Study Of The Tail Fin Rays Of Rainbow Trout (oncorhynchus Mykiss) Infected With The Parasite Myxobolus Cerebralis

A light, transmission and scanning microscope study of the rays (lepidotrichia) forming the tail fin of rainbow trout (Oncorhynchus mykiss) fingerlings infected with the parasite Myxobolus cerebralis showed that triactinomyxon adherence to the tail fin of host fingerlings occurred 10 min after infection. After 2 h of exposure, it was possible to observe triactinomyxon spores in the epidermis. Although the characteristic symptoms of the disease, such as a black tail and a change in tail morphology, were observed, there was no attack against the tissue forming the tail fin rays and triactinomyxon spores were not observed inside the leptotrichial matrix at any stage indicating that the spores do not reach the rays or that their observation was not possible under the conditions of the present study.343299304Antonio, D.B., Andree, K.B., McDowell, T.S., Hedrick, R.P., Detection of Myxobolus cerebralis in rainbow trout and oligochaete tissues by using a nonradioactive in situ hybridization (ISH) protocol (1998) J. Aquatic Animal Health, 10, pp. 338-347Arita, G.S., A re-examination of the functional morphology of the soft-rays in teleosts (1971) Copeia, 4, pp. 691-697Becerra, J., Montes, G.S., Bexiga, S.R.R., Junqueira, L.C.U., Structure of the tail fin inteleosts (1983) Cell Tissue Res., 230, pp. 127-137Blanc, M., Structure histologique des rayons de nageoires chez les poissons téléostéens (1947) Bull. Soc. Zool. France, 72, pp. 17-22Bouvet, J., Différenciation et ultrastructure du squelette distal de la nageoire pectorale chez la truite indigène (Salmo trutta fario L.). I. Différenciation et ultrastructure des lépidotriches (1974) Arch. Anat. Microsc. Morphol. Exp., 63, pp. 63-79Eiras, J.C., (1994) Elementos de Ictioparasitologia, p. 339. , Ed. Fundação Eng. António de Almeida, Universidade de Porto, PortugalEl-Matbouli, M., Fischer-Scherl, T., Hoffmann, R.W., Present knowledge on the life cycle, taxonomy, pathology and therapy of some myxosporea spp. important for freshwater fish (1992) Annu. Rev. Fish Dis., 3, pp. 367-402El-Matbouli, M., Hoffmann, R.W., Mandok, C., Light and electron microscopic observations on the route of the triactinomyxon-sporoplasm of Myxobolus cerebralis from epidermis into rainbow trout cartilage (1995) J. Fish Biol., 46, pp. 919-935El-Matbouli, M., Hoffmann, R.W., Schoel, H., McDowell, T.S., Hedrick, R.P., Whirling disease: Host specificity and interaction between the actinosporean stage of Myxobolus cerebralis and rainbow trout Oncorhynchus mykiss (1999) Dis. Aquat. Org., 35, pp. 1-12Goodrich, E.S., On the dermal fin-rays of fishes-living and extinct (1904) J. Microsc. Sci., 47, pp. 465-522Goss, R.J., Stagg, M.W., The regeneration of fins and fin rays in Fundulus heteroclitus (1957) J. Exp. Zool., 136, pp. 487-508Halliday, M.M., The biology of Myxosoma cerebralis: The causative organism of whirling disease of salmonids (1976) J. Fish Biol., 9, pp. 339-357Harrison, R.J., Über die Entwicklung der nicht knorpelig vorgebildeten skeletteile in den Flossen der Teleostier (1893) Arch. Mikrosk. Anat., 42, pp. 248-278Hedrick, R.P., El-Matbouli, M., Adkison, M.A., MacConnell, E., Whirling disease: Re-emergence among wild trout (1998) Immunol. Rev., 166, pp. 365-376Hofer, B., Über die Drehkrankheit der Regenbogenforelle (1903) Allgemeine Fischereizeitung, 28, pp. 7-8Hoffman, G.L., Intercontinental and transcontinental dissemination and transfaunation of fish parasites with emphasis on whirling disease (Myxosoma cerebralis) (1970) Dis Fish and Shellfish, pp. 69-81. , Snieszko S.F. ed., Washington, DC, American Fisheries SocietyHoffman, G.L., Dunbar, C.E., Bradford, A., Whirling disease of trout caused by Myxosoma cerebralis in the United States (1962) Bureau of Sport Fisheries and Wildlife, Special Scientific Report-Fisheries, 427, pp. 1-15Kemp, N.E., Park, I.H., Regeneration of lepidotrichia and actinotrichia in the tail fin of the teleost Tilapia mossambica (1970) Dev. Biol., 22, pp. 321-342Krukenberg, C.F., Über die chemische Beschaffenheit der sog. Hornfaden von Mustelus und über die Zusammensetzung der keratinosen Hollen um die Eier von Scyllium stellate (1885) Mitt. Zool. Stat. Neapel., 6, pp. 286-296Marty, G.D., McDowell, T.S., Georgiadis, M.P., Hedrick, R.P., Comparative susceptibility of rainbow trout and brown trout to experimental infections with Myxobolus cerebralis (1999) Proceedings of the Whirling Disease Symposium, pp. 45-49. , February 18-20, Missoula, MontanaMontes, G.S., Becerra, J., Toledo, O.M.S., Gordilho, M.A., Junqueira, L.C.U., Fine structure and histochemistry of the tail fin ray in teleosts (1982) Histochemistry, 75, pp. 363-376Moss, M.L., The biology of acellular teleosts bone (1963) Ann. Nat. Acad. Med. Sci., 109, pp. 337-350Schachte, J.H., Petrie, C.J., Mack, A., Comparative sensitivity of two strains of rainbow trout and one steelhead trout to natural infections by the parasite Myxobolus cerebralis (1997) Proceedings of the Whirling Disease Symposium, pp. 63-65. , March 6-8, Logan, U