Potential hazards associated with the consumption of Scombridae fish: Infection and toxicity from raw material and processing.

Scombridae fish (tuna, bonito and mackerel) have significant ecological and economic values. They are very appreciated by consumers worldwide for their high-quality flesh and for their high nutritional value. However, consumption of Scombridae fish is potentially hazardous. Indeed, several cases of infections and toxicity linked to the consumption of Scombridae fish as raw, or processed food products have been reported worldwide. In this review, we presented the most common health risks associated with Scombridae fish consumption. Diseases associated with the consumption of these fish are generally infectious or toxic and are caused by biological hazards, such as bacteria, viruses, parasites or chemicals hazards that enter the body through contaminated fish (polycyclic aromatic hydrocarbons, histamine) or by physical contaminants, such as heavy metals. The risks of contamination exist throughout the food chain, from primary production to the preparation of products for consumption.

Morphology, seasonality and molecular characterization of Ceratomyxa draconis n. sp. parasite of Trachinus draco (L.) from the Bay of Bizerte, Tunisia.

The specimens of Trachinus draco collected from the Bay of Bizerte were found to be infected with a new Ceratomyxa species described as Ceratomyxa draconis n. sp. The sequence of small subunit ribosomal RNA gene obtained in this study differs from other Ceratomyxa sequences available in GenBank. Mature spores of this species were elongated and crescent-shaped in sutural view, measuring 7.4 ± 0.77 (6.4-8.0) µm in thickness and 30.8 ± 1.65 (28.8-32.8) µm in width. The polar capsules were spherical, equal in size, and measuring 3.3 ± 0.2 (3.6-4.0) µm in diameter. The Ceratomyxa draconis n. sp. showed a clearly seasonal variation of prevalence with highest prevalence noted during summer months.

Ceratomyxa aegyptiaca n. sp. (Myxozoa: Myxosporea) from the gall-bladder of Solea aegyptiaca Chabanaud (Pleuronectiformes: Soleidae) in a Tunisian coastal lagoon.

A new marine myxosporean species, Ceratomyxa aegyptiaca n. sp. is described from the gall-bladder of Solea aegyptiaca Chabanaud collected from the Ghar El Melh Lagoon in northeastern Tunisia. Mature spores are elongate and crescent-shaped, measuring 8-11 µm in length and 48-58 µm in width. The polar capsules are spherical, 3.2-4 µm in diameter and equal in size. Trophozoites are polysporous and float free in the bile or are attached on the epithelium of the gall-bladder. Morphological data and molecular analysis based on 18S rDNA sequences are provided. The 18S rDNA of C. aegyptiaca is readily distinguishable from that of other myxozoan species, as the genetically most similar myxozoan parasite, C. seriolae Yokoyama & Fukuda, 2001 (AB530265) collected from Seriola quinqueradiata Temminck & Schlegel in Japanese waters, shares with it only 67.5% identical nucleotides over a 1,680-bp long fragment of 18S rDNA.

Ultrastructural observations on the development of Ceratomyxa aegyptiaca (Myxozoa: Bivalvulida) infecting Solea aegyptiaca (Pleuronectiformes: Soleidae) from Tunisian coastal lagoon.

Ultrastructural description of Ceratomyxa aegyptiaca Yemmen, Marton, Eszterbauer and Bahri, 2012 infecting the gallbladder of Solea aegyptiaca Chabanaud, 1927 from a tunisian north-east costal lagoon, was presented in this study. The primary cell was attached to the gallbladder epithelium and presented at one side cytoplasmic projections corresponding to pinocytotic invaginations. Netherless, early sporogonic stages development was carried with contact to the epithelial cells of gallbladder. Immature spores were identified in early sporoblasts by their valvogenic, capsulogenic and binucleated sporoplasmic cells. Capsulogenesis was asynchronous. Each capsulogenic cell presented a large condensed nucleus and a capsular primordium that extended into an external tube. The eversion and coiling of the external tube gave rise to the polar filament, which displayed six turns and an apical plug.