Anguillicoloides crassus infection of European eel, Anguilla anguilla (L.), in inland waters of Estonia: history of introduction, prevalence and intensity

2010 ◽  
Vol 26 ◽  
pp. 74-80 ◽  
Author(s):  
A. Kangur ◽  
P. Kangur ◽  
K. Kangur ◽  
A. Järvalt ◽  
M. Haldna
Keyword(s):  
Anguilla Anguilla ◽  
Inland Waters ◽  
European Eel ◽  
History Of ◽  
Anguillicoloides Crassus

scholarly journals Is the continental life of the European eel Anguilla anguilla affected by the parasitic invader Anguillicoloides crassus ?

2013 ◽  
Vol 280 (1754) ◽  
pp. 20122916 ◽  
Author(s):  
François Lefebvre ◽  
Géraldine Fazio ◽  
Béatrice Mounaix ◽  
Alain J. Crivelli
Keyword(s):  
Reproductive Potential ◽  
Adaptive Immune Response ◽  
Anguilla Anguilla ◽  
Individual Variability ◽  
Growth Potential ◽  
Size Increase ◽  
European Eel ◽  
History Of ◽  
Internal Marker ◽  
Anguillicoloides Crassus

Quantifying the fitness cost that parasites impose on wild hosts is a challenging task, because the epidemiological history of field-sampled hosts is often unknown. In this study, we used an internal marker of the parasite pressure on individual hosts to evaluate the costs of parasitism with respect to host body condition, size increase and reproductive potential of field-collected animals for which we also determined individual age. In our investigated system, the European eel Anguilla anguilla and the parasitic invader Anguillicoloides crassus , high virulence and severe impacts are expected because the host lacks an adaptive immune response. We demonstrated a nonlinear relationship between the severity of damage to the affected organ (i.e. the swimbladder, our internal marker) and parasite abundance and biomass, thus showing that the use of classical epidemiological parameters was not relevant here. Surprisingly, we found that the most severely affected eels (with damaged swimbladder) had greater body length and mass (+11% and +41%, respectively), than unaffected eels of same age. We discuss mechanisms that could explain this finding and other counterintuitive results in this host–parasite system, and highlight the likely importance of host panmixia in generating great inter-individual variability in growth potential and infection risk. Under that scenario, the most active foragers would not only have the greatest size increase, but also the highest probability of becoming repeatedly infected—via trophic parasite transmission—during their continental life.

The life cycle of Paraquimperia tenerrima: a parasite of the European eel Anguilla anguilla

2005 ◽  
Vol 79 (2) ◽  
pp. 169-176 ◽  
Author(s):  
J.A. Shears ◽  
C.R. Kennedy
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Anguilla Anguilla ◽  
European Eel ◽  
Temperature Dependent ◽  
Free Living ◽  
Freshwater Invertebrate ◽  
Third Stage ◽  
History Of ◽  
Whole Life Cycle

AbstractPrevious studies on the life history of the nematode eel specialist Paraquimperia tenerrima (Nematoda: Quimperiidae) have failed to determine whether an intermediate host is required in the life cycle. In the laboratory, eggs failed to hatch below 10°C, hatching occurring only at temperatures between 11 and 30°C. Survival of the free-living second stage larvae (L2) was also temperature dependent, with maximal survival between 10 and 20°C. Total survival of the free-living stages (eggs and L2) is unlikely to exceed a month at normal summer water temperatures, confirming that parasite could not survive the 6 month gap between shedding of eggs in spring and infection of eels in early winter outside of a host. Eels could not be infected directly with L2, nor could a range of common freshwater invertebrate species. Third stage larvae (L3) resembling P. tenerrima were found frequently and abundantly in the swimbladder of minnows Phoxinus phoxinus from several localities throughout the year and were able to survive in this host in the laboratory for at least 6 months. Third stage larvae identical to these larvae were recovered from minnows experimentally fed L2 of P. tenerrima, and eels infected experimentally with naturally and experimentally infected minnows were found to harbour fourth stage larvae (L4) and juvenile P. tenerrima in their intestines. Finally, the whole life cycle from eggs to adult was completed in the laboratory, confirming that minnows are an obligate intermediate host for P. tenerrima.

Infection of European eel, Anguilla anguilla (L.), with the nematode Anguillicoloides crassus (Kuwahara, Niimi et Itagaki, 1974) in Polish waters

2012 ◽  
Vol 15 (2) ◽  
pp. 253-257 ◽  
Author(s):  
R. Popielarczyk ◽  
S. Robak ◽  
K. Siwicki
Keyword(s):  
Infection Intensity ◽  
Anguilla Anguilla ◽  
Mean Value ◽  
European Eel ◽  
Szczecin Lagoon ◽  
The Mean ◽  
The Individual ◽  
Anguillicoloides Crassus ◽  
Anatomical Pathology

Infection of European eel, Anguilla anguilla (L.), with the nematode Anguillicoloides crassus (Kuwahara, Niimi et Itagaki, 1974) in Polish waters The aim of this study was to determine the degree of Anguillicoloides crassus infection in European eel inhabiting Polish waters based on selected parasitic descriptors and on anatomical pathology of the swimbladder using macroscopic methods. In all, 154 European eel specimens were sampled from eleven sites in Poland and A. crassus was present in the swimbladder of 114 fish. The intensity of A. crassus infection in all the eel specimens ranged from 1 to 62 parasites at a mean value of 7.5. High values of mean infection intensity were noted in samples from Pomeranian lakes Bukowo, Łebsko, and Jamno. The health of the swimbladder was evaluated using the swimbladder degenerative index (SDI). The mean value of the SDI for all of the eel examined was 3.3, and extensively degenerated swimbladders were observed mainly in samples in the Szczecin Lagoon and from lakes. According to the individual SDI ratings, 9.1% of the eel specimens did not exhibit pathological symptoms of the swimbladder (SDI-0) and an extremely damaged (SDI-6) swimbladder was noted in 11.7% of the fish examined. In the case of eel infected with A. crassus, higher SDI values were reflected in initially increasing shares in subsequent categories. In fish that were not infected with the nematode, only 20% (8 individuals) of the swimbladders showed no symptoms of pathology (SDI-0).

Infection by Anguillicoloides crassus in a riverine stock of European eel, Anguilla anguilla

2010 ◽  
Vol 17 (6) ◽  
pp. 485-492 ◽  
Author(s):  
S. COSTA-DIAS ◽  
E. DIAS ◽  
J. LOBÓN-CERVIÁ ◽  
C. ANTUNES ◽  
J. COIMBRA
Keyword(s):  
Anguilla Anguilla ◽  
European Eel ◽  
Anguillicoloides Crassus

scholarly journals Elemental composition of otoliths as a discriminator of life stage and growth habitat of the European eel, Anguilla anguilla

2005 ◽  
Vol 56 (5) ◽  
pp. 629 ◽  
Author(s):  
W. N. Tzeng ◽  
K. P. Severin ◽  
C. H. Wang ◽  
H. Wickström
Keyword(s):  
Elemental Composition ◽  
Environmental History ◽  
Life Stage ◽  
Anguilla Anguilla ◽  
Primary Component ◽  
European Eel ◽  
Yellow Eel ◽  
Minor Elements ◽  
Electron Probe Microanalyser ◽  
History Of

The hypothesis that elemental composition of otoliths of the eel (Anguilla spp.) changes with life stage and growth habitat was tested in the present study. The minor elements Cl, Na, K, Mg, Ca, Sr and P in otoliths of European eels (Anguilla anguilla) were examined by using an Electron Probe Microanalyser (EPMA) equipped with wavelength dispersive spectrometers (Cameca SX-50). Yellow-stage eels were collected from coastal waters and lakes of Sweden in 1987, 1988, 1991, and 1994, with ages ranging from 5 to 18 years old. Strontium maps and profiles of Sr : Ca ratio, as well as the elver check in otoliths, were used to classify life history stages of the eels as leptocephalus, and freshwater- and seawater-resident yellow eels. Canonical score plots of the otolith elemental compositions of the freshwater-resident yellow eel were completely separated from those of leptocephalus and seawater-resident yellow eel, but the latter two partially overlapped. Strontium is the primary component in determining the discrimination, but the nutrient-related (S and P), and the physiologically controlled elements (Na and Cl), may also play an important role in the discrimination. These results indicate that multiple-elemental information can provide additional insight into the migratory environmental history of diadromous fishes.

scholarly journals A mechanical approach to understanding the impact of the nematode Anguillicoloides crassus on the European eel swimbladder

2020 ◽  
Vol 223 (17) ◽  
pp. jeb219808
Author(s):  
Helen A. L. Currie ◽  
Nicholas Flores Martin ◽  
Gerardo Espindola Garcia ◽  
Frances M. Davis ◽  
Paul S. Kemp
Keyword(s):  
Mechanical Damage ◽  
Severe Infection ◽  
Anguilla Anguilla ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
European Eel ◽  
Sargasso Sea ◽  
Mechanical Integrity ◽  
The Impact ◽  
Anguillicoloides Crassus

ABSTRACTOne of the most detrimental factors in the drastic decline of the critically endangered European eel (Anguilla anguilla) was the inadvertent introduction of the invasive nematode Anguillicoloides crassus. Infection primarily affects the swimbladder, a gas-filled organ that enables the eel to control its depth in the water. A reduction in swimbladder function may be fatal for eel undergoing their spawning migration to the Sargasso Sea, a journey of over 5000 km. Although the physiological damage caused by this invasive parasite is well studied through the use of quantifiable gross pathological indices, providing a good measure of the swimbladder health status, they cannot separate the role of mechanical and morphological damage. Our study examined the appropriateness of three commonly used indices as a measure of mechanical damage by performing uniaxial tensile tests on swimbladder specimens obtained from an infected eel population. When the test results were compared with the gross pathological indices it was found that thickness correlated most strongly with mechanical damage, both confirming and, more importantly, explaining the counterintuitive findings of earlier work. In a damaged swimbladder, the immune response leads to a trade-off; increasing wall thickness raises the pressure required for organ rupture but decreases strength. The results indicate that for moderate infection the mechanical integrity of the swimbladder can be maintained. For severe infection, however, a reduction in mechanical integrity may reach a tipping point, thereby affecting the successful completion of their oceanic migration.

scholarly journals Characteristics of illegal inland fishing according to the opinions of Polish fisheries guards

2020 ◽  
Vol 28 (2) ◽  
pp. 125-132
Author(s):  
Maciej Mickiewicz ◽  
Arkadiusz Wołos ◽  
Marek Trella
Keyword(s):  
Perca Fluviatilis ◽  
Anguilla Anguilla ◽  
Esox Lucius ◽  
Inland Waters ◽  
European Eel ◽  
Sander Lucioperca ◽  
Great Problem ◽  
Frequent Type

AbstractPoaching is still a great problem in Poland. Officers of the fisheries guard from three regions in northeast Poland rich in natural inland waters were surveyed. The most frequent type of poaching encountered by the officers was that practised by recreational fishers using rods (ranking of 4.4 points on a scale of 0–5) followed by poaching stemming from poverty or unemployment (3.4 points), and poaching by professional fishermen was ranked the lowest (1.5 points). Organized poaching was identified as the most dangerous for ichthyofauna (42% of responses), followed by poaching by recreational fishers (28%) and poaching stemming from poverty or unemployment (23%). According to the officers surveyed, the species that were targeted by poachers most frequently were the predators: pike, Esox lucius (98% of responses), European eel, Anguilla anguilla, pikeperch, Sander lucioperca and perch, Perca fluviatilis.

scholarly journals In-situ non-lethal rapid test to accurately detect the presence of the nematode parasite, Anguillicoloides crassus, in European eel, Anguilla anguilla

2020 ◽  
Author(s):  
M. De Noia ◽  
R. Poole ◽  
J. Kaufmann ◽  
C. Waters ◽  
C. Adams ◽  
...  
Keyword(s):  
Rapid Test ◽  
Anguilla Anguilla ◽  
Nematode Parasite ◽  
European Eel ◽  
In Situ Extraction ◽  
Predictive Values ◽  
Non Invasive ◽  
Specificity And Sensitivity ◽  
Anguillicoloides Crassus

AbstractAnguillicoloides crassus is an invasive nematode parasite of the European eel, Anguilla anguilla, and one of the primary drivers of eel population collapse. The presence of the parasite has been shown to impact many features of eel physiology and life history. Early detection of the parasite is vital to limit the spread of A. crassus. However, until recently, accurate diagnosis of infection could only be achieved via terminal dissection. To support A. anguilla fisheries management in the context of A. crassus we developed a rapid non-lethal and non-invasive environmental DNA method to detect the presence of the parasite in the swim bladder. Screening of 131 wild eels was undertaken between 2017 and 2019 Ireland and UK to validate the procedure. DNA extractions and PCR were conducted using both a Qiagen Stool kit at Glasgow University and in situ using Whatman qualitative filter paper No. 1 and a miniPCR DNA Discovery System™. Primers were specifically designed from the cytochrome oxidase mtDNA gene region. In situ extraction and amplification takes approx. 3h for up to 16 individuals with higher specificity and sensitivity compare to the laboratory Qiagen kit extraction. The local diagnostic procedure demonstrated Positive Predictive Values at 96% and Negative Predictive Values at 87%. Our method will be a powerful tool in the hands of fisheries managers to help protect this iconic but critically endangered species. It will allow a non-invasive monitoring of the A. crassus dispersion across the European waters.

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