Conference Presentations by Wiem Boussellaa
Despite their potential ecological and environmental effects, parasites of exotic fish remain an ... more Despite their potential ecological and environmental effects, parasites of exotic fish remain an underestimated
component of ecosystem functioning. Among these parasites, Digenea have the most complex life cycles that make
them difficult to be introduced. In the Gulf of Gabes (Central Mediterranean Sea), four herbivorous fish are present: two
native Sarpa salpa and Sparisoma cretense and two lessepsian Siganus rivulatus and Siganus luridus. These fishes are
assumed to have feeding analogies that increase the possibility to be infested by the same digenean species.
Comparative parasitological studies of these fishes in sympatric sites are crucial to understand parasite circulation.
Thirteen S. rivulatus, 33 S. luridus, 30 S. cretense and 20 S. salpa were studied for their digenean parasites. The two
lessepsian S. rivulatus and S. luridus have the same and only parasite Aponorus sigani. Sparisoma cretense has only one
species Schikhobalotrema sparisomae and S. salpa is parasitised with 6 species Centroderma spinosissima, Mesometra
orbicularis, Mesometra brachycoelia, Wardula capitellata, Lepocreadium pegorchis, Robphildollfusium fractum.
No parasites switching between these herbivorous fish were observed. Absence of intermediate host and phylogenetic
barrier may prevent transfer of parasite. The introduced species was considerably less parasitised than those from
native locality (10 species were reported from S. rivulatus and S. luridus of Red Sea and only one species from
Mediterranean Sea). A. sigani is a co-introduced parasite established with its host and its intermediate host in
Mediterranean Sea.
Papers by Wiem Boussellaa
CBM - Cahiers de Biologie Marine, 2016
The presence of the Lessepsian migrant red-eye round herring Etrumeus golanii (Clupeidae) is conf... more The presence of the Lessepsian migrant red-eye round herring Etrumeus golanii (Clupeidae) is confirmed in Tunisian coastal waters with the record of 7 specimens captured in June 2014 in the Gulf of Gabes. Total length of E. golanii individus captured on the Tunisian coast is comprised between 22.5 and 26.5 cm. All specimens are mature females with gonads weighing between 3.97 and 5.25 g. Morphometric and meristic characteristics of the species are described with notes on its parasites. Different developmental stages of 3 parasites Lecithochirium jaffense (Digenea), Anisakis sp. (Nematoda) and Gnathia sp. (Isopoda) were collected. This new record of E. golanii may confirm the rapid range expansion of this Lessepsian migrant in the Central Mediterranean Sea, as well as the infection with parasites newly reported in this host.
PeerJ, 2018
Background Parasites can play various roles in the invasion of non-native species, but these are ... more Background Parasites can play various roles in the invasion of non-native species, but these are still understudied in marine ecosystems. This also applies to invasions from the Red Sea to the Mediterranean Sea via the Suez Canal, the so-called Lessepsian migration. In this study, we investigated the role of parasites in the invasion of the Lessepsian migrant Sphyraena chrysotaenia in the Tunisian Mediterranean Sea. Methods We compared metazoan parasite richness, prevalence and intensity of S. chrysotaenia (Perciformes: Sphyraenidae) with infections in its native congener Sphyraena sphyraena by sampling these fish species at seven locations along the Tunisian coast. Additionally, we reviewed the literature to identify native and invasive parasite species recorded in these two hosts. Results Our results suggest the loss of at least two parasite species of the invasive fish. At the same time, the Lessepsian migrant has co-introduced three parasite species during the initial migration ...
Background. Parasites can play various roles in the invasion of non-native species, but these are... more Background. Parasites can play various roles in the invasion of non-native species, but these are still understudied in marine ecosystems. This also applies to invasions from the Red Sea to the Mediterranean Sea via the Suez Canal, the so-called Lessepsian migration. In this study, we investigated the role of parasites in the invasion of the Lessepsian migrant Sphyraena chrysotaenia in the Tunisian Mediterranean Sea. Methods. We compared metazoan parasite richness, prevalence and intensity of S. chrysotaenia (Perciformes: Sphyraenidae) with infections in its native congener Sphyraena sphyraena by sampling these fish species at seven locations along the Tunisian coast. Additionally, we reviewed the literature to identify native and invasive parasite species recorded in these two hosts. Results. Our results suggest the loss of at least two parasite species of the invasive fish. At the same time, the Lessepsian migrant has co-introduced three parasite species during the initial migration to the Mediterranean Sea, that are assumed to originate from the Red Sea of which only one parasite species has been reported during the spread to Tunisian waters. In addition, we found that the invasive fish has acquired six parasite species that are native in the Mediterranean Sea. However, parasite richness, prevalence and intensity were overall much lower in the invasive compared to the native fish host in the Mediterranean Sea. Discussion. These results suggest that the Lessepsian migrant may affect native fish hosts by potentially altering the dynamics of native and invasive parasite-host interactions via parasite release, parasite co-introduction and parasite acquisition. They further suggest that the lower infection levels in the invasive fish may result in a competitive advantage over native fish hosts (enemy release hypothesis). This study demonstrates that cross-species comparisons of parasite infection levels are a valuable tool to identify the different roles of parasites in the course of Lessepsian migrations.
The presence of the Lessepsian migrant red-eye round herring Etrumeus golanii (Clupeidae) is conf... more The presence of the Lessepsian migrant red-eye round herring Etrumeus golanii (Clupeidae) is confirmed in Tunisian coastal waters with the record of 7 specimens captured in June 2014 in the Gulf of Gabes. Total length of E. golanii individus captured on the Tunisian coast is comprised between 22.5 and 26.5 cm. All specimens are mature females with gonads weighing between 3.97 and 5.25 g. Morphometric and meristic characteristics of the species are described with notes on its parasites. Different developmental stages of 3 parasites Lecithochirium jaffense (Digenea), Anisakis sp. (Nematoda) and Gnathia sp. (Isopoda) were collected. This new record of E. golanii may confirm the rapid range expansion of this Lessepsian migrant in the Central Mediterranean Sea, as well as the infection with parasites newly reported in this host. Résumé : Un nouveau signalement du poisson lessepsien Etrumeus golanii (Teleostei : Clupeidae) dans le Golfe de Gabès, Tunisie avec des notes sur ses parasites. Cette étude confirme la présence de l'espèce lessepsienne, la sardine ronde à yeux rouges Etrumeus golanii (Clupeidae) sur les côtes tunisiennes, avec le signalement de 7 spécimens capturés en juin 2014 dans le golfe de Gabès. Tous les spécimens sont des femelles matures avec des gonades pesant entre 3,97 et 5,25 g. Les caractéristiques morphométriques et méristiques de l'espèce sont décrites avec une note sur ses parasites. Trois parasites de stades de développement différents Gnathia sp. (Isopoda) Anisakis sp. (Nematoda) et Lecithochirium jaffense (Platyhelminthes) ont été récoltés. Ce nouveau signalement d'E. golanii peut confirmer l'expansion rapide de ce migrateur lessepsien en Mer Méditerranée centrale, ainsi que l'infection par des parasites nouvellement signalés chez cet hôte.
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Conference Presentations by Wiem Boussellaa
component of ecosystem functioning. Among these parasites, Digenea have the most complex life cycles that make
them difficult to be introduced. In the Gulf of Gabes (Central Mediterranean Sea), four herbivorous fish are present: two
native Sarpa salpa and Sparisoma cretense and two lessepsian Siganus rivulatus and Siganus luridus. These fishes are
assumed to have feeding analogies that increase the possibility to be infested by the same digenean species.
Comparative parasitological studies of these fishes in sympatric sites are crucial to understand parasite circulation.
Thirteen S. rivulatus, 33 S. luridus, 30 S. cretense and 20 S. salpa were studied for their digenean parasites. The two
lessepsian S. rivulatus and S. luridus have the same and only parasite Aponorus sigani. Sparisoma cretense has only one
species Schikhobalotrema sparisomae and S. salpa is parasitised with 6 species Centroderma spinosissima, Mesometra
orbicularis, Mesometra brachycoelia, Wardula capitellata, Lepocreadium pegorchis, Robphildollfusium fractum.
No parasites switching between these herbivorous fish were observed. Absence of intermediate host and phylogenetic
barrier may prevent transfer of parasite. The introduced species was considerably less parasitised than those from
native locality (10 species were reported from S. rivulatus and S. luridus of Red Sea and only one species from
Mediterranean Sea). A. sigani is a co-introduced parasite established with its host and its intermediate host in
Mediterranean Sea.
Papers by Wiem Boussellaa
component of ecosystem functioning. Among these parasites, Digenea have the most complex life cycles that make
them difficult to be introduced. In the Gulf of Gabes (Central Mediterranean Sea), four herbivorous fish are present: two
native Sarpa salpa and Sparisoma cretense and two lessepsian Siganus rivulatus and Siganus luridus. These fishes are
assumed to have feeding analogies that increase the possibility to be infested by the same digenean species.
Comparative parasitological studies of these fishes in sympatric sites are crucial to understand parasite circulation.
Thirteen S. rivulatus, 33 S. luridus, 30 S. cretense and 20 S. salpa were studied for their digenean parasites. The two
lessepsian S. rivulatus and S. luridus have the same and only parasite Aponorus sigani. Sparisoma cretense has only one
species Schikhobalotrema sparisomae and S. salpa is parasitised with 6 species Centroderma spinosissima, Mesometra
orbicularis, Mesometra brachycoelia, Wardula capitellata, Lepocreadium pegorchis, Robphildollfusium fractum.
No parasites switching between these herbivorous fish were observed. Absence of intermediate host and phylogenetic
barrier may prevent transfer of parasite. The introduced species was considerably less parasitised than those from
native locality (10 species were reported from S. rivulatus and S. luridus of Red Sea and only one species from
Mediterranean Sea). A. sigani is a co-introduced parasite established with its host and its intermediate host in
Mediterranean Sea.