Macroparasite Community and Asymmetry of the Yellow Eel Anguilla Anguilla in Salses-Leucate Lagoon, Southern France

Abstract

European eel parasites, in particular invasive species, are suspected to have a strong influence on the population dynamics of their host. The aim of this work was to study the relationship between parasitic fauna of yellow eels caught at Salses-Leucate lagoon and the fluctuating asymmetry (FA) of some functional bilateral traits: pectoral fins, eyes and otoliths. Epidemiological distance matrices and FA distance matrices were calculated on the basis of the Euclidian distances between each pair of eel and were then compared with a Mantel test in order to establish if there was a relationship between parasitism and FA. Our results revealed different morphological characteristics between eels caught at different dates; only otoliths were found asymmetric. The parasite richness was of 10 species, 1 Nematoda, 1 Acanthocephala, 1 Monogenea and 7 Digenea. We failed to find a significant relationship between asymmetry and parasitism, except for parasites found in the stomach. We discussed the results in the light of the eel life cycle, the specificity of parasite -eel systems and the impact of parasites on the host physiology. Key-words:Parasites, eels, fluctuating asymmetry, distance matrices, SalsesLeucate lagoon. COMMUNAUTÉ DES MACROPARASITES ET ASYMÉTRIE CHEZ L'ANGUILLE JAUNE ANGUILLA ANGUILLA DANS LA LAGUNE DE SALSES-LEUCATE, SUD DE LA FRANCE RÉSUMÉLes parasites de l'anguille européenne, en particulier les espèces invasives, sont supposés avoir une grande influence sur la dynamique des populations de leur hôte. Ce travail se propose d'étudier la relation entre la faune parasitaire d'anguilles jaunes prélevées dans la lagune de Salses-Leucate et l'asymétrie fluctuante (FA) de traits bilatéraux fonctionnels : les nageoires pectorales, les yeux et les otolithes. Des matrices de distance épidémiologique ainsi que des matrices de distance de FA ont été calculées sur la base des distances euclidiennes entre anguilles prises deux à deux et ont ensuite été comparées par un test de Mantel afin d'établir s'il existait une relation entre elles. Nos

Macroparasite communities in European eels,Anguilla anguilla, from French Mediterranean lagoons, with special reference to the invasive speciesAnguillicola crassusandPseudodactylogyrusspp.

“…was not found in Salses-Leucate lagoon, except in July 2004. A previous study showed that records of P. anguillae in Salses-Leucate lagoon were anecdotal (Fazio et al, 2005). This result suggests unfavourable environmental conditions for the parasite in this site.…”

Fluctuating asymmetry and exogenous stress in fishes: a review

“…Campbell and Emlen (1996) failed to find a significant relationship between FA of five meristic characters in chinook salmon O. tshawytscha and bacterial kidney infection caused by Renibacterium salmoninarum. Fazio et al (2005) likewise found no relationship between parasite load and FA for fin, eye, or otolith measurements in the eel Anguilla anguilla, nor did Loot et al (2001) find a relationship between Ligula intestinalis infestation and FA in a number of morphometric characters in roach Rutilus rutilus. Landrum (1966), Downhower et al (1990), Shaikin (1992), Bergstrom and Reimchen (2000, Lajus (2001), Lajus et al (2003), Prieto et al (2005) Natural stressors…”

“…Rearing density Leary et al (1991Leary et al ( , 1992 Condition Jarvi et al (1996), Somarakis et al (1997b), Sanchez-Galan et al (1998), Folkvord et al (2000, Sunderland (2001), Robinson and Wardrop (2002), Bakker et al (2006), Gronkjaer and Sand (2003), Fey and Hare (2008) Infection/parasites Escos et al (1995), Campbell and Emlen (1996), Berg et al (1997), Reimchen (1997), Reimchen and Nosil (2001a, b), Loot et al (2001), Reimchen (2002, 2005), Fazio et al (2005), Prieto et al (2005), Pecinkova et al (2007) Predators/predation Moodie and Reimchen (1976), Moodie (1977), Bergstrom and Reimchen (2003) Anthropogenic stressors…”

“…Deviation from perfect bilateral symmetry can be seen as three distinct types: fluctuating asymmetry (FA), directional asymmetry (DA), and antisymmetry (AA). FA is the random deviation of a character from perfect bilateral symmetry, statistically represented by a right side minus left side (R-L) mean of zero and Berg et al (1997), Fazio et al (2005), Franco et al (2002), Goncalves et al (2002), Lucentini et al (1998) Lochmann (2005, 2006)*, Jagoe and Haines (1985), Loot et al (2001), Lucentini et al (1998), Sunderland (2001) Otolith length 10 3 30.0 Alados et al (1993), Ames et al (1979)*, Fazio et al (2005, Fey and Hare (2008), Franco et al (2002), Lochmann (2005*, 2006), Gronkjaer and Sand (2003)*, Jagoe and Haines (1985), Jarvi et al (1996) Otolith diameter 10 2 20.0 Alados et al (1993), Ames et al (1979)*, Escos et al (1995, Fazio et al (2005), Fey and Hare (2008), Franco et al (2002)*, Lochmann (2005, 2006), Jagoe and Haines (1985), Panfili et al (2005) (2001) Characters were significant in the references marked with an asterisk (*)…”

“…et al (2008),Berg et al (1997),Fazio et al (2005),Franco et al (2002),Goncalves et al (2002),Lucentini et al (1998),Marques et al (2005),Pecinkova et al (2007)*,Robinson and Wardrop (2002)*, Sunderland (2001)*, Turner et al (2007)*; Urbach et al et al (1999), Estes et al (2006)*, Fazio et al (2005), Green and Lochmann (2005, 2006), Loot et al (2001), Marques et al (2005), Ozsoy et al (2007)*, Vollestad et al et al (2008), Berg et al (1997)*, Goncalves et al (2002), Lucentini et al (1998), Marques et al (2005), Pecinkova et al (2007)*, Sunderland (2001)*, Turner et al and Hare (2008)*, Franco et al (2002), Green and Lochmann (2005, 2006), Gronkjaer and Sand (2003)*, Panfili et al (2005), Somarakis et al et al (1999)*, Ames et al (1979)*, Estes et al (2006)*, Jagoe and Haines (1985), et al (2005), Franco et al (2002), Green and Lochmann (2005, 2006), Panfili et al (2005), Somarakis et al et al (1979)*, Estes et al (2006)*, Jagoe and Haines (1985)-Hassan and Shwafi (1997), Allenbach et al (1999)*, Franco et al (2002), Loot et al (2001), Fazio et al (2005), Green and Lochmann (2005, 2006*), Loot et al et al (2000), Franco et al (2002)*, Panfili et al (2005), Somarakis et al (1997b), Vollestad and Hindar…”