Amoeba‐like Infections in Cultured Marine Fishes: Systemic Infection in Pompano Trachinotus falcatus L. from Singapore and Gill Disease Associated with Paramoeba sp. in Sea Bream Sparus aurata L. from Greece

Two cases of Amoeba‐like infections in cultured warmwater marine fish are described, an unusual systemic infection in pompano Trachinotus falcatus L. from Singapore and a gill infection in Mediterranean sea bream Sparus aurata L. All pompano showed marked systemic infection of Amoeba‐like parasites in gills, kidney, intestine, pancreas and spleen. The most severe lesions were in the gills and renal tissue with minimal tissue reaction in other organs.     

Gill morphology in two Mediterranean Sea fishes of similar feeding preferences: sea bream (Sparus aurata L) and sea bass (Dicentrarchus labrax)

The aim of the present study was to describe the gill morphology of the gilthead sea bream and sea bass fishes that showed the same feeding habits. Our study focused on the gross morphological, scanning and light microscopical features of the gills, where a many differences in the gill arches and gill rakers surface in both species were explained. Our results marked that; there was an interbranchial median elevation appeared in sea bream. The gill arches length and the gaps between decreased medial wards in both species. The gill rakers had similar arrangement and varied number in both species. The first lateral rakers row was the longest one in sea bass. However the gill filaments appeared in double rows. Gill filaments were long at middle and short at extremities of gill arch in both species. Scanning electron microscopy revealed the surfaces of gill arch covered by a mosaic of pavement cells, varied sized pores of chloride cells and many pointed spines on the rakers ventral border in both species. Two types of taste buds marked on the gill arches and rakers in sea bass. Many lamellae appeared on filaments in both species.     

Determination of sulfadiazine,trimethoprim, and N4‐acetyl‐sulfadiazine in fish muscle plus skin by Liquid Chromatography–Mass Spectrometry. Withdrawal‐time calculation after in‐feed administration in gilthead sea bream (Sparus aurata L.) fed two different diets

This study presents a depletion study for sulfadiazine and trimethoprim in muscle plus skin of gilthead sea bream (Sparus aurata L.). N⁴‐acetyl‐sulfadiazine, the main metabolite of sulfadiazine (SDZ), was also examined. The fish were held in seawater at a temperature of 24–26 °C. SDZ and trimethoprim (TMP) were administered orally with medicated feed for five consecutive days at daily doses of 25 mg SDZ and 5 mg TMP per kg of fish body weight per day. Two different diets, fish oil‐ and plant oil‐based diets, were investigated. Ten fish were sampled at each of the days 1, 3, 5, 6, 8, 9, 10, and 12 after the start of veterinary medicine administration. However for the calculation of the withdrawal periods, sampling day 1 was set as 24 h after the last dose of the treatment. Fish samples were analyzed for SDZ, TMP, and acetyl‐sulfadiazine (AcSDZ) residues by liquid chromatography–mass spectrometry. SDZ and TMP concentrations declined rapidly from muscle plus skin. Considering a maximum residue limit of 100 μg/kg for the total of sulfonamides and 50 μg/kg for TMP residues in fish muscle plus skin, the withdrawal periods of the premix trimethoprim‐sulfadiazine 50% were calculated as 5 and 6 days, at 24–26 °C, in fish oil (FO) and plant oil (PO) groups, respectively. The investigation of this work is important to protect consumers by controlling the undesirable residues in fish.