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Medo A, Ohte N, Doi H, Kamdee K, Koba K, Arai N, Mitsunaga Y, Kume M, Kojima D, Nose T, Yokoyama A, Viputhanumas T, Mitamura H. Trophic niche partitioning and intraspecific variation in food resource use in the genus Pangasianodon in a reservoir revealed by stable isotope analysis of multiple tissues. JOURNAL OF FISH BIOLOGY 2024; 105:814-824. [PMID: 38880940 DOI: 10.1111/jfb.15842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 05/20/2024] [Accepted: 05/28/2024] [Indexed: 06/18/2024]
Abstract
Understanding the mechanism by which non-native fish species integrate into native communities is crucial for evaluating the possibility of their establishment success. The genus Pangasianodon, comprising Pangasianodon gigas and Pangasianodon hypophthalmus, has been introduced into reservoirs, which are non-native habitats, for fishery stock enhancement. P. gigas and P. hypophthalmus often successfully establish and co-occur in several Thai reservoirs, but there is little information on differences in food resource use between the two species. To investigate the trophic niche width of P. gigas and P. hypophthalmus in a Thai reservoir, we conducted stable carbon and nitrogen ratio (δ13C and δ15N) analyses. We examined the degree of individual specialization in both species using the δ13C and δ15N values of muscle and liver tissues, which provides long- and short-term diet information. The isotopic niches did not overlap between P. gigas and P. hypophthalmus. The δ15N value of P. gigas was significantly higher than that of P. hypophthalmus, whereas the δ13C value did not significantly differ between the two species. The isotopic niche sizes were larger in P. hypophthalmus than in P. gigas. Individual specialization was observed in P. hypophthalmus but not in P. gigas, indicating that intraspecific variation in food resource use was larger in P. hypophthalmus compared to P. gigas. These findings suggest that trophic niche partitioning was one of the factors facilitating the establishment success of P. gigas and P. hypophthalmus in a reservoir, but the establishment process may differ between the two species.
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Affiliation(s)
- Ayano Medo
- Graduate School of Informatics, Kyoto University, Kyoto, Japan
- Center for Ecological Research, Kyoto University, Otsu, Japan
| | - Nobuhito Ohte
- Graduate School of Informatics, Kyoto University, Kyoto, Japan
| | - Hideyuki Doi
- Graduate School of Informatics, Kyoto University, Kyoto, Japan
| | | | - Keisuke Koba
- Center for Ecological Research, Kyoto University, Otsu, Japan
| | - Nobuaki Arai
- Field Science Education and Research Center, Kyoto University, Kyoto, Japan
| | | | - Manabu Kume
- Field Science Education and Research Center, Kyoto University, Kyoto, Japan
| | - Daichi Kojima
- Graduate School of Informatics, Kyoto University, Kyoto, Japan
| | - Takashi Nose
- Graduate School of Informatics, Kyoto University, Kyoto, Japan
| | - Ayako Yokoyama
- Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Thavee Viputhanumas
- Inland Aquaculture Research and Development Division, Department of Fisheries, Bangkok, Thailand
| | - Hiromichi Mitamura
- Field Science Education and Research Center, Kyoto University, Kyoto, Japan
- Graduate School of Agriculture, Kyoto University, Kyoto, Japan
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2
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Anderson D, Cervantez O, Bucciarelli GM, Lambert MR, Friesen MR. Feral frogs, native newts, and chemical cues: identifying threats from and management opportunities for invasive African Clawed Frogs in Washington state. PeerJ 2024; 12:e17307. [PMID: 38742097 PMCID: PMC11090105 DOI: 10.7717/peerj.17307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 04/05/2024] [Indexed: 05/16/2024] Open
Abstract
Invasive species threaten biodiversity globally. Amphibians are one of the most threatened vertebrate taxa and are particularly sensitive to invasive species, including other amphibians. African clawed frogs (Xenopus laevis) are native to Southern Africa but have subsequently become invasive on multiple continents-including multiple parts of North America-due to releases from the pet and biomedical trades. Despite their prevalence as a global invader, the impact of X. laevis remains understudied. This includes the Pacific Northwest of the USA, which now hosts multiple expanding X. laevis populations. For many amphibians, chemical cues communicate important information, including the presence of predators. Here, we tested the role chemical cues may play in mediating interactions between feral X. laevis and native amphibians in the Pacific Northwest. We tested whether native red-legged frog (Rana aurora) tadpoles display an antipredator response to non-native frog (X. laevis) or native newt (rough-skinned newts, Taricha granulosa) predator chemical stimuli. We found that R. aurora tadpoles exhibited pronounced anti-predator responses when exposed to chemical cues from T. granulosa but did not display anti-predator response to invasive X. laevis chemical cues. We also began experimentally testing whether T. granulosa-which produce a powerful neurotoxin tetrodotoxin (TTX)-may elicit an anti-predator response in X. laevis, that could serve to deter co-occupation. However, our short-duration experiments found that X. laevis were attracted to newt chemical stimuli rather than deterred. Our findings show that X. laevis likely poses a threat to native amphibians, and that these native species may also be particularly vulnerable to this invasive predator, compared to native predators, because toxic native newts may not limit X. laevis invasions. Our research provides some of the first indications that native Pacific Northwest species may be threatened by feral X. laevis and provides a foundation for future experiments testing potential management techniques for X. laevis.
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Affiliation(s)
- David Anderson
- Department of Biology, Saint Martin’s University, Lacey, WA, USA
| | - Olivia Cervantez
- Department of Biology, Saint Martin’s University, Lacey, WA, USA
| | - Gary M. Bucciarelli
- Department of Wildlife, Fish, and Conservation Biology, University of California, Davis, CA, United States of America
| | - Max R. Lambert
- Science Division, Washington Department of Fish and Wildlife, Olympia, WA, USA
| | - Megan R. Friesen
- Department of Biology, Saint Martin’s University, Lacey, WA, USA
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3
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Pauwels OSG, Brecko J, Baeghe D, Venderickx J, Vanderheyden A, Backeljau T. Morphological, acoustic and genetic identification of a reproducing population of the invasive African clawed frog Xenopuslaevis (Anura, Pipidae) recently discovered in Belgium. Zookeys 2023; 1184:41-64. [PMID: 38023767 PMCID: PMC10664028 DOI: 10.3897/zookeys.1184.103702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Accepted: 10/01/2023] [Indexed: 12/01/2023] Open
Abstract
Using external morphology of adults and tadpoles, osteology from high-resolution microcomputed tomography, vocalization analysis, and DNA sequence data, the identity of a reproducing Belgian population of invasive Xenopus at the current northernmost edge of the distribution of the genus in Europe was assessed. All data concur to an identification as Xenopus (Xenopus) laevis (Daudin, 1802). Genetically it is most closely related to populations of the Cape region in South Africa. No studies on the natural history of the Belgian Xenopus population and its impact on the local environment have been made to date.
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Affiliation(s)
- Olivier S. G. Pauwels
- Scientific Heritage, Royal Belgian Institute of Natural Sciences, Rue Vautier 29, B-1000 Brussels, BelgiumScientific Heritage, Royal Belgian Institute of Natural SciencesBrusselsBelgium
| | - Jonathan Brecko
- Scientific Heritage, Royal Belgian Institute of Natural Sciences, Rue Vautier 29, B-1000 Brussels, BelgiumScientific Heritage, Royal Belgian Institute of Natural SciencesBrusselsBelgium
- Royal Museum for Central Africa, Leuvensesteenweg 13, B-3080 Tervuren, BelgiumRoyal Museum for Central AfricaTervurenBelgium
| | - Dimitri Baeghe
- Evolutionary Biology and Ecology (CP 160/12), Department of Organismic Biology, Faculty of Sciences, Université Libre de Bruxelles, Avenue F.D. Roosevelt 50, B-1050 Brussels, BelgiumUniversité Libre de BruxellesBrusselsBelgium
| | - Jeroen Venderickx
- Scientific Heritage, Royal Belgian Institute of Natural Sciences, Rue Vautier 29, B-1000 Brussels, BelgiumScientific Heritage, Royal Belgian Institute of Natural SciencesBrusselsBelgium
- Operational Directorate Natural Environment, Royal Belgian Institute of Natural Sciences, Vautierstraat 29, B-1000 Brussels, BelgiumOperational Directorate Natural Environment, Royal Belgian Institute of Natural SciencesBrusselsBelgium
| | - Ann Vanderheyden
- Barcoding Facility for Organisms and Tissues of Policy Concern (BopCo), Royal Belgian Institute of Natural Sciences, Vautierstraat 29, B-1000 Brussels, BelgiumBarcoding Facility for Organisms and Tissues of Policy Concern (BopCo), Royal Belgian Institute of Natural SciencesBrusselsBelgium
| | - Thierry Backeljau
- Barcoding Facility for Organisms and Tissues of Policy Concern (BopCo), Royal Belgian Institute of Natural Sciences, Vautierstraat 29, B-1000 Brussels, BelgiumBarcoding Facility for Organisms and Tissues of Policy Concern (BopCo), Royal Belgian Institute of Natural SciencesBrusselsBelgium
- Evolutionary Ecology Group, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, BelgiumUniversity of AntwerpAntwerpBelgium
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4
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Bianchi-Costa IC, Quirino BA, Cardozo ALP, Yofukuji KY, Aleixo MHF, Fugi R. Water-level fluctuations lead to changes in the diet of an omnivorous fish in a floodplain. NEOTROPICAL ICHTHYOLOGY 2023. [DOI: 10.1590/1982-0224-2022-0064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
Abstract The hydrological regime leads to fluctuations in the availability of food resources for fish, which may reflect in their diet variation. Our main goal was to analyze the relationship between water-level fluctuations and the diet and the body condition of Trachelyopterus galeatus in the Upper Paraná River floodplain. The fish used in the study were sampled quarterly along nine years, at nine sampling stations. Our results showed that diet of T. galeatus varied in response to oscillations in the hydrometric level, with the consumption of terrestrial invertebrates being positively related to hydrometric level, while the consumption of aquatic invertebrates was negatively related. The trophic niche breadth and feeding activity were not affected by hydrometric level, but the fish body condition was positively affected. The high food plasticity allows T. galeatus to consume the most available resources (e.g., terrestrial invertebrates in high water levels), which probably contributed to the increase in its body condition in higher hydrometric levels. In summary, the hydrological dynamic is fundamental for the diet variation of omnivorous fish, which can take advantage of the resource availability according to the hydrometric level, increasing its body condition when allochthonous resources as terrestrial invertebrates are supposed to be more available.
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Affiliation(s)
| | | | | | | | | | - Rosemara Fugi
- Universidade Estadual de Maringá, Brazil; Núcleo de Pesquisas em Limnologia, Ictiologia e Aquicultura, Brazil
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Bökenhans V, Galván D, Bigatti G, Averbuj A. Stable Isotopes Reveal Algal Assimilation in the Carnivorous Sea Slug Pleurobranchaea maculata (Quoy & Gaimard, 1832) on Patagonian Coasts. MALACOLOGIA 2022. [DOI: 10.4002/040.065.0106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Verena Bökenhans
- LARBIM-IBIOMAR, CCT CONICET-CENPAT, Bvd. Brown 2915, U9120ACV Puerto Madryn, Chubut, Argentina
| | - David Galván
- CESIMAR-CCT CONICET-CENPAT, Bvd. Brown 2915, U9120ACV Puerto Madryn, Chubut, Argentina
| | - Gregorio Bigatti
- LARBIM-IBIOMAR, CCT CONICET-CENPAT, Bvd. Brown 2915, U9120ACV Puerto Madryn, Chubut, Argentina
| | - Andrés Averbuj
- LARBIM-IBIOMAR, CCT CONICET-CENPAT, Bvd. Brown 2915, U9120ACV Puerto Madryn, Chubut, Argentina
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6
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Huang Q, Sim SB, Geib SM, Childers A, Liu J, Wei X, Han W, Posada-Florez F, Xue AZ, Li Z, Evans JD. Identification of sex chromosomes and primary sex ratio in the small hive beetle, a worldwide parasite of honey bees. Gigascience 2022; 12:giad056. [PMID: 37489752 PMCID: PMC10367126 DOI: 10.1093/gigascience/giad056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 04/20/2023] [Accepted: 07/03/2023] [Indexed: 07/26/2023] Open
Abstract
BACKGROUND The small hive beetle (SHB), Aethina tumida, has emerged as a worldwide threat to honey bees in the past two decades. These beetles harvest nest resources, feed on larval bees, and ultimately spoil nest resources with gelatinous slime together with the fungal symbiont Kodamaea ohmeri. RESULTS Here, we present the first chromosome-level genome assembly for the SHB. With a 99.1% representation of conserved (BUSCO) arthropod genes, this resource enables the study of chemosensory, digestive, and detoxification traits critical for SHB success and possible control. We use this annotated assembly to characterize features of SHB sex chromosomes and a female-skewed primary sex ratio. We also found chromosome fusion and a lower recombination rate in sex chromosomes than in autosomes. CONCLUSIONS Genome-enabled insights will clarify the traits that allowed this beetle to exploit hive resources successfully and will be critical for determining the causes of observed sex ratio asymmetries.
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Affiliation(s)
- Qiang Huang
- Honeybee Research Institute, Jiangxi Agricultural University, 330045, Nanchang, China
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Sheina B Sim
- Daniel K. Inouye US Pacific Basin Agricultural Research Center Tropical Pest Genetics and Molecular Biology Research, USDA, Agricultural Research Service, Hilo, HI 96720, USA
| | - Scott M Geib
- Daniel K. Inouye US Pacific Basin Agricultural Research Center Tropical Pest Genetics and Molecular Biology Research, USDA, Agricultural Research Service, Hilo, HI 96720, USA
| | - Anna Childers
- Beltsville Agricultural Research Center, Bee Research Laboratory, USDA, Agricultural Research Service, Beltsville, MD 20705, USA
| | - Junfeng Liu
- Periodicals Agency, Jiangxi Agricultural University, 330045, Nanchang, China
| | - Xiuxiu Wei
- Honeybee Research Institute, Jiangxi Agricultural University, 330045, Nanchang, China
| | - Wensu Han
- Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, China
| | - Francisco Posada-Florez
- Beltsville Agricultural Research Center, Bee Research Laboratory, USDA, Agricultural Research Service, Beltsville, MD 20705, USA
| | - Allen Z Xue
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Zheng Li
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Jay D Evans
- Beltsville Agricultural Research Center, Bee Research Laboratory, USDA, Agricultural Research Service, Beltsville, MD 20705, USA
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7
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Premachandra T, Cauret CMS, Conradie W, Measey J, Evans BJ. Population genomics and subgenome evolution of the allotetraploid frog Xenopus laevis in southern Africa. G3 (BETHESDA, MD.) 2022; 13:6916838. [PMID: 36524354 PMCID: PMC9911082 DOI: 10.1093/g3journal/jkac325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 12/02/2022] [Accepted: 12/02/2022] [Indexed: 12/23/2022]
Abstract
Allotetraploid genomes have two distinct genomic components called subgenomes that are derived from separate diploid ancestral species. Many genomic characteristics such as gene function, expression, recombination, and transposable element mobility may differ significantly between subgenomes. To explore the possibility that subgenome population structure and gene flow may differ as well, we examined genetic variation in an allotetraploid frog-the African clawed frog (Xenopus laevis)-over the dynamic and varied habitat of its native range in southern Africa. Using reduced representation genome sequences from 91 samples from 12 localities, we found no strong evidence that population structure and gene flow differed substantially by subgenome. We then compared patterns of population structure in the nuclear genome to the mitochondrial genome using Sanger sequences from 455 samples from 183 localities. Our results provide further resolution to the geographic distribution of mitochondrial and nuclear diversity in this species and illustrate that population structure in both genomes corresponds roughly with variation in seasonal rainfall and with the topography of southern Africa.
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Affiliation(s)
- Tharindu Premachandra
- Department of Biology, McMaster University, Life Sciences Building Room 328, 1280 Main Street West, Hamilton, ON L8S4K1, Canada
| | - Caroline M S Cauret
- Department of Biology, McMaster University, Life Sciences Building Room 328, 1280 Main Street West, Hamilton, ON L8S4K1, Canada,Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA
| | - Werner Conradie
- Port Elizabeth Museum (Bayworld), P.O. Box 13147, Humewood, Gqeberha 6013, South Africa,Department of Conservation Management, Natural Resource Science and Management Cluster, Faculty of Science, Nelson Mandela University, George Campus, George 6019, South Africa
| | - John Measey
- Corresponding author: Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Stellenbosch 7602, South Africa.
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8
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Balzani P, Haubrock PJ. Expanding the invasion toolbox: including stable isotope analysis in risk assessment. NEOBIOTA 2022. [DOI: 10.3897/neobiota.76.77944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Species introductions are a major concern for ecosystem functioning, socio-economic wealth, and human well-being. Preventing introductions proved to be the most effective management strategy, and various tools such as species distribution models and risk assessment protocols have been developed or applied to this purpose. These approaches use information on a species to predict its potential invasiveness and impact in the case of its introduction into a new area. At the same time, much biodiversity has been lost due to multiple drivers. Ways to determine the potential for successful reintroductions of once native but now extinct species as well as assisted migrations are yet missing. Stable isotope analyses are commonly used to reconstruct a species’ feeding ecology and trophic interactions within communities. Recently, this method has been used to predict potentially arising trophic interactions in the absence of the target species. Here we propose the implementation of stable isotope analysis as an approach for assessment schemes to increase the accuracy in predicting invader impacts as well as the success of reintroductions and assisted migrations. We review and discuss possibilities and limitations of this methods usage, suggesting promising and useful applications for scientists and managers.
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9
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Abstract
Anurans have been introduced in many parts of the world and have often become invasive over large geographic areas. Although predation is involved in the declines of invaded amphibian populations, there is a lack of quantitative assessments evaluating the potential risk posed to native species. This is particularly true for Pelophylax water frogs, which have invaded large parts of western Europe, but no studies to date have examined their predation on other amphibians in their invaded range. Predation of native amphibians by marsh frogs (Pelophylax ridibundus) was assessed by stomach flushing once a month over four months in 21 ponds in southern France. Nine percent of stomachs contained amphibians. Seasonality was a major determinant of amphibian consumption. This effect was mediated by body size, with the largest invaders ingesting bigger natives, such as tree frogs. These results show that invasive marsh frogs represent a threat through their ability to forage on natives, particularly at the adult stage. The results also indicate that large numbers of native amphibians are predated. More broadly, the fact that predation was site- and time-specific highlights the need for repeated samplings across habitats and key periods for a clear understanding of the impact of invaders.
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10
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Fuad MMH, Vetešník L, Šimková A. Is gynogenetic reproduction in gibel carp (Carassius gibelio) a major trait responsible for invasiveness? JOURNAL OF VERTEBRATE BIOLOGY 2021. [DOI: 10.25225/jvb.21049] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Md Mehedi Hasan Fuad
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic; e-mail: ,
| | - Lukáš Vetešník
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic; e-mail: ,
| | - Andrea Šimková
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic; e-mail: ,
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11
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Pichler A, Walters TL, Frischer ME, Nejstgaard JC, Ptáčníková R. Application of species-specific primers to estimate the in situ diet of Bythotrephes [Cladocera, Onychopoda] in its native European range via molecular gut content analysis. JOURNAL OF PLANKTON RESEARCH 2021; 43:945-956. [PMID: 34858079 PMCID: PMC8632759 DOI: 10.1093/plankt/fbab070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 09/24/2021] [Indexed: 06/13/2023]
Abstract
The study of invasive species often focuses on regions of recent introduction rather than native habitats. Understanding an invasive species in its natural environment, however, can provide important insights regarding the long-term outcome of invasions. In this study we investigated the diet of the invasive spiny water flea, Bythotrephes longimanus, in two Austrian perialpine lakes, where it is native. The gut contents of wild-caught Bythotrephes individuals were estimated by quantitative polymerase chain reaction, targeting species-specific fragments of the barcoding region of the cytochrome c oxidase I gene of potential prey. The observed prey spectrum of Bythotrephes in the study lakes consisted primarily of Eudiaptomus gracilis and Diaphanosoma brachyurum. The Daphnia longispina complex, Leptodora kindtii and Mesocyclops leuckarti also contributed to the diet. Results indicate that Bythotrephes is a generalist feeder with a preference for epilimnetic prey.
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Affiliation(s)
- Arthur Pichler
- WasserCluster Lunz – Biological Station GmbH, Dr. Carl Kupelwieser Promenade 5, 3293 Lunz am See, Austria
- University of Vienna, Department of Functional and Evolutionary Ecology, Althanstraße 14, 1090 Vienna, Austria
| | - Tina L Walters
- University of Georgia, Skidaway Institute of Oceanography, 10 Ocean Science Circle, Savannah, GA 31411, USA
| | - Marc E Frischer
- University of Georgia, Skidaway Institute of Oceanography, 10 Ocean Science Circle, Savannah, GA 31411, USA
| | - Jens C Nejstgaard
- Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Zur alten Fischerhütte 2, D-16775 Stechlin, Germany
| | - Radka Ptáčníková
- WasserCluster Lunz – Biological Station GmbH, Dr. Carl Kupelwieser Promenade 5, 3293 Lunz am See, Austria
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12
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A Case of Mistaken Identity: Genetic and Anatomical Evidence Reveals the Cryptic Invasion of Xenopus tropicalis in Central Florida. J HERPETOL 2021. [DOI: 10.1670/20-083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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13
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Ginal P, Moreira FD, Marques R, Rebelo R, Rödder D. Predicting terrestrial dispersal corridors of the invasive African clawed frog Xenopus laevis in Portugal. NEOBIOTA 2021. [DOI: 10.3897/neobiota.64.60004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Invasive species, such as the mainly aquatic African clawed frog Xenopus laevis, are a main threat to global biodiversity. The identification of dispersal corridors is necessary to restrict further expansion of these species and help to elaborate management plans for their control and eradication. Here we use remote sensing derived resistance surfaces, based on the normalised difference vegetation index (NDVI) and the normalised difference water index (NDWI) accounting for behavioural and physiological dispersal limitations of the species, in combination with elevation layers, to determine fine scale dispersal patterns of invasive populations of X. laevis in Portugal, where the frog had established populations in two rivers. We reconstruct past dispersal routes between these two invaded rivers and highlight high risk areas for future expansion. Our models suggest terrestrial dispersal corridors that connect both invaded rivers and identify artificial water bodies as stepping stones for overland movement of X. laevis. Additionally, we found several potential stepping stones into novel areas and provide concrete information for invasive species management.
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14
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Andersen D, Borzée A, Jang Y. Predicting global climatic suitability for the four most invasive anuran species using ecological niche factor analysis. Glob Ecol Conserv 2021. [DOI: 10.1016/j.gecco.2020.e01433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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15
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Ginal P, Mokhatla M, Kruger N, Secondi J, Herrel A, Measey J, Rödder D. Ecophysiological models for global invaders: Is Europe a big playground for the African clawed frog? JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2020; 335:158-172. [PMID: 33264517 DOI: 10.1002/jez.2432] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 10/18/2020] [Accepted: 11/15/2020] [Indexed: 11/06/2022]
Abstract
One principle threat prompting the worldwide decline of amphibians is the introduction of nonindigenous amphibians. The African Clawed Frog, Xenopus laevis, is now one of the widest distributed amphibians occurring on four continents with ongoing range expansion including large parts of Europe. Species distribution models (SDMs) are essential tools to predict the invasive risk of these species. Previous efforts have focused on correlative approaches but these can be vulnerable to extrapolation errors when projecting species' distributions in nonnative ranges. Recent developments emphasise more robust process-based models, which use physiological data like critical thermal limits and performance, or hybrid models using both approaches. Previous correlative SDMs predict different patterns in the potential future distribution of X. laevis in Europe, but it is likely that these models do not assess its full invasive potential. Based on physiological performance trials, we calculate size and temperature-dependent response surfaces, which are scaled to geographic performance layers matching the critical thermal limits. We then use these ecophysiological performance layers in a standard correlative SDM framework to predict the potential distribution in southern Africa and Europe. Physiological performance traits (standard metabolic rate and endurance time of adult frogs) are the main drivers for the predicted distribution, while the locomotor performance (maximum velocity and distance moved in 200 ms) of adults and tadpoles have low contributions.
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Affiliation(s)
- Philipp Ginal
- Herpetological Section, Zoologisches Forschungsmuseum Alexander Koenig (ZFMK), Bonn, Germany
| | - Mohlamatsane Mokhatla
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa.,Rondevlei Scientific Services, Garden Route National Park, South African National Parks, Sedgefield, South Africa
| | - Natasha Kruger
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa.,Université de Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR 5023 LEHNA, Villeurbanne, France
| | - Jean Secondi
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR 5023 LEHNA, Villeurbanne, France.,Faculté des Sciences, Université d'Angers, Angers, France
| | - Anthony Herrel
- Département Adaptations du Vivant, MECADEV UMR7179 CNRS/MNHN, Paris, France
| | - John Measey
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa
| | - Dennis Rödder
- Herpetological Section, Zoologisches Forschungsmuseum Alexander Koenig (ZFMK), Bonn, Germany
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16
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Secondi J, Raux F. An invasive amphibian drives antipredator responses in two prey at different trophic positions. Behav Ecol 2020. [DOI: 10.1093/beheco/araa036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Generalist invasive predators consume prey at different trophic levels and generate drastic changes in local communities. However, the long-term effects of predation may be reduced by eco-evolutionary responses of native populations. The capacity of prey species distributed across the trophic network to develop antipredator responses may determine the ecosystem potential to buffer against the invader. The African clawed frog is a major invader on several continents. Because of its large size, generalist diet, and aquatic lifestyle, we predicted the development of antipredator responses in prey species at different trophic levels. We tested for behavioral shifts between populations within and outside the invasive range in the herbivorous snail Physella acuta and the predatory heteropteran, the backswimmer Notonecta glauca. We detected antipredator responses in both prey species. In sympatry, P. acuta stayed higher in the water column, while N. glauca spent more time swimming underwater and less time surfacing when the predator cues were present. In allopatry, P. acuta dived deeper and N. glauca spent more time surfacing and stayed longer still underwater. In both species, sympatric populations showed evidence of olfactory recognition of the frog. Our results show that the introduction of a top predator like Xenopus laevis in the pond ecosystem drives behavioral antipredator responses in species across the trophic network. Eco-evolutionary processes may allow some degree of long-term resilience of pond communities to the invasion of X. laevis.
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Affiliation(s)
- Jean Secondi
- UMR5023 LEHNA, ENTPE, CNRS, University of Lyon, Université Claude Bernard Lyon 1, 43, Boulevard du 11 novembre 1918, F-69622 Villeurbanne, France
- Faculté des sciences, Université d’Angers, 2 bld Lavoisier, F-49045 Angers, France
| | - Fanny Raux
- Faculté des sciences, Université d’Angers, 2 bld Lavoisier, F-49045 Angers, France
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17
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Courant J, Adil L, De Kegel B, Adriaens D, Herrel A. Conserved growth rate and age structure of Xenopus laevis in the edge and core of an expanding population. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz088] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Abstract
Invasive species represent a unique opportunity to study the evolutionary mechanisms driving range expansions. Although range expansion is expected to be associated with increased reproduction and dispersal at the range edge, Xenopus laevis seems to decrease its reproductive investment and to enhance dispersal at the range edge. Evidence of increased dispersal at the edge of expanding populations occurring simultaneously with a faster growth rate has been reported for other organisms. Here, we focused on the growth rate and age structure at the range edge vs. the range core in an expanding population of X. laevis. We used skeletochronology to characterize the age of 250 individuals captured at the range core and edge of this expanding population. Using the Von Bertalanffy equation, we then compared individual growth rates between locations. We found no significant changes in growth rate or age structure between edge and core samples. This result suggests that the reduced investment in reproduction recorded in another study at the range edge might compensate for the increased dispersal without impacting growth in this population. This implies that the resource allocation in an expanding population might thus be more diverse than commonly assumed.
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Affiliation(s)
- Julien Courant
- UMR 7179, Département Adaptation du vivant, CNRS/MNHN, 55 rue Buffon, Paris, France
| | - Layla Adil
- UMR 7179, Département Adaptation du vivant, CNRS/MNHN, 55 rue Buffon, Paris, France
| | - Barbara De Kegel
- Evolutionary Morphology of Vertebrates, Ghent University, K.L. Ledeganckstraat, Ghent, Belgium
| | - Dominique Adriaens
- Evolutionary Morphology of Vertebrates, Ghent University, K.L. Ledeganckstraat, Ghent, Belgium
| | - Anthony Herrel
- UMR 7179, Département Adaptation du vivant, CNRS/MNHN, 55 rue Buffon, Paris, France
- Evolutionary Morphology of Vertebrates, Ghent University, K.L. Ledeganckstraat, Ghent, Belgium
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18
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Cuevas-Caballé C, Riutort M, Álvarez-Presas M. Diet assessment of two land planarian species using high-throughput sequencing data. Sci Rep 2019; 9:8679. [PMID: 31213615 PMCID: PMC6581950 DOI: 10.1038/s41598-019-44952-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 05/29/2019] [Indexed: 11/30/2022] Open
Abstract
Geoplanidae (Platyhelminthes: Tricladida) feed on soil invertebrates. Observations of their predatory behavior in nature are scarce, and most of the information has been obtained from food preference experiments. Although these experiments are based on a wide variety of prey, this catalog is often far from being representative of the fauna present in the natural habitat of planarians. As some geoplanid species have recently become invasive, obtaining accurate knowledge about their feeding habits is crucial for the development of plans to control and prevent their expansion. Using high throughput sequencing data, we perform a metagenomic analysis to identify the in situ diet of two endemic and codistributed species of geoplanids from the Brazilian Atlantic Forest: Imbira marcusi and Cephaloflexa bergi. We have tested four different methods of taxonomic assignment and find that phylogenetic-based assignment methods outperform those based on similarity. The results show that the diet of I. marcusi is restricted to earthworms, whereas C. bergi preys on spiders, harvestmen, woodlice, grasshoppers, Hymenoptera, Lepidoptera and possibly other geoplanids. Furthermore, both species change their feeding habits among the different sample locations. In conclusion, the integration of metagenomics with phylogenetics should be considered when establishing studies on the feeding habits of invertebrates.
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Affiliation(s)
- Cristian Cuevas-Caballé
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | - Marta Riutort
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | - Marta Álvarez-Presas
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain.
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain.
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19
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Courant J, Secondi J, Guillemet L, Vollette E, Herrel A. Rapid changes in dispersal on a small spatial scale at the range edge of an expanding population. Evol Ecol 2019. [DOI: 10.1007/s10682-019-09996-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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20
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Anastácio PM, Ribeiro F, Capinha C, Banha F, Gama M, Filipe AF, Rebelo R, Sousa R. Non-native freshwater fauna in Portugal: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 650:1923-1934. [PMID: 30286358 DOI: 10.1016/j.scitotenv.2018.09.251] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 09/19/2018] [Accepted: 09/19/2018] [Indexed: 06/08/2023]
Abstract
We present the most updated list of non-native freshwater fauna established in Portugal, including the Azores and Madeira archipelagos. This list includes 67 species at national level but corresponds to 84 species records, of which 53 are in the mainland, 23 in the Azores and 8 in Madeira archipelagos. We also discuss the progression of the cumulative number of introductions since 1800 and identify the most probable vectors of introduction, main taxonomic groups and their regions of origin. Furthermore, we review the existing knowledge about ecological and economic impacts, invasion risk and potential distribution of invaders, under present and future climatic conditions, and the applied management actions, including the production of legislation. Along the 20th century the number of successful introductions increased at an approximate rate of two new species per decade until the beginning of 1970s. Since then, this rate increased to about 14 new species per decade. These introductions were mainly a result of fisheries, as contaminants or for ornamental purposes. Fish and mollusks are the taxonomic groups with more established species, representing more than half of the total. Most species (>70%) are native from other regions of Europe and North America. Studies about ecological or socioeconomic impacts are more common for fish, crustaceans and mollusks. Impacts for most amphibians, reptiles and mammals are not thoroughly studied. A few studies on the impacts and management actions of health-threatening mosquitoes are also available. The potential distribution in the Portuguese territory was modelled for 26 species. Only a minority of these models provides projections of distributions under scenarios of future climate change. A comparison of the Portuguese and EU legislation shows large discrepancies in the invasive species lists. Using the EU list and a ranking procedure for the national context, we identify freshwater species of high national concern for which actions are urgently needed.
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Affiliation(s)
- Pedro M Anastácio
- MARE - Marine and Environmental Sciences Centre, Departamento de Paisagem Ambiente e Ordenamento, Escola de Ciências e Tecnologia, Universidade de Évora, Évora, Portugal.
| | - Filipe Ribeiro
- MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal
| | - César Capinha
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos da Universidade do Porto, Campus Agrário de Vairão, R. Padre Armando Quintas, 4485-661 Vairão, Portugal; CEABN/InBIO, Centro de Ecologia Aplicada, Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal
| | - Filipe Banha
- MARE - Marine and Environmental Sciences Centre, Departamento de Paisagem Ambiente e Ordenamento, Escola de Ciências e Tecnologia, Universidade de Évora, Évora, Portugal
| | - Mafalda Gama
- MARE - Marine and Environmental Sciences Centre, Departamento de Paisagem Ambiente e Ordenamento, Escola de Ciências e Tecnologia, Universidade de Évora, Évora, Portugal
| | - Ana F Filipe
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos da Universidade do Porto, Campus Agrário de Vairão, R. Padre Armando Quintas, 4485-661 Vairão, Portugal; CEABN/InBIO, Centro de Ecologia Aplicada, Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal
| | - Rui Rebelo
- Department of Animal Biology and Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa (cE3c-FCUL), Lisbon, Portugal
| | - Ronaldo Sousa
- CBMA - Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Braga, Portugal
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21
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Courant J, Vollette E, Secondi J, Herrel A. Changes in the aquatic macroinvertebrate communities throughout the expanding range of an invasive anuran. FOOD WEBS 2018. [DOI: 10.1016/j.fooweb.2018.e00098] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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22
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Thorp CJ, Vonesh JR, Measey J. Cannibalism or congeneric predation? The African clawed frog,
Xenopus laevis
(Daudin), preferentially predates on larvae of Cape platannas,
Xenopus gilli
Rose & Hewitt. Afr J Ecol 2018. [DOI: 10.1111/aje.12577] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Corey J. Thorp
- Centre for Invasion Biology, Department of Botany & Zoology Stellenbosch University Stellenbosch South Africa
| | - James R. Vonesh
- Centre for Invasion Biology, Department of Botany & Zoology Stellenbosch University Stellenbosch South Africa
- Department of Biology Virginia Commonwealth University Richmond Virginia
| | - John Measey
- Centre for Invasion Biology, Department of Botany & Zoology Stellenbosch University Stellenbosch South Africa
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23
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van Wilgen NJ, Gillespie MS, Richardson DM, Measey J. A taxonomically and geographically constrained information base limits non-native reptile and amphibian risk assessment: a systematic review. PeerJ 2018; 6:e5850. [PMID: 30425887 PMCID: PMC6230440 DOI: 10.7717/peerj.5850] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 09/27/2018] [Indexed: 11/20/2022] Open
Abstract
For many taxa, new records of non-native introductions globally occur at a near exponential rate. We undertook a systematic review of peer-reviewed publications on non-native herpetofauna, to assess the information base available for assessing risks of future invasions, resulting in 836 relevant papers. The taxonomic and geographic scope of the literature was also compared to a published database of all known invasions globally. We found 1,116 species of herpetofauna, 95% of which were present in fewer than 12 studies. Nearly all literature on the invasion ecology of herpetofauna has appeared since 2000, with a strong focus on frogs (58%), particularly cane toads (Rhinella marina) and their impacts in Australia. While fewer papers have been published on turtles and snakes, proportionately more species from both these groups have been studied than for frogs. Within each herpetofaunal group, there are a handful of well-studied species: R. marina, Lithobates catesbeianus, Xenopus laevis, Trachemys scripta, Boiga irregularis and Anolis sagrei. Most research (416 papers; 50%) has addressed impacts, with far fewer studies on aspects like trade (2%). Besides Australia (213 studies), most countries have little location-specific peer-reviewed literature on non-native herpetofauna (on average 1.1 papers per established species). Other exceptions were Guam, the UK, China, California and France, but even their publication coverage across established species was not even. New methods for assessing and prioritizing invasive species such as the Environmental Impact Classification for Alien Taxa provide useful frameworks for risk assessment, but require robust species-level studies. Global initiatives, similar to the Global Amphibian Assessment, using the species and taxonomic groups identified here, are needed to derive the level of information across broad geographic ranges required to apply these frameworks. Expansive studies on model species can be used to indicate productive research foci for understudied taxa.
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Affiliation(s)
- Nicola J van Wilgen
- Cape Research Centre, South African National Parks, Steenberg, Western Cape, South Africa.,Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Matieland, South Africa
| | - Micaela S Gillespie
- Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Matieland, South Africa
| | - David M Richardson
- Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Matieland, South Africa
| | - John Measey
- Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Matieland, South Africa
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24
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Thorp CJ, Alexander ME, Vonesh JR, Measey J. Size-dependent functional response of Xenopus laevis feeding on mosquito larvae. PeerJ 2018; 6:e5813. [PMID: 30386704 PMCID: PMC6204824 DOI: 10.7717/peerj.5813] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 09/21/2018] [Indexed: 11/29/2022] Open
Abstract
Predators can play an important role in regulating prey abundance and diversity, determining food web structure and function, and contributing to important ecosystem services, including the regulation of agricultural pests and disease vectors. Thus, the ability to predict predator impact on prey is an important goal in ecology. Often, predators of the same species are assumed to be functionally equivalent, despite considerable individual variation in predator traits known to be important for shaping predator–prey interactions, like body size. This assumption may greatly oversimplify our understanding of within-species functional diversity and undermine our ability to predict predator effects on prey. Here, we examine the degree to which predator–prey interactions are functionally homogenous across a natural range of predator body sizes. Specifically, we quantify the size-dependence of the functional response of African clawed frogs (Xenopus laevis) preying on mosquito larvae (Culex pipiens). Three size classes of predators, small (15–30 mm snout-vent length), medium (50–60 mm) and large (105–120 mm), were presented with five densities of prey to determine functional response type and to estimate search efficiency and handling time parameters generated from the models. The results of mesocosm experiments showed that type of functional response of X. laevis changed with size: small predators exhibited a Type II response, while medium and large predators exhibited Type III responses. Functional response data showed an inversely proportional relationship between predator attack rate and predator size. Small and medium predators had highest and lowest handling time, respectively. The change in functional response with the size of predator suggests that predators with overlapping cohorts may have a dynamic impact on prey populations. Therefore, predicting the functional response of a single size-matched predator in an experiment may misrepresent the predator’s potential impact on a prey population.
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Affiliation(s)
- Corey J Thorp
- Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Stellenbosch, South Africa
| | - Mhairi E Alexander
- Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Stellenbosch, South Africa.,Institute for Biomedical and Environmental Health Research (IBEHR), School of Health and Life Sciences, University of the West of Scotland, Paisley, UK
| | - James R Vonesh
- Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Stellenbosch, South Africa.,Department of Biology, Virginia Commonwealth University, Richmond, VA, USA.,Center for Environmental Studies, Virginia Commonwealth University, Richmond, VA, USA
| | - John Measey
- Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Stellenbosch, South Africa
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25
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Mohanty NP, Measey J. What's for dinner? Diet and potential trophic impact of an invasive anuran Hoplobatrachus tigerinus on the Andaman archipelago. PeerJ 2018; 6:e5698. [PMID: 30310745 PMCID: PMC6173161 DOI: 10.7717/peerj.5698] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 09/05/2018] [Indexed: 11/30/2022] Open
Abstract
Amphibian invasions have considerable detrimental impacts on recipient ecosystems. However, reliable risk analysis of invasive amphibians still requires research on more non-native amphibian species. An invasive population of the Indian bullfrog, Hoplobatrachus tigerinus, is currently spreading on the Andaman archipelago and may have significant trophic impacts on native anurans through competition and predation. We carried out diet analyses of the invasive H. tigerinus and native anurans, across four habitat types and two seasons; we hypothesized that (i) small vertebrates constitute a majority of the H. tigerinus diet, particularly by volume and (ii) the diet of H. tigerinus significantly overlaps with the diet of native anurans, thereby, leading to potential competition. We assessed the diet of the invasive H. tigerinus (n = 358), and individuals of the genera Limnonectes (n = 375) and Fejervarya (n = 65) and found a significant dietary overlap of H. tigerinus with only Limnonectes. Small vertebrates, including several endemic species, constituted the majority of H. tigerinus, diet by volume, suggesting potential impact by predation. Prey consumption and electivity of the three anurans indicated a positive relationship between predator-prey body sizes. Individuals of H. tigerinus and Fejervarya chose evasive prey, suggesting that these two taxa are mostly ambush predators; individuals of Limnonectes chose a mixture of sedentary and evasive prey indicating that the species employs a combination of ‘active search’ and ‘sit and wait’ foraging strategies. All three species of anurans mostly consumed terrestrial prey. This intensive study on a genus of newly invasive amphibian contributes to knowledge of the impact of amphibian invasions, and elucidates the feeding ecology of H. tigerinus, and species of the genera Limnonectes and Fejervarya. We also stress the necessity to evaluate prey availability and volume in future studies for meaningful insights into diet of amphibians.
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Affiliation(s)
- Nitya Prakash Mohanty
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa.,Andaman & Nicobar Environment Team, Wandoor, Port Blair, Andaman and Nicobar Islands, India
| | - John Measey
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa
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26
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Heng K, Chevalier M, Lek S, Laffaille P. Seasonal variations in diet composition, diet breadth and dietary overlap between three commercially important fish species within a flood-pulse system: The Tonle Sap Lake (Cambodia). PLoS One 2018; 13:e0198848. [PMID: 29912953 PMCID: PMC6005523 DOI: 10.1371/journal.pone.0198848] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 05/25/2018] [Indexed: 11/19/2022] Open
Abstract
Tropical lakes and their associated floodplain habitats are dynamic habitat mosaics strongly influenced by seasonal variations in hydrologic conditions. In flood-pulse systems, water level oscillations directly influence the connectivity to floodplain habitats for fish. Here, we aimed to investigate whether seasonal changes in the water level of a flood-pulse system (the Tonle Sap Lake, Cambodia) differentially affect diet breadth and dietary overlap of three common and commercially important fish species (Anabas testudineus, Boesemania microplepis and Notopterus notopterus) presenting important differences in their life-cycle (e.g. seasonal migration). For this purpose, the three fish species were sampled at four locations spread over the lake and their stomach contents extracted for analyses. Dietary differences were investigated across seasons regarding the diet composition and diet breadth of each species as well as the amount of dietary overlap between species. We found that the proportion of empty stomachs changed similarly across seasons for the three species, thus suggesting that ecological differences between species are not sufficient to outweigh the effect of seasonal variations in resource abundance. In contrast, changes in diet composition were species-specific and can be explained by ecological and behavioral differences between species. Diet breadth differed between species in all seasons, except during the wet season, and tended to be higher during the dry season when dietary overlap was the lowest. These variations likely result from changes in the diversity and amount of resources and may lead to habitat use shifts with potential implications for competitive interactions. In particular, increasing connectivity to floodplain habitats may reduce the competitive pressure during the wet season, while resource scarcity during the dry season may constrain individuals to diversify their diet to avoid competition. Overall, our results suggest a considerable plasticity in the feeding behavior of the three species as demonstrated by seasonal variation in both diet breadth and dietary overlap. Such variations can be explained by a number of factors and processes, including changes in resource availability or competitive interactions between individuals for resources, whose relative influence might vary depending on the magnitude and the timing of the flood-pulse driving the connectivity to floodplain habitats. Gaining knowledge on the seasonal evolution of fish’s diet is relevant for fisheries management and conservation and our result could be used to guide aquaculture development in Cambodia.
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Affiliation(s)
- Kong Heng
- EDB, Université de Toulouse, CNRS, ENFA, UPS, Toulouse, France
- EcoLab, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France
| | - Mathieu Chevalier
- EDB, Université de Toulouse, CNRS, ENFA, UPS, Toulouse, France
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
- * E-mail:
| | - Sovan Lek
- EDB, Université de Toulouse, CNRS, ENFA, UPS, Toulouse, France
| | - Pascal Laffaille
- EcoLab, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France
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27
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Courant J, Secondi J, Vollette J, Herrel A, Thirion JM. Assessing the impacts of the invasive frog, Xenopus laevis, on amphibians in western France. AMPHIBIA-REPTILIA 2018. [DOI: 10.1163/15685381-17000153] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
As invasive species are one of the principal threats on global biodiversity, assessing their impact is a crucial element of conservation biology. Quantifying the possible impacts of an invasive population represents the first step in the establishment of efficient management plans. In this study, we applied a method of site-occupancy modeling to estimate the influence of an invasive frog, Xenopus laevis, on the amphibian species richness in western France. In our analyses we took into account habitat characteristics (i.e. the size and general shape of the ponds), the structure of the aquatic vegetation, the presence of other vertebrates, and the physicochemical parameters of the pond. Richness was negatively related to the abundance of X. laevis and to the time since colonization as estimated by the distance of the pond to the site of introduction. Habitat niche breadth of native amphibians did not differ between invaded and non-invaded areas. This might be a consequence of the homogeneity of the habitats selected for our study. The lack of heterogeneity in the abiotic factors, the absence of a correlation between species richness and these abiotic factors, and the correlation of the abundance and time since colonization by X. laevis with species richness suggest a negative effect of this species on local amphibians. This result highlights the importance of conservation and management plans aiming to limit the expansion of this invasive species.
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Affiliation(s)
- Julien Courant
- 1UMR 7179 C.N.R.S/M.N.H.N., Département d’Ecologie et de Gestion de la Biodiversité. 57 rue Cuvier, Case postale 55, 75231 Paris Cedex 5, France
| | - Jean Secondi
- 2Université de Lyon, UMR 5023 Écologie des Hydrosystèmes Naturels et Anthropisés, Université Lyon 1, ENTPE, CNRS, F - 69622 Villeurbanne, France
- 3UMR 6554 LETG – LEESA, Université d’Angers. 2, boulevard Lavoisier, 49000 Angers, France
| | - Julie Vollette
- 4Association Objectifs Biodiversités. 22, rue du docteur Gilbert, 17250 Pont l’Abbé d’Arnoult
| | - Anthony Herrel
- 1UMR 7179 C.N.R.S/M.N.H.N., Département d’Ecologie et de Gestion de la Biodiversité. 57 rue Cuvier, Case postale 55, 75231 Paris Cedex 5, France
- 5Ghent University, Evolutionary Morphology of Vertebrates, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium
| | - Jean-Marc Thirion
- 4Association Objectifs Biodiversités. 22, rue du docteur Gilbert, 17250 Pont l’Abbé d’Arnoult
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28
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De Villiers FA, Measey J. Overland movement in African clawed frogs ( Xenopus laevis): empirical dispersal data from within their native range. PeerJ 2017; 5:e4039. [PMID: 29134157 PMCID: PMC5683045 DOI: 10.7717/peerj.4039] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 10/24/2017] [Indexed: 11/20/2022] Open
Abstract
Dispersal forms are an important component of the ecology of many animals, and reach particular importance for predicting ranges of invasive species. African clawed frogs (Xenopus laevis) move overland between water bodies, but all empirical studies are from invasive populations with none from their native southern Africa. Here we report on incidents of overland movement found through a capture-recapture study carried out over a three year period in Overstrand, South Africa. The maximum distance moved was 2.4 km with most of the 91 animals, representing 5% of the population, moving ∼150 m. We found no differences in distances moved by males and females, despite the former being smaller. Fewer males moved overland, but this was no different from the sex bias found in the population. In laboratory performance trials, we found that males outperformed females, in both distance moved and time to exhaustion, when corrected for size. Overland movement occurred throughout the year, but reached peaks in spring and early summer when temporary water bodies were drying. Despite permanent impoundments being located within the study area, we found no evidence for migrations of animals between temporary and permanent water bodies. Our study provides the first dispersal kernel for X. laevis and suggests that it is similar to many non-pipid anurans with respect to dispersal.
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Affiliation(s)
- F André De Villiers
- Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Stellenbosch, South Africa
| | - John Measey
- Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Stellenbosch, South Africa
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