UPV Theses and Dissertations
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Item Does a coral reef enhance the productivity of its surrounding waters?Peñafiel, Christen P. (University of the Philippines Visayas, 2019-06)ABSTRACT 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.Item Survival of nursery-reared juvenile milkfish, Chanos-chanos at different transport density, temperature and anaesthetic combinationsFailaman, Alan N. (University of the Philippines Visayas, 2020-06)ABSTRACT Experiments were conducted to optimize transport conditions of nursery cultured juvenile milkfish in a closed plastic bag based transport system. In the first experiment combined effects of temperature (25-27°C, 20-22°C and 15-17°C) and anesthetics (2-phenoxyethanol at 200 mgL-1 for initial sedation and 80 mgL-1 for transport sedation) on oxygen consumption and survival ofjuvenile milkfish, Chanos chanos, were evaluated. Another experiment was conducted to optimize transport conditions at fish densities of 200, 400, 600, 800 and 1000 gL-1 for 4, 8, 12,16 and 20 hour duration. The study showed no significant difference on oxygen consumption rates ofmilkfishjuveniles subjected to various water temperature range and anesthetic combinations. Temperature range of 20 to 22°C in combination with anaesthetic (2-phenoxyethanol) application was the best condition for long duration confinement of milkfish juvenile in closed plastic transport bags. The study established the optimum juvenile milkfish transport density and the effective transport duration. With anaesthetic application (2-phenoxyethanol), juvenile milkfish density of 600 gL-1 is effective for 20 hours oftransport duration, 800 gL-1 for 8 hours oftransport duration and 1000 gL-1 effective for 4 hours transport duration. These results provide a practical protocol for the transport of juvenile milkfish from the nursery culture area to the grow-out production area.Item Antioxidative activities and lactic acid bacteria composition of fermented frigate tuna at different salt-fish ratioOrtizo, Rhessa Grace G. (University of the Philippines Visayas, 2019-06)ABSTRACT 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.Item 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)ABSTRACT 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.Item Catch composition, morphology, and some aspects of reproductive biology of Inimicus sinensis caught by baby otter trawl in Carles, Iloilo, PhilippinesDelloro, Emmanuel S. Jr. (University of the Philippines Visayas, 2019-06)ABSTRACT 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.Item Effects of sodium iodide-enriched brine shrimp (Artemia salina) on the growth, survival and metamorphosis of rabbitfish (Siganus guttatus) bloch larvaeCabanilla-Legaspi, Ma. Irene Cabigona (University of the Philippines Visayas, 2018-06)ABSTRACT 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.Item Nutritional value of fish silage, with Gracilaria Sp. and Abalone Viscera as poultry feedPatadjai, Andi Besse (University of the Philippines Visayas, 2004-11)ABSTRACT Study on fish silage prepared with Gracilaria sp., with and without abalone viscera was conducted to evaluate the rate of hydrolysis during the ensiling process. The fish-Gracillaria sp.-abalone viscera silage was further subjected to nutritional value test as poultry feed. Three silage were prepared using 5% propionic acid and formic acid (ratio 1:1) to contain: a) 100% fish by catch (Silage F), b) 70% fish by catch and 30% Gracilaria sp. (Silage FG) and c) 70% fish by catch, 25% Gracilaria sp. and 5% abalone viscera (Silage FGA). These silage were stored for 15 days and stirred daily. Chemical components such as pH, amino nitrogen, polypeptide, and monosaccharide content were determined at regular intervals within the 15-day ensiling period. Isonitrogenous feeds were then formulated to contain fish-Gracillaria sp.- abalone viscera silage Feed (II) and fish silage (Feed III). Nutritional value of these diet (i.e. Feed II and Feed III) were compared with that of commercial feed (Feed I) which was used as the control, based on the growth response of chickens. Results showed that rate of decrease in pH value was sufficiently rapid to stabilize the three silage. Silage F showed significantly higher pH value throughout the ensiling period, compared with Silage FG and Silage FGA. No significant difference (P<0.05) was, however, found between Silage FG and Silage FGA. Results can be attributed to incorporation of Gracilaria sp. in silage production, which provided favorable condition to decrease the pH value. Amino nitrogen content of all silage increased with ensiling time. Silage F exhibited the highest amino nitrogen content during 15 days of ensiling, followed by that of Silage FGA. Although the amino nitrogen content of Silage FGA was higher than that of Silage FG, significant differences (P<0.05) were noted only after 12 days of ensiling. Polypeptide content of all silage decreased after 3 days of ensiling. Silage FGA exhibited the highest polypeptide content after 9 days of ensiling. Monosaccharide content of all silage fluctuated during the ensiling period. However, the highest value was noted with Silage FGA, followed by Silage FG on the 3rd day of ensiling. This could be attributed to the highest polysaccharide hydrolysis rate exhibited by Silage FGA throughout the ensiling period. The best feed conversion ratio (FCR) and protein efficiency ratio (PER) were obtained with chickens given feed containing fish-Gracilaria sp. -abalone viscera silage (Feed II) during the 3-week feeding time. Body weights of chickens given Feed II were significantly higher than those given Feed III until the 3rd week of feeding. Reduction of fish content by as much as 30% and its substitution with 25% of Gracilaria and 5% of abalone viscera in silage (Feed II) gave the same effect on growth rate of chickens as that of silage made up of 100% fish (Feed III), and commercial feed (Feed I) without any mineral deficiency symptoms (e.g. slipped tendon or leg weakness and abnormal feather growth). Fish-Gracilaria .sp.-abalone viscera silage could be used as an ingredient for the production of an acceptable/palatable and nutritious feed for poultry.Item Quality changes in Tilapia (Oreochromis niloticus) after delayed icing and subsequent storage in iceSaluan-Abduhasan, Fathma (College of Fisheries, University of the Philippines in the Visayas, 1985-04)ABSTRACT Quality changes in tilapia (Oreochromis niloticus) iced directly on harvesting were compared to those occurring when icing was delayed. Chemical and sensory examinations showed that the shelf life of tilapia was 26 days when iced immediately. 20 days and 16 days with 4 and 8 hours delay, respectively. Fish kept at ambient temperature for 12 hours were rejected after one day in ice. These results suggest that for every hour delay in icing the effective shelf life is reduced by approximately one day up to the 8th hour delay. Total volatile nitrogen values increased with storage time. Likewise, K-value and hypoxanthine values increased as storage time increased. The initial bacterial load ranged from 103- 104 cfu/g of fish with H2S-producers count of less than 100 cfu/g of fish. At rejection, the microbial load was 108~109 cfu/g of fish with HgS- producers count of 106-107 cfu/g. The typical off odours of naturally spoiling fish have been reproduced in blocks of sterile muscle by organisms such as Alteromonas putrefaciens, Pseudomonas sp, pseudomonas maltophilia, Pseudomonas flourescens and pseudomonas stutzeri.Item Some aspects of ecology, biology, and fishery of the horse mussel Modiolus metcalfei (Hanley, 1843) in Dumangas, IloiloUba, Kaent Immanuel N. (University of the Philippines Visayas, 2019-06)ABSTRACT The exploitation of Modiolus metcalfei in Dumangas, Iloilo has been going on since the 1970s. It has undergone the cycle of resource depletion to recovery but its management remains hindered by the poor understanding of its ecology, biology, and fishery. The present study characterized the habitat, investigated the aspects of morphology, allometry, asymmetry, feeding biology, and analyzed the value chain of M. metcalfei fishery in the area. Monitoring of physicochemical parameters, sediment grain size and organic matter content, estimation of population density were conducted for six months. Morphology, allometry, and asymmetry were investigated using combined linear and geometric morphometric methods while pre-ingested food and plankton composition in the water were determined qualitatively. Moreover, interviews and observations were conducted to analyze the value chain of the horse mussel fishery. Although the physicochemical parameters were at optimal levels, results in the analysis of asymmetry indicated developmental instability and ecological stress. The primary factors influencing the variation in morphology were sex and environmental fluctuations. The horse mussel mainly relied on phytoplankton, primarily diatoms, for food. The lack of support from enablers, lack of adequate enforcement, and lack of post-harvest infrastructure hindered the full development of the fishery. Moreover, poverty dimensions were revealed in the analysis of the value chain. To craft better management policies, studies on the population dynamics and reproductive biology are recommended.Item Influence of cooling of crab (Scylla spp.) juveniles on the physiological changes and survival during storageGeromiano, Merlyn F. (University of the Philippines Visayas, 2017-06)ABSTRACT Considering that aquaculture of mud crabs is still dependent on wild seeds, mortalities associated with capture, handling and storage aggravates the problem of lack of seeds which is one of the major constraints affecting the development of the mud crab aquaculture industry. Having cold rooms for maintaining optimum environment for storage has been recommended, however these facilities are not available in all levels of the industry and can only be found in some of the major traders. To address this issue, this study tested a handling and storage scheme that can be used at various points along the harvest to market chain. In lieu of cooling crabs in a chamber, crabs were directly immersed in seawater of different temperatures (4°C, 7°C, 15°C and 29°C) and stored for 48h, 72h and 96h. Crabs that were cooled at 15°C for 3 min showed highest survival (88-90%) after 48h, 72h and 96h of storage. In addition, the least accumulation of glucose and lactic acid in the haemolymph was detected in crabs cooled at 15°C regardless of the storage period, which suggests that crabs were fess stressed when cooled at this temperature.