Abstract
Four species of Triclads belonging to three families, Dugesia polychroa and Dugesia mediterranea (Dugesiidae), Planaria torva (Planariidae) and Dendrocoelum lacteum (Dendrocoelidae) were studied for chromosome banding: C-banding for all the species, ASG banding for Dugesia polychroa and G-banding for Dugesia polychroa and Dugesia mediterranea. C-banding results for Dugesia lugubris-polychroa group suggest a high level of heterochromatin evolution in the group. Small bands strictly limited to the centromeric region were seen in Dugusia lugubris and this pattern is similar to the patterns of some species belonging to other families, notably Planaria torva and Dendrocoelum lacteum. This could be considered a primitive character. In contrast numerous heterochromatin bands which are useful to characterize the different karyotypes were seen in Dugesia polychroa and Dugesia mediterranea. Our data suggest that heterochromatin is important in freshwater triclad speciation.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Ball, I. R., 1979. The karyotypes of two Dugesia species from Corfù, Greece (Platyhelminthes, Turbellaria). Bijd. Dierkunde 48: 187–190.
Benazzi, M., 1982. Speciation events evidenced in Turbellaria. In C. Barigozzi (ed.) Mechanisms of speciation. Alan R. Liss New York: 301–304.
Benazzi, M. & G. Benazzi-Lentati, 1976. Animal cytogenetics. I. Platyhelminthes. Gebr. Borntraeger, Berlin & Stuttgart, 182 pp.
Benazzi, M. & I. Puccinelli, 1973. A Robertsonian translocation in the freshwater Triclad Dugesia lugubris: karyometric analysis and evolutionary inferences. Chromosoma, 40: 193–198.
Benazzi, M., J. Baguñà, R. Ballester, I. Puccinelli & R. Del Papa, 1975. Further contributions to the taxonomy of the Dugesia lugubris-polychroa group, with description of Dugesia mediterranea n. sp.. Boll. Zool. 42: 81–89.
Benazzi M., D. Formenti, M. G. Manfredi Romanini, C. Pellicciari & C. A. Redi, 1981. Feulgen DNA content and C-banding of Robertsonian transformed karyotypes in Dugesia lugubris. Caryologia 34: 129–139.
Galleni, L., R. Canovai, A. Esposito & R. Stanyon, 1989. Characterization of turbellarian chromosomes. II. C-banding in Dugesia lugubris (Tricladida: Paludicola). Trans. am. Microsc. Soc., 108: 304–308.
Galleni, L., R. Canovai, M. Gualandi, C. Pellicciari, S. Garagna & R. Stanyon, 1986. Fine characterization of turbellarian chromosomes. I. Giemsa and Quinacrine banding in Dugesia polychroa (O. Schmidt). Genetica 71: 47–50.
Galleni, L., R. Canovai & R. Stanyon, 1991. Characterization of turbellarian chromosomes. III. C-banding in Polycelis nigra (Tricladida-Paludicola). The nucleus 34: 119–122.
Holmquist, G. P., 1990. Contents of G and R bands defy contemporary paradigms. In T. Sharma (eds), Trends in Chromosome Research, Springer-Verlag, Narosa Publishing House, New Delhi: 39–52.
Pellicciari, C., S. Garagna, D. Formenti, C. A. Redi, M. G. Manfredi Romanini & M. Benazzi, 1986. Feulgen-DNA amounts and karyotype lengths of three planarian species of the genus Dugesia. Experientia 42: 75–77.
Ribas, M., M. Pala, R. A. Vacca, M. Riutort & J. Baguñà, 1988. Taxonomic status of the western Mediterranean asexual populations of the Dugesia (D.) gonocephala group. Morphological, karyological and biochemical data. In Ax/Ehlers/Sopott-Ehlers (eds), Free living and Symbiotic Platyhelminthes, Gustav Fischer Verlag, Stuttgart, New York 36: 129–137.
Sluys, R. & H. De Jong, 1984. Chromosome morphological studies of Dugesia gonocephala s. 1. (Platyhelminthes, Tricladida). Caryologia, 37 n. 1–2: 9–20.
Teshirogi, W. & S. Ishida, 1981. Studies on the speciation of japanese freshwater planarian Polycelis auricolata based on the analysis of its karyotypes and constitutive proteins. Hydrobiologia 84: 69–77.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Canovai, R., Stocchino, G., Privitera, I. et al. Chromosome bands in freshwater triclads. Hydrobiologia 305, 85–90 (1995). https://doi.org/10.1007/BF00036367
Issue Date:
DOI: https://doi.org/10.1007/BF00036367