GOVPH

Sex: Male
Education:

• Post-doctoral Research Fellow, University of Idaho, USA, 2017
• Doctor of Philosophy in Fisheries (Aquaculture), University of the Philippines Visayas, 2012
• Master of Science in Fisheries (Aquaculture) Pangasinan State University, 2007
• Bachelor of Science in Fisheries (Aquaculture) Central Luzon State University, 2004

Field of Specialization:
Fisheries (Aquaculture)
Environmental Sciences

Researches:

Article title: Dietary incorporation of Sweet Potato Ipomoea batatas shots improved growth performance and haematological profile of Tilapia Oreochromis niloticus in Hapa Nets.
Authors: Francies Nuestro Baleta, Patricia Magistrado-Candelaria, Diomerl Edward Bondad Baldo, Love Joy Pallaya-Baleta, Lander Cezat Plantado, Mylene Concina Navarro
Publication title: Aquatic Research 5(1): 1-10, 2022

Abstract:
This study was conducted to evaluate the potential of sweet potato Ipomoea batatas powder (IbSPP), hot-water extracts (IbSPHWE) and crude ethanolic extracts (IbSPCEE) as growth promoter and immunoenhancer for tilapia cultured in hapa nets. Fish were divided randomly into four Treatments: T1 (control group) was fed a practical diet (PD) while T2, T3 and T4 were fed PD + IbSP powder (P), PD + IbSP hot-water extract (HWE), PD + IbSP Crude Ethanol Extracts (CCE), respectively. The growth indices and haematological profile of cultured fish were recorded after four months of feeding experiment. The final weight, weight gain, specific growth rate, condition factor, FCR, PER, FER were significantly higher in fishes that received PD +IbSPHWE than those that received either PD, PD + IbSPCEE or PD+ IbSPP only. The same trend was observed with the RBC, Hb, HCT, WBC and the PLT and its indices. The study has demonstrated that incorporation of the hot-water extracts of I. batatas could improve the growth performance and increase immunocompetence of O. niloticus as evidenced by improved haematological profile.
Full text link https://doi.org/10.3153/AR22001

Article title: Growth performance and economic viability of dietary inclusion of Ipomoea batatas L. shoot powder and extracts in the practical diets of Oreochromis niloticus L.. In: Egyptian
Authors: Love Joy Pallaya-Baleta, FrancisNuestro Baleta, Patricia Magistrado-Candelaria, Lander Cezar Plantado, Diomerl Edward Bondad Baldo, Mylene Concina Navarro, Jericho Lara Encinas
Publication title: The Egyptian Journal of Aquatic Research, 2021

Abstract:
The study aims to determine the growth performance and economic viability of the dietary supplementation of camote i.e., Ipomoea batatas L. powder and extracts in the diets of the Nile tilapia. The fish were reared in twelve 1 m3 hapa nets installed in a 500 m2 pond. Four groups of fish were used in the experiment; the control group was fed with formulated practical diets (PD), and diets supplemented with either camote shoot powder (PD + CSP), hot-water extract (PD + CSHWE), and crude ethanol extract (PD + CSCEE). The feeding trial lasted 12 weeks. The weight gain (WG), feed conversion ratio (FCR), feed efficiency ratio (FER), protein efficiency ratio (PER), specific growth rate (SGR), and condition factor (CF) were studied. The economic viability was determined through the cost of production, gross profit, cost-and-return, and profitability analyses. The fish fed with PD + CSHWE exhibited improved growth performance as evidenced by an increase in WG, FER, PER, SGR, and CF, while showing low values of FCR. The economic analyses also revealed that PD + CSHWE was the most economically feasible diet based on the cost of production, gross profit, cost-and-return, and profitability analyses. The study had proven that the incorporation of CSHWE in practical diets could improve the growth performance and increase profitability if used for tilapia culture.
Full text link https://doi.org/10.1016/j.ejar.2021.11.005

Article title: Growth and Immune Response of Pangasius hypophthalmus Fed Diets Containing Seaweed Extracts as Immunostimulants.
Authors: Francis Nuestro Baleta and Jonathan Mallillin Bolaños
Publication title: Brazilian Archives of Biology and Technology 62:1-11, 2019

Abstract:
Growth and immune response of Pangasius hypophthalmus were evaluated after feeding the fish with diets containing hot-water extracts (HWE) of Sargassum oligocystum as immunostimulant at 100, 300, and 500 mg kg-1 diet. Basal diet for P. hypophthalmus served as the control. The experimental diets were administered for 12 weeks. At the end of the feeding experiment, growth and haematological profile of fish were evaluated. Result showed that final weight, weight gain, daily growth rate and feed conversion ratio were significantly increased in the fish that received 300 and 500 mg kg-1 HWE of S. oligocystum. Evaluation of the haematological profile showed that white blood cells red blood cells, hemoglobin, hematocrit and platelet of P. hypophthalmus that received the HWE of S. oligocystum were significantly higher than the control group. Overall, our results indicate that the use of S. oligocystum HWE improves growth and haematological profile in P. hypophthalmus.
Full text link https://doi.org/10.1590/1678-4324-2019180083

Article title: Assessment of Tilapia Cage Framing Practices in Relation to the Occurrence of Fish Mortality Along the Fish Cage Belt in Magat Reservoir, Philippines.
Authors: Francis Nuestro Baleta, Jonathan Mallillin Bolaños, and William Catli Medrano
Publication title: Journal of Fisheries and Environment 43(2): 1-13, 2019

Abstract:
The present study was conducted in Magat Reservoir, Philippines, to determine the profile and practices of tilapia cage farmers in relation to the occurrence of fish mortality. Eight stations were established: Station 1 (Baligatan), Station 2 (Namnama), Station 3 (Halag 1), Station 4 (Halag 2), Station 5 (Halag 3), Station 6 (Taliktik), Station 7 (Dallaw) and Station 8 (Isla Berde). A total of 80 households were interviewed from December 2016 to May 2017. Results showed that most incidents of fish mortality in cages occurred during the summer season (March to June). Farmers perceived the primary causes of fish mortality in Magat Reservoir to include fluctuating temperature (91.25%), water quality (83.75%), pollution and predation by birds (each 76.25%), parasite infestation (56.25%) and diseases (50%). Reduced feeding, isolation of the infected fish and proper stocking are the major activities conducted by the fish farmers to prevent the occurrence of fish mortality at Magat Reservoir.
Full text link https://tinyurl.com/5n8jha85

Article title: Phytochemical screening and antimicrobial properties of Sargassum oligocystum and Sargassum crassifolium Extracts.
Authors: Francis N. Baleta, Jonathan M. Bolaños, Oliva C. Ruma, Amaro N. Baleta, and Jayson D. Cairel
Publication title: Journal of Medicinal Plants Studies 5(1): 382-387, 2017

Abstract:
The present study was conducted to investigate the phytochemical contents and evaluate the antimicrobial property of Sargassum oligocystum and Sargassum crassifolium extracts collected from the coast at Diora-Zinungan, Santa Ana, Cagayan, Philippines. Extracts of powdered seaweed were prepared using sequential extraction with different organic solvents in order to increasing the polarity (Ethanol, n-hexane, dichloromethane and ethyl acetate and aqueous). Five fractions (Ethanol, n-hexane, dichloromethane ethyl acetate and aqueous) were examined for antimicrobial activity by using disc diffusion assay on thirteen (13) strains of aquaculture pathogen. The extracts showed the presence of phytochemical constituents like flavonoids, tannins, phenolics, sterols and terpenoids and the absence of saponins. Among the tested extracts for antimicrobial activity, ethanolic extracts was determined to be the best solvent for isolation of antimicrobial compounds from the tested seaweeds followed by n-hexane, dichloromethane ethyl acetate and aqueous. The extract of the S. oligocystum and S. crassifolium showed presence of different groups of secondary metabolites such as flavonoids, tannins, phenolics, sterols and terpenoids which are important indicators of the microbial properties of seaweeds.
Full text is available upon request to the author

Article title: Design, fabrication and operation of fishing gears used along the coastal areas of Isabela, Philippines.
Authors: Francis Nuestro Baleta, Jaymark Guilalao Beltijar and Jonathan Mallillin Bolaños
Publication title: International Journal of Fisheries and Aquatic Studies 5(2):319-323, 2017

Abstract:
The study was conducted to document the design, fabrication and operation of fishing gears used along the coastal areas of Dinapigue, Palanan, Divilacan and Maconacon, Isabela, Philippines. There were thirty-three (33) different fishing gears identified and documented along the four studied stations. The fishing gears documented include; eighteen (18) lines, eight (8) nets, five (5) hand instruments, two (2) barriers and traps, one (1) aggregating device and one (1) accessory fishing device. Hook and line, multiple hooks and line and troll line are the most commonly used fishing gears by the fisher folks along the four study area. The most expensive fishing lines were kitang (set bottom long line) and the cheapest fishing gears were the bakulkol (hook and line) in terms of fabrication. Fisherfolks from the coastal towns of Dinapigue and Palanan uses payaw (fish aggregating device) to increase catch of tuna using multiple hooks and line
Full text link https://tinyurl.com/mr26vpaj

Article title: Croton oil Croton tiglium fruit water extracts as piscicides under simulated farm condition
Authors: Melrose Miguel Guerrero, Francis Nuestro Baleta and Jonathan Mallillin Bolaños
Publication title: International Journal of Fauna and Biological Studies 4(1): 81-85, 2017

Abstract:
The study evaluated the potential of C. tiglium fruit water extracts (0.5, 1, 2, 4, 8 and 15 ml 1-1) as piscicides for G. affinis, O. niloticus and C. gariepinus under simulated farm condition. Based on the 24, 48 and 72 h of exposure to all concentrations, the G. affinis, O. niloticus and C. gariepinus showed no significant differences on mortality except C. gariepinus at 0.5 ml 1-1. However, based on the 96 h of exposure to all concentrations 100 per cent mortality of G. affinis, O. niloticus and C. gariepinus was observed and showed no significant differences. The G. affinis and O. niloticus were the most susceptible fishes among the test organisms. The toxicity tests showed that C. tiglium has the potential to be used as piscicides, which can be an alternate to an expensive and scarcely available imported rotenone for eradication of undesirable fish species present in fish ponds. Signs of agitated behaviors, respiratory distress and abnormal nervous behaviors including eventual deaths were observed in exposed fish. Control fish neither died nor exhibited any unusual clinical signs.
Full text link https://tinyurl.com/2d2b96xz

Article title: Influence of seasonal variation on the utilization and catch composition of fishing gears in Palanan, Isabela seashore, Philippines.
Authors: Hezron Gonzales Padios, Francis Nuestro Baleta and Jonathan Mallillin
Bolaños
Publication title: International Journal of Fisheries and Aquatic Studies 5(1): 314-318, 2017

Abstract:
The study determined and documented the influence of seasonal variation on the utilization and catch composition of fishing gears along the coastal area of Palanan, Isabela. Ocular inspection of fishing gears and personal interviews were conducted at the stations namely: Dicotcotan San Isidro, Sabang Maligaya, Culasi, and Dimolid. Results showed a diversity of fishing gears and fish species documented along the study area at two seasons. The most commonly used fishing gears during the onset of summer and rainy seasons are: troll line, bottom set gill net, troll with bait fish (lonoy), bottom hook and line (pasayad), multiple hook and line (ug-og), multiple hook troll line (saliw-siw tuna), and spear. On the other hand, the most documented fish species caught by fishing gears are skipjack tuna, frigate tuna, scads, indo pacific sail fish, sardines and flying fish in summer and surgeon fish, siganids, and snapper for the rainy season.
Full text is available upon request to the author

Article title: Acceptability of selected herbs as off- odor remover and flavor enhancer for dried parrot fish Scarus rivulatus.
Authors: Reymar Oliva Gonzales, Francis Nuestro Baleta, Jonathan Mallillin Bolaños
Publication title: International Journal of Food Science and Nutrition 2(2): 31-37, 2017

Abstract:
Acceptability of calamansi leaves, guava leaves and lemon grass aqueous extracts as off-odor and off-flavor remover and flavor enhancer to dried Parrot fish Scarus rivulatus were evaluated in terms of color, aroma, taste and texture and general acceptability. Students (high school and college) professionals (professors and researcher) pupils and cook served as panelists for the sensory and organoleptic evaluation. Dried parrot fish treated with guava leaf extract is the most preferred and highly acceptable by the panelists. Analysis of the sensory and organoleptic evaluation also show that dried parrot fish treated with either guava leaf, lemon grass and calamansi leaf extract is highly acceptable based on the different criteria of evaluation. Similarly, the guava leaf extract also masked the off-odor of dried Parrot fish. Proximate composition analysis of dried parrot fish treated with herbs revealed 80.2% crude protein, 0.065% crude fiber, 037% crude fat, 19.83% moisture and 10.15% ash.
Full text link https://tinyurl.com/pd5cac9u

Article title: Sensory, organoleptic, and proximate composition of smoked surgeon fish Acanthurus sp. using selected herbs as flavor enhancer.
Authors: Ariel Miguel Opeña, Francis Nuestro Baleta, Jonathan Mallillin Bolaños
Publication title: International Journal of Food Science and Nutrition 2(1): 174-181, 2017

Abstract:
The study evaluated the sensory, organoleptic and proximate composition of smoked Surgeon fish Acanthurus sp. using the extracts of either calamansi leaves, lemon grass or guava leaves. Effectiveness of these herbs as off-odor and off-flavor remover and flavor enhancer were evaluated in terms of color, aroma, taste, texture and general acceptability. Panelists include ten (10) members each from the group of cook, pupils, students (high school and college) and professionals (professors and researcher). Results of the study revealed that smoked Surgeon fish treated with guava leaf extract is the most preferred and highly acceptable by the panelists. Analysis of the sensory and organoleptic evaluation also shows that smoked Surgeon fish treated with either guava leaf, lemongrass, calamansi leaf extracts is highly acceptable based on the different criteria of evaluation. Similarly, the guava leaf extract also masked the off-odor of smoked Surgeon fish. The smoked surgeon fish treated with guava leaf extract were also subject to carcass analysis. Proximate composition revealed that smoked Surgeon contains 54.77% crude protein, 0.58% crude fiber, 11.38% crude fat, 29.55% moisture and 13.07% ash
Full text link https://tinyurl.com/h7r5e2dt

Article title: Antimicrobial Properties of Sargassum spp. (Phaeophyceae) against Selected Aquaculture pathogens.
Authors: Jonathan Mallillin Bolaños, Francis Nuestro Baleta and Jayson Domingo Cairel
Publication title: International Journal of Current Microbiology and Applied Sciences 6(2): 1024-1037, 2017

Abstract:
The purpose of this study was to investigate the antibacterial and anti-fungal activities of four species Sargassum namely: Sargassum polycystum, Sargassum oligocystum, Sargassum crassifolium and Sargassum cristaefolium collected along the coastal areas of Diora-Zinungan Sta. Ana Cagayan, Philippines. Extracts of powdered seaweeds were prepared using sequential extraction with different organic solvents in order to increasing the polarity (Ethanol, n-hexane, dichloromethane and ethyl acetate and aqueous). Five fractions (Ethanol, n hexane, dichloromethane ethyl acetate and aqueous) were examined for antimicrobial activity by using disc diffusion assay on thirteen (13) strains of aquaculture pathogens. The n-hexane, dichloromethane, ethyl acetate extracts displayed different antimicrobial activity against different aquaculture pathogenic bacteria and fungi
whereas ethanolic extracts showed higher antimicrobial activity than aqueous extracts. The extracts of Sargassum sp. showed a significant antimicrobial activity against Grampositive and Gram-negative as well as the fungus. Among the tested brown seaweeds, Sargassum polycystum exhibited the better antimicrobial activity that has potentially used as antimicrobial agent and as natural immunostimulant with aquaculture industry for the treatment of microbial diseases and improvement of the health status of commercially important aquaculture species.
Full text link https://tinyurl.com/5n7rw4bk

Article title: Species Composition of Marine Food Fishes at Palanan, Isabela as Influenced by Seasonal Variation.
Authors: Amaro Nuestro Baleta Jr and Francis Nuestro Baleta
Publication title: International Journal of Fisheries and Aquatic Studies 4(3): 254-260, 2016

Abstract:
The present study was conducted to document the species composition of marine food fishes caught along the coastal waters of Palanan, Isabela at the onset of summer and rainy seasons. Ocular visits and personal interviews were conducted along the four landing sites at Palanan, Isabela namely; Dicotcotan, Sabang, Culasi and Dimolid. A total of seventy four (74) fish species belonging to 37 families and 9 orders were documented during the study periods. The families with the highest number of species identified were Acanthuridae and Carangidae with both eight species documented. Acanthurus lineatus (Blue-lined Surgeonfish) and Atule mate (Yellow-tailed Scad) were the most predominant species along the family Acanthuridae and Carangidae, respectively for both summer and rainy seasons. However, pelagic fish that belongs to the family Carangidae, Scombridae, Coryphaenidae, Synodontidae, Sphyraenidae, and Istiophoridae were very rare during rainy season. There were 19 species distributed to 8 families which are considered as by-catch and low-valued fish along the 4 landing sites of Palanan, Isabela.
Full text link https://tinyurl.com/2jhvxtkj

Article title: Phytoplankton Identification and Water Quality Monitoring Along the Fish Cage Belt at Magat Reservoir, Philippines.
Authors: Francis Nuestro Baleta and Jonathan Mallillin Bolaños
Publication title: International Journal of Fisheries and Aquatic Studies 4(3): 254-260, 2016

Abstract:
The present study was conducted to identify phytoplankton and characterize the physico-chemical parameters of waters from the fish cage belt at Magat Dam Reservoir, Philippines. Five stations were established along the fish cage belt at Magat Reservoir, namely: Station 1 (Magat Aqua Park), Station 2 (Namnama), Station 3 (Halag 1), Station 4 (Halag 3) and Station 5 (Baligatan). Water samples were collected twice weekly for three months. Water parameters that were monitored includes: temperature, transparency, dissolved oxygen, pH, ammonia and phosphate. Among the water parameters monitored, temperature, transparency, dissolved oxygen, pH, ammonia and phosphate were within the acceptable range for fish culture. Thirty (30) species of phytoplankton were identified belonging to four classes. Division Chlorophyta (14 genera), was the most abundant followed by Bacillariophyta (10 genera), Cyanophyta (4 genera), and Euglenophyta (2 genera). The most dominant microalgae documented includes: Pediastrum, Scenedesmus, Closterium, Merismepodia and Nitzschia.
Full text link https://tinyurl.com/3z36ea2m

Article title: Species Composition, Diversity and Abundance of Mangroves along the Estuarine area of Maligaya, Palanan, Isabela, Philippines.
Authors: Francis Nuestro Baleta and Ronald Santiago Casalamitao, Jr.
Publication title: International Journal of Fisheries and Aquatic Studies 4(2): 303-307, 2016

Abstract:
Present study was conducted to document the species composition, abundance and diversity of
mangroves found along the river side of Maligaya, Palanan, Isabela. Seven stations were established along the study area using the line transect method. Species composition data revealed 14 species of mangroves identified from 6 families namely: Rhizophoraceae, Acanthaceae, Avicenniaceae, Sterculiaceae, Palmae and Melianceaeare were present during the study period. The most abundant species across the seven stations are Nypa fruticans, Bruguiera sexangula, Avicennia lanata and Xylocarpus granatum. Highest diversity was recorded at 0.099 individuals per 500 m2 for Nypa fruticans. Station 5 revealed the highest species richness and repetition index while Station 7 recorded the highest diversity as indicated by various indices of diversity. Results revealed that the mangrove forest of Maligaya, Palanan, Isabela has a diverse species of mangroves.
Full text link https://tinyurl.com/mu6z28n8

Article title: Some Notable Microalgae of the Principal Tributaries of Rio Grande de Cagayan, Philippines.
Authors: Francis Nuestro Baleta, Jonathan G Donato, Jonathan M Bolaños
Publication title: International Journal of Fauna and Biological Studies 3(3): 13-16, 2016

Abstract:
The study was conducted to identify and document the microalgae present in the principal tributaries of Rio Grande de Cagayan, and the Blue Lagoons of Palanan, Isabela. Water samples were collected by bucket from the identified sampling sites along the Siffu, Mallig, Ilagan and Magat rivers from July 2013 to January 2014. Thirty four (34) species of microalgae were identified belonging to four classes. Division Chlorophyta (17 genera), was the most abundant followed by Baccillariophyta (10 genera), Cyanophyta (4 genera), Euglenophyta (3 genera), and the most predominant genera of microalgae found along the major tributaries at Rio Grande de Cagayan and Palanan, Isabela, Philippines were the Chorella, Kirchneriella, Scendesmus Pediastrum and Oedogonium (a chlorophyta), Aulacosiera, Cymbella, Navicula, Nitzschia and Pinnularia (a bacillariophyta) Cylindrospermum and Oscillatoria (a cyanophyta) and Euglena (a euglenophyta).
Full text link https://tinyurl.com/4b5f5694

Article title: Species Composition, abundance, and diversity of seaweeds along the intertidal zone of Nangaramoan, San Vicente, Sta. Ana, Cagayan, Philippines.
Authors: Francis N. Baleta and Jayson P. Nalleb
Publication title: AACL Bioflux 9(2): 250-259, 2016

Abstract:
This study was conducted to determine the species composition, abundance and diversity of seaweeds found along the intertidal zone of Nangaramoan, San Vicente, Sta. Ana, Cagayan. The line transect method was used to identify and quantify the seaweeds abounding the three established stations divided into five quadrates. Representative specimens were also taken and seaweed-associated flora and fauna were documented. A total of 31 different species of seaweeds were identified in the study area belonging Rhodophyta (Galaxauraceae, Gelidiellaceae, Corallinaceae, Gracilariaceae, Solieriaceae, Lomentariceae, Rhodomelaceae, Rhodymeniaceae), Phaeophyta (Dictyotaceae, Cystoseiraceae, Scytosiphonaceae, Sargassaceae) and Chlorophyta (Ulvaceae, Anadyomenaceae, Siphonocladaceae, Caulerpaceae, Halimedaceae, Dasycladaceae). The most abundant seaweed species across the three stations are: Turbinaria ornata, Mastophora rosea, Coelothix irregularis, Padina australis, Padina sanctae-crucis, Padina minor, Ulva clathrata, Ulva fasciata, Chaetomorpha crassa, Caulerpa racemosa and Halimeda opuntia. The seaweed species identified also have different densities ranging from 0.002 to 7.955 per m2. P. sanctae-crusis had the highest density. With regards to frequency and relative frequency, C. irregularis, P. australis, P. sanctae-crucis, P. minor, T. ornata, U. fasciata, and C. crassa, appear in all 15 quadrates in Station 1, 2 and 3. Species richness, repetition index, Simpson's indices of diversity and its reciprocal were calculated to determine diversity of seaweeds along the study area. Station 3 obtained the highest species richness and repetition index. On the other hand, Station 2 recorded the highest diversity as indicated by the Simpson's index. When subjected to Simpson's index of diversity and Simpson's reciprocal index analyses, Station 2 also obtained the highest diversity. The intertidal zone of Nangaramoan San Vicente, Sta. Ana Cagayan has a diverse species of seaweeds as indicated by the results of abundance, distribution and diversity indices.
Full text link https://tinyurl.com/4dvthewk

Article title: Sargassum oligocystum as Immunostimulants: Effects on the Immune response and Disease Resistance of Nile Tilapia Oreochomis niloticus L
Authors: F. N. Baleta and M. J. Libatique
Publication title: Northern Philippines Journal 1(1): 25-34, 2015

Abstract:
No available
Full text available upon request to the author

Article title: Molluscicidal and Piscicidal activities of extracts of Castor Ricinus communis Bean for Aquaculture Management.
Authors: Francis Nuestro Baleta, Marites M. Ramos-Castro, May Anne S. Canceran
Publication title: The Israeli Journal of Aquaculture - Bamidgeh 67: 1177-1182, 2015

Abstract:
The study assessed the molluscicidal and piscicidal activities of castor plant Ricinus communis using its fruit (dried and fresh) against large and small golden apple Snails (GAS) and mosquito fish. We focused on the laboratory determination of lethal concentrations LC 50 and LC 100 through a static bioassay test. Separate experiments were performed for GAS and mosquito fish and ten experimental animals where stocked in each experimental unit. Based on a 24-hour lethal concentration (LC 100), the toxicity for large GAS was 96.21 ml/L for fresh fruits, 124.02 ml/L for dried beans. For small GAS, the toxic concentrations were 91.75 ml/L for dried beans, and 105.89 ml/L for fresh fruits. For the 24-h LC 50 , the toxicity to large GAS of the two extracts were 47.05 ml/L for dried beans, and 39.28 ml/L for fresh fruits, and for small GAS they were 44.87 ml/L for dried beans, and 51.17 ml/L for fresh fruit. The lethal concentration LC 100 for mosquito fish (Gambusia affinis Baird and Gerard) was 2.08 ml/L for fresh extract and 1.71 ml/L for dried extract, while LC 50 on the 24-hour basis was 0.88 ml/L for fresh extract, and 0.35 ml/L for dried extract.
Full text link https://tinyurl.com/mw9n4j8y

Article title: Efficacy of Sargassum oligocystum Extract on the Innate Immunity of White Shrimp Litopenaeus vannamei and its resistance against Vibrio alginolyticus
Authors: Francis Nuestro Baleta, Yong-Chin Lin, Yu-Yuan Chen, Jiann-Chu Chen, Su-Tuen Yeh, Dedi Fazriansyah Putra and Chien-Lun Huang
Publication title: Journal of Fisheries Society of Taiwan 40(4): 241-256, 2013

Abstract:
This study was to examine immune response of white shrimp Litopenaeus vannamei and its resistance against Vibrio alginolyticus when shrimp received Sargassum oligocystum extract (SOE). Shrimp which had been immersed in seawater containing SOE at 300 and 500 mg/l for 4 h, hemocyte count and other immune parameters including phenoloxidase (PO) activity, respiratory burst (RB), superoxide dismutase (SOD) activity, glutathione peroxidase (GPx) activity, and lysozyme activity significantly compared to the control shrimp. The expressions of LGBP and PX, and mitotic index of hematopoietic tissue (HPT) of shrimp immersed in SOE at 100, 300 and 500 mg/l after 4 h were significantly higher than those of control shrimp. Shrimp immersed in 100, 300, and 500 mg/L SOE showed increased phagocytic activity and clearance efficiency to V. alginolyticus. Shrimp which had been immersed in seawater containing 100, 300 and 500 mg/l SOE after 4 h were challenged with V. alginolyticus at 4.5 x 106 colony-forming unit (cfu)/ shrimp, and then placed in seawater. The survival rate of shrimp immersed in 300 and 500 mg/l SOE was signicantly higher than that of control shrimp over 12~120 h. In conclusion, shrimp immersed in seawater containing SOE at 300 mg/l increase resistance, phagocytic activity and clearance efficiency against V. alginolyticus as an evidence of increases in hemocyte count, other immune parameters, expressions of LGBP and PX, and mitotic index of HPT
Full text link https://tinyurl.com/2p9cesb3

Article title: Biological Activity of the Extracts of Sargassum oligocystum against Aquaculture Pathogenic Bacteria.
Authors: Baleta, FN; Laureta, LV; Apines-Amar, MJS; Padilla, PIP; Quinitio, GF
Publication title: Israeli Journal of Aquaculture-Bamidgeh 63: 667-672, 2011

Abstract:
Sargassum oligocystum (Phaeophyceae) was collected from the coastal area of Sta. Ana, Cagayan, Philippines, and used in in vitro antibacterial assays against six pathogenic bacteria commonly occurring in aquaculture. The extracts (methanol, n-hexane, dichloromethane, ethyl acetate, aqueous) were screened against Vibrio harveyi, V. parahaemolyticus, V. alginolyticus, Flavobacterium aurantiacum, Streptococcus faecalis, and Pseudomonas aeruginosa. The methanol extract showed strong antibacterial activity against V. harveyi, S. faecalis, and P. aeruginosa and moderate activity against the rest of the test pathogens. In general, V. harveyi was the most susceptible strain to all the extracts. This study suggests that extracts of S. oligocystum may be promising sources of antibacterial agents for use in aquaculture.
Full text available upon request to the author

Article title: Sex Reversal of Nile Tilapia Oreochromis niloticus L. by Egg Immersion technique: The Effect of Hormone concentration and Immersion Time.
Authors: Arsenia G. Cagauan, Francis N. Baleta and Jose S. Abucay
Publication title: Proceedings from the Sixth International Symposium on Tilapia in Aquaculture, 2004

Abstract:
The study evaluated sex reversal of Nile tilapia O. niloticus by immersing the eggs in different concentrations of 17-methyl testosterone (0, 200, 400, 600, 800 µg l-1)exposed for different times (24, 48, 72, 96 hrs). The main effects of hormone concentration (HC), immersion time (IT) and their interaction effect (HC x IT) on hatching percentage, survival and percentages of male and female were determined. The main effects of HC and IT and their interaction significantly influenced hatching percentage, sex and survival of O. niloticus (P<0.001). Hatching percentage decreased with increased IT. Similarly, survival of treated fry in net enclosures was affected by the increasing IT. Increased per cent male was observed with increasing HC and IT. The main effect of HC showed that the highest per cent male of about 84% was obtained at 800 µg l-1,followed by about 79% at 600 µg l-1,75% at 400 µg l-1,about 67% at 200 µg l-1,and lowest in the control (59%) (P<0.05). The main effect of IT that gave the highest per cent male of about 79% was at the longest duration of 96-hours. The interaction effect of HC x IT showed that the HC greater than 400 ug.l-1 appeared to be better in effecting higher percentages of males at longer ITs. Highest per cent male of 91% was attained at 800 ug l-1 HC at 96-hour IT comparable with the 88-89% in 400-600 µg l-1 HC at the same IT. Hence, from this study the HC and IT of eggs that gave the highest per cent male was identified. The study has proven that it is possible to induce sex reversal of O. niloticus by egg immersion, an alternative technique from the traditional sex reversal method of feeding the fry with hormone-treated feeds.
Full text link https://tinyurl.com/t8hpj2xj

Contact details: This email address is being protected from spambots. You need JavaScript enabled to view it.