0000000000004564
AUTHOR
Pilar Alvarez-pellitero
Immunological and pathological status of gilthead sea bream (Sparus aurata L.) under different long-term feeding regimes
The possible influence of the feeding regime (FR) on the immune system and pathological status of gilthead sea bream was studied. Two growth trials were performed starting at different seasons (trial 1 = March; trial 2 = June) under controlled experimental conditions. In both trials, FR-1 groups received a restricted amount of food, whereas FR-2 groups were fed to visual satiety. The pathology study included parasitological and bacteriological examination, and the immunological traits analysed were respiratory burst activity of head kidney leucocytes, serum lysozyme and alternative pathway complement activity (ACH50). The immunological status of gilthead sea bream not only was not impaired …
Cardicola aurata sp. n. (Digenea: Sanguinicolidae) from Mediterranean Sparus aurata L. (Teleostei: Sparidae) and its unexpected phylogenetic relationship with Paradeontacylix McIntosh, 1934
A new sanguinicolid trematode, Cardicola aurata sp. n., is described from gilthead seabream Sparus aurata L., from off the Spanish Mediterranean coast. The morphology of C. aurata sp. n. generally agrees with the diagnosis of the genus, however, in contrast to all other reported Cardicola spp. the male pore is located sub-medially at the posterior end of the body instead of sinistrally before the posterior end of the body. Based on a comparison of the morphology as well as partial 28S and ITS2 rDNA sequence data from the present species with that from closely related species, it was decided to emend the diagnosis of Cardicola rather than create a new genus, as the aberrant position of the m…
Virulence and Molecular Typing of Vibrio harveyi Strains Isolated from Cultured Dentex, Gilthead Sea Bream and European Sea Bass
Vibrio harveyi was isolated from internal organs or ulcers of diseased and apparently healthy gilthead sea bream (Sparus aurata) and European sea bass (Dicentrarchus labrax) cultured in several fish farms located on the Spanish Mediterranean coast. The prevalence of the bacterium was significantly higher in European sea bass than in gilthead sea bream, and was closely related to the season in both fish species, occurring almost exclusively on warm months (June to November). After phenotypic characterization, a selection of forty five isolates from gilthead sea bream, sea bass, and several isolates previously obtained from common dentex (Dentex dentex) of the same area, were molecularly type…
Interactions between bacteria and Cryptosporidium molnari in gilthead sea bream (Sparus aurata) under farm and laboratory conditions
The possible interaction of Cryptosporidium molnari and bacteria in gilthead sea bream (Sparus aurata) was studied. Epidemiological data from a pathological survey under farm conditions were analyzed. In addition, parasite and bacteria burdens were studied in experimental models in which naturally and experimentally parasitized fish were challenged with a particular strain of Vibrio harveyi (H57). All the bacteria species present were studied. Under farm conditions, the parasite was more prevalent when mortality or morbidity cases (study C) occurred than in randomly sampled fish (study B). In study C, parasite abundance was significantly higher in bacteria-negative fish, and total bacteria …
Carriage of potentially fish-pathogenic bacteria in Sparus aurata cultured in Mediterranean fish farms.
A bacteriological survey of gilthead sea bream Sparus aurata from different fish farms and culture systems on the Spanish Mediterranean coast was conducted. Three different studies were performed. Study A included hatchery-reared larvae; Study B, periodic examination of randomly sampled growing fish; and Study C, growing fish sampled only during mortality/morbidity events. In Studies B and C, sea cages, earth ponds and indoor tanks were surveyed, and in both cases diseased (showing clinical signs) and non-diseased fish were included. In Study A, a shift from Vibrio spp. (30 d after hatching) to oxidative species (60 d after hatching) was detected, and no mortality events were registered. Th…
Occurrence and virulence of Pseudoalteromonas spp. in cultured gilthead sea bream (Sparus aurata L.) and European sea bass (Dicentrarchus labrax L.). Molecular and phenotypic characterisation of P. undina strain U58
During two long-term bacteriological surveys in European sea bass (Dicentrarchus labrax L.) and gilthead sea bream (Sparus aurata L.) culture facilities on the Spanish Mediterranean coast, four different species of Pseudoalteromonas were found in the internal organs of animals. Pseudoalteromonas undina, Pseudoalteromonas haloplanktis, P. espejiana and Pseudoalteromonas sp. were isolated from 9% out of 177 European sea bass and 11.7% out of 547 gilthead sea bream and they were recovered as pure cultures in 50% of isolations. Among fish with positive bacterial growth, Pseudoalteromonas was more prevalent in sea bass showing clinical signs (27.7%) and in gilthead sea bream without clinical sig…
Bacteria associated with winter mortalities in laboratory-reared common dentex (Dentex dentex L.)
A pathological study was conducted on laboratory-reared juvenile common dentex (Dentex dentex) suffering trickling and continuous mortalities. During a 3-month period (October-December), water temperature, clinical signs and mortalities were recorded. Moribund or dead fish were examined for bacteria and parasites. Bacteria were isolated from head kidney and external ulcers, and samples from the gills, intestine, stomach, trunk kidney, gall bladder and liver were taken for histology. Cumulative mortality reached 73%, and 80% of fish examined were positive for bacteria (102 isolates). Vibrio splendidus was the most prevalent in head kidney (59.7%) and ulcers (88.9%), and it was frequently iso…