Predation on native fish eggs by invasive round goby revealed by species‐specific gut content DNA analyses

2020 ◽  
Vol 30 (8) ◽  
pp. 1566-1577
Author(s):  
Elisabeth Lutz ◽  
Philipp Emanuel Hirsch ◽  
Karen Bussmann ◽  
Joschka Wiegleb ◽  
Hans‐Peter Jermann ◽  
...  
Keyword(s):  
Round Goby ◽  
Native Fish ◽  
Gut Content ◽  
Fish Eggs ◽  
Dna Analyses ◽  
Species Specific

scholarly journals Egg predation on native fish by invasive round goby revealed by species-specific gut content DNA analyses

2019 ◽  
Author(s):  
Elisabeth Lutz ◽  
Philipp Hirsch ◽  
Karen Bussmann ◽  
Joschka Wiegleb ◽  
Hans-Peter Jermann ◽  
...  
Keyword(s):  
Freshwater Fish ◽  
Round Goby ◽  
Neogobius Melanostomus ◽  
Native Fish ◽  
Gut Content ◽  
Egg Predation ◽  
Spawning Period ◽  
Molecular Approaches ◽  
Longitudinal Connectivity ◽  
Species Specific

1.Conservation of riverine fish typically aims at improving access to spawning grounds and the restoration of longitudinal connectivity requires substantial investments. However, the removal of migration barriers also enables the upstream invasion of non-native species into spawning areas, with potential negative effects on recruitment of threatened freshwater fish through egg or fry predation. 2.Detecting egg predation is often challenging. Visual gut inspections are thought to underestimate predation on soft material such as eggs and fry, which hampers the discovery of predators preying upon these life-stages. For soft materials, molecular approaches may therefore offer a more sensitive tool for detection. 3.Here, we uncover such a macroscopically invisible conservation issue caused by predation of invasive round goby (Neogobius melanostomus) predation on eggs or fry of threatened common nase (Chondrostoma nasus) in Switzerland.4.In addition, this manuscript presents species-specific molecular assays for five more valuable native fish, including endangered salmonid and cyprinid river spawners, and confirms the applicability of the assays in a series of laboratory and field feeding experiments involving eggs and fish tissue. The manuscript also provides a guiding tool for conservation managers regarding the use and applicability of different molecular approaches in gut-content analysis.5.Our results inspire recommendations for local conservation measures such as a temporary reduction of round goby densities at the spawning site prior to the spawning period, and demonstrate how the targeted application of species-specific molecular markers can inform freshwater fish management.

scholarly journals The value of quantitative environmental DNA analyses for the management of invasive and endangered native fish

2021 ◽  
Author(s):  
Jack Rojahn ◽  
Luke Pearce ◽  
Dianne M. Gleeson ◽  
Richard P. Duncan ◽  
Dean M. Gilligan ◽  
...  
Keyword(s):  
Environmental Dna ◽  
Native Fish ◽  
Dna Analyses

scholarly journals Effects of hydraulic engineering restoration measures on invasive gobies in a large river (Danube, Austria)

2019 ◽  
Vol 22 (2) ◽  
pp. 437-453 ◽  
Author(s):  
David Ramler ◽  
Hubert Keckeis
Keyword(s):  
Large Scale ◽  
Population Control ◽  
Round Goby ◽  
Direct Methods ◽  
Large River ◽  
Invasive Species Control ◽  
General Decline ◽  
Species Specific ◽  
The Impact ◽  
Restoration Measures

Abstract Invasive gobies can have severe detrimental effects on local fish communities, however, direct methods for population control are often insufficient (i.e. fishing) or not feasible (i.e. poisoning). Indirect methods, such as habitat modifications in the course of restoration programs, appear promising but are poorly studied. In this study, we investigate the effects of different restoration measures on the abundance and occurrence of non-native gobies in the main stem of a free-flowing section of the Danube and attempt to disentangle these measures from general large-scale trends by applying a Before-After-Control-Impact design. We found three invasive goby species (racer, bighead, and round goby) in the sampling area, partly with very high abundances. Four to six years after the installation, the measures had negative (riprap removal), neutral (side arm reconnection), or positive (groyne field adaptations) effects on goby abundances. We conclude that the impact of the measures depends on the type of intervention, is species-specific, and is largely related to substrate composition. Independent from the effect of the measures, abundances of bighead and round goby dropped in the project and reference sections after the pre-survey. This general decline probably indicates a stabilization phase of the goby populations on a lower level, but may also be influenced by a major flood event. Nevertheless, our results indicate a high potential of shoreline modifications for invasive species control, calling for considering and incorporating them in river restoration programs.

scholarly journals The use of species-specific TaqMan probes for identifying early stage gadoid eggs following formaldehyde fixation

2008 ◽  
Vol 65 (9) ◽  
pp. 1573-1577 ◽  
Author(s):  
Freya Goodsir ◽  
Michael J. Armstrong ◽  
Peter R. Witthames ◽  
David L. Maxwell ◽  
Clive J. Fox
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Early Stage ◽  
Melanogrammus Aeglefinus ◽  
Fish Eggs ◽  
Important Species ◽  
Taqman Probes ◽  
Positive Rate ◽  
Identification Technique ◽  
Species Specific

Abstract Goodsir, F., Armstrong, M. J., Witthames, P. R., Maxwell, D. L., and Fox, C. J. 2008. The use of species-specific TaqMan probes for identifying early stage gadoid eggs following formaldehyde fixation. – ICES Journal of Marine Science, 65: 1573–1577. Surveys of fish eggs are increasingly being used to monitor the spawning areas and stock status of commercially important species such as Atlantic cod (Gadus morhua), but early stage cod eggs are visually indistinguishable from those of several other common co-occurring species, including haddock (Melanogrammus aeglefinus) and whiting (Merlangius merlangus). In recent surveys in the Irish and North Seas, a molecular identification technique (TaqMan multiplex real-time polymerase chain-reaction) assay has been used to overcome this problem. The method needs high-quality DNA, so the current protocol requires that individual “cod-like” eggs are “presorted” from plankton hauls on board ship and immediately preserved in ethanol. This increases seagoing staff costs, can be a difficult process at sea, and means that plankton sampling cannot be undertaken from non-specialized vessels such as fishing boats. Successful application of TaqMan probes to DNA from eggs preserved in formalin would overcome these problems, but previous attempts have resulted in poor success. In this study, batches of hatchery-sourced cod, haddock, and whiting eggs were fixed in 4% buffered formalin for up to 3 weeks, then transferred to a formaldehyde-free solution for 1, 2, or 3 months. After these periods they were assessed visually for fixation quality and analysed using species-specific TaqMan probes. Eggs, which had been fixed for up to 3 weeks in formalin, were identified successfully, although the positive rate (84–96%) was slightly lower than samples preserved throughout in ethanol (92–99%). There was no increase in the percentage of eggs misidentified comparing formalin-fixed and ethanol-preserved material. These results suggest that TaqMan probes can be applied successfully to fish eggs fixed in 4% buffered formalin for up to 3 weeks.

scholarly journals A K+-selective CNG channel orchestrates Ca2+ signalling in zebrafish sperm

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Sylvia Fechner ◽  
Luis Alvarez ◽  
Wolfgang Bönigk ◽  
Astrid Müller ◽  
Thomas K Berger ◽  
...  
Keyword(s):  
Danio Rerio ◽  
Cyclic Nucleotides ◽  
Marine Invertebrates ◽  
Sperm Head ◽  
K Channel ◽  
Fish Eggs ◽  
Cng Channel ◽  
Activation Mechanisms ◽  
Species Specific ◽  
Sea Urchin Sperm

Calcium in the flagellum controls sperm navigation. In sperm of marine invertebrates and mammals, Ca2+ signalling has been intensely studied, whereas for fish little is known. In sea urchin sperm, a cyclic nucleotide-gated K+ channel (CNGK) mediates a cGMP-induced hyperpolarization that evokes Ca2+ influx. Here, we identify in sperm of the freshwater fish Danio rerio a novel CNGK family member featuring non-canonical properties. It is located in the sperm head rather than the flagellum and is controlled by intracellular pH, but not cyclic nucleotides. Alkalization hyperpolarizes sperm and produces Ca2+ entry. Ca2+ induces spinning-like swimming, different from swimming of sperm from other species. The “spinning” mode probably guides sperm into the micropyle, a narrow entrance on the surface of fish eggs. A picture is emerging of sperm channel orthologues that employ different activation mechanisms and serve different functions. The channel inventories probably reflect adaptations to species-specific challenges during fertilization.

scholarly journals From Fish Eggs to Fish Name: Caviar Species Discrimination by COIBar-RFLP, an Efficient Molecular Approach to Detect Fraud in the Caviar Trade

Molecules ◽  
2019 ◽  
Vol 24 (13) ◽  
pp. 2468 ◽  
Author(s):  
Anna Maria Pappalardo ◽  
Agnese Petraccioli ◽  
Teresa Capriglione ◽  
Venera Ferrito
Keyword(s):  
Dna Analysis ◽  
Acipenser Transmontanus ◽  
Species Discrimination ◽  
Molecular Approach ◽  
Huso Huso ◽  
Fish Eggs ◽  
Restriction Patterns ◽  
Cyclopterus Lumpus ◽  
Seafood Products ◽  
Species Specific

The demand for caviar is growing as is its price on the market. Due to the decline of true caviar production from sturgeons, eggs from other fish species and other animals have been used as substitutes for caviar. The labels on these products should indicate the species from which the eggs were derived, but the label can be misleading in some cases. In this context, species identification using DNA analysis is crucial for traceability and authentication of caviar products. In this work, we applied the COIBar-RFLP procedure to obtain species-specific endonuclease restriction patterns useful to discriminate “caviar” species. The tested caviar products were identified as originating from eight species: Acipenser transmontanus, A. gueldenstaedtii, A. stellatus, A. baerii, Mallotus villosus, Huso huso, Cyclopterus lumpus and Eumicrotremus orbis. The results demonstrated that 14% of the caviar products examined have a label that does not indicate the species from which the eggs were originated. The MboI restriction enzyme produced specific profiles discriminating the eight species, confirming that the COIBar-RFLP is a useful approach for routine screening of seafood products due to its ease and rapid execution, as the results of screening can be obtained within 7 h, by-passing the need for sequencing.

scholarly journals Genetic Constitution and Pathogenicity of Lolium Isolates of Magnaporthe oryzae in Comparison with Host Species-Specific Pathotypes of the Blast Fungus

2004 ◽  
Vol 94 (5) ◽  
pp. 454-462 ◽  
Author(s):  
Y. Tosa ◽  
K. Hirata ◽  
H. Tamba ◽  
S. Nakagawa ◽  
I. Chuma ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Leaf Spot ◽  
Genome Organization ◽  
Internal Transcribed Spacer ◽  
Gray Leaf Spot ◽  
Genetic Constitution ◽  
Dna Fingerprints ◽  
Dna Analyses ◽  
Species Specific ◽  
Mating Tests

Fungal isolates from gray leaf spot on perennial ryegrass (prg isolates) were characterized by DNA analyses, mating tests, and pathogenicity assays. All of the prg isolates were interfertile with Triticum isolates and clustered into the crop isolate group (CC group) on a dendrogram constructed from rDNA-internal transcribed spacer 2 sequences. Since the CC group corresponded to a newly proposed species, Magnaporthe oryzae, all of the prg isolates were designated M. oryzae. However, DNA fingerprinting with MGR586, MGR583, and Pot2 showed that the prg isolates are divided into two distinct populations, i.e., TALF isolates and WK isolates. The TALF isolates were virulent only on Lolium species, whereas the WK isolates were less specific, suggesting that gray leaf spot can be caused not only by Lolium-specific isolates but also by less specific isolates. We designated the TALF isolates as Lolium pathotype. The TALF isolates showed diverse karyotypes in spite of being uniform in DNA fingerprints, suggesting that theyare unstable in genome organization.

Cholinesterases in Aquatic Biomonitoring: Assay Optimization and Species-Specific Characterization for a California Native Fish

Ecotoxicology ◽  
2005 ◽  
Vol 14 (6) ◽  
pp. 597-606 ◽  
Author(s):  
Andrew Whitehead ◽  
Susan L. Anderson ◽  
Alberto Ramirez ◽  
Barry W. Wilson
Keyword(s):  
Native Fish ◽  
Assay Optimization ◽  
Species Specific
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