Long-term observations on Anabaena circinalis Rabenhorst (Cyanophyta)
Tóm tắt
Field observations on Anabaena circinalis Rabenhorst over six summer seasonal appearances in two dams have shown that the frequency of occurence of heterocysts became fairly constant soon after the appearance of the species and decreased just before the end of the growing season. By contrast, akinete frequency reached a maximum, very early in the season, then decreased rapidly. Drought led to a decrease in occurrence of both Anabaena and of akinetes in several dams; this was possibly associated with an increasing concentration of NOx in the water. At Carcoar dam this akinete reduction was shown first in end-of-season figures. Drought also led to an end-of-season decrease there in the occurrence of heterocysts. Variations in morphology were noted. The coiling of the trichome, shape of akinete and relative position of heterocyst were all variable, although these characters are often assumed to be of taxonomic importance.
Tài liệu tham khảo
Cmiech, H. A., C. S. Reynolds & G. F. Leedale,1984. Seasonal periodicity, heterocyst differentiation and sporulation in planktonic Cyanophyceae in a shallow lake with special reference to Anabaena solitaria. Br. Phycol. J. 19: 245–257.
Desikachary, T. V., 1959. Cyanophyta. Indian Council of Agricultural Research, New Delhi. 686 pp.
Griffiths, A. J., 1984. A descriptive numericlature for isolates of Cyanobacteria. Br. Phycol. J. 19: 233–238.
May, Valerie, 1981. The occurrence of toxic Cyanophyte blooms in Australia. 127–142. In The Water Environment. Algal Toxins and Health W. W. Carmichael (ed.). Plenum Press. N.Y.
May, Valerie, 198XA. Algae of Carcoar Dam, New South Wales, Australia; Cunninghamia 2 (In Press).
May, Valerie, 198XB. The effect of drought and position in the dam on the algal composition of two dams in New South Wales. Cunninghamia 2 (In Press).
May, Valerie & J. Powell, (1986) 1987. Algae of the Peel River and the newly constructed Chaffey Dam, New South Wales, Australia. Cunninghamia. 1: 503–536.
Rippka, R., J. Deruelles, J. B. Waterbury, M. Herdman & R. Stainer, 1979. Generic assignments, strain histories and properties of pure cultures of Cyanobacteria. J. gen. Microbiol. 111: 1–61.
Satomi, Y., 1959. Relationships between seasonal change of Anabaena and environmental conditions in a farm dam. Bull, Jap. Soc. Sci. Fish. 24: 798–802.
Watanabe, M., H. Kiyosawa & H. Hayashi, 1985. Studies on the Planktonic Blue-green Algae 1. Anabaene macrospora Klebahn. from Kizaki. Bull. natn. Sci. Mus. B. Tokyo 11: 69–76.