Myxosporidia and macrophage centres in chub (Leuciscus cephalus)–quantitative interactions focus on Myxobolus cyprini

Abstract

Six myxosporidian species were found in chub (Leuciscus cephalus) originating from Lower Austrian rivers. The frequency of the parasites and their localization was recorded. In all chub, independent of size and origin, Myxobolus cyprini occurred predominantly in the macrophage centres (MCs) of the haematopoietic organs, spleen and kidney. Exclusively in the head kidney of young fish not yet described vermicular plasmodia containing spores of M. cyprini were found. In muscle tissue the prevalence of M. cyprini was comparatively low. Other species of Myxobolus characterized by plasmodial cysts frequently occurred in gills and swimbladder but were rarely detected, and only in small numbers, in the haematopoietic organs. The number of M. cyprini spores and the relative volume of MCs in the haematopoietic organs were estimated in order to examine possible correlations. Significant interrelated changes were found only in juvenile fish up to a size of 15 cm. In bigger fish, the number and size of macrophage aggregates were highly variable and independent of infection intensity and fish size, but the number of spores never exceeded that of the aggregated macrophages. The data suggest that due to an early date of infection M. cyprini is the only species which is closely associated with macrophage aggregation.

Do Spleen Macrophage Aggregates Undergo Season-Dependent Changes? A Stereomicroscopic Investigation in Wild Ohrid Trout (Salmo Letnica Kar.)

“…It is interesting that MACs in Ohrid trout spleen contained a low hemosiderin load, since it is well known that the distribution of hemosiderin is generally restricted to the spleen MACs and it is a normal feature both in fish and homeotherms [7,13,14]. Similar results are reported for chub, Leuciscus cephalus [24], where spleen MACs melanin was a dominant pigment. These studies are in accordance with the results from our investigation, revealing that MACs pigment composition is species specific or provoked by some exogenous factors.…”

Myxosporean plasmodial infection associated with ulcerative lesions in young-of-the-year Atlantic menhaden in a tributary of the Chesapeake Bay, and possible links to Kudoa clupeidae

“…Immune status of young fish may be an additional factor. Holzer & Schachner (2001) state that 'huge masses of myxosporidian developmental stages are usually conspicuous only in immature diseased fish which have not yet acquired immunity. ' Moran & Kent (1999) suggest that compromised immunity during prolonged periods of stress (such as smoltification and sexual maturation) permit the parasite to proliferate and/or reinfect fishes.…”

“…This indicates that infection, development, and spore maturation occurs within the first few months of life. A number of myxozoan parasites have been shown to infect primarily young fishes, especially in spring and early summer (Kent et al 1994, Rothwell et al 1997, Holzer & Schachner 2001. Other examples of myxosporean infections of young fishes include proliferative kidney disease in trout, whereby the fish are infected during April and May (Foote & Hedrick 1987), Sphaerospora truttae in salmon (Ozer & Wootten 2000), Myxobolus cerebralis infection in the rainbow trout Oncorhynchus mykiss (Markiw 1991), Myxobolus episquamalis infection in the sea mullet Mugil cephalus in the spring (Rothwell et al 1997), and Kudoa thyrsites infection in Atlantic salmon (St-Hilaire et al 1998).…”

Site preference of myxozoans in the kidneys of Hungarian fishes

“…In the case of old infections, it is difficult to provide proper diagnosis. Macrophages in melano-macrophage centres of the kidney and other organs can accumulate large masses of spores from the bloodstream (Roberts 1975, Dyková 1984, Molnár & Kovács-Gayer 1985, Holzer & Schachner 2001. When only a moderate number of spores are found inside these centres, the yellow or black coloured macrophages can be distinguished easily from the spores (Fig.…”