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E-International Scientific Research Journal, VOLUME – IV, ISSUE- 3, 2012, ISSN 2094-1749INTRODUCTIONSea urchin is one of the major fishery resources in the world which is rapidly expandingin many countries because of the high demand for its gonad or roe. However, wild stocks aredeclining in the major sea urchin fishing nations of the world (Keesing and Hall 1998; Andrew etal. 2002 as cited by Pearce et al. 2004). Market demand for sea urchin gonads is unlikely todiminish in the foreseeable future as Japan’s consumption of sea urchin product remains stableand as Japanese cuisine (e.g. sushi, sashimi) is rapidly becoming popular in the North Americanfood industry. It is unlikely that wild harvests alone will be able to supply future roe marketdemand. This scenario bodes well for the development of a successful sea urchin aquacultureindustry. According to Pearce et al. (2004) the two basic forms of sea urchin culture involves,first, spawning adult broodstock and rearing resultant larvae/juveniles to market size andsecond, enhancing gonads (i.e. increasing yield and/or quality) of wild caught adults held incaptivity by feeding them natural or prepared diets (Pearce et al. 2004).The most commercially in demand species of sea urchin in the Philippines is Tripneustesgratilla, locally known as “Maritangtang” among the Ilocanos. Its fishery is a major source oflivelihood in many coastal villages particularly along the northwestern coast of Luzon Island andin the Bicol region. Sea urchin is harvested for local and export markets generating millions ofpesos per annum (Talaue-McManus and Kesner 1995). However, there has been an alarmingdecline in the landed catch due to over-harvesting from the wild stock.Presently, there is an observed increase in the mariculture of this species along thenorthwestern coast of Luzon Island particularly in Pangasinan, Ilocos Sur and Ilocos Norte.Stock enhancement is also being done through seeding or planting of juveniles in open coastalareas. Inspite of these developments, there is still a dearth of the culture and managementguidelines for this resource. The mariculture of this resource for increased production and forits sustainable management is a promising venture in the area because of the presence of idealmariculture sites and abundant natural foods for the organism such as Sargassum and otherspecies of seaweeds and seagrasses.This study aimed to assess the viability of using prepared diets for the culture andgrowth of the organism on land-based conditions. This is important in increasing productionand continuous supply in the market and for future gonad enhancement studies to improve itsmarketability. Specifically, it aims to: (1) determine the somatic growth (wet weight and testdiameter) performance of the organism fed with prepared natural diets; (2) determine thegonad growth performance (gonadosomatic index) and gonad quality (color and granularity) ofthe organism fed with prepared diets; and (3) monitor the water parameters affecting thesomatic growth performance and gonad quality of the sea urchin.215

E-International Scientific Research Journal, VOLUME – IV, ISSUE- 3, 2012, ISSN 2094-1749MATERIALS AND METHODSLocation of the StudyThe experiment was set-up and conducted within the premises of the MMSU College ofAquatic Sciences and Applied Technology campus, Pias Sur, Currimao 2903, Ilocos Norte,Philippines.Experimental MediaNine polycarbonate plastic basins each measuring 60 cm in diameter by 25 cm depthwere used in the experiment. Seawater was pumped from the coast in front of the collegebuilding using a diesel water pump into four concrete tanks measuring 4.0 m x 2.5 m x 2.0 m (Lx W x D). Unfiltered seawater from the concrete tanks was pumped using a 0.5 HP electricwater pump into two circular fiberglass tanks measuring 1.0 m diameter x 1 m depth providedwith gravel and sand serving as filtration tanks that supply the nine experimental basins on aflow-through system. The culture basins were aerated with NSB electric air pumps.EXPERIMENTAL DESIGNThe experiment consisted of three feeding treatments, namely: Treatment I - controlconsisting of fresh unformulated Sargassum sp diet; Treatment II - dried Sargassum sp pellets;and Treatment III - fresh extruded Sargassum sp pellets with three equal replications (Table 1).The dried and fresh extruded pellets were mainly of Sargassum sp. Asia and Tabije (2003) foundout that Sargassum is a better natural feed affecting the growth and gonad development of T.gratilla as compared with the seagrass Enhalus acoroides. Arrangement of the culture basinswas done in a completely randomized design (CRD) (Fig. 1).Table 1. Feeding treatments and stocking density used in the study.Treatments Stocking density ReplicatesI. Control ( Fresh Diet) 38 individuals/basin 3II. Dried Pellets 38 individuals/basin 3III. Fresh Pellets 38 individuals/basin 3216

E-International Scientific Research Journal, VOLUME – IV, ISSUE- 3, 2012, ISSN 2094-1749Fig. 1. View of the experimental set-up.EXPERIMENTAL ORGANISMSThree hundred Forty two (342) post-juvenile T. gratilla with test diameter ranging from36.00 to 55.00 mm and weighing from 22.00 to 54.00 g (wet weight) were used in theexperiment. These were taken from the wild stock in Dadalaquiten, Sinait, Ilocos Sur,Philippines, a nearby municipality of about 15 kilometers from the experimental site.FEED PREPARATIONThe prepared dried pellets were composed of finely ground dried Sargassum sp. (sundriedfor 1-2 days before grinding) with 6% binder consisting of corn starch and gelatin. Thesteps in feed preparation following that of Alava (1996) were observed. The finely groundseaweed was sieved into uniform particle size. The binder was suspended into half of therequired water (the required water for a kilo of prepared feed is 1,200 ml) while the remaininghalf was boiled then the suspended binder was poured slowly to the boiled water stirringconstantly with low flame until jelly-like consistency was obtained. The gelatinized binder wasadded to the Sargassum and mixed. The feed mixture was pelletized at a size of 5mm diameterusing a manually-operated pelletizer (Fig 2), steamed with sea water for 5 minutes to enhancethe binding of ingredients with an improvised steamer set-up, fan-cooled and sun dried for oneday. The pelletized feeds were placed and sealed in plastic containers and refrigerated.The fresh extruded pellets, on the other hand, were prepared by grinding the freshSargassum and mixed with the finely ground Sargassum at 1:1 ratio after which the gelatinizedbinder (as prepared above) was added and mixed. The feed mixture was pelletized at a size of217

E-International Scientific Research Journal, VOLUME – IV, ISSUE- 3, 2012, ISSN 2094-17495 mm diameter using a manually-operated pelletizer. The pelletized feeds were givenimmediately to the organism while remaining pellets were placed and sealed in plasticcontainers for refrigeration. Refrigerated fresh extruded feeds were given to the organisms infour days.Fig. 2. Finely ground Sargassum sp. mixed with the binder and pelletized.EXPERIMENTAL PROCEDURE AND SAMPLINGThirty-eight sea urchin individuals were placed in each basin. They were fed with thefresh Sargassum diet daily on an ad libitum basis and with the prepared diets daily at 1.5 % ofwet body weight. Pearce et al. (2002) concluded in their research that gonad yield of the greensea urchin Strongylocentrotus droebachiensis is maximized at 0.5 to 1.0% body weight(BW)*day-1 feeding of prepared diets. Since T. gratilla is a tropical species which presumablyhas a higher metabolic rate than S. droebachiensis which is a temperate species, a feeding rateof 1.5% of BW*day-1 was tried. However, during the first week it was observed that the 1.5 %wet body weight feeding ration was inadequate hence this was increased to 2.0 % during thesecond week and to 3.0 % on the third week until the end of the study. Daily cleaning andmaintenance of basins were also done.Prior to stocking in the basins, the initial test diameter and weight of each experimentalorganism were measured and recorded. To monitor the somatic growth of sea urchin, theexperimental organisms were measured in terms of their test diameter (mm) both equatorialand polar using a Vernier caliper and wet weight with triple beam balance of 1.0 g sensitivity.Sampling was done once a week for a period of six weeks.Three test organisms randomly taken from each basin were shucked upon thetermination of the study to determine gonad growth in terms of the gonadosomatic index (GSI)and quality (color and granularity) (Fig 3). The GSI of the organisms was determined using thefollowing formula (Lozano 1995):218

E-International Scientific Research Journal, VOLUME – IV, ISSUE- 3, 2012, ISSN 2094-1749Wet - weight of gonadsGSI = x 100Wet - weight of sea urchinGonad quality in terms of color was determined using the Munsell Color Guide. Theguide has three simple variables that combine to describe colors as hue, value and chroma.This study used the hue Yellow-Red (10YR) which is preceded by numbers from 0 to 10 wherethe hue becomes more yellow and less red as the numbers increase. The value notation usedwas 8 (near white) and the chroma notation used ranged from 1 to 8 where the color becomesmore yellow with increasing number. The values based on the chroma notation were the onesrecorded in this study for gonad color comparison. The combination of a bright yellow colorand fine granularity of gonad is most preferred by the market (Blount and Worthington 2002).Fig. 3. Determination of the GSI and gonad quality of the test organisms.MONITORING OF WATER PARAMETERSThe water parameters which may affect the somatic growth and gonadal growth andquality of the experimental organisms were measured. Dissolved oxygen and temperaturewere measured by an Oaklon Dissolve Oxygen meter; salinity by an Atago refractometer; andpH by a pH paper.ANALYSIS OF DATAMeans and ranges were used to describe growth parameters of the test organisms andthe water parameters. Analysis of covariance (ANCOVA procedure of the SAS System) was usedto determine differences of somatic growth parameters among treatments with wet weightand test diameter as covariates. Analysis of variance (ANOVA procedure of the SAS System)was also used to determine the differences of the GSI, gonad color and granularity amongtreatments. A post test using the Duncan’s Multiple Range Test (DMRT) was used to furthertest significant findings.219

E-International Scientific Research Journal, VOLUME – IV, ISSUE- 3, 2012, ISSN 2094-1749Further, a correlation analysis using the Proc Corr procedure of the SAS System wasused to determine the strength of relationship of the somatic growth parameters, gonadgrowth and quality parameters, and water parameters.RESULTS AND DISCUSSIONSOMATIC GROWTHWet Weight. Growth increments in wet weight of sea urchins cultured in basins forfour months culture period (MCP) at different feeding treatments are shown in Table 2. Thevalues are adjusted means with initial weight as covariate. After one month culture period,Treatment I significantly (p = 0.05) had the highest weight increment of 20.62 g compared toTreatments II and III with 13.88 g and 8.35 g, respectively. Although there were no significantdifferences among treatments means of Treatments II and III, Treatment II relatively had thehigher mean growth increment in wet weight. The comparatively lower growth rates ofTreatments II and III may be due to the adjustments made by the organisms feeding with theprepared diet. It was observed that the organisms only fed on the prepared diets after threedays of introduction.At the succeeding culture periods (second, third and fourth month), the growthincrements in wet weight of the organisms did not significantly differ among the threetreatments, however, Treatment I generally had the highest wet weight growth incrementfollowed by Treatment II. Treatment III had the least wet weight growth increment.Highest wet weight growth increment in all treatments was observed during the firstMCP and had a decreasing trend towards the end of the study.The above results indicate that the test organisms fed with both the dried and freshpellets have almost similar growth in wet biomass with those fed with the fresh diet ofSargassum sp. The effect of prepared Sargassum sp. diet at 4.0 to 5.0% BW*day-1 on wetweight was even significantly higher (p

E-International Scientific Research Journal, VOLUME – IV, ISSUE- 3, 2012, ISSN 2094-1749III – FreshPellets37.88 8.35b 7.22a 9.78a 2.08a 27.43 6.86aMeans with different superscripts are significantly different at 5% level.*Adjusted mean with initial wet weight as covariate.Growth increments in equatorial test diameter of the sea urchins during the four MCPare shown in Table 3. The values are adjusted means with initial equatorial test diameter ascovariate. Although not significantly different, it was observed during the first MCP thatTreatment I had the highest mean growth increment in equatorial test diameter of 9.65 mmfollowed by Treatments II and III with 7.06 mm and 6.63 mm, respectively. However, on thesecond MCP until the end of the study, Treatment II comparatively had higher equatorial testdiameter growth increment than Treatments I and III. Again, there were no significantdifferences among treatments means. The overall mean also shows no significant differencesamong treatments which indicate that the prepared diets are comparable with the fresh dietgiven to the test organisms.Highest wet equatorial test diameter growth increment in all treatments was observedduring the first MCP and had a decreasing trend towards the third MCP with a slight increase inthe last month of culture. Bangi (2001) also observed the same trend for the same speciesgrown for six months in cages on sea-based conditions at Bolinao, Pangasinan, Philippines. Theorganisms had a mean test diameter increment of 6.89 mm fed with low Sargassum and 11.10mm for those fed with high quantity of Sargassum on the first month of culture. She observeda generally decreasing trend towards the fifth month of culture with 1.84 mm and 2.94 mm forthe low and high feeding of Sargassaum, respectively. There was a slight increase in testdiameter in both feeding treatments at the sixth month of culture. The values obtained in thisstudy are almost similar with the values she observed in her study.Table 3. Mean growth increment in equatorial test diameter* (mm) of the sea urchin T. gratillaat different feeding treatments for four MCP.FeedingTreatmentMonths After StockingInitial 1 2 3 4TotalMeanI – Fresh Diet(Control)II – DriedPelletsIII – FreshPellets44.98 9.65a 1.84a 0.25a 1.34a 13.08 3.27a45.51 7.06a 2.52a 0.27a 2.66a 12.51 3.13a45.47 6.63a 1.04a 0.16a 1.90a 9.73 2.43aMeans with different superscripts are significantly different at 5% level.221

E-International Scientific Research Journal, VOLUME – IV, ISSUE- 3, 2012, ISSN 2094-1749*Adjusted mean with initial equatorial test diameter as covariate.Table 4 shows the data on growth increments in polar test diameter of the testorganisms during the four MCP. The values are adjusted means with initial polar test diameteras covariate. Results show that there were no significant differences among the treatmentswhich indicate that the prepared diets are comparable with the fresh diet. It was also observedthat the highest growth increment in polar test diameter was during the first MCP whichfollows the trend on the growth in wet weight and equatorial test diameter.Further, although not significantly different, Treatment I also comparatively had thehighest growth increment in polar test diameter than Treatments II and III. Samples ofharvestable sea urchins representing the different treatments are shown in Appendix Figure 1.Table 4. Mean growth increment in polar test diameter* (mm) of the sea urchin T. gratilla atdifferent feeding treatments for four MCP.FeedingTreatmentMonths After StockingInitial 1 2 3 4TotalMeanI – Fresh Diet(Control)II – DriedPelletsIII – FreshPellets27.09 4.90a 1.30a 0.34a 1.40a 7.94 1.99a27.69 3.60a 1.28a 0.35a 0.35a 5.48 1.40a26.75 2.47a 0.79a 0.05a 0.40a 3.71 0.93aMeans with different superscripts are significantly different at 5% level.*Adjusted mean with initial polar test diameter as covariate.GONAD GROWTH AND QUALITYGonad growth and development measured in terms of gonadosomatic index and gonadquality determined in terms of color and granularity were assessed upon the termination of thestudy (Table 5). It was observed that spawning occurred as early as the second month ofculture period. Garvida and Asia (2004) also noted that T. gratilla grown in cages placed onland-based concrete tanks and fed with Sargassum sp reached maturity and spawned at about45 days of culture.The data showed that Treatment I had a significantly (p = 0.05) higher GSI of 5.77% thanTreatments II and III with 3.64 % and 3.40 %, respectively. Treatments II and III did not differsignificantly. Bangi (2001), in her study on the cage culture of the same species on sea-basedconditions, observed a mean gonad index ranging from 2.70 % to 5.16 % for the low Sargassumdiet and from 5.38 % to 8.14 % at the end of the six month culture period. The data obtained inthis study, although the organisms were grown in vitro conditions and fed with prepared diets,are comparable with her study. Garvida and Asia (2004) also observed an average GSI of the222

E-International Scientific Research Journal, VOLUME – IV, ISSUE- 3, 2012, ISSN 2094-1749organism reared for 75 days in land-based cages placed in concrete tanks ranging from 5.60 to7.47 %.Table 5. Mean GSI, gonad color and gonad granularity of the sea urchin T. gratilla at differentfeeding treatments for four MCP.FeedingTreatmentGonad Growth and Quality ParametersGSI (%) Color Granularity, mmI – Fresh Diet (Control) 5.77a 7.11a 0.037aII – Dried Pellets 3.64b 5.22b 0.028aIII – Fresh Pellets 3.40b 4.67b 0.033aMeans with different superscripts are significantly different at 5% level by DMRT.Gonad quality was measured by determining the gonad color and granularity of the testorganisms. For gonad color, higher values indicate brighter yellow colors which are consideredof better quality for the gonads. In the Munsell Color Chart, the value of 8 has the brightestyellow and becomes paler as the value decreases to 1. Results show that the fresh diettreatment (Treatment I) significantly had brighter yellow color (p = 0.05) than Treatments II andIII. However, in a follow-up study (Asia 2009) to optimize the feed ration of the organisms, theeffect of natural food and prepared Sargassum sp. diet at 4.0 to 5.0% BW*day-1 ongonadosomatic index and gonad color was comparable (p

E-International Scientific Research Journal, VOLUME – IV, ISSUE- 3, 2012, ISSN 2094-1749WATER PARAMETERSThe water parameters which are believed to have influences on the growth of the testorganisms such as dissolved oxygen, water temperature, salinity and pH were monitored duringthe course of the study (Table 6). The dissolved oxygen ranged from 5.12 to 8.43 mg*L-1throughout the culture period with an average of 6.47 mg*L-1 while the temperature rangedfrom 25.00 to 30.30 oC with an average of 27.94 oC. An increasing trend in dissolved oxygenand temperature was observed during the study period. For temperature, the increasing trendmay be due to the onset of summer. Salinity ranged from 33.00 to 35.00 ppt with an average of34.60 ppt while pH ranged from 7.0 to 8.0 with an average of 7.5 throughout the cultureperiod. The measurements of said parameters are within the favorable range for the growthand survival of the test organisms.Table 6. Water parameters monitored in the culture of the sea urchin T. gratilla for four MCP.ParametersDissolved Oxygen Range(mg*L-1)MeanWater Temperature Range(oC) MeanSalinity (ppt) RangeMeanpHRangeMeanMonthsFebruary March April May June5.12 – 6.98 5.76 – 6.50 5.41 – 6.97 6.55 – 8.43 5.81 – 7.496.13 6.16 6.20 7.14 6.7225.40-28.87 25.00-27.83 29.80-30.00 27.60-28.00 29.60-30.3026.48 25.53 29.87 27.82 30.04-----33.0 35.0 35.0 35.0 35.0-----7.0 8.0 7.5 7.5 7.5CORRELATION ANALYSESIn order to determine the degree of relationships that exist among the somatic andgonad growth and quality and the various water parameters, a correlation analysis was done asshown in Table 7. Observed water parameters such as dissolved oxygen, temperature, salinityand pH were within the favorable ranges for growth and survival of T. gratilla. Significantpositive correlation existed between wet weight and equatorial test diameter (r=0.78, p=0.01)and polar test diameter (r=0.97, p=0.0001). Likewise, equatorial test diameter and polar testdiameter are significantly positively related (r=0.80, p=0.01). Wet weight and gonadosomaticindex were also positively related (r=0.70, p=0.04); polar test diameter and gonadosomaticindex (r=.0.70, p=0.03); wet weight and gonad color (r=0.80, p=0.01); polar test diameter andgonad color (r=0.84, p=0.004); dissolved oxygen and wet weight (r=0.81, p=0.01); and dissolvedoxygen and polar test diameter (r=0.80, p=0.01). On the other hand, water temperature had asignificantly negative correlation with gonad color (r=-0.69, p=0.04).224

E-International Scientific Research Journal, VOLUME – IV, ISSUE- 3, 2012, ISSN 2094-1749Table 7. Correlation analysis of the different somatic and gonad growth and quality with thevarious water parameters.Pearson Correlation Coefficients, N = 9Prob > |r| under H0: Rho=0Wwt Etd Ptd GSI Color Gran DO TempWwt 1.0000 0.7825 0.9662 0.6953 0.7989 0.2664 0.8133 -0.33690.0127

E-International Scientific Research Journal, VOLUME – IV, ISSUE- 3, 2012, ISSN 2094-1749CONCLUSIONS AND RECOMMENDATIONSThe prepared diets were comparable with the fresh Sargassum sp. natural food in termsof somatic growth. For gonad growth and color, the fresh natural food gave better results;however in a follow-up study of Asia (2009) on optimizing the prepared feed ration, theprepared dried diet given at 4 to 5% BW/day was comparable with the fresh food in both thesomatic and gonad growth and quality performances of the organism. Prepared natural dietscan be given to the organisms in lieu of the fresh natural food.The successful introduction of prepared diets for the sea urchin T. gratilla can be ofgreat help in the development of the land-based aquaculture and stock enhancement of thisorganism for food production. Feeding prepared diets to the organism opens opportunities forfurther studies on gonad quality enhancement. Coloring pigments such as carotenoids fromnatural and artificial sources can already be incorporated in the diet of the organism to improveits quality for market and consumption. This necessitates further studies specificallyconcentrating on locally available pigment sources like tomato, squash yellow corn and the like.Pearce et al. (2004) found out that the green sea urchin Strongylocentrotus droebachiensis fedwith prepared diet mixed with β-carotene had a significantly better gonad quality than thosefed with kelp. Higher quality gonads command a higher value in the world market particularlythat of Japan.The study likewise demonstrated the viability of land-based culture of the organismusing both the fresh natural food and prepared diets. This will be important in sustaining a yearround harvest and possible broodstock source for hatchery and seed stock production. A viableand ready source of seed stock such as a hatchery in the northwestern part of Ilocos region isnecessary to carry out further studies and cater to the needs of the increasing adaptors of thegrow-out culture technology of the resource.ACKNOWLEDGMENTSThe authors acknowledge the support provided by the Mariano Marcos State Universityand its President, Dr. Miriam E. Pascua; Dr. Epifania O. Agustin and Dr. Sixto R. Pascua, Jr.,former Directors for Research and Development; Ms. Mary Ann B. Gorospe and to the otherstaffs of the MMSU Research Directorate for their numerous assistance in the preparation andfinalization of the manuscript; and the Commission on Higher Education for a travel grant topresent a poster of this paper at the 8 th Asian Fisheries Forum, Kochi, India on November 20-23,2007.226

E-International Scientific Research Journal, VOLUME – IV, ISSUE- 3, 2012, ISSN 2094-1749REFERENCESAlava, V. R. 1996. Practical notes in feed formulation. Lecture presented during the TrainingCourse on Fish Nutrition, Oct. 23 – Dec. 03, 1996, SEAFDEC, Tigbauan, Iloilo, Philippines.Asia, F. B. 2009. Optimizing prepared feed ration for somatic growth and gonad production ofthe sea urchin Tripneustes gratilla (Linnaeus, 1758). Asian Fisheries Science Journal22(1):71-84.Asia, F. B. and T. Tabije, Jr. 2003. Culture of the economically important sea urchin Tripneustesgratilla in Ilocos Norte. Research paper presented during the Agency In-house review ofR&D highlights. April 23-25, 2003, MMSU College of Agriculture and Forestry,MMSU, Batac, Ilocos Norte.Bangi, H.G.P. 2001. The effect of adult nutrition on somatic and gonad growth, egg quality andlarval development of the sea urchin Tripneustes gratilla Linnaeus 1758 (Echinodermata:Echinoidea). Thesis, Master of Science (Marine Biology), Marine Science Institute,College of Science, University of the Philippines. p 18.Blount, C. and D. Worthington. 2002. Identifying individuals of the sea urchin Centrostephanusrodgersii with high-quality roe in New South Wales, Australia. Fisheries Research58:341-348.Garvida, J. J. and F. B. Asia. 2004. Somatic growth and gonadal maturity of sea urchin(Tripneustes gratilla) fed with selected species of algae and seagrass in vivo condition.Research paper presented during the MMSU Agency In-House Review of R & DHighlights on May 4-7, 2004, Crops Research Laboratory, MMSU, Batac, Ilocos NorteKeesing, J. K. and K. C. Hall. 1998. Review of harvests and status of world sea urchin fisheriespoints to opportunities for aquaculture. J. Shellfish Res, 17:5 pp. 1597-1604.Lozano, J. 1995. Biological cycle and recruitment of Paracentrotus lividus(Echinodermata:Echinoidea) in two contrasting habitats. Mar. Ecol. Prog. Series122:179-191.Pearce, C. M., T. L. Daggett and S. M. C. Robinson. 2002. Effect of binder type andconcentration on prepared feed stability and gonad yield and quality of the green seaurchin, Strongylocentrotus droebachiensis. Aquaculture 205(3-4):301-323.Pearce, C.M., T.L. Daggett and S.M.C. Robinson. 2004. Effect or urchin size and diet on gonadyield and quality in the green sea urchin (Strongylocentrotus droebachiensis).Aquaculture 233:337-367.Talaue-McManus, L. and K.P. Kesner. 1995. Valuation of municipal sea urchin fishery andimplications of its collapse. In: Philippine Coastal Resource under Stress. 4th AnnualCommon Property Conference, Manila.227

E-International Scientific Research Journal, VOLUME – IV, ISSUE- 3, 2012, ISSN 2094-1749Appendix Figure 1. Samples of T. gratilla from the three treatments after four monthsof culture.Appendix Figure 2. Samples of gonads of T. gratilla from the three treatments after fourmonths of culture.228