Some characteristics of host–parasite relationship for Cryptocaryon irritans isolated from South China

Abstract

A survey on the host range for the parasitic ciliate Cryptocaryon irritans was carried out among the major maricultured fish species in the Huizhou region of Guangdong Province in South China, and some characteristics of its host-parasite relationship were described. The survey showed that all ten investigated species of fish (representing six different families) were infected with C. irritans with similar susceptibility. In chemoattraction assays, sera and mucus collected from investigated fish strongly attracts C. irritans theronts. Sera collected from infected orange-spotted groupers and yellow spotted grunts (Plectorhynchus cinctus) could immobilize C. irritans theronts, and their immobilization titers were 1:40 and 1:6.7, respectively. The surface antigens of C. irritans were demonstrated by indirect immunofluorescence and immunostaining assays using immune orange-spotted grouper serum and a monoclonal antibody against grouper IgM.

Immunological, ionic and biochemical responses in blood serum of the marine fish Trachinotus ovatus to poly-infection by Cryptocaryon irritans

“…The immunity was strengthened by subsequent infections, which was consistent with the results of Dan et al (2008). Among all of the fish species that have been experimentally infected with C. irritans Dan et al, 2008Dan et al, , 2013Luo et al, 2007Luo et al, , 2008, the highest documented SIT value by far is what we found in the pompano of group II. When challenged by a lethal dose of theronts, those fish were protected completely, whereas none of the fish in group I and the control survived.…”

“…34 kD soluble membrane proteins Luo et al, 2008). In this study, the SIT of group II was higher than that of both other groups.…”

“…RII proved to be useful for quantitatively assessing immune protection against C. irritans Luo et al, 2008). It has been reported that RII varies among species (Luo et al, 2008;Wang et al, 2010) and doses of theronts .…”

“…It has been reported that RII varies among species (Luo et al, 2008;Wang et al, 2010) and doses of theronts . The value was measured for each group by counting the number of trophonts on a pectoral fin .…”

Quantitative PCR assay for the detection of the parasitic ciliate Cryptocaryon irritans

“…Additionally, it could be very ecologically interesting that we only detected C. irritans in seawater 1 m deep. C. irritans has been known to display positive phototaxis [21] and/or chemoattraction [22]. It may be that, in the natural environment, C. irritans theronts swim from the bottom to the surface after excystment and then infect the host fish.…”