Masters Theses

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Antioxidative activities and lactic acid bacteria composition of fermented frigate tuna at different salt-fish ratio
Ortizo, Rhessa Grace G. (University of the Philippines Visayas, 2019-06)
The antioxidative activities and lactic acid bacteria (LAB) composition of fermented frigate tuna (Auxis thazard), locally known as tinabal, at different salt-fish ratios were investigated. Fresh frigate tuna were degutted and cleaned before the addition of salt at different salt-fish ratio (w/w), (1:3), (1:4), (1:5), (1:6), and then fermented at ambient temperature. Samples were taken on day 0, 1, 4, and 7 for the pH determination, total titratable acidity measurement, and the different antioxidant activity assays that include testing for radical scavenging activity of ABTS+, ferric reducing power, hydrogen peroxide and singlet oxygen radicals. Isolation of lactic acid bacteria (LAB) for bacterial identification was also conducted as well as the measurement of the degree of hydrolysis for peptide profile analysis of fermented product. Results show that the LAB viable count in the fermented samples increased, and the pH levels decreased with increasing % titratable acidity during the 7 days of fermentation. Isolated LAB and LAB-like species with gram positive, catalase negative, and non-spore forming properties were presumptively identified as Lactobacillus casei, Lactobacillus fermenti, Lactobacillus delbrueckii subsp. delbrueckii, Pediococcus pentosaceus, Leuconostoc spp., Enterococcus faecalis and Streptococcus spp. In this study, the free amino acids due to hydrolysis increased with fermentation time for the different salt-fish ratios and DH was influenced by the length of fermentation. The ethanolic extracts from F3 (1:6) sample showed strong antioxidative activities against ABTS+ radical, while sample Fl (1:4) showed high reduction of ferric ions, and sample F2 (1:5) exhibited high antioxidative activities against 1O2 radical which is the major cause of damage to bioactive compounds that leads to oxidative stress in fermented products. Results further revealed that tinabal could be a potential source of natural antioxidants for industrial uses. In addition, presence of important LABs in F2 (1:5) indicated that this fermented product could serve as a good source of LAB for applications to other fermented products as starters for improved product quality. In particular, tinabal fermented with F2 salt-fish ratio (1:5) has potential to be a functional food product that could benefit the consumers.
Bioactivities of protein hydrolysates from Chlorella sorokiniana
Tejano, Lhumen A. (College of Fisheries and Ocean Sciences, University of the Philippines Visayas, 2018-06)
Microalgal proteins can be a good source of nutrients and compounds with bioactivities. In this study, proteins from Chlorella sorokiniana were isolated by pH shift technology and enzymatically hydrolyzed using pepsin, bromelain, and thermolysin to produce hydrolysates. Molecular characteristics of the hydrolysates were determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and amino acid analysis. After membrane ultrafiltration, bioactivities of the hydrolysates and peptide fractions were determined. Results revealed that thermolysin exhibited the highest degree of hydrolysis with 18.08 + 1.13%, followed by bromelain, and lastly by pepsin, after 4 h of hydrolysis. SDS-PAGE results showed that the hydrolysis generated peptides exhibited molecular weights of mostly <10 kDa of the hydrolysates, much less than those of the large and diverse proteins of the protein isolate. The essential amino acid indices (EAAIs) suggest that the hydrolysates could be considered as good quality protein sources. In vitro bioactivity assays, on the other hand, revealed that the pepsin peptide fraction of <5 kDa showed the highest DPPH radical scavenging activity (48.86 + 1.95%). Only pepsin hydrolysates and pepsin peptide fractions displayed inhibition to Staphylococcus aureus and Escherichia coli. However, there are no significant differences among the Angiotensin I Converting Enzyme (ACE) inhibitory and reducing power activities of the hydrolysates and peptide fractions. Both the protein hydrolysates and peptide fractions were observed to have satisfactory pH and heat stabilities. Overall, the results suggest that C. sorokiniana proteins can be a good alternative source of valuable compounds with pharmaceutical and nutraceutical application potentials.
Catch composition, morphology, and some aspects of reproductive biology of Inimicus sinensis caught by baby otter trawl in Carles, Iloilo, Philippines
Delloro, Emmanuel S., Jr. (University of the Philippines Visayas, 2019-06)
The catch composition of bottom otter trawl or “baby trawl” in Carles, Iloilo, Philippines was assessed from twenty (20) hauling operation from December 2017 to February 2018. A total of 97 fish species belonging to 15 orders and 53 families were identified. Considering shrimp as target catch, commercial and discarded bycatch were estimated to be greater than 95%. Fishermen are utilizing the bycatch species, however, discarding of fish occurs during operation and high grading of catches. Venomous fishes such as scorpaenid, tetrarogid, aploactinid, and synanceid fishes were commonly thrown back to the sea. The morphology of the synanceid fish, which comprises part of the discarded bycatch, was also described. Inimicus cuvieri (Gray, 1835) and Inimicus sinensis (Valenciennes, 1833) were morphologically alike. However, comparison between sexes of I. sinensis showed secondary sexual characteristics. Thirty-three morphological measurements, including standard length and fourteen meristic counts were made on 99 specimens (47 male and 52 female). Most morphometric characters differed significantly between sexes while no differences were found in meristic counts. Fish external features were longer in male specimens. The head and body region were bigger in female specimens. Factor analysis, Principal Component Analysis (PCA), extracted two principal components from the significantly different parameters that explained 62.29 % of the cumulative variances. Variables that caused the variation in two major components were head width, upper jaw, lower jaw, snout, pre anal fin, and anal fin base lengths in PC1 (45.65 %); and orbit diameter and anal fin base length in PC2 (16.64 %). These differences seem to be connected with their adaptation to environment, reproduction, and behavior. Additionally, a single pore at the anterolateral surface of the body and pores above the lateral line are also described here but association to other organs were not yet found. Finally, studies on some aspects of reproductive biology of I. sinensis, which dominates the fishing ground, were also conducted. Gonadosomatic index (GSI) and size of females at 50% maturation were determined by logistic method and by plotting the GSI with standard length. Fecundity was calculated from 49 mature individuals through subsampling at different gonad lobes. The size at 50% maturity was estimated to be 127.2 mm, using the logistic model, which was likely supported by the abrupt increase in GSI values above 125 mm SL. Fecundity was estimated at 47 187±25 009 oocytes for fish sized 115.33-194.57 mm. Both GSI and fecundity showed low correlation to fish length. Additionally, the histological analysis of the gonad showed that this fish is gonochoristic and multiple spawner.
Characterization of the egg masses of Wedge Sea Hare, Dollabella auricularia (Lightfoot, 1786) from Danao-Carmen Cove, Cebu, Philippines
Pepito, Ador R. (University of the Philippines Visayas, 2016-06)
The egg mass locally, known as "lukot” of the wedge sea hare Dolabella auricularia is considered as one of the seafood products in the Visayas region. It is traditionally consumed as raw or an added ingredient to a soup made from fish or shellfish. Although there have been no reported incidence of food poisoning due to the consumption of these egg masses, a preliminary study revealed the potential presence of some toxic substances in the samples. Likewise, no detailed study on the chemical characteristics of these egg masses has been reported. Hence, this study was conducted to determine the toxicity potential and the effect of the post harvest treatment on the chemical quality of the egg mass. Different post harvest treatments were employed in this study includes: acidified, boiled and the combination of the two. Results show low toxicity potentials in all samples both treated and untreated. No significant differences among all treatments on the lowering of the toxicity potentials of the egg mass were observed. This low toxicity potential could be attributed to the effect of seasonal variation in the sample and its habitat. Different post harvest treatments, on the other hand, reveal different effects on the chemical characteristics of the egg masses. Acidified and the combination of acidified and boiled samples show high protein, carbohydrates and ash content. Boiling of samples resulted to an increase in moisture retention and potassium while acidified samples resulted in high calcium and potassium. Raw or fresh samples show high total fat, ash, sodium and zinc content. In terms of amino acid profile, the egg masses have six (6) essential, nine (9) non-essential and eight (8) other amino acid components. These results indicate that the egg masses of the wedge sea hare can be considered as a good potential exotic nutritious food commodity from marine environment. Its safety, however, largely depends on the condition of the environment where these egg masses are harvested.
Chemical changes in a limed and flooded acid sulfate fishpond
Baylon, Carlos C. (University of the Philippines at Los Baños, 1981-10)
Field and laboratory studies were conducted on an acid sulfate soil in Carles, Iloilo with the following objectives: a) to characterize the soils in the pond bottom and along the dikes of an acid sulfate fishpond; b) to follow-up some chemical changes occurring in the flooded acid sulfate ponds, and c) to evaluate the effect of liming on these chemical changes. The pH (1 :1 soil-water) of the air-dried soil samples collected from the pond bottom and along the dikes of the nursery ponds ranged from 2.2 to 4.6. This was significantly correlated with the lime requirement, extractable Al, active Fe and Mn, acetate-soluble sulfate and total sulfur content of the soil. In the field experiment, before lime treatment, the waters of the nursery ponds exhibited decreasing pH with time as well as increasing concentrations of dissolved Al and Fe. The level of Mn in the water was low due to the small amount of active Mn present in the soil. Acidity in the pond waters after a heavy rain was mainly due to the leaching of sulfuric acid from the dikes. Three lime treatments were used in the study: I-lton/ha of lime applied along the dikes and 3 tons/ha on the pond bottom, II - 3 tons/ha of lime on dikes and 1 ton/ha on the pond bottom, III - 4 tons/ha of lime on dikes and no lime on the pond bottom. Treatment II could be considered the most effective way of applying lime since the ponds in this treatment exhibited the highest mean water pH compared to the ponds of the other treatments. Fish mortalities were observed in one of the ponds (NP10 in Treatment III) which may be traceable to the low pH and high Al concentration in the pond water. The applied lime on the dike was not able to control the acidity because it washed down by the rains and covered with eroded soil. The SMP buffer method of determining lime requirement overestimated the lime required to control the acidity of the water in acid sulfate ponds.
A comparative study of the effects of supplementary feeding and artificial substrate on the production of milkfish fingerlings in brackishwater ponds
Adeyemi, Frederick F. (University of the Philippines Visayas, 1983-03)
The growth and survival of milkfish fry in response to supplementary feeding and artificial substrate were evaluated at stocking densities of 75 and 100 fry/m2 for a period of 56 days from August 21 to October 15, 1982. The study was conducted in eighteen 40m2 experimental nursery ponds of the University of the Philippines Brackishwater Aquaculture Centre, Leganes, Iloilo. A 3 x 2 factorial experiment in completely randomized design was used and six treatment combinations between level of inputs (no inputs, supplementary feeding or artificial substrate) and stocking density (75 or 100 fry/m2) were investigated with three replicates per treatment. The best fish growth was obtained in Treatment VI (100 fry/m2 with substrate) with mean final weight and length of 1.59 gm. and 5.36 cm. respectively while Treatment IV (100 fry/m2 without feeding or substrate) gave the poorest fish growth with mean final weight and length of 0.83 gm. and 4.60 cm. respectively. Differences in mean weight and length among treatments were, however, not statistically significant. Mean percentage survival was significantly higher at a stocking density of 75 fry/m2 (82.8%) than at 100 fry/m2 (64.1%) but supplementary feeding or artificial substrate ix did not show any statistically significant effect on survival. At either 75 or 100 fry/m2 stocking density, supplementary feeding gave a numerically higher percentage survival than artificial substrate. Economic analysis revealed that a stocking density of 75 fry/m2 without supplementary feeding or artificial substrate was the most profitable treatment with a return on investment of 39.2%. At a stocking density of 100 fry/ m2, supplementary feeding with rice bran was more profitable than the use of artificial substrate with returns on investment of 22.6% and 9.1% respectively.
Comparison of the catching efficiency of the traditional and modified fish corral in Panguil Bay
Acuña, Rodrigo E. (College of Fisheries and Ocean Sciences, University of the Philippines Visayas, 1997-12)
This study was conducted in two fishing sites of fish corral in Panguil Bay namely; Malaubang, Ozamiz City and Maquilao, Tangub City from November 21,1994 to July 10,1995. Two types of fish corral such as traditional and modified were identified. Results showed that average catch per trip was higher in the traditional fish corral (5.1 kg/day) compared to the modified fish corral (4.2 kg/day). The traditional fish corral also have a higher species richness (mean=105 species) against the modified (mean=50 species). About 90% of the catch of the traditional fish corral are commercially important species is significantly higher than the other type (50%). Catches of the traditional and modified fish corral largely consist of shrimps (Metapenaeus ensis: MFC; Penaeus indicus: TFC). Based on the relative density and weight of the total catch, Metapenaeus ensis (mean=222 individuals) is recorded as the most dominant species caught by the modified fish corral while Penaeus indicus (mean=38 individuals) exhibited as a dominant species in the traditional fish corral. Results of the statistical analyses on the data collected on irregular sampling dates show no significant difference on the catches between the traditional and modified. Significant difference is observed on the catches collected during the same sampling dates. Traditional fish corral is more efficient because it has higher catch per trip, species richness and high percentage of commercially important species. Modified fish corral as well, is effective with regards to its catch quantity, however it is inefficient in terms of its catch quality, i.e., of low commercial value.
Does a coral reef enhance the productivity of its surrounding waters?
Peñafiel, Christen P. (University of the Philippines Visayas, 2019-06)
Coral reefs have long been assumed and continually claimed to be origins of very high productivity, but how they attract organisms from and export nutrients to their neighboring waters remains largely unknown. Specifically, this study aimed at determining the space-time dynamics of nutrients and biomass redistribution around Hibotkan Rock Sanctuary (HRS), Banate, Iloilo, a sanctuary reef established by Municipal Fisheries Ordinance No. 12 covering an area of 25 ha. Twelve (12) sampling stations were established for space-time nutrient profiling, phytoplankton count, and supplementary measurements of water parameters, and four (4) stations for fish (biomass) visual survey. Results were analyzed using spatio-temporal plots and the Pearson correlation matrix (5% significant level). Nitrite was observed to be limiting, while nitrate was the most abundant in the waters of HRS. The predominant temporal variations of nutrients followed the flood tide (FT) and ebb tide (ET) cycles. In general, the tidal current direction appeared to control the redistribution of the nutrients (NO3-, NO2-, PO43-, and SiO44-). This study further revealed that stations of high nutrient concentration usually coincided with low levels of dissolved oxygen (DO). Species of fish observed were all indigenous and well-known inhabitants of the coral reefs. Furthermore, no other families of fishes (such as those of commercial value) were caught on record. Overall, there was no clear indication of import or export of living biomass in the HRS area. It can be inferred from the results that the fabled high productivity of coral reefs has no clear scientific basis; consequently, the Marine Protected Areas (MPAs) concept also appears to have no solid foundation.
The effect of common table salt added in different levels of water salinity as culture medium on growth and survival of prawn larvae Peneus monodon Fabricius
Abeto, Mario N. (College of Fisheries, University of the Philippines in the Visayas, 1989-09)
A study was conducted on the effect of common table salt added in waters of different salinity levels used to determine the survival rate, developmental stage, and carapace length of Penaeus monodon larvae from zoea one to post larva one. The following treatments which were adjusted to 33 ppt by adding varying amount of common table salt were: treatment I (8 ppt + 29 g/l) , treatment II (13 ppt + 23 g/l) , treatment III (18 ppt + 17 g/1), treatment IV (23 ppt + 11 g/1), and treatment V (28 ppt + 5/g) . Natural seawater with salinity of 33 ppt was used as control. Certain key ions like Na+, CL-, Ca2+, and Mg2+ were analyzed in each treatment. A sharp drop of. population in all treatments was recorded in the first 5 days of the zoeal stage. Treatment V gave the highest survival rate (25%) , but not significantly higher than treatment IV (20.5%) and control (18%); however, significantly higher than treatment III (10.5%) and treatment II (6.5%) at P<0.05. None of the larvae survived in treatment I after 5 days. Larvae exposed to treatment V had completed post larva one in 11 days (growth index 7). This was not significantly different, however, from those obtained from the control (growth index 6.6) and treatment IV (growth index 6.3). The lowest growth index value which was significantly lower than treatment V was obtained from treatment II and treatment III (growth index 6.0). During the first sampling, carapace length in treatment I reached 0.47 mm, succeeded by the following treatments: III (0.43 mm) , II (0.42 mm) , and V (0.40 mm). Treatment IV and control gave similar results (0.30 mm). After 2 days, rate of increase of CL had shifted from lower to high ionic concentrations culture media. At the end of the study the following carapace lengths were obtained: 1.2 mm for treatment V, 1.15 mm for control, and 1.08 mm for treatment IV. Values obtained from treatment II (0.94 mm) and treatment III (0.98 mm) were significantly lower than treatment V (1.15 mm). Rearing waters with higher concentrations of K+ and Mg2+ (control, treatments I, and II)showed better growth rate and percent survival than those media with relatively lower concentrations (treatments I, II, and III) . The addition of common table salt to low saline waters, however, did not compensate for the loss of physiologically important ions needed for growth and survival of prawn larvae.
Effect of cow and chicken manures on milkfish Chanos chanos (Forsskal) production in brackishwater ponds
Aduma, Ignatius A. (College of Fisheries, University of the Philippines in the Visayas, 1984-05)
A study using chicken and cow manures with basal application rates of 0.5 , 1,2 and 4 tons/ha was conducted. The effect of both manures on some selected physico-chemical properties of the pond soil and water, primary productivity, and milkfish Chanos chanos (Forsskal) yield were compared. Using 8 treatments with 3 replicates each in a completely randomized design, 24 units of 40 m2 ponds were stocked with 20 fingerlings/pond. The fish were cultured from September 22 to December 20, 1983 at the Brackishwater Aquaculture Center of the University of the Philippines in the Visayas College of Fisheries, Leganes, Iloilo, Philippines. The differences among treatments in terms of all physico-chemical parameters monitored were not significant except for the reactive phosphorus. Primary productivity in all treatments was at its peak during the 5th week, after which, it declined gradually apparently due to the combined effects of cloudy weather and low concentration of reactive phosphorus in the pond water. The highest mean net fish yield (680.9 kg/ha) and mean growth rate (1,54 g/day) were obtained in treatment 3 with 1 ton/ha of chicken manure. Treatment 2 (0*5 ton/ha of cow manure) had the lowest mean net fish yield (343.6 kg/ha) and likewise the lowest growth rate (0.80 g/day). The survival in all treatments was high, ranging from 95 to 100%. In general, chicken manure was superior to cow manure, however, fish production from the treatment with 2 tons/ha of cow manure was comparable to that of 2 tons/ha of chicken manure suggesting that cow manure could be used as organic fertilizer in brackish- water ponds for milkfish production.
Effect of different bio-augmentation agents on the biochemical composition of bacterial floc and growth of juvenile Penaeus monodon cultured in concrete tanks
Dianala, Rex Delsar B. (University of the Philippines Visayas, 2012-10)
The effect of bio-augmentation agents on the biochemical composition of biofloc, growth ofjuvenile Penaeus monodon, and antimicrobial activity of BFT water against Vibrio harveyi was investigated. P. monodon juveniles were cultured in pond soil-lined concrete tanks for 150 d using biofloc technology with bio-augmentation. Three commercial bio-augmentation agents (Pond Protect™, Pond Dtox™, BZT Waste Digester™) were tested against a control with no bio-augmentation agent application. At the end of the culture period, floc and shrimp collected for proximate analysis, and biofloc water tested for activity against V. harveyi. Average body weight (ABW), food conversion ratio (FCR), and specific growth rate (SGR) of the shrimp were computed. Bio augmentation with Pond Protect™ resulted in significantly higher (p < 0.05) crude protein content of the biofloc although this did not translate to higher shrimp yield nor growth performance. BZT Waste Digester™ as bio-augmentation agent significantly increased (p < 0.05) shrimp ABW. No apparent relationship between floc composition and shrimp carcass composition was observed. BFT water, with and without bioaugmentation agents, completely inhibited V. harveyi within 24 h. This study demonstrates that bio-augmentation agents could enhance the biochemical composition offloc and affect shrimp growth. BFT water was also shown to have potent antimicrobial properties against V. harveyi.
Effect of elevated carbon dioxide and phosphorus on nitrogen uptake, lipid content, and growth of Tetraselmis sp.
Ferriols, Victor Marco Emmanuel N. (Institute of Aquaculture, College of Fisheries and Ocean Sciences, University of the Philippines Visayas, 2011-04)
Effect of elevated carbon dioxide (CO2) and phosphorus levels on nitrogen uptake, lipid content, and growth of Tetraselmis sp. were investigated. Cultures of Tetraselmis sp. were added with CO2 and phosphorus at concentrations above those currently used in aquaculture practices in a factorial experiment. Three levels of CO2 (no addition, 5% v/v, and 10% v/v of the incoming air for aeration) and three levels of phosphorus added as NaH2PO4 (5, 10, 20 mg L’1) in modified F medium with NH4+ as the primary nitrogen source were used. Optical density (680 nm) and residual NH3-N in the culture medium were monitored daily over a culture period of 6 days. Relative growth rate (k'), nitrogen uptake (pg NH3-N cell’1 day1), and lipid content (% dry weight) were calculated and determined at the end of the culture period. No interactive effect between phosphorus and CO2 levels was observed in all variables measured (p > 0.05). Highest growth rate (k = 1.82±0.04), nitrogen uptake (0.316±0.008 μg NH3-N cell1 day1), and lipid content (10.95±0.15 %DW) were exhibited at 10% CO2 supplementation. Growth and nitrogen uptake were similar in treatments with elevated levels of phosphorus, but lipid yield (9.41±0.27 %DW) was lowest at 20 mg L1 of phosphorus supplementation (p < 0.05). These results showed the critical role of CO2 in nitrogen uptake, lipid content, and growth of Tetraselmis sp. It also indicates the potential of this algal species for waste water remediation, biofuel production, and carbon sequestration.
The effect of sex reversal treatment on the growth and survival of two strains of Nile tilapia (Oreochromis niloticus) and Mossambique tilapia (Oreochromis mossambicus) raised in brackishwater
Badillo, Susan Delos Santos (University of the Philippines Visayas, 2000-08)
A study to determine the effects of sex reversal (SRT) on the growth and survival of two strains of Nile tilapia (Oreochromis niloticus) and Mossambique tilapia (Oreochromis mossambicus) was conducted in four 2m x lm x 1.5m suspended hapa nets in UPV-IA Hatchery and Biology brackishwater fishpond for 75 days. The experimental treatments and codes used in this study were the following, Treatment GGn (GIFT/normal), Treatment GGsrt (GIFT/sex reversal), Treatment MMn (Moss/normal), Treatment MMsrt (Moss/sex reversal), Treatment GEn (GIFT-Egypt/normal) and Treatment GEsrt (GIFT-Egypt/sex reversal). Juvenile fry (average weight 0.0 1g) were subjected to sex reversal treatment by feeding fish diet with methyltestosterone at 60 mg per kg of feed for three weeks in freshwater. After SRT, the fingerlings were nursed in fine mesh net (0.5 mm mesh, 2m x 1m x 1m) for 30 days until the fish attained the weight from 3.0 g to 5.3 g. They were individually tagged by fin clipping method. They were acclimated from 0 ppt to 20 ppt prior to experimental proper. Juvenile fish of 3.40-5.44 g were communally stocked at 25 fish each treatment. Juvenile fish were fed with a commercial feed at 15% of their mean body weight per day from 1-30 days and 10% per day of their mean body weight from day 31-75 days culture period. Within the normal treatments, there was no significant (P>0.05) difference in mean body weights between Treatments GGn and GEn but both are significantly higher (P<0.01) than Treatment MMn. Within the sex reversed treatments, mean body weight in Treatment GGsrt was not significantly (P>0.05) different from Treatment GEsrt, but showed high significant (P<0.01) difference with Treatment MMsrt, similar to the normal treatments. The highest average final biomass of 808.88 g was obtained in Treatment GGsrt followed by Treatment GEsrt (795.58 g) and lowest in treatment MMn (367.63 g). The biomass gain of tilapia within the normal treatments ranged from 282.6 g to 672.95 g. Treatment GGn showed no significant (P>0.05) different from Treatment GEn, but both were significantly higher from Treatment MMn. The same trend was observed within sex reversal treatments. Treatment GGn obtained the highest (589.70%) percentage biomass gain and Treatment MMn (335.01%) was the lowest within the normal treatments. In sex reversal treatment, Treatment GGsrt has no significant difference with Treatment GEsrt, but both showed a high significant difference in Treatment MMsrt. Highest specific growth rate was observed in Treatment GGn (2.62 g day^-1) and lowest in Treatment MMn (1.97 g day^-1). Mean condition factor (MCF) of tilapia was highest in Treatment GGn (1.60), followed by Treatment GEn (1.56) and lowest in Treatment MMsrt (1.17). Within the normal treatments, Treatment GGn and GEn showed no significant difference (P>0.05), but both were significantly higher (P<0.01) than Treatment MMn. Within the SRT treatment, all treatments showed highly significant (P<0.01) difference from each other with highest at Treatment GGsrt and lowest at Treatment MMsrt. Mean survival ranged from 95% to 100%. Highest percent male population was obtained in hormone-treated fish (95-100%) compared to normal treatments (64-71%). Sex reversal treatment did not improve growth and survival of the two strains of Nile tilapia (O. niloticus), but improved the growth of Mossambique tilapia (O. mossambicus) significantly after 75 days under the conditions this experiment was conducted.
Effect of utilizing a combination of cow and chicken manures as organic fertilizer in fish pond
Babalola, Julius (College of Fisheries and Ocean Sciences, University of the Philippines Visayas, 1986-03)
An experiment was conducted utilizing twenty 40m2 ponds to investigate the effect of a combination of cow and chicken manures at the following ratios: 1000 kg/ha chicken manure: 3000 kg/ha cow manure; 1000 kg/ha chicken manure: 1000 kg/ha cow manure; 2000 kg/ha chicken manure only; 4000 kg/ha cow manure only; and no manure (control), on some selected physico-chemical properties of the pond, soil and water, primary productivity and production of red tilapia (0. mossambicus x 0. niloticus hybrid) following an (RCBD) - randomized complete block design. Each pond was stocked with 40 fingerlings of red tilapia and cultured for a 90-day period, at the Brackishwater Aquaculture Center of the University of the Philippines in the Visayas, College of Fisheries, Leganes, Iloilo, Philippines. Soil was analyzed for organic matter, phosphorus, nitrogen, pH, using Walkley and Black method, Olsen’s method, Kjehdahl method and pH meter respectively, following standard procedures described in method of soil analysis part II, (Black, 1965). Water oxygen was determined with YSI model 51-B, oxygen meter, salinity with Goldberg’s T/C refractometer pH with pH meter, phosphorus and NH3 - Nitrogen by methods described by Strickland and Parson, 1972. Reactive phosphorus of pond water improved due to the treatments, and supported fish food production leading to the high net fish yield obtained. Primary productivity, an index of living organisms in the pond, was high and suggests that the different treatments supported adequate fish food production. The highest net fish yield (651.03 kg/ha) was recorded in treatment IV (4 tons/ha cow manure only), while the lowest net yield (299.31 kg/ha) was recorded in treatment V (control). Treatments I (1 ton chicken manure and 3 tons cow manure/ ha) and II (1 ton chicken manure and 1 ton cow manure/ha) produced similar net fish yield, 431.97 kg/ha and 431.95 kg/ha, respectively. Treatment III, 2 tons/ha chicken manure only) gave a better net fish yield of 474.82 kg/ha, than treatments I and II. Cow manure can compare with chicken manure as organic fertilizer, in brackish water fish ponds for tilapia. A combination of 1 ton chicken manure and 1 ton cow manure per hectare could be as productive as 2 tons/ha chicken manure only, in tilapia production.
Effects of dietary pH on growth performance and feed utilization of Nile tilapia (Oreochromis niloticus)
Fabay, Ryan V. (University of the Philippines Visayas, 2020-06)
Two feeding trials were conducted to investigate the effects of dietary pH (pH 2.5, 3.7, 4.6, 5.7-control, pH 7.0, and pH 8.0) and dietary acid source (acetic acid, citric acid, hydrochloric acid and control-no acid) on growth rate and feed utilization efficiency of the Nile tilapia fry. In addition, attractability indices of the diets at different pH and dietary acid sources were determined. Results of the first feeding trial showed that the feed with pH adjusted to 4.6 resulted in increased growth rate and improved feed utilization efficiency in the Nile tilapia. In the second feeding trial, the use of either hydrochloric, citric or acetic acid in adjusting the pH to the optimal 4.6 did not affect the growth performance of the fish. This study demonstrated that pH and not actually the kind of acid diet promoted growth and efficiency in the Nile tilapia fry. Furthermore, this study provides new information on the use of acid in aquaculture as feed additive for tilapia fry, which can be added to fish feed literature.
Effects of different levels of Pinus tebulaeformis pollen on growth and stress resistance of milkfish fry (Chanos chanos)
Baldove, Analyn B. (University of the Philippines Visayas, 2010-06)
The present study investigated the effects of different inclusion levels of pine pollen from Pinus tabulaeformis Carr. on the growth performance and stress resistance of milkfish fry (Chanos chanos). Milkfish fry with average body weight of 0.02 g were stocked in 15 tanks (40 fish per tank). A control diet (without pine pollen) and four experimental diets were prepared containing different levels of pine pollen at 0 g kg^-1, 1.3 g kg^-1, 2.6 g kg^-1, 3.8 g kg^-1, and 5.1 g kg^-1 was fed to the experimental fish for 60 days. At the termination of the experiment, milkfish were subjected to acute ammonia and high salinity shock test. The result of feeding trial revealed that milkfish fed diets containing different levels of pine pollen stowed significantly higher growth (p < 0.05) in terms of weight gain, specific growth rate, feed conversion ratio, and protein efficiency ratio than the control diet. Survival of the milkfish during the trial were not significantly different among treatments (p > 0.05). Survival rates of milkfish groups exposed to high salinity stock test for 72 h were not significantly different from each other (p > 0.05). In contrast, results of the ammonia stress test revealed that the survival rates of milkfish fed with the diets containing (2.6 to 5.1 g kg^-1) were significantly higher (p <0 .05) than those fed with diets containing 1.3 g kg^-1 and the control diet Optimum dietary PP level was estimated using the quadratic model by using SGR and FCR values and found to be is 2.9 g kg^-1 and 3.0 g kg^-1, respectively. conclusion, pine pollen can be used as a supplement in milkfish diet to enhance growth and stress resistance against environmental stressors like ammonia.
The effects of different salinity and organic matter levels on the growth of blue-green algae
Bantillo, Rosario R. (College of Fisheries and Ocean Sciences, University of the Philippines Visayas, 1983-03)
A one-month culture of lab-lab to determine the growth of blue-green algae in three levels of salinity ( 15 ppt = S1, 30 ppt = S2 and 45 ppt S3) and two levels of organic matter (3.4 to 4.4% = OM1 and 6.5 to 7.8% = OM2) was conducted using a twenty-two plastic containers (diameter = 43 cm; height - 49 cm) at the University of the Philippines in the Visayas Brackishwater Aquaculture Center, Leganes, Iloilo. The study utilized a 3 x 2 factorial experiment in completely randomized design with three replicates. Organic matter levels of the soil affected the chemical properties of soil and water (available phosphorus, reactive phosphorus, ammonia-nitrogen and pH). The higher the organic matter level, the higher the pH and the concentrations of ammonia and phosphorus. On the other hand, salinity did not apparently affect the fluctuations in ammonia, phosphorus and pH due to water replenishment to maintain treatment levels of salinity. Earlier rapid growth of blue-green algae commencing on the 3rd to the 15th day was observed at higher organic matter level. While at lower organic matter level, this occurred only on the 18th to the 28th day. Blue-green algae population (units/ml) was observed highest in treatment IV (S1 OM2; 1,262,113) followed by treatments III (S3OM1 ;761,338); II (S2OM1; 514,788); I (S1OM1 ;494,375); V (S2OM2; 413,750); and, the lowest was obtained from treatment VI (S3OM2; 394,275). The relative percentage proportion of blue-green algae in the lab-lab complex showed that it composed 17.7% in treatment IV, 16.86 % in treatment III, 16.64% in treatment II, 15.82% in treatment I, 15.2% in treatment V and 14.9% in treatment VI. These, however, did not significantly vary among treatments. A low correlation coefficient (r) between the population count and the selected parameters: reactive phosphorus, water pH, soil pH and available phosphorus was obtained while a negative correlation was obtained between the population and ammonia-nitrogen. Significantly higher biomass (ash-free dry weight) of lab-lab was obtained in higher organic matter (OM2) and at 45 ppt salinity (S3). The highest biomass (ash-free dry weight) was obtained in treatment VI (S3OM2; 0.160 g/cm2) while the lowest was obtained in treatment I (S1OM1 0.012 g/cm2). The algal count of lab-lab also showed a significant difference in the organic matter levels but no significant difference on the salinity levels. The highest algal count was obtained in treatment V (S2OM2; 6,773,542 units/ml) and the lowest count was obtained in treatment II (S2OM1; 2,328,792 units/ml). However, the primary productivity based on O2 production showed a significantly higher production in the lower organic matter and at higher salinity level (30 ppt.). The highest O2 concentration was obtained in treatment III (S3OM1 ;5.759 ppm) and the lowest was obtained in treatment V (S2OM2; 4.19 ppm).
The effects of different salinity and organic matter levels on the growth of blue-green algae
Bantillo, Rosario R. (University of the Philippines Visayas, 1983-03)
A one-month culture of lab-lab to determine the growth of blue-green algae in three levels of salinity ( 15 ppt = S1, 30 ppt = S2 and 45 ppt S3) and two levels of organic matter (3.4 to 4.4% = OM1 and 6.5 to 7.8% = OM2) was conducted using a twenty-two plastic containers (diameter = 43 cm; height = 49 cm) at the University of the Philippines in the Visayas Brackishwater Aquaculture Center, Leganes, Iloilo. The study utilized a 3 x 2 factorial experiment in completely randomized design with three replicates. Organic matter levels of the soil affected the chemical properties of soil and water (available phosphorus, reactive phosphorus, ammonia-nitrogen and pH). The higher the organic matter level, the higher the pH and the concentrations of ammonia and phosphorus. On the other hand, salinity did not apparently affect the fluctuations in ammonia, phosphorus and pH due to water replenishment to maintain treatment levels of salinity. Earlier rapid growth of blue-green algae commencing on the 3rd to the 15th day was observed at higher organic matter level. While at lower organic matter level, this occurred only on the 18th to the 28th day. Blue-green algae population (units/ml) was observed highest in treatment IV (S1 OM2; 1,262,113) followed by treatments III (S3OM1 761,338); II (S2OM1; 514,788); I (S1 OM1 494,375); V (S2OM2; 413,750); and, the lowest was obtained from treatment VI (S3OM2; 394,275). The relative percentage proportion of blue-green algae in the lab-lab complex showed that it composed 17.7% in treatment IV, 16.86 % in treatment III, 16.64% in treatment II, 15.82% in treatment I, 15.2% in treatment V and 14.9% in treatment VI. These, however, did not significantlyvary among treatments. A low correlation coefficient (r) between the population count and the selected parameters: reactive phosphorus, water pH, soil pH and available phosphorus was obtained while a negative correlation was obtained between the population and ammonia-nitrogen. Significantly higher biomass (ash-free dry weight) of lab-lab was obtained in higher organic matter (OM2) and at 45 ppt salinity (S3). The highest biomass (ash-free dry weight) was obtained in treatment VI (S3OM2; 0.160 g/cm2) while the lowest was obtained in treatment I (S1OM1 0.012 g/cm2). The algal count of lab-lab also showed a significant difference in the organic matter levels but no significant difference on the salinity levels. The highest algal count was obtained in treatment V (S2OM2; 6,773,542 units/ml) and the lowest count was obtained in treatment II (S2 OM1; 2,328,792 units/ml). However, the primary productivity based on O2 production showed a significantly higher production in the lower organic matter and at higher salinity level (30 ppt.). The highest O2 concentration was obtained in treatment III (S3OM1 5.759 ppm) and the lowest was obtained in treatment V (S2 OM2; 4.19 ppm).
Effects of sodium iodide-enriched brine shrimp (Artemia salina) on the growth, survival and metamorphosis of rabbitfish (Siganus guttatus) bloch larvae
Cabanilla-Legaspi, Ma. Irene C. (University of the Philippines Visayas, 2018-06)
Metamorphosis is considered the most crucial stage in larval fish development that dictates the overall larval fish survival and production output in a hatchery system. This physiological process is modulated by thyroid hormones produced from the thyroid gland the biosynthesis of which is dependent on the supply and availability of the mineral iodine. The present study evaluated the supplementation of iodine to rabbitfish (Siganus guttatus) larvae to determine the influence of this mineral on thyroid hormone levels, metamorphosis, growth performance, stress tolerance and survival. To efficiently deliver iodine to the larvae, the enrichment protocol was optimized by exposing the Artemia to increasing concentrations of this mineral (0.05 g L-1,0.1 g L-1, 0.2 g L-l, 0.4 g L-1 and 0.8 g L-1). The best iodine enrichment treatment was selected (0.8 g NaI L-1) and used to evaluate the influence of this mineral on larval development, growth, metamorphosis, stress tolerance and survival. Results suggest that growth of rabbitfish in terms of body weight was higher in the treated group (0.20±0.01g) as compared to the control group (0.14±0.01g). This significant growth response is associated with accelerated period of metamorphosis by 11.2 days and a lower muscle fiber count in the treated group (0.003±0.005 μm2-1). Higher levels of triiodothyronine (T3) and thyroxine (T4) were also observed in the group receiving the iodine-enriched Artemia that coincides with the larvae’s accelerated period to metamorphose. T3 in the treated group (15.31±1.22 ng g-1) is higher compared with the control (8.67±1.5 ng g-1) and T4 in the treated group (459.25±136.9 ng g-1) is also higher compared with the control group (170.86±92.55ng g-1) at 27 days after hatching which coincides with the onset of metamorphosis leading to early metamorphosis of larvae in the treated group. In addition, the present results showed that the larvae in treated group were significantly tolerant to stress, quantified as the cumulative stress index (15.33±2.40 CSI) indicating the positive response of the larvae to the dietary iodine enrichment. In summary, sodium iodide-enriched live food (Artemia) accelerated rabbitfish larvae metamorphosis, improved growth and stress tolerance in rabbitfish larvae. The results of this study can be used as a model iodine enrichment protocol to improve the hatchery output of other high-valued marine fish species in culture.
Effects of sodium Iodine -enriched brine shrimp (Artemia salina) on the growth, survival and metamorphosis of Rabbitfish (Siganus guttatus) bloch larvae
Legaspi, Ma. Irene C. (Institute of Aquaculture, College of Fisheries and Ocean Sciences, University of the Philippines Visayas, 2018-06)
Metamorphosis is considered the most crucial stage in larval fish development that dictates the overall larval fish survival and production output in a hatchery system. This physiological process is modulated by thyroid hormones produced from the thyroid gland the biosynthesis of which is dependent on the supply and availability of the mineral iodine. The present study evaluated the supplementation of iodine to rabbitfish (Siganus guttatus) larvae to determine the influence of this mineral on thyroid hormone levels, metamorphosis, growth performance, stress tolerance, and survival. To efficiently deliver iodine to the larvae, the enrichment protocol was optimized by exposing the Artemia to increasing concentrations of this mineral (0.05 g L-1,0.1 g L-1, 0.2 g L-l, 0.4 g L-1 and 0.8 g L-1). The best iodine enrichment treatment was selected (0.8 g NaI L-1) and used to evaluate the influence of this mineral on larval development, growth, metamorphosis, stress tolerance, and survival. Results suggest that growth of rabbitfish in terms of body weight was higher in the treated group (0.20±0.01g) as compared to the control group (0.14±0.01g). This significant growth response is associated with accelerated period of metamorphosis by 11.2 days and a lower muscle fiber count in the treated group (0.003±0.005 μm2-1). Higher levels of triiodothyronine (T3) and thyroxine (T4) were also observed in the group receiving the iodine-enriched Artemia that coincides with the larvae’s accelerated period to metamorphose. T3 in the treated group (15.31±1.22 ng g-1) is higher compared with the control (8.67±1.5 ng g-1) and T4 in the treated group (459.25±136.9 ng g-1) is also higher compared with the control group (170.86±92.55ng g-1) at 27 days after hatching which coincides with the onset of metamorphosis leading to early metamorphosis of larvae in the treated group. In addition, the present results showed that the larvae in treated group were significantly tolerant to stress, quantified as the cumulative stress index (15.33±2.40 CSI) indicating the positive response of the larvae to the dietary iodine enrichment. In summary, sodium iodide-enriched live food (Artemia) accelerated rabbitfish larvae metamorphosis, improved growth and stress tolerance in rabbitfish larvae. The results of this study can be used as a model iodine enrichment protocol to improve the hatchery output of other high-valued marine fish species in culture.