Invasive Fish Research Articles

Effect of an invasive fish species on nutrient cycling and on the community structure: an experimental approach

Effect of an invasive fish species on nutrient cycling and on the community structure: an experimental approach

Using citizen science data to uncover the invasion of the non-native fish, Hemibagrus wyckioides (Fang and Chaux, 1949) in Peninsular Malaysia

Using citizen science data to uncover the invasion of the non-native fish, Hemibagrus wyckioides (Fang and Chaux, 1949) in Peninsular Malaysia

Large-scale serial replacement of invasive tench (Tinca tinca) by invasive carp (Cyprinus carpio) in the presence of redfin perch (Perca fluviatilis) in the Murray-Darling River system, Australia

Ecosystems worldwide are increasingly being invaded by multiple species, and the rate of biological invasion is accelerating, leading to more interactions among invasive species. One such interaction that has received little attention is the phenomenon of ‘serial replacement’ or ‘over-invasion’, where an established invasive species is supplanted by a second invasive species. Understanding this interaction is important as controlling the second species could inadvertently lead to an increase in the abundance of the first species. We used a hierarchical state-space model to analyse changes in annual abundances (commercial catch-per-unit-effort) of three invasive fish species, tench (Tinca tinca), common carp (Cyprinus carpio) and redfin perch (Perca fluviatilis), in the Murray-Darling River system (MDRS), Australia between 1954–2002. Tench were present at low abundances until the mid-1970 s, before declining to the point of no commercial catch post-1989. This rapid decline coincided with a significant increase in carp abundance, suggesting that carp may have driven the tench decline through habitat modification (particularly the destruction of aquatic plants), consistent with findings from European studies that show the disappearance of tench from ponds with intensive carp farming. Redfin perch populations, were inferred to be much less impacted by the invading carp population. While carp were present in the MDRS for the duration of the study, the rapid increase in carp abundance in the early 1970 s coincided with the introduction of a specific genetic lineage—the “Boolarra strain”. Our analysis provides compelling evidence of serial replacement of long-established tench by invading common carp triggered by the introduction of a novel carp strain.

Within-population variation in an invasive fish' sociability when associating with conspecifics or heterospecifics.

Behavioural traits are key to promote invasion success because they are easier to adjust to changing environmental conditions than morphological or life history traits. Often, research has overlooked variance in behavioural traits within populations or has assumed it to be mere noise. However, a recent focus towards individual variation of behaviour of successful invaders has revealed new and more profound insights into the invasion process. Behavioural variation within a population could lead to more successful invasions, as they include individuals with diverse behaviours, which ensures at least some individuals could be able to cope with changing conditions. The aim of this research was to examine if invasive guppies (Poecilia reticulata) present within-population differences in their sociability (time spent associating with a shoal) when interacting with conspecifics or heterospecifics. Guppies presented significant differences in their individual tendencies to associate with conspecific or heterospecific shoals. There were among-individual differences in the time spent shoaling with conspecifics versus heterospecifics, where most individuals did not differ in their sociability with conspecifics or heterospecifics, and only 22% of individuals presented a higher tendency to associate with conspecifics. Our results are the first to show individual differences in fish' tendencies to associate with heterospecifics among individuals of the same population and rearing conditions. Given that associations with heterospecific natives have been found to be as beneficial as associations with conspecifics for invaders, our results contribute to the understanding of mechanisms behind heterospecific sociability between natives and invaders.

Extraction and characterization of collagen from the skin of Pterygoplichthys spp. (armored catfish) from Chiapas

Because of its biocompatibility and safety, collagen is a valuable biomaterial that is used in various industries. While traditionally sourced from terrestrial mammals, collagen extracted from fish waste is a promising alternative due to its chemical properties and low cost. In Mexico, Pterygoplichthys spp. is considered an invasive species, inedible, and of limited commercial importance due to the low muscle content and skin covered with rigid bony plates. This study aimed to extract and characterize collagen from the skin of Pterygoplichthys spp. obtained from two communities in Chiapas, Mexico. Our results show that the extracted collagen is type 1, with a yield of 43.0% (dry weight). Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis revealed the presence of two alpha chains (α1, α2) and a beta and gamma component, consistent with type 1 collagen. Liquid chromatography coupled to mass spectrophotometry analysis identified peptide sequences homologous to those reported in other species. This study highlights the potential of Pterygoplichthys spp. skin collagen as a viable alternative to mammalian collagen. The efficiency of the extraction process and the identification of peptides resembling those of the other species underscore the feasibility of utilizing collagen from the skin of Pterygoplichthys spp. in industrial applications, offering a sustainable solution to environmental and economic challenges. Practical Application: Collagen extracted from the skin of Pterygoplichthys spp., an invasive fish species, can serve as a sustainable alternative to mammalian collagen, offering a cost-effective biomaterial with properties suitable for various industrial applications.

Speed kills? Migrating sea lamprey increase speed when exposed to an antipredator cue but make worse short-term decisions

There is growing evidence that a natural repellent, injury-released alarm cues, can be used to guide the movements of invasive fishes to achieve management goals. However, because this process involves perception, downstream cognitive processing of sensory information affects decisions regarding expression of antipredator behavior. Response habituation, wherein repeated or continuous exposure to a cue reduces behavioral response rates, is an oft-cited challenge for use of predation cues as conservation tools. Habituation may be delayed or prevented by altering the concentration and/or the temporal pattern of odor release (pulses of odor vs continuous application). We examined the effects of varying odor concentration and exposure regime (continuous vs pulsed) on behavioral response of adult sea lamprey (Petromyzon marinus) to conspecific alarm cue in a two-choice maze. We found that exposure to alarm cue induced more frequent and rapid upstream movement, regardless of exposure regime. There was also clear evidence of a speed-accuracy tradeoff, wherein sea lamprey that took longer to arrive at the bifurcation in the maze were more likely to avoid the arm activated with alarm cue. We could not ascertain the value of increasing concentration or pulsing the alarm cue on preventing habituation, as habituation did not occur. We hypothesize dishabituation to the alarm cue occurred immediately prior to testing due to handling that may have inadvertently simulated an unsuccessful predator attack. If true, incorporating dishabituating stimuli may prove a useful means to maintain the efficacy of alarm cue when applied as a repellent to manipulate the movements of sea lamprey.

Invasive fish species in Romanian freshwater. A review of over 100 years of occurrence reports

Effective management of invasive alien species requires location-specific strategies involving the regular update of distribution maps to identify spatial patterns, trends, and pathways of entry and the spread and hotspots of those invasions. However, a comprehensive overview of invasive alien fish species in Romania is lacking. To fill this gap, we compiled a database with occurrences of alien fish species in Romania from diverse sources, including published literature, our own field data, online databases, social media, and online questionnaires. Occurrence data covers the 1910–2022 period. From a total of 52 alien fish species reported as present in Romania’s waterways, we assigned an invasive status to 11 species, of which Pseudorasbora parva, Lepomis gibbosus, Carassius gibelio, and Ameiurus spp. are widespread. Based on the currently available occurrence records, we evaluated the presence and distribution of invasive alien fish species at the watershed level, concluding that invasive alien fish species are present in all Romanian watersheds. We identified several hotspots consistent with the main points of entry and spread of invasive alien fish species, principally located in western, central, and eastern Romania, i.e., Mures, Crisuri, and Siret watersheds.

Interspecific differences in swimming performance, behavior and survival between native Italian gudgeon (Gobio benacensis Pollini, 1816) and non-native European gudgeon (Gobio gobio Linnaeus, 1758)

Introduction of non-native species is an important cause of biodiversity decline in rivers. Separated by mountains and salt water, the freshwater fish fauna in Italy has experienced a natural isolation from fish in continental Europe. As a consequence, several Italian fish species have diverged from their European sister species, likely with unique adaptations to the local environment. Relatedly, the region is also susceptible to the invasion of non-native fish, and today almost half the fish species present are of non-native origin. Several of these non-native species have Italian congeners susceptible to competition and hybridizations, and, in the long run, displacements and extinctions. One such example is the Italian gudgeon (Gobio benacensis) and its European congener European gudgeon (Gobio gobio). During the last few decades the European gudgeon was introduced in Italian waters and has since spread rapidly, causing progressive declines in the Italian species. As for several other similar species pairs, little is known about potential differences in ecology and behavior. Here we study differences between Italian and European gudgeons in a controlled laboratory environment, using a combined open field and provoked escape response test, as well as tracking their sympatric survival over time in the hatchery. The smaller Italian gudgeon displayed a lower maximum swimming speed compared to the larger European gudgeon. The Italian gudgeon also experienced substantially higher sympatric mortality, resulting in only European gudgeon surviving to the end of the experiment. Contrary to expectations, no difference was seen in boldness and the Italian gudgeon displayed a higher movement activity, moving a larger distance in an open field test, compared to its European sister species. The reported differences could play a role in the replacement process, and may also have impacts on the surrounding ecosystem, and the prey and predators that have coevolved with the Italian species.

First record of stone moroko (Pseudorasbora parva), an invasive alien fish species, in water bodies of urban green areas in Poland

Abstract Invasive alien species are currently a major ecological problem. One such species is stone moroko, Pseudorasbora parva (Gobionidae), which has only been found to date in natural or agricultural water bodies (lakes, rivers and streams, carp ponds). Therefore, the current study is the first description of stone moroko in urban green areas (Warsaw, Poland). The fish were caught with a hydrobiological net. Four catches were conducted in ponds located in Morskie Oko Park (pond 1) and the Saxon Garden (pond 2) – two in fall and two in the spring, while two spring catches were conducted in Dolinka Służewska Park (stream). The population in pond 2 apparently survived the winter, and the fish caught in June displayed visible signs of sexual dimorphism and were significantly larger (average body mass: 1648 ± 1123 mg; range: 460–6090 mg) than those caught in the pond in the two fall samplings (404 ± 122 mg; 154–729 mg). After recording substantial numbers of specimens in the fall, no fish were caught in pond 1 during either of the spring catches, while only a few moroko were caught in the stream in April (1212 ± 869 mg; 454–2901 mg) and none were caught in June. Throughout the study, 59 specimens were caught in pond 1, 74 in pond 2, and 7 in the stream.

Market development for an invasive fish species: Blue catfish in the Chesapeake Bay, US

This research investigated market development for invasive blue catfish from the Chesapeake Bay, US. A small number of interviews with seafood processors and a large online survey of seafood consumers in the US Mid-Atlantic and Southeast (n = 1010) were used to understand factors influencing demand. The survey included a choice experiment to elicit consumer preferences for blue catfish in comparison to substitute seafood products and tested the effects of providing various types of information. Processors noted broad industry concerns related to labor availability and input costs and felt that expansion of the blue catfish market depended upon increasing consumer awareness and product familiarity. Consumer surveys revealed only one-third of respondents had consumed wild-caught blue catfish, though another third indicated they would be willing to try it. In the choice experiment, providing information on production method and product origin were found to increase consumer demand across seafood products. For blue catfish, providing additional information increasing consumer product familiarity or detailing the harmful ecological effects also increased demand. Mean consumer willingness-to-pay for blue catfish was estimated to be $9.70/lb, but increased to $22/lb in an information-rich scenario. These findings suggest a large potential market for invasive blue catfish in the US Mid-Atlantic and Southeast, with demand dependent on consumer product familiarity.

Trematode Diplostomum pseudospathaceum inducing differential immune gene expression in sexual and gynogenetic gibel carp (Carassius gibelio): parasites facilitating the coexistence of two reproductive forms of the invasive species.

Parasite-mediated selection is considered one of the potential mechanisms contributing to the coexistence of asexual-sexual complexes. Gibel carp (Carassius gibelio), an invasive fish species in Europe, often forms populations composed of gynogenetic and sexual specimens. The experimental infection was induced in gynogenetic and sexual gibel carp using eye-fluke Diplostomum pseudospathaceum (Trematoda), and the transcriptome profile of the spleen as a major immune organ in fish was analyzed to reveal the differentially expressed immunity-associated genes related to D. pseudospathaceum infection differing between gynogenetic and sexual gibel carp. High parasite infection was found in gynogenetic fish when compared to genetically diverse sexuals. Although metacercariae of D. pseudospathaceum are situated in an immune-privileged organ, our results show that eye trematodes may induce a host immune response. We found differential gene expression induced by eye-fluke infection, with various impacts on gynogenetic and sexual hosts, documenting for the majority of DEGs upregulation in sexuals, and downregulation in asexuals. Differences in gene regulation between gynogenetic and sexual gibel carp were evidenced in many immunity-associated genes. GO analyses revealed the importance of genes assigned to the GO terms: immune function, the Notch signaling pathway, MAP kinase tyrosine/threonine/phosphatase activity, and chemokine receptor activity. KEGG analyses revealed the importance of the genes involved in 12 immunity-associated pathways - specifically, FoxO signaling, adipocytokine signaling, TGF-beta signaling, apoptosis, Notch signaling, C-type lectin receptor signaling, efferocytosis, intestinal immune network for IgA production, insulin signaling, virion - human immunodeficiency virus, Toll-like receptor signaling, and phosphatidylinositol signaling system. Our study indicates the limited potential of asexual fish to cope with higher parasite infection (likely a loss of capacity to induce an effective immune response) and highlights the important role of molecular mechanisms associated with immunity for the coexistence of gynogenetic and sexual gibel carp, potentially contributing to its invasiveness.

Response of an invasive aquatic crustacean to the fish toxicant rotenone

Lepak JM, Pate WM, Cadmus P, Hansen AG, Gallaher KD, Silver DB. 2024. Response of an invasive aquatic crustacean to the fish toxicant rotenone. Lake Reserv Manage. 40:317–324 Fisheries managers have used the piscicide rotenone for invasive fish control and other management objectives for decades, yet the effects of rotenone on some aquatic species are not well understood. We tested the effects of rotenone on an invasive crustacean Mysis diluviana that can have deleterious effects on aquatic food webs (e.g., zooplankton communities) and ultimately some native and sport fishes. The median 50% lethal concentration (LC50) was assessed for M. diluviana at 24, 48, 96, and 192 h using active rotenone concentrations from 0 to 4111 ppb. At 24 and 48 h, LC50s were not reached, and at 96 and 192 h, LC50s were estimated at 4853 (95% CI = 1280–8426) and 668 (385–952) ppb, respectively, above (∼25-fold and 3-fold) recommended rotenone application concentrations to control fishes. Our results suggest that rotenone concentrations and exposure times used for controlling invasive fishes are likely to have limited to no effect on invasive M. diluviana populations. Thus, if M. diluviana control is a management objective, rotenone applications targeting invasive fishes are unlikely to contribute to this objective, and other methods should be considered that take advantage of potential vulnerabilities of M. diluviana, like temperature and light sensitivity.

Rapid assessment of invasion front and biological impact of the invasive fish Coreoperca herzi using quantitative eDNA metabarcoding

Rapid assessment of invasion front and biological impact of the invasive fish Coreoperca herzi using quantitative eDNA metabarcoding

Simple on-site extraction and GC-MS analysis of rotenone and degradation products for monitoring invasive fish eradication treatments in fresh and brackish waters

The introduction of invasive fish species to aquatic ecosystems has been demonstrated to cause disastrous ecological effects. Current conservation strategies regard rotenone-containing piscicide formulations, such as commercial product CFT Legumine, as a potentially viable alternative to the cumbersome traditional approaches to fish eradication. This consideration relies on the fast degradation of rotenone and its relatively rapid dissipation from the environment. Piscicide treatments in fragile aquatic ecosystems should thus monitor not only rotenone concentrations following application, but also other byproducts and degradation products. We present a methodology for the analysis of rotenoids in fresh and brackish waters that addresses two main challenges: the accurate determination of applied concentrations in different salinity concentrations by performing a simplified on-site solid-phase extraction, overcoming the fast degradation of rotenone in sample storage conditions, and the selective analysis of rotenoid byproducts and degradation products by gas chromatography coupled to mass spectrometry. Limits of quantification were below the ecological no-effect concentration of rotenone (2 µg/L) and average recoveries exceeded 80%. Accuracy (compared to expected values) and precision (deviation of replicates) ranged from 78 to 103% and 3 to 14%, respectively, across various rotenoid concentrations. These metrics are more than satisfactory for the intended application of this simplified procedure. The method was applied to piscicide-treated samples, revealing significant and fast degradation of parent rotenoids in storage conditions, as well as a non-negligible accumulation of rotenone in the particulate fraction of water that could impact the effectivity of eradication efforts.

Fish Invasion of Prairie Pothole Wetlands Reduces Amphipod Abundance, A Key Vertebrate Forage

Fish Invasion of Prairie Pothole Wetlands Reduces Amphipod Abundance, A Key Vertebrate Forage

Innovative Solution for Invasive Species and Water Pollution: Hydrochar Synthesis from Pleco Fish Biomass

In recent years, the invasive pleco fish has emerged as a global concern due to its adverse effects on ecosystems and economic activities, particularly in various water bodies in Mexico. This study introduces an innovative solution, employing microwave-assisted hydrothermal carbonization (MHTC) to synthesize hydrochar from pleco fish biomass. The research aimed to optimize synthesis conditions to enhance hydrochar yield, calorific value, and adsorption capacities for fluoride and cadmium in water. MHTC, characterized by low energy consumption, high reaction rates, and a simple design, was employed as a thermochemical process for hydrochar production. Key findings revealed that through response surface analysis, the study identified the optimal synthesis conditions for hydrochar production, maximizing yield and adsorption capacities while minimizing energy consumption. Physicochemical characterization demonstrated that hydrochars derived from pleco fish biomass exhibited mesoporous structures with fragmented surfaces, resembling hydroxyapatite, a major component of bone. Hydrochars derived from pleco fish biomass exhibited promising adsorption capacities for fluoride and cadmium in water, with hydrochar from Exp. 1 (90 min, 160 °C) showing the highest adsorption capacity for fluoride (4.16 mg/g), while Exp. 5 (90 min, 180 °C) demonstrated superior adsorption capacity for cadmium (98.5 mg/g). Furthermore, the utilization of pleco fish biomass for hydrochar production not only offers an eco-friendly disposal method for invasive species but also addresses fluoride and cadmium contamination issues, contributing to sustainable waste management and water treatment solutions. The resulting hydrochar, rich in solid fuel content with low pollutant emissions, presents a promising approach for waste management and carbon sequestration. Moreover, the optimized synthesis conditions pave the way for sustainable applications in energy production, addressing critical environmental and public health concerns. This research provides valuable insights into the potential of microwave-assisted hydrothermal carbonization for transforming invasive species into valuable resources, thereby mitigating environmental challenges and promoting sustainable development.

A decade-long study demonstrates that a population of invasive sea lamprey (Petromyzon marinus) can be controlled by introducing sterilized males

The release of sterilized insects to control pest populations has been used successfully during the past 6 decades, but application of the method in vertebrates has largely been overlooked or met with failure. Here, we demonstrate for the first time in fish, that a small population of sea lamprey (Petromyzon marinus; Class Agnatha), arguably one of the most impactful invasive fish in the world, can be controlled by the release of sterilized males. Specifically, the release of high numbers of sterile males (~ 1000's) into a geographically isolated population of adult sea lamprey resulted in the first multiyear delay in pesticide treatment since treatments began during 1966. Estimates of percent reduction in recruitment of age-1 sea lamprey due to sterile male release ranged from 7 to 99.9% with the precision of the estimate being low because of substantial year-to-year variability in larval density and distribution. Additional monitoring that accounts for recruitment variability in time and space would reduce uncertainty in the degree to which sterile male release reduces recruitment rates. The results are relevant to vertebrate pest control programs worldwide, especially as technical opportunities to sterilize vertebrates and manipulate sex ratios expand.

Risk Perception: Chemical Stimuli in Predator Detection and Feeding Behaviour of the Invasive Round Goby Neogobius melanostomus.

The round goby Neogobius melanostomus is a notoriously invasive fish originating from the Ponto-Caspian region that in recent decades has successfully spread across the globe. One of its primary impacts is direct predation; in addition, when entering new ecosystems, the round goby is likely to become a food resource for many higher native predators. However, little is known either about the indirect effects of predators on the round goby as prey or its feeding behaviour and activity. The non-consumptive effect of the presence of higher native predators presumably plays an important role in mitigating the impact of non-native round gobies as mesopredators on benthic invertebrate communities, especially when both higher- and mesopredators occupy the same habitat. We tested the food consumption probability and gut evacuation rates in round gobies in response to chemical signals from a higher predator, the European eel Anguilla anguilla. Gobies were placed individually in experimental arenas equipped with shelters and exposed to water from a tank in which (a) the higher predator had actively preyed on a heterospecific prey, earthworms Lumbricus sp. (the heterospecific treatment; HS); (b) the higher predator had fed on round gobies (the conspecific treatment; CS); or (c) the water was provided as a control treatment (C). To ensure exposure to the chemical stimuli, this study incorporated the application of skin extracts containing damaged-released alarm cues from the CS treatment; distilled water was used for the remaining treatments. No significant differences were observed in either the food consumption probability or gut evacuation rate in the tested treatments. Despite the lack of reaction to the chemical stimuli, round gobies did exhibit high evacuation rates (R = 0.2323 ± 0.011 h-1; mean ± SE) in which complete gut clearance occurred within 16 h regardless of the applied treatment. This rapid food processing suggests high efficiency and great pressure on resources regardless of the presence or not of a higher predator. These findings hint at the boldness of round gobies, which did not exhibit any pronounced threat sensitivity. This would seem to suggest great efficiency in food processing and a potential competitive advantage over local native species when colonising new ecosystems, irrespective of the presence of native predators. Our study did not detect any non-consumptive effect attributable to the higher predator, given that the feeding activity of the invasive round goby was not altered.

Application of germ cell transplantation in generation of surrogate fish gametes: implication for control of invasive species

Germ cell (GC) transplantation (GCT) in teleost is widely used for surrogate gametes production and revitalization of reproductive competence in senescent fish species. Here,an innovative application of GCT is described for control of invasive fish population those compete with the native fish fauna of anecosystem. The donor GCs isolated from zebra fish (Daniorerio) and transplanted through the genital papilla into the gonads of recipients medaka (Oryziaslatipes) that were depleted of endogenous GCs by Busulfan(40 mg/kg BW; 2 dosage) and water temperature (38?C) treatments. Three months after GCT, the donor GCs were able to recolonize the recipients' gonads and resume gamatogenesis. The presence of donor-derived gametes was confirmed by PCR in 70% and 61% of the surrogate O. latipesmales and females, respectively. Four months after the GCT, artificial and natural spawning trails were conducted by crossingsurrogate parents with their wild counterparts. Such crosses produced 40% pure O. latipes individuals whereas remaining 60% embryos, although fertilized, but embryonic development was ceased hours after fertilization. The application of GCT described here could be useful for ecosystem management especially for control of invasive fish species those causes huge economical losses worldwide.. KEYWORDS :Germ cell transplantation; population control; ecosystem management; surrogate fish; assisted reproductive technology.

Density‐dependent trophic consequences of invasive mrigal carp on native mud carp in Chinese fresh waters

Abstract Understanding the strength, direction and consequences of the trophic impacts of invasive fish on functionally analogous native fishes is important in invasion impact assessment and for informing management programmes. As functionally analogous native and invasive fishes can share prey resources, there is high potential for competitive interactions, which could affect trophic niche sizes and positions. The highly invasive mrigal carp Cirrhinus mrigala and native mud carp Cirrhinus molitorella now co‐exist in many freshwaters in southern China, raising concern on the consequences for mud carp. The trophic interactions of the two species and their consequences (for growth rates and trophic niche sizes as the isotopic niche, calculated using δ13C and δ15N) were tested in a pond enclosure experiment based on additive and substitutive treatments using fish in allopatric and sympatric contexts, with results compared with invaded wild communities. In the experiment, specific growth rates decreased significantly as fish abundance in treatments increased. These density‐dependent effects were observed in both species and were independent of whether the treatment was allopatric or sympatric. In allopatric treatments, isotopic niches of mud carp increased in size with fish number. Conversely, in sympatric treatments, mud carp isotopic niche size decreased with increased mrigal carp number. For mrigal carp, isotopic niche sizes decreased as fish number increased in both allopatric and sympatric treatments. In sympatric experiment treatments, the isotopic niches of mud carp and mrigal carp were always divergent. This was, however, in contrast to four invaded wild communities, where the isotopic niches of the two fishes always had some overlap. Experimental and field data suggest that although native mud carp could be impacted by mrigal carp, these impacts might only manifest when the species are at very high abundances and inter‐specific competitive interactions could be intense. These results also suggest the two species have mechanisms that reduce their inter‐specific interactions to minimise their competitive interactions, thus any ecological impacts from mrigal carp might manifest more from indirect than direct processes.