Parasitologia hungarica

Author(s): Molnár, K.
Title: Comments on the host, organ and tissue specificity of fish myxosporeans and on the types of their intrapiscine development
Title: Megjegyzések a halakban élő myxosporeák gazda-, szerv- és szövetspecifitásáról és halon belüli fejlődésük variációiról
Year: 1994
Volume: 27
Pages: 5-20.

Abstract: Different fish-parasitic myxosporeans are characterized by a varying degree of host specificity. While certain species have very strict specificity and can colonize only a single fish species, most species of Myxosporea share several closely related fish species as hosts. Myxosporeans are tissue-specific parasites and always develop in a specific host tissue. The author assumes that the development of all myxosporean species includes an intracellular stage. Organ specificity depends on the tissue types that occur in the given organ. The author distinguishes three main types of development: Myxobolus-type, Hoferellus-type and Sphaerospora-type development. Myxobolus-type myxosporeans develop in large Plasmodia (or, according to an incorrect but generally used term: cysts). Some species of them showing muscle or nervous tissue specificity usually complete their development intracellular and form spores within the cell. Host cells of small size, however, are destroyed during the growth of the parasite: the developmental stages released from them usually become surrounded by cells of the same type, and the parasite continues its development within the capsule formed by these cells. From plasmodia developing on the surface or in organs having efferent ducts the spores are usually excreted directly into the outworld; while the spores of species developing in the inner organs are transported by the blood to organs suitable for spore dejection. Coelozoic (Hoferellus-type) development means that the early development of myxosporeans takes place in the cells lining the efferent ducts while the second stage occurs in the lumen of the said ducts. During Sphaerospora-type development a short intracellular stage, one or two blood stages characterized by a series of internal cleavage, and a coelozoic or intercellular sporogonic stage can be distinguished.
Keywords: host specificity, Myxosporea, tissue specificity, organ specificity, types of intrapiscine development

Journal: Parasitologia Hungarica
Journal abbreviation:
ISSN: 0303-688X
Publisher: Magyar Parazitológusok Társasága, Budapest
Editor(s): K. Murai, É., Thoma, A., Gubányi, A. & Tajti, T. Zs.