National Committee on Marine Sciences (NCMS)
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- Inbreeding levels in selected populations of rainbow trout, Oncorhynchus mykissPante, Ma. Josefa R.; Gjerde, Bjarne; McMillan, Ian (Elsevier BV, 2001-01)Inbreeding levels in three nucleus breeding populations of rainbow trout (Oncorhynchus mykiss) under selection for six generations were investigated. The inbreeding levels across generations as estimated from pedigree information (Pi) and effective population size (Ne) with the assumption of no selection and random mating, among the three populations were all at 11.3% or less. The levels of inbreeding estimated from Ne were generally lower than those calculated from Pi, except in the initial generations. The average rates of inbreeding (ΔF) calculated from Ne and Pi were 0.99% and 2.00%, respectively, for population 1; 0.90% and 0.53%, for population 2; and 0.72% and 1.38%, for population 3. These rates of inbreeding correspond to Ne of 50 and 25, for population 1; 55 and 94, for population 2; and 70 and 36, for population 3. These rates were within the acceptable range 2% to 0.2%, corresponding to Ne of 31 to 250 for avoiding loss of fitness as suggested by Meuwissen and Woolliams [Meuwissen, T.H.E., Woolliams, J.A., 1994. Effective sizes of livestock populations to prevent a decline in fitness. Theor. Appl. Genet. 89, 1019–1026.]. A large proportion of individuals had inbreeding coefficients (F) greater than zero across generations for each population but the individual F were generally below 12.5%. The occurrence of inbreeding can be detrimental to populations undergoing artificial selection. Therefore, the F levels reported here should be followed-up by a study on the impact of inbreeding on important performance traits in rainbow trout.
- Growth, mortality and recruitment pattern of the brown mussel, Modiolus metcalfei (Bivalvia: Mytilacea), in Panguil Bay, Southern PhilippinesTumanda, Marcelino I.; Yap, Helen T.; McManus, Liana T.; Ingles, Jose A.; López, Mai G. (Elsevier BV, 1997-08)A stock assessment study of Modiolus metcalfei in Panguil Bay, Southern Philippines, was conducted to determine growth parameters of the species and the status of the fishery given the current harvesting efforts of this resource in the bay. Growth parameter estimates yielded mean K and Lα values of 2.04 year−1 and 62.50 mm, respectively. The recruitment pattern appeared to be unimodal, with the peak occurring during the months of May–July. Spat settlement ratios for May and July were 1.6 and 2.0 spat per live adult mussel, respectively. Settling spat showed preference to attach onto the shells and exposed byssal threads of live adult mussels. Catch curve analysis showed total mortality (Z) value of 7.64 year−1; fishing mortality (F) was 5.60 year−1. Exploitation rate was 73% of total mortality, and was attributed to intensive mussel gathering by local fishermen. Fishing mortality shows an over-exploited stock that necessitates some management intervention to maintain the sustainability of the fishery resource.
- Proximate analysis of the flour and starch from Enhalus acoroides (L.f.) Royle seedsMontaño, M. Nemesio E.; Bonifacio, Ronald S.; Rumbaoa, Rowena Grace O. (Elsevier BV, 1999-11)The seeds of the tropical seagrass Enhalus acoroides were analyzed for their nutritive components to assess their dietary value for humans. Proximate analysis of flour prepared by grinding the dried seeds gave the following results: 9.8% moisture; 8.8% protein; 0.2% fat; 72.4% carbohydrates; 2.4% crude fiber; 6.4% ash; 933 mg/kg calcium; 2392 mg/kg phosphorous; and 2813 mg/kg iron. Correspondingly, proximate analysis of the starch prepared from the flour with a 50% yield, resulted in the following: 11% moisture; 0.8% protein; 0.1% fat; 87.6% carbohydrates; 0.4% crude fiber; 0.5% ash; 320 mg/kg calcium; 210 mg/kg phosphorous and; 220 mg/kg iron. Comparison of the proximate analysis results and the calculated caloric values of the seagrass seed flour and starch showed similarity with those of terrestrial origin.
- Transcriptome analysis of growth variation in early juvenile stage sandfish Holothuria scabraOrdoñez, June Feliciano F.; Galindez, Gihanna Gaye S.T.; Gulay, Karina Therese; Ravago-Gotanco, Rachel (Elsevier, 2021-12)The sandfish Holothuria scabra is a high-value tropical sea cucumber species representing a major mariculture prospect across the Indo-Pacific. Advancements in culture technology, rearing, and processing present options for augmenting capture production, stock restoration, and sustainable livelihood activities from hatchery-produced sandfish. Further improvements in mariculture production may be gained from the application of genomic technologies to improve performance traits such as growth. In this study, we performed de novo transcriptome assembly and characterization of fast- and slow-growing juvenile H. scabra from three Philippine populations. Analyses revealed 66 unigenes that were consistently differentially regulated in fast-growing sandfish and found to be associated with immune response and metabolism. Further, we identified microsatellite and single nucleotide polymorphism markers potentially associated with fast growth. These findings provide insight on potential genomic determinants underlying growth regulation in early juvenile sandfish which will be useful for further functional studies.The authors are grateful to the following individuals and institutions for providing samples and facilitating their collection: D. Ticao of (Finfish Hatcheries, Inc.); Dr. M.A. Juinio-Menez, ˜ J.R. Gorospe, C. Edullantes, B. Rodriguez, A. Rioja, T. Catbagan, and G. Peralta of Bolinao Marine Laboratory, University of the Philippines Marine Science Institute; and E. Tech (Palawan Aquaculture Corp.).
- The harmful raphidophyte Chattonella (Raphidophyceae) in Western Pacific: Its red tides and associated fisheries damage over the past 50 years (1969–2019)Lum, Wai Mun; Benico, Garry; Doan-Nhu, Hai; Furio, Elsa; Leaw, Chui Pin; Leong, Sandric Chee Yew; Lim, Po Teen; Lim, Weol Ae; Lirdwitayaprasit, Thaithaworn; Lu, Songhui; Nguyen, Nguyen Van; Orlova, Tatiana Yu.; Rachman, Arief; Sakamoto, Setsuko; Takahashi, Kazuya; Teng, Sing Tung; Thoha, Hikmah; Wang, Pengbin; Yñiguez, Aletta T.; Wakita, Kazumi; Iwataki, Mitsunori (Elsevier, 2021-07)Red tides and associated fisheries damage caused by the harmful raphidophyte Chattonella were reassessed based on the documented local records for 50 years to understand the distribution and economic impacts of the harmful species in the Western Pacific. Blooms of Chattonella with fisheries damage have been recorded in East Asia since 1969, whereas they have been only recorded in Southeast Asia since the 1980s. Occurrences of Chattonella have been documented from six Southeast Asian countries, Indonesia, Malaysia, Philippines, Singapore, Thailand and Viet Nam, with mass mortalities mainly of farmed shrimp in 1980–1990s, and farmed fish in 2000–2010s. These occurrences have been reported with the names of C. antiqua, C. marina, C. ovata, C. subsalsa and Chattonella sp., owing to the difficulty of microscopic species identification, and many were not supported with molecular data. To determine the distribution of C. marina complex and C. subsalsa in Southeast Asia, molecular phylogeny and microscopic observation were also carried out for cultures obtained from Indonesia, Malaysia, Japan, Philippines, Russia, Singapore and Thailand. The results revealed that only the genotype of C. marina complex has been detected from East Asia (China, Japan, Korea and Russia), whereas both C. marina complex (Indonesia and Malaysia) and C. subsalsa (Philippines, Singapore and Thailand) were found in Southeast Asia. Ejection of mucocysts has been recognized as a diagnostic character of C. subsalsa, but it was also observed in our cultures of C. marina isolated from Indonesia, Malaysia, Japan, and Russia. Meanwhile, the co-occurrences of the two harmful Chattonella species in Southeast Asia, which are difficult to distinguish solely based on their morphology, suggest the importance of molecular identification of Chattonella genotypes for further understanding of their distribution and negative impacts.We thank Drs Yuuki Kosaka, Winnie Lik Sing Lau, Ing Kuo Law and Toh Hii Tan for their sampling assistances. We thank Dr. Sadaaki Yoshimatsu for providing a culture strain TAI-93, and Drs Mineo Yamaguchi and Haruo Yamaguchi for support on maintenance and rDNA analysis of the culture. This work was carried out under international collaboration of the IOC/WESTPAC-HAB project and Core-to-Core Program (B. Asia-Africa Science Platforms) of the Japan Society for the Promotion of Science (JSPS). This work was partially supported by Japanese JSPS Kakenhi 19H03027 and 19KK0160 (MI), Malaysian MOHE HICOE IOES and FRGS (PTL), Vietnamese VAST NVCC17.02/21-21 (HD-N), and the Japanese Fund-in-Trust (MEXT).
- Community structure of periphytic diatoms in early-stage marine biofilms in a mariculture-impacted areaBaure, Jerwin; San Diego-McGlone, Maria Lourdes; Juinio–Meñez, Marie Antonette (Science and Technology Information Institute, 2022-07-06)Periphytic diatoms constitute a major part of complex unicellular aggregations called marine biofilm or periphyton, of which little is known about in tropical marine environments. The early-stage community structure of periphytic diatom genera on two artificial substrates – glass slide and polycarbonate sheets was characterized. These artificial substrates were placed underwater for 6 d and examined on Days 1, 3, and 6 in four sites around Santiago Island, Bolinao, Pangasinan, Philippines, with different relative distances from the intensive milkfish mariculture area. Correlations of diatom community structures in these sites with physico-chemical factors were investigated. The five most abundant diatom genera – namely, Cylindrotheca, Nitzschia, Navicula, Amphora, and Pleurosigma – exhibited a weak correlation with nutrients. Less abundant genera Pseudonitzschia, Haslea, Bacillaria, Thalassionema, Rhizosolenia, Eucampia, Diploneis, Asterionellopsis, Chaetoceros, Bacteriastrum, Licmophora, Skeletonema, Lioloma, Thalassiosira, and Thalassiothrix showed a positive correlation with nutrients. Among sites, the highest benthic diatom cell densities (4.6 × 105 cells cm−2) after 6 d was found in Lucero. Generic richness and diversity varied among sites, with the highest diversity (H’ = 1.58) on Day 1 in Tomasa, the site nearest to the mariculture area, whereas the highest richness (D = 2.17–3.26) for all days and diversity (H’ = 1.38–1.52) for Days 3 and 6 were recorded in Silaqui, the most distal site. Generally, the highest diversity and richness were found on Day 1, which then decreased on succeeding days in all sites. The lack of a clear patternin community structure among sites relative to the proximity of these sites to the mariculture area may in part be attributed to the presence of other nutrient sources. Results of the study provide baseline information on the variability of periphytic diatom community structure in a mariculture-impacted area, and insights on how benthic diatoms may be used in monitoring the impacts of nutrient pollution.This work was supported by the Department of Science and Technology–Philippine Council for Agriculture, Aquatic, and Natural Resources Research and Development under Grant QMSR-MRRDMEC-295-1449. The authors would like to thank Tirso O. Catbagan and Garry R. Bucol for their assistance during field sampling, and Timothy James Cipriano for the site map. We would also like to thank the Marine Biogeochemistry Laboratory of the Marine Science Institute, University of the Philippines Diliman for providing environmental data.
- Restriction site-associated DNA sequencing reveals local adaptation despite high levels of gene flow in Sardinella lemuru (Bleeker, 1853) along the northern coast of Mindanao, PhilippinesLabrador, Kevin; Palermo, Joseph Dominic; Agmata, Altair; Ravago-Gotanco, Rachel; Pante, Ma. Josefa (Frontiers Media SA, 2022-02-24)Stock identification and delineation are important in the management and conservation of marine resources. These were highlighted as priority research areas for Bali sardinella (Sardinella lemuru) which is among the most commercially important fishery resources in the Philippines. Previous studies have already assessed the stocks of S. lemuru between Northern Mindanao Region (NMR) and Northern Zamboanga Peninsula (NZP), yielding conflicting results. Phenotypic variation suggests distinct stocks between the two regions, while mitochondrial DNA did not detect evidence of genetic differentiation for this high gene flow species. This paper tested the hypothesis of regional structuring using genome-wide single nucleotide polymorphisms (SNPs) acquired through restriction site-associated DNA sequencing (RADseq). We examined patterns of population genomic structure using a full panel of 3,573 loci, which was then partitioned into a neutral panel of 3,348 loci and an outlier panel of 31 loci. Similar inferences were obtained from the full and neutral panels, which were contrary to the inferences from the outlier panel. While the full and neutral panels suggested a panmictic population (global FST ∼ 0, p > 0.05), the outlier panel revealed genetic differentiation between the two regions (global FST = 0.161, p = 0.001; FCT = 0.263, p < 0.05). This indicated that while gene flow is apparent, selective forces due to environmental heterogeneity between the two regions play a role in maintaining adaptive variation. Annotation of the outlier loci returned five genes that were mostly involved in organismal development. Meanwhile, three unannotated loci had allele frequencies that correlated with sea surface temperature. Overall, our results provided support for local adaptation despite high levels of gene flow in S. lemuru. Management therefore should not only focus on demographic parameters (e.g., stock size and catch volume), but also consider the preservation of adaptive variation.We would like to acknowledge the assistance provided by Ma. Rio Naguit, Asuncion De Guzman, Jerry Garcia, Jhunrey Follante, Joshep Mercene, and John Christopher Azcarraga in sample collection and initial processing. We also acknowledge the research staff of the Marine Molecular Ecology and Evolution Laboratory (MMEEL), as well as the Marine Genomics and Molecular Genetics Laboratory (MGMGL) and its head, Arturo Lluisma, for providing valuable input in the conduct of the experiment and analysis of the data. Finally, we extend our gratitude to Demian Willette, Laura David, and Jonas Quilang for their valuable feedback on the manuscript.
- Associated effects of shading on the behavior, growth, and survival of Stichopus cf. horrens juvenilesRioja, Rose Angeli; Palomar-Abesamis, Nadia; Juinio–Meñez, Marie Antonette (Springer Science and Business Media LLC, 2021-07-07)Stichopus cf. horrens is an emergent culture species. It is known to be nocturnal and negatively phototactic; hence, determining its behavioral and growth responses to different light regimes is essential in optimizing culture protocols. This study examined the interactive effects of shading and relative food availability on the feeding pattern, absolute growth rates, and survival of juvenile S. cf. horrens. Six-month-old juveniles (4.27 to 19.41 g) were reared in replicate aquaria with three different shading treatments (covered, exposed, and half-covered aquaria) under ambient light conditions for 30 days. Juveniles in the exposed treatment with high microalgal biomass (13.44 ± 4.57 mg/g) had the highest growth rates (0.10 ± 0.05 g/day) but also the highest mortality (50%). In contrast, juveniles in the covered treatment had the lowest growth (−0.07 ± 0.03 g/day) but the highest survival (100%). Growth rates in the half-covered treatment were comparable with the exposed, and survival was higher than in the covered treatment. These indicate a trade-off between growth associated with more food and mortality risks due to light-induced stress. Juveniles in the half-covered treatment showed a significant preference to stay in the shaded portion whenever they were inactive during the day, suggesting avoidance to high light intensities (4726.51 ± 1582.43 Lux). Results of this study suggest that careful calibration of light intensities in nursery systems may help enhance juvenile growth. For indoor systems that may have limited space or surfaces for microalgal growth, cultured benthic diatom can be added to the partially covered tanks to increase the food available for the juveniles.
- Yield estimates, catch, effort and fishery potential of the reef flat in Cape Bolinao, PhilippinesCampos, W. L.; del Norte-Campos, A. G. C.; McManus, J. W. (Hindawi Limited, 1994-10)Catch, fishing effort and yield estimates of the Cape Bolinao reef flat fishery in Lingayen Gulf, Philippines are provided, based on data collected from May 1987 to April 1988. The dynamics of the dominant species, the rabbitfish Siganus fuscescens, suggest that such fisheries are capable of maintaining a high production in site of heavy fish in pressure. However, yield comparisons with those of other reef fisheries in the Indo-Pacific region, along with characteristics of the catch and the use of multiple gear types, suggest that current extraction rates should not be increased.