First assessment of Perkinsosis and brown ring disease co-infection in Ruditapes decussatus in the North Lake of Tunis (southern Mediterranean Sea)

Carpet shell clam populations on the Tunisian coastline are susceptible to several microbial pathogen challenges. In this study we report the results of five years' surveillance, conducted from January 2004 till June 2009, for detection of Perkinsosis and brown ring disease (BRD). The survey covered three sites of natural populations of Ruditapes decussatus in a Tunisian lagoon, the North Lake of Tunis. Perkinsosis was detected preferentially in winter periods from the external and marine site, BRD was detected more frequently in the summer periods in a more proximal collection site (in the lake) and was positively correlated with concentrations of heterotrophic Vibrio sp. Our results suggest that several factors other than temperature and salinity might explain spatial distribution variability and natural intensities for these infections in carpet shell clam populations.

Protozoan and myxozoan infections in wild gilthead seabream (Sparus aurata L.) from North Lake of Tunis, Tunisia

A total of 150 gilthead seabream Sparus aurata L., from North Lake of Tunis, Tunisia, were studied for protozoan and myxozoan parasites. The parasitological survey revealed the presence of ectoparasites (Amyloodinium ocellatum Brown, 1931, Trichodina lepsii Lom, 1962 on the gills) and endoparasites (Ceratomyxa sparusaurati Sitjà-Bobadilla, Palenzuela et Alvarez-Pellitero, 1995 infecting the gallbladder, and Eimeria sparis Sitjà-Bobadilla, Palenzuela et Alvarez-Pellitero, 1996 parasitizing the intestine). This is the first record of Amyloodinium ocellatum, Trichodina lepsii, Ceratomyxa sparusaurati, and Eimeria sparis in S. aurata from Tunisian waters. Data on prevalence and intensity of infection are provided. A comparison of the present species with previously described species in cultured gilthead seabream from other Mediterranean countries is also presented. In this study Trichodina lepsii is identified for the first time in Sparus aurata. A taxonomic description of this species based on silver nitrate method is provided.