|Classification of Tilapiine fishes with immunological methods|
Oberst, S. (1992). Classification of Tilapiine fishes with immunological methods, in: Progress in aquaculture research: proceedings of the 4th German-Isreali Status Seminar held on October 30-31, 1990. Spec. Publ. Eur. Aquacult. Soc, 17: pp. 215-220
In: (1992). Progress in aquaculture research: proceedings of the 4th German-Isreali Status Seminar held on October 30-31, 1990. Spec. Publ. Eur. Aquacult. Soc, 17. European Aquaculture Society: Oostende. ISBN 90-71625-11-7. 360 pp., more
In: Spec. Publ. Eur. Aquacult. Soc, more
It is the aim of the presented studies to develop biochemical and immunological methods for classification of populations and species of tilapiine fishes (Cichlidae, Perciformes). Three commercially important species, Tilapia aurea, T. nilotica and T. galilaea, were used for the establishment of classification methods under laboratory conditions, but with the final purpose of field applicability. A future prospect is to extend the developed techniques in order to identify other species already used in aquaculture, as well as wild endemic populations in different African regions, where the question of genetic conservation is of increasing importance.Blood components have been used as test substances because of their easy technical accessibility, and the advantage of obtaining samples without the need to kill the investigated specimen.First, a variety of lectins were used in agglutination asays with native and enzyme treated erythrocytes of the three Tilapia species. The existence of carbohydrate moieties on the surface of Tilapia erythrocytes was shown, and species identification became possible by positive or negative agglutination reactions of enzyme-treated erythrocytes and specific lectins. Further more, Tilapia individuals were immunized with xenoantigenic Tilapia erythrocytes, and species-specific antisera were obtained, which enabled differentiation among the three species in agglutination tests. Parallel intraspecific immunizations resulted in individual-specific antisera, indicating the existence of individual blood group properties.Disc electrophoretic separation of erythrocyte content in acrylamide gels revealed species-specific patterns of hemoglobin bands which differed in mobility and number. Finally, N-acetyl-glucosamine-containing serum glycoproteins of the three Tilapia species were analyzed in lectin-blot tests after disc electrophoretic separation. Species-specific fractions were indicated by several lectins.