101
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Oueslati J, Rayes A, Nasr CB, Lefebvre F. Synthesis and Characterization of Two New Compounds: N(C2H4NH3)3(H2TO4)(HTO4)·2H2O (T = P, As). PHOSPHORUS SULFUR 2007. [DOI: 10.1080/10426500500269992] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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102
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Nassar G, Sabra M, Lefebvre F, Toubal M, Nongaillard B, Noel Y. Design of low-frequency ultrasonic sensors for the analysis of the draining stage of cheese production. ULTRASONICS 2006; 44:e1045-e1050. [DOI: 10.1016/j.ultras.2006.05.100] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/29/2023]
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103
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Kefi R, Ben Nasr C, Lefebvre F, Rzaigui M. Hydrothermal synthesis and characterization of a new zinc phosphate [Zn2.5(HPO4)2(PO4)][C6H10N2]·5H2O. Polyhedron 2006. [DOI: 10.1016/j.poly.2006.05.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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104
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Kefi R, Nasr CB, Lefebvre F, Rzaigui M. The Synthesis and Characterization of a New Layered Chlorozincophosphate Zn(HPO4)Cl[C4H10N]. PHOSPHORUS SULFUR 2006. [DOI: 10.1080/10426500600614782] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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105
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Oueslati A, Touati A, Nasr CB, Lefebvre F. The Synthesis and Characterization of 2-Amino-3-methylpyridinium Dihydrogenmonophosphate: (C6H9N2)H2PO4. PHOSPHORUS SULFUR 2006. [DOI: 10.1080/10426500600614196] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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106
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Kumbar SM, Shanbhag G, Lefebvre F, Halligudi S. Heteropoly acid supported on titania as solid acid catalyst in alkylation of p-cresol with tert-butanol. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.molcata.2006.05.024] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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107
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Mrad ML, Nasr CB, Rzaigui M, Lefebvre F. Synthesis, Crystal Structure, and NMR Spectroscopy of a New P-Phenylenediamonium Diphosphate [ p-NH 3C 6H 4NH 3]H 2P 2O 7. PHOSPHORUS SULFUR 2006. [DOI: 10.1080/10426500500366558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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108
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Dérue C, Gibouin D, Lefebvre F, Studer D, Thellier M, Ripoll C. Relative Sensitivity Factors of Inorganic Cations in Frozen-hydrated Standards in Secondary Ion MS Analysis. Anal Chem 2006; 78:2471-7. [PMID: 16615752 DOI: 10.1021/ac051518u] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We describe the measurement, at 100 K, of the SIMS relative sensitivity factors (RSFs) of the main physiological cations Na+, K+, Mg2+, and Ca2+ in frozen-hydrated (F-H) ionic solutions. Freezing was performed by either plunge freezing or high-pressure freezing. We also report the measurement of the RSFs in flax fibers, which are a model for ions in the plant cell wall, and in F-H ionic samples, which are a model for ions in the vacuole. RSFs were determined under bombardment with neutral oxygen (FAB) for both the fibers and the F-H samples. We show that referencing to ice-characteristic secondary ions is of little value in determining RSFs and that referencing to K is preferable. The RSFs of Na relative to K and of Ca relative to Mg in F-H samples are similar to their respective values in fiber samples, whereas the RSFs of both Ca and Mg relative to K are lower in fibers than in F-H samples. Our data show that the physical factors important for the determination of the RSFs are not the same in F-H samples and in homogeneous matrixes. Our data show that it is possible to perform a SIMS relative quantification of the cations in frozen-hydrated samples with an accuracy on the order of 15%. Referencing to K permits the quantification of the ionic ratios, even when the absolute concentration of the referencing ion is unknown. This is essential for physiological studies of F-H biological samples.
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109
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Mrad ML, Ben Nasr C, Rzaigui M, Lefebvre F. Synthesis and Crystal Structure of a New Adduct 4-Benzyl Piperidinium Dihydrogenphosphate Phosphoric Acid [C 12H 16NH 2] 2 (H 2PO 4) 2 H 3PO 4. PHOSPHORUS SULFUR 2006. [DOI: 10.1080/104265090968613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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110
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Poulin R, Lefebvre F. Alternative life-history and transmission strategies in a parasite: first come, first served? Parasitology 2005; 132:135-41. [PMID: 16393362 DOI: 10.1017/s003118200500870x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2005] [Revised: 07/04/2005] [Accepted: 07/04/2005] [Indexed: 11/06/2022]
Abstract
Alternative transmission strategies are common in many parasitic organisms, often representing discrete phenotypes adopted in response to external cues. The facultative truncation of the normal 3-host life-cycle to a 2-host cycle in many trematodes provides an example: some individuals mature precociously, via progenesis, in their intermediate host and produce eggs without the need to reach a definitive host. The factors that determine how many and which individuals adopt the truncated life-cycle within a parasite population remain unknown. We investigated the occurrence of progenesis in the trematode Stegodexamene anguillae within its fish intermediate host. Location within the host was a key determinant of progenesis. Although the size and egg output of progenetic metacercariae encysted in host gonads did not differ from those of the few progenetic metacercariae in other host tissues, the likelihood of metacercariae becoming progenetic was much higher for those in the gonads than those elsewhere in the host. Progenetic parasites can only evacuate their eggs along with host eggs or sperm, providing a link between the parasite's transmission strategy and its location in the host. Host size and sex, and the presence of other parasite species in the host, did not affect the occurrence of progenesis in S. anguillae. However, the proportion of metacercariae in host gonads and the proportion of progenetic metacercariae both decreased with increasing numbers of S. anguillae per host. These results suggest that progenesis is adopted mostly by the parasites that successfully establish in host gonads. These are generally the first to infect a fish; subsequent arrivals settle in other tissues as the gonads quickly become saturated with parasites. In this system, the site of encystment within the fish host both promotes and constrains the adoption of a facultative, truncated life-cycle by the parasite.
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111
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Lefebvre F, Poulin R. Progenesis in digenean trematodes: a taxonomic and synthetic overview of species reproducing in their second intermediate hosts. Parasitology 2005; 130:587-605. [PMID: 15977895 DOI: 10.1017/s0031182004007103] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Precocious egg production, i.e. progenesis, has been documented for a number of species in scattered reports throughout the trematode literature. The last 2 extensive studies on the subject date from Buttner in the early 1950s (in French) and from Tang in the early 1980s (in Chinese). Overall, 43 species were then known for their ability to produce eggs at the metacercarial stage while still in the second intermediate host. Here, we update the list, and document the existence of progenesis in a total of 79 digenean trematode species, for which we provide information on the taxonomy of the hosts, the facultative or obligate character of progenesis, relevant references, as well as some other pertinent biological information. We then review the subject by asking 7 questions of fundamental evolutionary importance. These include: What favours progenetic development? What are the associated costs and benefits? How are progenetic eggs released from the host? While exposing the various opinions of previous authors, we attempt to give a synthetic overview and stress on the importance of the metacercarial cyst wall (whether it is present, and if so its thickness) in the evolution and the adoption of a progenetic life-cycle.
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112
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Ni KF, Shan GR, Weng ZX, Sheibat-Othman N, Fevotte G, Lefebvre F, Bourgeat-Lami E. Synthesis of Hybrid Core−Shell Nanoparticles by Emulsion (Co)polymerization of Styrene and γ-Methacryloxypropyltrimethoxysilane. Macromolecules 2005. [DOI: 10.1021/ma050334e] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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113
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Lefebvre F, Poulin R. Life history constraints on the evolution of abbreviated life cycles in parasitic trematodes. J Helminthol 2005; 79:47-53. [PMID: 15831113 DOI: 10.1079/joh2004273] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Abbreviations of the complex life cycle of trematodes, from three to two hosts, have occurred repeatedly and independently among trematode lineages. This is usually facultative and achieved via progenesis: following encystment in the second intermediate host, the metacercaria develops precociously into an egg-producing adult, bypassing the need to reach a definitive host. Given that it provides relatively cheap insurance against a shortage of definitive hosts, it is not clear why facultative progenesis has only evolved in a few taxa. Here a comparative approach is used to test whether progenetic trematodes are characterized by larger body size and egg volumes, two traits that correlate with other key life history features, than other trematodes. These traits may constrain the evolution of progenesis, because precocious maturation might be impossible when the size difference between the metacercaria and a reproductive adult is too large. First, trematode species belonging to genera in which progenesis has been documented were found not to differ significantly from other trematode species. Second, using within-genus paired comparisons across 19 genera in which progenesis has been reported, progenetic species did not differ, with respect to body size or egg size, from their non-progenetic congeners. Third, using intraspecific paired comparisons in species where progenesis is facultative, no difference was observed in the sizes of eggs produced by worms in both the intermediate and definitive host, suggesting that opting for progenesis does not influence the size of a worm's eggs. Overall, the lack of obvious differences in body or egg size between trematodes with truncated life cycles and those with the normal three-host cycle indicates that basic life history characteristics are not acting as constraints on the evolution of progenesis; trematodes of all sizes can do it. Why facultative progenesis is not more widespread remains a mystery.
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114
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Devassy BM, Shanbhag G, Lefebvre F, Böhringer W, Fletcher J, Halligudi S. Zirconia-supported phosphotungstic acid as catalyst for alkylation of phenol with benzyl alcohol. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.molcata.2004.12.028] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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115
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Bartholome C, Beyou E, Bourgeat-Lami E, Chaumont P, Lefebvre F, Zydowicz N. Nitroxide-Mediated Polymerization of Styrene Initiated from the Surface of Silica Nanoparticles. In Situ Generation and Grafting of Alkoxyamine Initiators. Macromolecules 2005. [DOI: 10.1021/ma048501i] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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116
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Devassy BM, Halligudi S, Elangovan S, Ernst S, Hartmann M, Lefebvre F. Zirconia supported phosphotungstic acid as an efficient catalyst for resorcinol tert-butylation and n-heptane hydroisomerization. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.molcata.2004.06.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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117
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Devassy BM, Shanbhag G, Lefebvre F, Halligudi S. Alkylation of p-cresol with tert-butanol catalyzed by heteropoly acid supported on zirconia catalyst. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.molcata.2003.09.015] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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118
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Lefebvre F, Deblock Y, Campistron P, Ahite D, Fabre JJ. Development of a new ultrasonic technique for bone and biomaterials in vitro characterization. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 2003; 63:441-6. [PMID: 12115753 DOI: 10.1002/jbm.10261] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Classical techniques based on bone imaging allow visual examination or provide quantitative parameters like bone mineral density, which is a mass per unit of surface. Unfortunately, these techniques are generally expensive. A new method of bone characterization that uses ultrasound techniques is presented in this article. This method is able to evaluate mechanical properties like Young's modulus E and cortical bone thickness with low-frequency transducers and does not require the use of a coupling medium. Some results of Young's modulus measurements are presented and compared to the literature values and the pulse echo method.
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119
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Lefebvre F, Contournet P, Priour F, Soulas O, Crivelli AJ. Spatial and temporal variation in Anguillicola crassus counts: results of a 4 year survey of eels in Mediterranean lagoons. DISEASES OF AQUATIC ORGANISMS 2002; 50:181-188. [PMID: 12219974 DOI: 10.3354/dao050181] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We present the results of a survey of anguillicolosis in the Rh6ne River delta. From January 1997 to December 2000, a total of 13,319 eels (Anguilla anguilla from elver to silver phase) were examined, in which we found 22,227 swimbladder nematodes (Anguillicola crassus adults and pre-adults). A generalised linear model (GLM) framework was used to explore the relative contribution of various factors to the occurrence, intensity and abundance of the parasite. We reveal a major influence of the month of sampling, and we document the existence of a seasonal pattern with regular peaks in early summer and late winter. In contrast, the year of sampling is of secondary importance, and no particular trend in the development of the infection can be detected. More than a decade after the first record of A. crassus in the Rhĵne River delta, anguillicolosis has thus attained a constant infection rate of nearly 50%, with a mean number of 3 or 4 macroscopic lumen worms per infected eel. The eel length strongly influences the intensity and the abundance of the nematode, but has little if any effect on the probability of being infected. There exists a linear relationship between eel size and the number of parasites, but not between eel size and prevalence. We observe a decrease in the proportion of infected individuals among elver eels. We discuss this result in relation to the possible mortality of heavily infected individuals and/or a change in the eels' alimentary diet.
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120
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Bourgeat-Lami E, Tissot I, Lefebvre F. Synthesis and Characterization of SiOH-Functionalized Polymer Latexes Using Methacryloxy Propyl Trimethoxysilane in Emulsion Polymerization. Macromolecules 2002. [DOI: 10.1021/ma012230j] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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121
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Devassy BM, Halligudi SB, Hegde SG, Halgeri AB, Lefebvre F. 12-Tungstophosphoric acid/zirconia--a highly active stable solid acid--comparison with a tungstated zirconia catalyst. Chem Commun (Camb) 2002:1074-5. [PMID: 12122671 DOI: 10.1039/b200722c] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A highly active and stable zirconia supported 12-tungstophosphoric acid catalyst is found to be 2-3 times more active in benzylation and acylation reactions than a tungstated zirconia catalyst.
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122
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Nedez C, Theolier A, Lefebvre F, Choplin A, Basset JM, Joly JF. Surface organometallic chemistry of tin: reactivity of tetraalkyltin complexes and tributyltin hydride toward silica. J Am Chem Soc 2002. [DOI: 10.1021/ja00055a049] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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123
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Nedez C, Lefebvre F, Choplin A, Basset JM, Benazzi E. Surface Organometallic Chemistry of Tin: Thermal Transformation, under Vacuum, of >Si-O-Sn(n-Bu)3 Supported on Silica. J Am Chem Soc 2002. [DOI: 10.1021/ja00086a037] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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124
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Nedez C, Choplin A, Lefebvre F, Basset JM, Benazzi E. Surface Organometallic Chemistry of Tin: Formation of the Grafted Organometallic Complex (.scharw.Si-O)2Sn(n-C4H9)2 by Reaction of H2Sn(n-C4H9)2 with the Surface of a Partially Dehydroxylated Silica. Inorg Chem 2002. [DOI: 10.1021/ic00084a021] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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125
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Lefebvre F, Contournet P, Crivelli AJ. The health state of the eel swimbladder as a measure of parasite pressure by Anguillicola crassus. Parasitology 2002; 124:457-63. [PMID: 12003069 DOI: 10.1017/s0031182001001378] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We have developed an index based on macroscopic criteria to easily assess the health state of the eel swimbladder as a result of infection by the nematode Anguillicola crassus. In the sampling area (brackish lagoons of the French Mediterranean coast), 92% of the host sample (1,251 eels covering all size classes) showed pathological signs of infection. The general trend was for increasing damage as eel size increased, thus suggesting accumulation of pathological effects. We also revealed a non-linear relationship between the swimbladder index and the abundance of living worms. In particular, we showed that severely damaged swimbladders harboured very few living nematodes. We argue that the swimbladder degenerative index more closely reflects the parasite pressure than does classic parasite count. We found seasonal variation in the swimbladder index, with maximum damage occurring in July and thereafter a trend for healthy individuals. We discuss the possibility that the seasonal decrease in the swimbladder index could reflect the death of the more severely affected individuals during the warmest months.
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