Abstract
Five different karyotypes were present in germinating statoblasts obtained from a sampling of a predominately or exclusively asexually reproducing population of Pectinatella gelatinosa from Lake Tatara-numa, Japan. Karyotypes were consistent in having 18 chromosomes, a unique telocentric, a pair of minute metacentrics, and at least one prominently secondarily constricted element. In a number of cases, a sampling of statoblasts from a single large colony yielded more than one karyotype, perhaps because there had been fusion of smaller colonies with different karyotypes. Some individual statoblasts may have been chimeric, but this was not conclusively demonstrated. The possibility of asexually-maintained permanent chimerism in phylactolacmates involving karyotypically distinct ectodermal and peritoneal cell lines is discussed. Karyotypically, P. gelatinosa is more similar to Lophopodella carteri than to Pectinatella magnifica.
Similar content being viewed by others
References
Annandale, N., 1908. Three Indian Phylactolacmata. Rec. Indian Mus. 2: 169–174.
Backus, B. T., 1977. Some bryozoan karyotypes and chromosome numbers. Genet. Res. 29: 181–191.
Backus, B. T., 1979. Bryozoan chromosomes: some evolutionary implications. In: G. P. Larwood and M. B. Abbott (eds.). Advances in bryozoology. Academic Press, London. pp. 1–9.
Bushnell, J. H., 1973. The freshwater Ectoprocta: a zoogeographical discussion. In: G. P. Larwood (ed.), Living and fossil Bryozoa. Academic Press, London. pp. 503–521.
Kligerman, A. D. & Bloom, S. E., 1977. Rapid chromosome preparations from solid tissues of fishes. J. Fish. Res. Bd. Can. 34: 266–269.
Mukai, H., 1974. Germination of the statoblasts of a freshwater bryozoan, Pectinatella gelatinosa. J. exp. Zool. 187: 27–40.
Mukai, H., 1982. Development of freshwater bryozoans (Phylactolaemata). In: F. W. Harrison and R. R. Cowden (eds), Developmental biology of freshwater invertebrates. Alan R. Liss, Inc., New York. pp. 535–576.
Mukai, H., Karasawa, T. & Matsumoto, Y., 1979. Field and laboratory studies on the growth of Pectinatella gelatinosa Oka, a freshwater bryozoan. Sci. Rep. Fac. Educ. Gunma Univ. 28: 27–57.
Mukai, H. & Oda, S., 1980a. Histological and histochemical studies on the epidermal system of higher phylactolaemate bryozoans. Annotnes zool. jap. 53: 1–17.
Mukai, H. & Oda, S., 1980b. Comparative studies on the statoblasts of higher phylactolaemate bryozoans. J. Morph. 165: 131–155.
Oda, S., 1974. A note on Bryozoa in Lake Shoji, Japan. Proc. Jap. Soc. Syst. Zool. 15: 19–23.
Oda, S. & Nakamura, R. M., 1980. Sexual reproduction in Pectinatella gelatinosa, a freshwater bryozoan. Proc. Jap. Soc. Syst. Zool. 19: 38–44.
Oka, A., 1891. Observation of fresh-water Polyzoa. J. Coll. Sci. imp. Univ. Tokyo 4: 89–150.
Potter, R., 1979. Bryozoan karyotypes and genome sizes. In: G. P. Larwood and M. B. Abbott (eds.). Advances in bryozoology. Academic Press, London. pp. 11–32.
Tazima, I., Inoue, S. & Gopal Dutt, N. H., 1984. Oogenesis in the freshwater bryozoan, Pectinatella gelatinosa: light microscopy. Z. mikrosk.-anat. Forsch, Leipzig 98: 193–197.
Toriumi, M., 1956. Taxonomical study on fresh-water Bryozoa. XV. Pectinatella gelatinosa Oka. Sci. Rep. Tohoku Univ. 22: 29–33.
Vorstman, A. G., 1928. Some freshwater Bryozoa at West Java. Treubia 10: 1–14.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Backus, B.T., Mukai, H. Chromosomal heteromorphism in a Japanese population of Pectinatella gelatinosa and karyotypic comparison with some other phylactolaemate bryozoans. Genetica 73, 189–196 (1987). https://doi.org/10.1007/BF00055273
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00055273