Results obtained on seasonal growth, yield and physical properties of agar in Gelidiella acerosa and Gracilaria edulis for a period of one year are presented. Vegetation of these two species occurred throughout the year with two peak growth periods

Chennubhotla, V S Krishnamurthy

Kalimuthu, S

Najmuddin, M

Panigrahy, R

Selvaraj, M

CMFRI Digital Repository

&dlJJl,J Ihs. Uti/no 9 (I & 2) : 45-48, 1986 CHANGES IN GROWTH AND PHYCOCOLLOm CONTENT OF GELID/ELLA ACEROSA AND GRAC/LARIA EDUL/S v. S. K. Che ...... bhotla·, S. Kalim .. thu, M. Najm .. cIdia, R. p .......... y aad M. SelvaraJ a.p-l c..tre of CeDtnl Maria. ,lalt • .t.. R ... rda IaotItute, Maria. ,Ia_ .. 623 520, WIa. AMtract Results obtained on seasonal growth, yield and physical properties of agar in Gllidit/Ia lIClTosa and Graci/aria etlu/is for a period of one year are presented. Vegetation of these two species occurred throughout the year with two peak growth periods. In G. acerosa the agar content varied from 26'1 to 50'8 % and gel strength from 147 to 325 glcm'. In G. etlulis the yield of agar ranged from 26'5 to 45'0 % and gel strength from 69 to 139 glcm'. Seasonal variations observed in growth and yield, gel strength, setting and melting temperature of agar were not conspicuous in both these red algae. IDtrocIuctioa Studies on ,easonal vaflatlons in growth and agar content of Indian agarophytes are necessary in order to harvest them during suitable periods for getting maximum yield of agar. Seasonal variations in growth , yield ' and physical properties of agar were reported for Graci/aria verrutOSIl (Thomas, 1977), G. corticat. (Oza, 1978) Gelidium ""ilium and P/erocladia "'/erop/aws (Kaliaperumal and Umamaheswara Rao, 1981 ). Information on these aspects is not available for other agar yielding seaweeds especially for the species growing around Mandapam, which is the main seaweed harvesting centre in India. Hence, studies were made for a period of one year on GeliditU. lIClTosa and Graci/aria edu/is growing at Mandapam area and the results obtained are presented in this paper. Material. aad Methocb Plants or Geliditlla acerosa (Forsskal)Feldmann et Hamel from Krusadai Island and Kilakarai and Graci/ari. ,tlulis (Gmelin) Silva from Krusadai Island were collected every month during spring tides for a period of one year during 1976-1978. Totally 50 plants were measured randomly for each species to determine the stature of plants . Agar was extracted by cooking 20 g of bleached and pulverized material in a water bath for 4 hr,. The material and distilled water were used in the ratio of I : 30. The extractive was filtered , cooled at room temperature and fro!Cn for 24 bro. in a deep freezer . The frozen gel _ .s thawed and dried in the sun for I or 2 days and then in an oven at 60" d to a const nt weight. The gel strength of I , 5 % agar was estimated using a gelometer (Funaki and Kojima, 1951). The setting and melting temperature of 1'5 % agar were determined with a thermometer following the movement of glass beads in the setting and melting gels. Three replicates were done to estimate agar content and to determine the physical properties of agar. Reault. Data collected on growth, yield and physical properties of agar of G. ,,"rosll are presented in .PreRnt addft.: Central Marine Fisheries Research Institute, Cochin-682031, India. CENTRAL  MARINE FISHERIES RESEARCH INSTITUTE, COCHIN.46 ~ ,. U> .. Z " I .J 0. h .. 6 :t 1:1 ~ 2 0: ~ .. 4 0 0 .J '" 3' > I-~ :t i;;-300 ~ ~ ., E 220 .J .. "' -" 140 .g 80 "' !!i 70 ~ 60 0: "' ~ 50 "' .. 40 ........ MELTlf'«i TEMPERATURE 0--~ SETT!OO TEMPERATURE J FMA MJJASOND 1977 Fig. 1. Seasonal changes in growth and yield, melting temperature growing at Krusadai gel strength, setting and of agar of G. OClrosa Island. Figs. I and 2 and G. edulis in Fig. 3. In G. aUTosa growing at Krusadai Island, though there were no regular changes in the growth behaviour, plants with maximum size occurred during the periods March-May and July-September (Fig. I). The yield of agar varied from 30'0 % to 50'8 % with minimum value in July and maximum value in January. The gel strength ranged from 147 g/cm".in August to 325 glcml in June-July. The setting temperature varied from 43~ C to 52° C and melting temperature from 69° C to 84° C (Fig. 1). In G. acerosa occurring at Ki lakarai also, the growth was irregular. But plants with maximum stature were found during April-May, November-January and March (Fig. 2) The agar content ranged from 26' \ % in May to 46'8 % in November. The gel strength varied from 162 glcm I in September to 320 glcm" in November. The setting temperature ranged from 42° C to 49° C and melting temperature from 610 C to 83° C. In G. edulis growing at Krusadai Island, maximum growth of plants was observed during January-March and August-October. Minimum quantity of 26'5 % agar in June and maximum quantity of 45 '0 % agar in ~ . ~E !!s~ 4 '< " - -1 ~ o ~--------------------~ ~ l!s 40 9 ~ 20~----------~~------4 I-1: 280 .. -"N z e ~ ~ 2 40 "e u>'" .J-"' " 200 160 .\---.!:..--...t:---------l .~ 10 Ii II: 50 ~ ... ............ .::::.~ MfLTlNG TEMPERATURE 0. _ . SETTING TEMPERATURE ... ~ 0 0 __ 0 -_0.....° 0... --0--0'" .. 0 .......... 0"" "'" "'0" .. 30 L-r-r-~.-,-,__r~~_r-,F-,M~ AMJJASOND J o 1971 I 1978 Fig. 2. Seasonal variations in growth and yield . gel strength, setting and melting temperature of agar of C. aarOSiJ occurring at Kilakarai. CENTRAL  MARINE FISHERIES RESEARCH INSTITUTE, COCHIN.November were obtained. The gel · strength ranged from 69 glcm~ in May to 139 glcm~ in August. The setting temperature varied from 44° C to 50· C and melting temperature from 61· C to 78" C. (Fig. 3). Di8C1lSUon From the foregoing account it is clear that vegetation of G. acerosa and G. edulis occur in ' all months of the year in the vicinity of Mandapam with two peak growth periods in a year. It coincides with the observations made earlier on the growth behaviour of G. 'lcerosa (Umamaheswara Rao, 1973 a and Thomas et al., 1975), G. cortica/4 (Umamaheswara Rao, 1972), G. edulis and G. folifera (Umamaheswara Rao, 1973 b) growing at Mandapam area. In the present study the yield and gel strength of agar is more in G. acerosa than in G. edulis. l The maximum yield of agar obtained from these 2 species agrees with the earlier investigations on the agar content in G. actrosa (Umamabeswara Rao, 1970; Chennubhotla et al., 1977 and Thomas et ai., 1975) and G. edulis (Umamaheswara Rao, 1970 and Chennubhotla et al., 1977). The yield of agar . estimated in G. act rosa and G. edulis during the present study is found to be higher than that observed in Gracilaria erassa (Umamaheswara Rao, 1970), G. corticala (Oza, 1978) and G. foliifera (Umamaheswara, 1970 and Subba Rao el al., 1977) and it can be compared with G. corticata (Umamaheswara Rao, 1970 and 1978 and Subba Rao .t al., 1977), G. ftrgusonii (Subba Rao ,t al., 1977), G. verrucosa (Thomas, 1977), Gelidiella indica (Subba Rao .t al., 1977), Gelidium pusillum and PlArocladia MtAroplatos (Kaliaperumal and Umamaheswara Rao, 1981). 47 'E<IO B I!? ~30 , oJ Q. 0 "-0 20 I-J: " iiiJ: 10 ~ 0~------------------------1 ~ 45 ~ ~ 35 !II .. # 25~--------~~~------~ ~ 140 ,,-Z'" '" E ~o1-" 100 ., E oJ" ",-" Fig. 3. Monthly variations in growtn and yield, gel strength , setting and melting temperature or agar in C. tdulis. ,t al. , 1975), G. corticata (Ou, 1978) and G. OITTUCosa (Thomas, 1977). But there are no regular seasonal changes in the yield and gel strength of agar in the two red algae studied as observed in P. helAroplalos (Kaliaperumaland Umamaheswara Rao, 1981). There is no relationship between the growth cycle, yield and gel strength of agar in G. acerosa and G. ed.lis during the present investigation. But in general the suitable period. for harvesting these two agarophytes are January-March and July-September for Seasonal variations in yield and gel strength getting more yield of agar with higher get of agar were reported in G. acerosa (Thomas strength. CENTRAL  MARINE FISHERIES RESEARCH INSTITUTE, COCHIN.48 Admowlecla:eDleJlts We are thankful to Dr. E.G. Silas, fonner Director, Central Marine Fisheries Research Institute, Cochin for encouragement and facilities provided. Our thanks are due to Dr. P. V. Ramachandran Nair, Scientist S-3 and Head, Fishery Environment and Manage-ment Division, CMFRI, and Dr. N. Kalia-perumal, Scientist S-2, Regional Centre of CMFRI, Mandapam Camp for their help . LITERATURE CITED Chcnnubhotia, V. S. K ., Najmuddin, M. and Bidyadhar Nayak. 1977. A comparative study of the yield and physical properties of agar·agar from different blench of seaweeds. s..UMd /Us. UI;!n., 2 : 87·90. Funaki, K . and Kojima, Y. 1951. Studit";S on the properties of agar-aga r from Gracilaria c~flT­«idu Part 3. Bull. Jap. Soc. Sri. , Fw.. , 16 : Wl-404. Kaliaperu.mal, N. and Umamaheswara Rao, M. 1981. Studies 011 the standing crop and phycocolloid of G,/iJium plUillum and PI"",/adia "''''of>ialos. India. J. Bot. 4: 91·95. Oza, R.M. 1978. Studies 011 [ndian Gracilaria IV. Seasonal variation in agar and gel strength of CracilDria corticola J. Ag. occurring on the coast of Veraval. Bot. mar. 21 : 165-167 . Subba Rao, P.V., Rarna Rao, K. and Subbaramaiah, K. 1977. Screening of certain red seaweeds for phyoocolloids. &aw<td /Us. UtiJ • . , 2 : 82-86. Thomas, P.C. 1977. Seasonal variation in the yield. and physical properti(s of agar-agar from G<a<iI.ria _sa (Hudson) Papenf"". &awud /Us. Uliln., 2: 78-81. Thomas, P.C., Rama Rao, K. and Subbaramaiah, K . 1975. Periodicity in growth and production of agar of Gelidulla acerosa (Fol"'5skal) Fdd. et. Hamel. Indian J. mar. Sci., 4 : 210-212. Umamaheswara Rao, M. 1970. The economicseaweedl of India. Bull. ant. mar. Fish. Rts. but. No. 20 pp. 1-68. Umamaheswara Rao, M. observati<tns on some Mandapam coast . Proc. 38 : 298·307. 1972. Ecological intertidal algae of [nJian Mil. Sci. Aco/,. Umamaheswara Rao, M. 1973 a. Growth and repro-duction of GelidU1Ja acerrua in the Palk Bay and Gulf of Mannar near Mandapam. Indian J. Fish., 20 : 411·416. Umamaheswara Rao, M. 1973 h. Growth and reproduction in some species of Graci/aria and Graciiario/JSI:s in the Palk Bay. Indian J. FisA .. 20 : 182-192. Umamaheswara Rao, M. 1978. Seaweed resources or Andhc.l Pradesh. Stawt,t/ Rts. Utillt., 3 : 51-55. CENTRAL  MARINE FISHERIES RESEARCH INSTITUTE, COCHIN.

Changes in growth and phycocolloid content of Gelidiella acerosa and Gracilaria edulis

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Changes in growth and phycocolloid content of Gelidiella acerosa and Gracilaria edulis

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