Studies on Gracilaria gracilis (Stackhouse) Steentoft, Farnham and Irvine and Gracilaria aculeata (Hering) Papenfuss from southern Africa. I. The influence of temperature, irradiance, salinity and nitrogen-nutrition on growth

South African Journal of Botany

Volumn 63, Issue 6, 1997, Pages 465-473

  Wilson, A J ^a   Critchley, A T ^a  

^a UNIVERSITY OF THE WITWATERSRAND   (South Africa)

Author keywords

Bifactorial growth analysis; Gracilaria aculeata; Gracilaria gracilis; Growth; Irradiance; Nitrogen; Salinity; Temperature

Indexed keywords

GROWTH; IRRADIANCE; MACROALGAE; NITROGEN; SALINITY; TEMPERATURE;

(SOUTHERN); AFRICA;

ACULEATA; ALGAE; EUKARYOTA; GRACILARIA ACULEATA; GRACILARIA GRACILIS;

EID: 0031418899     PISSN: 02546299     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0254-6299(15)30800-0     Document Type: Article

References (97)

1. ANDERSON, R.J., SIMONS, R.H. & JARMAN, N.G. 1989. Commercial seaweeds in southern Africa: A review of utilization and research. S. Afr. J. Mar. Sci. 8: 277-299.
2. ANDERSON, R.J., LEVITT, G.J. & SHARE, A. 1996. Experimental investigations for the mariculture of Gracilaria in Saldanha Bay, South Africa. J. Appl. Phycol. 8: 421-430.
3. ANDERSON, R.J., MONTEIRO, P.M.S. & LEVITT, G.J. 1996. The effect of localised eutrophication on competition between Ulva lactuca (Ulvaceae, Chlorophyta) and a commercial resource of Gracilaria verrucosa (Gracilariaceae, Rhodophyta). Hydrobiologia 326/327: 291-296.
4. ASSAD-LUDEWIGS, I.Y. & DE OLIVEIRA, E.C. 1986. Growth of a Brazilian species of Gracilaria (Rhodophyta) under different conditions of light and temperature. Book of Abstracts, International Seaweed Symposium 12: 25.
5. BEER, S. & LEVY, I. 1983. Effects of photon fluence rate and light spectrum composition on growth, photosynthesis and pigment relations in Gracilaria sp. J. Phycol. 19: 516-522.
6. BENOTTO, S. & VAN DER BEER, D. 1991. Applied ecology studies on the possible commercial exploitation of cyanobacteria, microalgae and marine seaweeds. Int. J. Mar. Biol. Oceanogr. 17 (1): 15-33.
7. BIRD, C.J. & McLACHLAN, J. 1986. The effect of salinity on distribution of species of Gracilaria Grev. (Rhodophyta, Gigartinales): An experimental assessment. Bot. Mar. 29: 231-238.
8. BIRD, C.J., McLACHLAN, J. & DE OLIVEIRA, E.C. 1986. Gracilaria chilensis sp. nov. (Rhodophyta, Gigartinales) from Pacific South America. Can. J. Bot. 64: 2928-2934.
9. BIRD, C.J., RAGAN, M., CRITCHLEY, A.T., RICE, E.T. & GUTELL, R.R. 1994. Molecular relationships among the Gracilariaceae (Rhodophyta): further observations on some undetermined species. Eur. J. Phycol. 7: 291-301.
10. BIRD, K.T. 1987. Gracilaria cultivation in the Caribbean. Paper presented at the Caribbean Aquaculture and Trade Expo., Puerto Rico. 13 pp.
11. BIRD, K.T., HANISAK, M.D. & RYTHER, J. 1981. Chemical quality and production of agars extracted from Gracilaria tilvahiae grown in different nitrogen enrichment conditions. Hydrobiohgia 24: 441-444.
12. BIRD, K.T., CHEN, L.C.-M. & McLACHLAN, J. 1979. Effects of temperature, light and salinity on growth in culture of Chondrus crispus, Furcellaria lumbricalis. Gracilaria tikvahiae (Gigartinales, Rhodophyta) and Fucus serratus (Fucales, Phaeophyta). Bot. Mar.22: 521-27.
13. BRANCH, G. & BRANCH, M. 1985. The Living Shores of Southern Africa. Struik Publishers, Cape Town.
14. CANCINO, J.M., MUNOZ, M. & ORELLANA, M.C. 1987. Effects of epifauna on algal growth and quality of the agar produced by Gracilaria verrucosa (Hudson) Papenfuss. Hydrobiologia 151/152: 233-237.
15. CAUSEY, J.T.. PRYTHERCH, J.P., McCASKILL, J., HUMM, H.J. & WOLF, F.A. 1946. Influence of environmental factors upon the growth of Gracilaria confervoides. Cited in: Mclachlan, J., Bird, C.J. 1986. Gracilaria (Gigartinales, Rhodophyta) and productivity. Aquatic Botany 26: 21-49.
16. CAUSEY, J.T.. PRYTHERCH, J.P., McCASKILL, J., HUMM, H.J. & WOLF, F.A. 1946. Influence of environmental factors upon the growth of Gracilaria confervoides. Cited in: Mclachlan, J., Bird, C.J. 1986. Gracilaria (Gigartinales, Rhodophyta) and productivity. Aquatic Botany 26: 21-49.
17. CHIANG, Y.-M. 1981. Cultivation of Gracilaria (Rhodophyta, Gigartinales) in Taiwan. In: Xth International Seaweed Symposium, ed. T. Levring. pp. 569-573. Walter de Gruyter and Co., Berlin.
18. CHIANG, Y.-M. & LIN, J.-L. 1989. Nitrate uptake by nitrogen-starved plants of the red alga Gracilaria tenuistipitata var. liui. Jpn J. Phycol. 37: 187-193.
19. CRAIGIE, J.S., WEN, Z.C. & VAN DER MEER, J.P. 1984. Interspecific, intraspecitic and nutritionally-determined variations in the composition of agars from Gracilaria spp. Bot. Mar. 27: 55-61.
20. CRITCHLCY, A.T. & ROTMANN, K.W.G. 1992. Industrial processing of seaweeds in Africa: The South African experience. In: Proceedings of the First International Workshop on Sustainable Seaweed Resource Development in Sub-Saharan Africa, eds, K. Mshigeni, J.J. Bolton, A.T. Critchley & G. Kiangi, pp. 85-97. Windhoek, Namibia.
21. CRITCHLEY, A.T., ROTMANN, K.W.G., MOLLOY, F.J. 1991. The Namibian seaweed industry: Present and potential. Biores. Technol. 38: 137-143.
22. DAWES, C.J. 1987. The biology of commercially important tropical marine algae. Cited in: Kapraun, D.F. & Dutcher, .I.A. 1991. Cytophotometric estimation of inter-and intraspecific nuclear DNA content variation in Gracilaria and Gracilariopsis (Gracilariales. Rhodophyta). Bot. Mar. 34: 139-144.
23. DAWES, C.J. 1987. The biology of commercially important tropical marine algae. Cited in: Kapraun, D.F. & Dutcher, .I.A. 1991. Cytophotometric estimation of inter-and intraspecific nuclear DNA content variation in Gracilaria and Gracilariopsis (Gracilariales. Rhodophyta). Bot. Mar. 34: 139-144.
24. DAWES, C.P. 1992. Rope cultivation of Gracilaria in Namibia: Prospects ? In: Proceedings of the First International Workshop on Sustainable Seaweed Resource Development in SubSaharan Africa, eds K. Mshigeni, J.J. Bolton, A.T. Critchley & G. Kiangi, pp. 99-109. Windhoek, Namibia.
25. DAWES, C.P. 1995. Suspended cultivation of Gracilaria in the sea. J. Appl. Phycol. 7: 303-313.
26. DE BOER, J.A., GUIGLY, H.J., ISRAEL, T.L. & D'ELIA, C.R 1978. Nutritional studies of two red algae. I. Growth rate as a function of nitrogen source and concentration. J. Phycol. 14: 261-266.
27. DE CASTRO, T.R., GUANZON Jr., N.G. & EUHAN, M.R.J. 1991. Assessment of stocks of a natural Gracilaria population on Panay Island, Philippines. Bot. Mar. 34: 383-386.
28. DE OLIVEIRA, E.C. 1989. The rationale for seaweed cultivation in South America. In: Workshop: Cultivation of Seaweeds in Latin America, eds E.C. de Oliveira & N. Kautsky. pp. 135-141. Univ. S. Paulo/Int. Foundation for Science, Brazil.
29. DRING, M.J. 1982. The Biology of Marine Plants. Edward Arnold, London. 199 pp
30. EDDING, M., LEON, C. & AMBLER, R. 1987. Growth of Gracilaria sp. in the laboratory. Hydrobiologia 151/152: 375-379.
31. EKMAN, P. 1991. Physiology and chemical composition of some cultivated seaweeds with emphasis on the agarophyte Gracilaria sordida (Gigartinales, Rhodophyta). Acta Univ. Ups., Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science 312. 45 pp.
32. EKMAN, P., YU, S. & PEDERSEN, M. 1991. Effects of altered salinity, darkness and algal nutrient status on floridoside and starch content, α-galactosidase activity and agar yield of cultivated Gracilaria sordida. Br. phycol. J. 26: 123-131.
33. ENGELDOW, H.R. & BOLTON, J.J. 1992. Environmental tolerance in culture and agar content of Gracilaria verrucosa (Hudson) Papenfuss (Rhodophyta, Gigartinales) from Saldanha Bay. S. Afr. J. Bot. 58(4): 263-267.
34. FEI, X.G., HUANG, L.J. 1991. Artificial sporeling and field cultivation of Gelidium in China. Hydrobiologia 221: 119-124.
35. FREDERICQ, S. & HOMMERSAND, M.H. 1990. Diagnoses and key to the genera of the Gracilariaceae (Gracilariales, Rhodophyta). Hydrobiologia 204/205: 173-178.
36. FRIEDLANDER, M. 1991. Growth rate, epiphyte biomass and agar yield of Gracilaria confena in an annual outdoor experiment. 1. Irradiance and nitrogen. Biores. Technol. 38: 203-208.
37. FRIEDLANDER, M., KROM, M.D. & BEN-AMOTZ, A. 1991. The effect of light and ammonium on growth, epiphytes and chemical constituents of Gracilaria conferta in outdoor cultures. Bot. Mar. 34: 161-166.
38. FRIEDLANDER, M., SHALEV, R., GANOR, T., STRIMLING, S. 1987. Seasonal fluctuations of growth rate and chemical composition of Gracilaria cf. conferta in outdoor culture in Israel. Hydrobiologia 151/152: 501-507.
39. GUANZON, N.G. Jr. & DE CASTRO, T.R. 1992. The effects of different stocking densities and some abiotic factors on cage culture of Gracilaria sp. (Rhodophyta. Gigartinales). Bot. Mar. 35: 239-243.
40. GUO-ZHONG, R., JI-CHENG, W. & MEI-QIN, C. 1984. Cultivation of Gracilaria by means of low rafts. Hydrobiologia 116/117: 72-76.
41. HAGLUND, K. 1992. Photosynthesis and growth of some marine algae, with emphasis on the rhodophyte Gracilaria tenuistipitata. Acta Univ. Ups., Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science 377. 48 pp.
42. HAGLUND, K. & PEDERSEN, M. 1992. Growth of the red alga Gracilaria tenuistipitata at high pH. Influence of some environmental factors and correlation to an increased carbonicanhydrase activity. Bot. Mar. 35: 579-587.
43. HANISAK, M.D. 1990. The use of Gracilaria tikvahiae (Gracilariales, Rhodophyta) as a model system to understand the nitrogen nutrition of cultured seaweeds. Hydrobiologia 204/205: 79-87.
44. HANISAK, M.D. & RYTHER, J.H. 1984. Cultivation biology of Gracilaria tikrahiae in the United States. Hydrobiologia 116/117: 295-298.
45. HANSEN, J.E., PACKARD, J.E. & Doyle, W.T. 1981. Mariculture of red seaweeds. Cited in: Rueness, J. & Tananger, T. 1984. Growth in culture of four red algae from Norway with potential for mariculture. Hydrobiologia 116/117: 303-307.
46. HANSEN, J.E., PACKARD, J.E. & Doyle, W.T. 1981. Mariculture of red seaweeds. Cited in: Rueness, J. & Tananger, T. 1984. Growth in culture of four red algae from Norway with potential for mariculture. Hydrobiologia 116/117: 303-307.
47. HUNT, R. 1978. Plant Growth Analysis. Studies in Biology, No 96. Edward Arnold, London. 67 pp.
48. HURTADO-PONCE, A.Q. 1990. Vertical rope cultivation of Gracilaria (Rhodophyta) using vegetative fragments. Bot. Mar. 33: 477-481.
49. HURTADO-PONCE, A.Q. & UMEZAKI, I. 1987. Growth rate studies of Gracilaria verrucosa (Gigartinales, Rhodophyta). Bot. Mar. 30: 223-226.
50. JAYASRIYA, P.M.A. 1989. Preliminary observations on the culture of Gracilaria edulis using spore-setting techniques. Gracilaria Production and Utilization in the Bay of Bengal Region 45: 34-36.
51. KAIN, J.M. 1991. Cultivation of attached seaweeds. In: Seaweed Resources in Europe: Uses and Potential, eds M.D. Guiry & G. Blunden, pp. 309-377. John Wiley and Sons Ltd.
52. KAIN, J.M. & NORTON, T.A. 1990. Marine Ecology. In: The Biology of the Red Algae, eds. K.M. Cole & R.G. Sheath, pp. 377-22. Cambridge University Press, New York.
53. KAUTSKY, L. 1989. Factors limiting seaweed production. In: Workshop: Cultivation of Seaweeds in Latin America, eds de Oliveira, E.C. & Kautsky, N., pp. 9-16. Univ. S. Paulo/Int. Foundation for Science, Brazil.
54. KIM, D.H. 1970. Economically important seaweeds, in Chile - I) Gracilaria. Bot. Mar. 13: 140-162.
55. KOCH, E.W. & LAWRENCE, J. 1987. Photosynthetic and respiratory responses to salinity changes in the red alga Gracilaria verrucosa. Bot. Mar. 30: 327-329.
56. LAING, W.A., CHRISTELLER, J.T., TERZAGHI, B.E. 1989. The effect of temperature, photon flux density and nitrogen on growth of Gracilaria sordida Nelson (Rhodophyta). Bot. Mar. 32: 439-445.
57. LAPOINTE, B.E. & RYTHER, J.H. 1978. Some aspects of growth and yield of Gracilaria tikvahiae in culture. Cited in: Haglund, K. 1992. Photosynthesis and growth of some marine algae, with emphasis on the rhodophyte Gracilaria tenuistipitata. Acta Univ. Ups., Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science 377. 48 pp.
58. LAPOINTE, B.E. & RYTHER, J.H. 1978. Some aspects of growth and yield of Gracilaria tikvahiae in culture. Cited in: Haglund, K. 1992. Photosynthesis and growth of some marine algae, with emphasis on the rhodophyte Gracilaria tenuistipitata. Acta Univ. Ups., Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science 377. 48 pp.
59. LAPOINTE, B.E. & RYTHER, J.H. 1979. The effects of nitrogen and seawater flow rate on the growth and biochemical composition of Gracilaria foliifera var. angustissima in mass outdoor culture. Bot. Mar. 22: 529-537.
60. LAPOINTE, B.E., DAWES, C.J. & TENORE, K.R. 1984. Interactions between light and temperature on the physiological ecology of Gracilaria tikvahiae (Gigartinales, Rhodophyta). II. Nitrate uptake and levels of pigments and chemical constituents. Cited in: McLachlan, J. & Bird, C.J. 1986. Gracilaria (Gigartinales, Rhodophyta) and productivity. Aquatic Bot. 26: 27-49.
61. LAPOINTE, B.E., DAWES, C.J. & TENORE, K.R. 1984. Interactions between light and temperature on the physiological ecology of Gracilaria tikvahiae (Gigartinales, Rhodophyta). II. Nitrate uptake and levels of pigments and chemical constituents. Cited in: McLachlan, J. & Bird, C.J. 1986. Gracilaria (Gigartinales, Rhodophyta) and productivity. Aquatic Bot. 26: 27-49.
62. LEVY, I., BEER, S. & FRIEDLANDER, M. 1990. Strain selection ln Gracilaria spp. 2. Selection for high and low temperature resistance in G. verrucosa sporelings. J. Appl. Phycol. 2: 163-171.
63. LIGNELL, A. 1988. Physiology and cultivation of marine seaweeds with emphasis on Gracilaria secundata (Rhodophyta, Gigartinales). Acta Univ. Ups. 120: 15-17 Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science 120. 48 pp.
64. LIGNELL, A., EKMAN P. & PEDERSEN, M. 1987. Cultivation technique for marine seaweeds allowing controlled and optimized conditions in the laboratory and on a pilot scale. Bot. Mar. 30: 417-424.
65. MACLER, B.A. & ZUPAN, J.R. 1991. Physiological basis for the cultivation of the Gelidiaceae. Hydrobiologia 221: 83-90.
66. McLACHLAN, J. & BIRD, C.J. 1984. Geographical and experimental assessment of the distribution of Gracilaria species (Rhodophyta: Gigartinales) in relation to temperature. Helgolander Meeres. 38: 319-334.
67. McLACHLAN, J., BIRD, C.J. 1986. Gracilaria (Gigartinales, Rhodophyta) and productivity. Aquatic Bot. 26: 27-49.
68. MOLLOY, F.J. 1992. Studies on the Ecology and Production of Seaweeds of Economic and Potential Economic Importance on the Namibian Coast. PhD Thesis, University of Cape Town, South Africa 253pp.
69. MOLLOY, F.J. & BOLTON, J.J. 1992. The more important seaweed resources on the Namibian coast, with special reference to Gracilaria In: Proceedings of the First International Workshop on Sustainable Seaweed Resource Development in Sub-Saharan Africa, eds. K. Mshigeni, J.J. Bolton, A.T. Critchley & G. Kiangi, pp. 23-219. Windhoek, Namibia.
70. MOLLOY, F.J. & BOLTON, J.J. 1995. Distribution, biomass and production of Gracilaria in Luderitz Bay. Namibia. J. Appl. Phycol. 7: 381-392.
71. MOLLOY, F.J. & BOLTON, J.J. 1996. The effect of season and depth on the growth of Gracilaria gracilis at Luderitz, Namibia. Bot. Mar. 39: 407-413.
72. MURANO, E., TOFFANIN, R., ZANETTI, F., KNUTSEN, S.H., PAOLETTI, S. & RIZZO, R. 1992. Chemical and macromolecular characterisation of agar polymers from Gracilaria dura (C. Agardh) J. Agardh (Gracilariaceae, Rhodophyta). Carbohydrate Polymers 18: 171-178.
73. NELSON, S.G., YANG, S.-S., WANG, C.-Y. & CHIANG, Y.-M. 1983. Yield and quality of agar from species of Gracilaria (Rhodophyta collected from Taiwan and Micronesia. Bot. Mar. 26: 361-366.
74. PENNIMAN, C.A. & MATHIESON, A.C. 1985. Photosynthesis of Gracilaria tikvahiae McLachlan (Gigartinales, Rhodophyta) from the Great Bay Estuary, New Hampshire. Bot. Mar. 28: 427-435.
75. PENNIMAN, C.A., MATHIESON, A.C. & PENNIMAN, C.E. 1986. Reproductive phenology and growth of Gracilaria tikvahiae McLachlan (Gigartinales, Rhodophyta) in the Great Bay Estuary, New Hampshire. Bot. Mar. 29: 147-154.
76. PERONE, C., CECERE E. & FELICINI, G.P. 1991. Culture studies on carageenan producing red alga from the Mar Piccolo of Taranto (Italy). Oebalia 27(1): 73-88.
77. PROVASOLI, L. 1986. Media and prospects for the cultivation of marine algae. In: Cultures and collections of algae, eds. A. Watanabe & A. Hattori. Japn. Soc. Plant Physiol. Tokyo, pp. 63-75.
78. REBELLO, J., OHNO, M., CRITCHLEY, A.T. & SAWAMURA, M. 1996. Growth rates and agar quality of Gracilaria gracilis (Stackhouse) Steentoft from Namibia, southern Africa. Bot. Mar. 39: 273-279.
79. RHENZI, W.C.L., GUANGHENG, L., ZHONGCUN, W., LIANGFENG, D., JINGPUR, Z. & XIAOHANG, H. 1989. Some aspects of the growth of in pond culture. Gracilaria Production and Utilization in the Bay of Bengal Region 45: 27-30.
80. ROTMANN, K.W.G. 1987. The collection, utilization and potential farming of red seaweeds in Namibia. Cited in Critchley A.T (1993) Gracilaria (Rhodophyta, Gracilariales): An economically important agarophyte. Hydrobiologia 151/152: 301-305.
81. ROTMANN, K.W.G. 1987. The collection, utilization and potential farming of red seaweeds in Namibia. Cited in Critchley A.T (1993) Gracilaria (Rhodophyta, Gracilariales): An economically important agarophyte. Hydrobiologia 151/152: 301-305.
82. ROTMANN, K.W.G. 1990. Saldanha Bay, South Africa: recovery of Gracilaria verrucosa (Gracilariales. Rhodophyta). Hydrobiologia 204/205: 325-330.
83. RUENESS, J. & TANANGAR, T. 1984. Growth in culture of four red algae from Norway with potential for mariculture. Hydrobiologia 116/117: 303-307.
84. RYAN, K.G & NELSON, W.A. 1991. Comparative study of reproductive development in two species of Gracilaria (Gracilariales, Rhodophyta). I. Spermatogenesis. Cryptogamic Botany 2/3: 229-233.
85. SANTELICES, B. (1978) Multiple interaction of factors in the distribution of some Hawaiian Gelidiales (Rhodophyta). Cited in Santelices, B. (1991) Production ecology of Gelidium. Hydrobiologia 221: 31-44.
86. SANTELICES, B. (1978) Multiple interaction of factors in the distribution of some Hawaiian Gelidiales (Rhodophyta). Cited in Santelices, B. (1991) Production ecology of Gelidium. Hydrobiologia 221: 31-44.
87. SMIT, A.J., ROBERTSON, B.L. & DU PREEZ, D.R. 1997. Influence of ammonium-N pulse concentrations and frequency, tank condition and nitrogen starvation on growth rate and biochemical composition of Gracilaria gracilis. J. Appl. Phycol. 8: 473-481.
88. THORHAUG, A. & MARCUS, J.H. 1981. The effects of temperature and light on attached forms of tropical and semi-tropical macroalgae potentially associated with OTEC (Ocean Thermal Energy Conversion) machine operation. Bot. mar. 24: 393-398.
89. TRA, T.D. 1989. The culture of Gracilaria verrucosa in Tarn Giang Lagoon, Thua Thien Hue Province, S. R. Vietnam. Gracilaria Production and utilization in the Bay of Bengal Region 45: 20-24.
90. TRONO, G.C. 1993. Eucheuma and Kappaphycus: Taxonomy and cultivation. In: Seaweed Cultivation and Marine Ranching, eds. M. Ohno & A.T. Critchley, JICA, Japan, pp. 75-88.
91. TRONO, G.C. et AZANZA-CORRALES, R. 1981. Seasonal variation in the biomass and reproductive states of Gracilaria in Manila Bay. In: Xth International Seaweed Symposium. Walter de Gruyter and Co., Berlin, 743-748.
92. TSEKOS, I. & KARATAGLIS, S. 1974. Der einluss der temperatur auf das wachstum von karposporen-keimlingen der Rhodophycee Gracilaria confervoides (L.) Grev. Cited in: McLachlan, J. & Bird, C. J. 1986. Gracilaria (Gigartinales, Rhodophyta) and productivity. Aquatic Botany 26: 27-49.
93. TSEKOS, I. & KARATAGLIS, S. 1974. Der einluss der temperatur auf das wachstum von karposporen-keimlingen der Rhodophycee Gracilaria confervoides (L.) Grev. Cited in: McLachlan, J. & Bird, C. J. 1986. Gracilaria (Gigartinales, Rhodophyta) and productivity. Aquatic Botany 26: 27-49.
94. WHYTE, J.N.C., ENGLAR, J.R., SAUNDERS, R.G. & LINDSAY, J.C. 1981. Seasonal variations in biomass, quantity and quality of agar, from the reproductive and vegetative stages of Gracilaria (verrucosa-type). Bot. Mar. 24: 493-501.
95. WILSON, A.J. 1990. The influence of photoperiod and temperature on the growth and reproduction of Gracilaria spp. and Sargassum heterophyllum. Honours thesis. University of the Witwatersrand, Johannesburg.
96. XIN, C.J. 1989. Gracilaria culture in China. In: Gracilaria Production and Utilization in the Bay of Bengal Region 45: 13-17.
97. YU, S. & PEDERSEN, M. 1990. The effect of salinity on the activity of α-galactosidase of the red algae Gracilaria sordida and G. tenuistipitata. Bot. Mar. 33: 385-391.