http://hdl.handle.net/10862/175 Proceedings of the Symposium on Culture and Utilization of Algae in Southeast Asia, 8-11 December 1981, Tigbauan, Iloilo, Philippines Thu, 09 Apr 2026 15:39:10 GMT 2026-04-09T15:39:10Z https://repository.seafdec.org.ph:443/bitstream/id/3f05b9b3-8a10-4603-b55f-170575497ae4/ http://hdl.handle.net/10862/175 http://hdl.handle.net/10862/190 Water quality assessment of the Langat River, Selangor, Malaysia using the natural algal periphyton community and laboratory bioassays of two Chlorella species Anton, Ann Dogma Jr., Ireneo J.; Trono Jr., Gavino C.; Tabbada, R. A. The physico-chemical conditions in 10 sampling stations off the headwaters of the Langat River, Selangor, Malaysia were studied. Monitoring was done twice a month from June to December 1980. Changes in water quality were observed downstream. A total of 35 taxa of periphyton in four main divisions of algae were identified. The decrease in the number of species in downstream stations could be due to changes in the river rather than to chemical pollution. Two species of Chlorella , namely, C. pyrenoidosa and C. vulgaris , were grown in filtered river water obtained from the different sampling stations to assess their growth responses. Results suggest that pollution in the Langat River was caused mainly by heavy siltation rather than chemical pollutants. Mon, 01 Jan 1990 00:00:00 GMT http://hdl.handle.net/10862/190 1990-01-01T00:00:00Z http://hdl.handle.net/10862/189 Antithamnion sparsum , its life history and hybridization with A. defectum in culture Lee, I. K.; Boo, S. M. Dogma Jr., Ireneo J.; Trono Jr., Gavino C.; Tabbada, R. A. Antithamnion sparsum isolated from the southern and western coasts of Korea showed a basically Polysiphonia -type life history. However, it sometimes exhibited a monoecious reproduction and the carpospores released from the cystocarp by self-fertilization unexpectedly developed into plants bearing spermatangia alone. These male plants were not functional up to 60 days in culture. The results of intraspecific crosses between populations of A. sparsum were successful and the hybrid carpospores gave rise to normal tetrasporophytes. On the other hand, the interspecific crosses between A. sparsum and A. defectum were only partly successful, as evidenced by gonimoblast development and the release of carpospores in case of A. sparsum (male) x A. defectum (female), but not in A. sparsum (female) x A. defectum (male). These results seem to suggest that both species are still undergoing speciation. Mon, 01 Jan 1990 00:00:00 GMT http://hdl.handle.net/10862/189 1990-01-01T00:00:00Z http://hdl.handle.net/10862/188 Life history of Acrothrix pacifica and Sphaerotrichia divaricata in laboratory cultures Umezaki, Isamu Dogma Jr., Ireneo J.; Trono Jr., Gavino C.; Tabbada, R. A. The life histories of Acrothrix pacifica and Sphaerotrichia divaricata in the Chordariales, Phaeophyceae were studied in the laboratory. Both species showed an alternation of macroscopic sporophyte (2n) and microscopic gametophyte (n). In A. pacific , unfused gametes developed into haploid sporophytes under cooler conditions or into gametophytes under warmer conditions. In S. pacifica , unfused gametes developed into gametophytes under warmer conditions. Mon, 01 Jan 1990 00:00:00 GMT http://hdl.handle.net/10862/188 1990-01-01T00:00:00Z http://hdl.handle.net/10862/187 Utilization of seaweeds in Thailand Lewmanomont, Khanjanapaj Dogma Jr., Ireneo J.; Trono Jr., Gavino C.; Tabbada, R. A. Different seaweeds harvested from natural stocks are utilized in Thailand as human food and animal feed and for medicinal purpose and extraction of crude agar. Gracilaria and Porphyra are the most exploited commercially. Commercial cultivation through seaweed farming is recommended. Mon, 01 Jan 1990 00:00:00 GMT http://hdl.handle.net/10862/187 1990-01-01T00:00:00Z