Piscine Cryptosporidiosis: a slow emerging disease in aquaculture

• Main Authors: Sitjà-Bobadilla, Ariadna, Redondo, Mª José, Álvarez-Pellitero, Mª del Pilar, Palenzuela, Oswaldo
• Format: Conference Object
• Language: English
• Published: Pennsylvania State University 2011
• Subjects: Turbot
• Online Access: http://hdl.handle.net/10261/82977

Comunicación presentada en el 1st Annual World Congress of Microbes WCM celebrado en Pekín del 30 de julio al 1 de agosto de 2011. Piscine Cryptosporidium have been described in ornamental and cultured species. The two main species are C. molnari infecting the stomach of gilthead sea bream (GSB) (Sparus aurata) and European sea bass (Dicentrarchus labrax) and C. scophthalmi parasitizing the intestine of turbot (Psetta maxima). Recently, C. molnari has also been described in the stomach of murray cod (MC) (Maccullochella peelii peelii) (Baragahare et al., 2011). Piscine Cryptosporidium fit most of the diagnostic features of the genus, but oocyts differ in their deep location within the epithelium. The limited genetic data available so far suggests the existence of a fish clade which branches off at a basal position relative to all other Cryptosporidium genotypes. Clinical signs consist of abdominal swelling and ascites in GSB, mild to moderate gastritis, wasting, fluid distension of stomach and intestine in MC. The parasite invokes the destruction of the epithelium in GSB, MC and turbot. Trickling mortalities are associated to the parasite in some GSB stocks. The commonest effects are delayed growth and higher susceptibility to handling procedures and opportunistic bacteria. Data collected from hatcheries and growing systems along the Spanish coasts have shown that these coccidians are ubiquitous, as most facilities are infected. There seems to be age-related differences in susceptibility, with the highest prevalence of infection in young fish, and adults are rarely infected. The parasite enters fish at hatchery stages through water or food and spreads rapidly. This may be favored by cannibalism and by direct transmission, as demonstrated experimentally for C. molnari by oral intubation and cohabitation. Therefore, potential production losses for the aquaculture industry are envisaged. Peer Reviewed