Migratory life history of European eel Anguilla anguilla from freshwater regions of the River Asi, southern Turkey and their high otolith Sr:Ca ratios

Abstract.—Restocking programs of the European eel Anguilla anguilla have been conducted for nearly one century in Latvia. To evaluate the efficiency of the eel restocking program and reveal the migratory life histories of European eels in Latvian waters, a total of 75 individuals was collected from the mouth of River Daugava (Daugavgrīva, brackish), a nearby lake (Lake Ķīšezers, freshwater), and a coastal site (Mērsrags, brackish). The naturally-recruited eels consisted of two saltwater types: eels that lived in saltwater and did not enter freshwater (SW, 0–7%) and eels that experienced both freshwater and saltwater, referred to as inter-habitat-shifter (IHS, 60–85%). Restocked eels consisted of purely freshwater types (FW, 7–36.7%)without any exposure to saltwater. Average Sr:Ca ratios at the edge of otoliths were different among sites and origins, and corresponded to the salinities of sampling sites. The mean age at first freshwater entry of IHS was 4.8 ± 2.3 years and was similar to previous studies in Lithuania. The growth rates of FW eels in the river mouth and coast were significantly slower than that of IHS eels (p < 0.001 and 0.012). The use of otolith Sr:Ca ratios as a natural mark to distinguish restocked eels here enabled the assessment of restocking efficiency.

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

Journal of Helminthology ◽

10.1079/joh2004270 ◽

2005 ◽

Vol 79 (2) ◽

pp. 169-176 ◽

Cited By ~ 4

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.

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Life history scan using otolith Sr：Ca ratios of diadromous fish in the Gouno River, western Japan.

Ecology and Civil Engineering ◽

10.3825/ece.18.147 ◽

2015 ◽

Vol 18 (2) ◽

pp. 147-154 ◽

Cited By ~ 1

Author(s):

Tetsuya UMINO ◽

Masaki YAMAMOTO ◽

Naoki SASADA ◽

Kenichi OHARA

Keyword(s):

Life History ◽

Diadromous Fish ◽

Otolith Sr:Ca Ratios ◽

Sr:Ca Ratios ◽

Western Japan

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

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2012.2916 ◽

2013 ◽

Vol 280 (1754) ◽

pp. 20122916 ◽

Cited By ~ 19

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.

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Diversity of migratory environmental history of the mullets Mugil cephalus and M. curema in Mexican coastal waters as indicated by otolith Sr:Ca ratios

Ciencias Marinas ◽

10.7773/cm.v38i1a.1905 ◽

2012 ◽

Vol 38 (1A) ◽

pp. 73-87 ◽

Cited By ~ 12

Author(s):

AL Ibañez

Keyword(s):

Environmental History ◽

Coastal Waters ◽

Mugil Cephalus ◽

Otolith Sr:Ca Ratios ◽

History Of ◽

Sr:Ca Ratios

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Facultative amphidromy and pelagic larval duration plasticity of Rhinogobius formosanus (Teleostei, Gobioidei)

ZooKeys ◽

10.3897/zookeys.951.50429 ◽

2020 ◽

Vol 951 ◽

pp. 91-107

Author(s):

Te-Yu Liao ◽

Wen-Chien Huang ◽

Yoshiyuki Iizuka ◽

Ming-Tai Chou ◽

Jen-Chieh Shiao

Keyword(s):

Life History ◽

Early Life History ◽

Pelagic Larval Duration ◽

Early Developmental Stage ◽

Larval Duration ◽

Otolith Sr:Ca Ratios ◽

Growth Increments ◽

Sr:Ca Ratios ◽

Otolith Sr:Ca Ratio ◽

Feitsui Reservoir

Rhinogobius formosanus Oshima, 1919 has long been considered an amphidromous goby. However, a landlocked population recently found in the Jingualiao Creek upstream of the Feitsui Reservoir in Taipei suggests that R. formosanus may complete its life in the river. This study aims to verify the habitat use of the landlocked population of R. formosanus collected from the Feitsui Reservoir and an amphidromous population collected in Malian Creek using otolith Sr:Ca ratio analysis. The hypothesis that early life history varies between the landlocked and migratory gobies was also tested. Genetic analyses show that the Feitsui Reservoir and Malian Creek populations are not genetically different. Rhinogobius formosanus from Malian Creek showed high-to-low otolith Sr:Ca ratios suggesting that these specimens spent a planktonic larval stage in the sea followed by a freshwater life at later stages. In contrast, R. formosanus from the Feitsui Reservoir showed constant lower otolith Sr:Ca ratios, implying a landlocked life history of fish in the creek upstream of the reservoir. In addition, the analysis of growth increments showed a longer pelagic larval duration for the fish in the Malian Creek (58.8 days) than those in the Feitsui Reservoir (38.8). Variation of pelagic larval duration in two genetically homogenous populations implies acclimatization to the reservoir by the landlocked gobies. This study shows that R. formosanus, like some other congeners, is capable of adapting to a freshwater landlocked environment in its early developmental stage and supports the hypothesis that landlocked populations may have a shorter pelagic larval duration.

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

Marine and Freshwater Research ◽

10.1071/mf04167 ◽

2005 ◽

Vol 56 (5) ◽

pp. 629 ◽

Cited By ~ 8

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.

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