction into one of these ponds had been in 2000, with establishment of an abundant population (density in March 2005: 6.1 ± 3.2 m−2). Their transfer into the adjacent pond only occurred during brief periods of seasonal connection; this population was of low abundance (density in March 2005: 0.6 ± 0.5 m−2) and was still colonising the pond at the time of sampling. In the low-density population, individuals were significantly faster growing, maturing earlier (generally in their first year of life) and more fecund at length and age (mean batch fecundity at 50 mm: 883 compared with 473 eggs). These traits were advantageous in maximising early life reproduction, facilitating their colonisation and population establishment, a process already completed in the high-density population.
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length weight relationships of the invasive topmouth gudgeon Pseudorasbora parva in ten lakes in the uk
Journal of Applied Ichthyology, 2007Co-Authors: J. R. Britton, Gareth D. DaviesAbstract:Summary The topmouth gudgeon (Pseudorasbora parva) is a species that is becoming invasive in UK waters. Few biological studies have been completed on the species in this extended range, resulting in sparse information in some aspects of their invasion biology. Regarding length–weight relationships, this is remedied in this study by providing data for 10 lake populations in the UK. Using fish length range 2.5–11.8 cm, values of a and b in the length–weight equation are provided. Values of b ranged between 2.76 and 3.32. Across all lakes, the relationship was W = 0.011L3.03, with weight in grams and length (fork) in cm.
Carlos Garcia De Leaniz - One of the best experts on this subject based on the ideXlab platform.
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Trophic Plasticity of the Highly Invasive Topmouth Gudgeon (Pseudorasbora parva) Inferred From Stable Isotope Analysis
Frontiers in Ecology and Evolution, 2020Co-Authors: Matteo Rolla, Sofia Consuegra, Carlos Garcia De LeanizAbstract:A wide trophic niche and high trophic plasticity are often invoked to explain the successful establishment of many aquatic invaders, but there is little information regarding the diet of most invasive fish in European waters. We combined stomach content and stable isotope analysis (SIA) of 13C and 15N to examine the trophic niche of the highly invasive topmouth gudgeon (Pseudorasbora parva) in four contrasting ponds and reservoirs in South Wales. Marked differences in diet and trophic position were found among neighbouring systems only a few kilometres apart. The most diverse diet was found in ponds with the fewest number of inter-specific competitors, and resulted in topmouth gudgeon having the highest condition factor, the widest variation in δ13C and δ15N values, and the highest carbon content, typical of generalist feeders. In contrast, topmouth gudgeon that coexisted with other cyprinids, were much more likely to have empty stomachs and relied almost exclusively on plant seeds, resulting in fish having a poor condition factor and low trophic position. Comparisons with other trophic studies indicate that variation in isotope values among neighbouring sites can exceed variation across continents, making it difficult to predict the diet or trophic impacts of the invasive topmouth gudgeon. Given the importance of obtaining reliable data on trophic position for risk assessment, our study shows that the use of SIA could be used to prioritize control and eradication measures that take into account trophic plasticity.
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Trophic plasticity of the highly invasive topmouth gudgeon (Pseudorasbora parva) inferred from stable isotope analysis
2019Co-Authors: Matteo Rolla, Sofia Consuegra, Carlos Garcia De LeanizAbstract:A wide trophic niche and high trophic plasticity are often invoked to explain the successful establishment of many aquatic invaders, but there is little information regarding the diet of most invasive fish in European waters. We combined stomach content and stable isotope analysis (SIA) of 13C and 15N to examine the trophic niche of the highly invasive topmouth gudgeon (Pseudorasbora parva) in four contrasting ponds and reservoirs in South Wales. Marked differences in diet and trophic position were found among neighbouring systems only a few kilometres apart. The most diverse diet was found in ponds with the fewest number of inter-specific competitors, and resulted in topmouth gudgeon having the highest condition factor, the widest variation in {delta}13C and {delta}15N values, and the highest carbon content, typical of generalist feeders. In contrast, topmouth gudgeon that coexisted with other cyprinids, were much more likely to have empty stomachs and relied almost exclusively on plant seeds, resulting in fish having a poor condition factor and low trophic position. Comparisons with other trophic studies indicate that variation in isotope values among neighbouring sites can exceed variation across continents, making it difficult to predict the diet or trophic impacts of the invasive topmouth gudgeon. Given the importance of obtaining reliable data on trophic position for risk assessment, our study shows that the use of SIA could be used to prioritize control and eradication measures that take into account trophic plasticity.
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Monitoring the eradication of the highly invasive topmouth gudgeon (Pseudorasbora parva) using a novel eDNA assay
2018Co-Authors: Chloe Victoria Robinson, Carlos Garcia De Leaniz, Matteo Rolla, Sofia ConsuegraAbstract:Aquatic Invasive Species (AIS) represent an important threat for Biodiversity and are one of the factors determining the ecological integrity of water bodies under the Water Framework Directive. Eradication is one of the most effective tools for the management of invasive species but has important economic and ecological trade-offs and its success needs to be carefully monitored. We assessed the eradication success of the topmouth gudgeon (Pseudorasbora parva), an invasive fish that poses significant risks to endemic aquatic fauna, in four ponds previously treated with the piscicide Rotenone using a novel environmental DNA (eDNA)-qPCR assay. Topmouth gudgeon was detected in all four treated ponds using 750 mL water samples and in three of the ponds using 15 mL samples, despite the eradication treatment. The highly sensitive qPCR assay detected topmouth gudgeon in a significantly greater proportion of sites (77.5%) than eDNA detection methods based on conventional PCR (35%). Our results highlight the difficulties of eradicating invasive fish and the need to incorporate reliable monitoring methods as part of a risk management strategy under the Water Framework Directive.
