Parasitic inventory of Balistes capriscus(Teleostei:Balistidae)from the Gulf of Gabès(Southern Tunisia,Central Mediterranean Sea)

Objective:To investigate the parasitic inventory of Balistes capriscus(Teleostei:Balistidae)(B.capriscus)from the Gulf of Gabès(Southern Tunisia,Central Mediterranean Sea).Methods:A parasitological survey of the grey triggerfish B.capriscus(Gmelin,1788)from the Gulf of Gabès(Southern Tunisia,Central Mediterranean Sea)was conducted monthly from May 2007 to April 2009.A total of 480 fishes were collected from commercial catches by pelagic trawl net at different fishing ports at Chebba(34°14'N,11°06'E),Kerkennah(34°45'N,11°17'E)and Zarzis(33°41'N,11°48'E).The weight,the size,the sex,the date and the area of capture of each specimen were recorded.B.capriscus were then examined to search for ectoparasites and endoparasites.For each parasite species,parasitological indices were calculated.Results:Five species of parasites were identified,among which a new species of Digenea Hypocreadium caputvadum was discovered and two species of parasites were reported for the first time in the Mediterranean.Conclusions:It is the first inventory of the ecto and endoparasites of grey triggerfish collected from the Gulf of Gabès Mediterranean Sea.

Influence of season,size and sex on the dynamic of gill metazoan parasite infesting the Balistes capriscus(Teleostei:Balistidae)of the Gulf of Gabès(Tunisia)

Objective:To investigate the effects of season,size and sex on the dynamic of gill metazoan parasite infesting the Balistes capriscus(Gmelin,1788)(Teleostei:Balistidae)(B.capriscus)of the Gulf of Gabès(Southern Tunisia,Central Mediterranean Sea).Methods:A parasitological survey of the grey triggerfish B.capriscus from the Gulf of Gabès(Southern Tunisia,Central Mediterranean Sea)was conducted monthly from June 2011 to June 2012.A total of 1080 fish were collected from commercial catches by pelagic trawl net at different fishing ports at Chebba(34°14'N,11°06'E),Kerkennah(34°45'N,11°17'E)and Zarzis(33°41'N,11°48'E).The weight,size,sex,date and area of capture of each specimen were recorded.Then,B.capriscus was examined to search for ectoparasites.For each parasite species,parasitological indices were calculated.Results:The parasite species are indentified as two copepods:Naobranchia variabilis,Taneacanthus ballistae and a monogenean:Ancyrocephalus balisticus.The parasitological indices depend significantly on seasonality;the highest prevalence of Naobranchia variabilis,Taneacanthus ballistae and Ancyrocephalus balisticus(28.89%,35.93%and 55.56%respectively)was recorded during summer season(June–August),while the lowest prevalence of each(6.3%,4.44%,8.15%)recorded during winter season(December–February).Furthermore the parasitological indices depend significantly on the host size but not on host sex.Conclusions:Our data suggest that the dynamic of gill metazoan parasite infesting B.capriscus is a result of a complex of biotic and abiotic factors.It is the first study on the effects of season,size and sex on the dynamic of gill metazoan parasite infesting B.capriscus(Teleostei:Balistidae)of the Gulf of Gabès(Southern Tunisia,Central Mediterranean Sea).