Journal Articles - UP - MSI
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- The genus Sargassum (Phaeophyta, Sargassaceae) from Balibago, Calatagan, PhilippinesAng, P. O.; Trono, G. C. (Walter de Gruyter GmbH, 1987)Eight species of Sargassum: S. baccularia (Mertens) C. Agardh, S. cinctum J. Agardh, S. crassifolium J. A-gardh, S. ilicifolium (Turner) C. Agardh, S. notarisii Zanardini, S. oligocystum Montagne, S. paniculatum J. Agardh, and S. siliquosum J. Agardh are reported from Balibago, Calatagan, Philippines. Growth and changes in the morphology of the two most common species, S. paniculatum and S. siliquosum, were noted throughout their different growth phases over 1 1/2 years. Collections of material representing growth stages of the other species were made at periodic intervals. The more consistent morphological characters for each species were recognized and their utility in taxonomic work was discussed. These characters include outline and length/width ratio of the leaves characteristic of each branching order of laterals, shape and size of the vesicles, muricatous nature of the terminal branchlets, branching pattern of the receptacles, morphology of the female receptacles and the type of holdfast.
- Wound healing in cultured Eucheuma alvareziivar. tambalang DotyAzanza-Corrales, R.; Dawes, C. J. (Walter de Gruyter GmbH, 1989)Wound healing in segments of Eucheuma alvarezii var. tambalang grown in enriched media in the laboratory can be divided into four stages based on histological and cytological changes. During the first stage, approximately 2—4 days after wounding, proteinaceous and phenolic substances concentrate on pit plugs of cells adjacent to the wounded surface. In the second stage, about the sixth day, cellular extensions are produced from the pits of medullary and cortical cells of sub-wound layer. During the third stage, about the 8th day, the cellular extensions divide several times and elongate towards the surface. A new cortical or wound tissue is formed during the fourth stage beginning on the 12th day. The wound tissue is continuous with the old cortex within 3 weeks.
- Effect of desiccation on Tridacna derasa seed: Implications for long distance transportLopez, M.D.G.; Heslinga, G.A. (Elsevier BV, 1985-11)Savings in freight cost from removal of the byssus and adherent material from T. derasa seed may not offset man-hours required for pre-shipment preparation, and decreased seed viability.
- A comparison of two benthic survey methodsMingoa, S. S. M.; Menez, L. A. B. (Springer, 1988)The belt transect and the flowmeter methods, used to survey sedentary benthic organisms, were compared based on abundance estimates of tridacnid clams in the Cagayan Islands, Philippines, in April 1985. Two-way ANOVA and chi-square tests (P<0.05) show that both methods recorded similar estimates for the number of clams (regardless of species), both methods gave similar estimates for the number of individuals per species, and one or both methods may be biased for certain sizes of clams. Individuals smaller than 6 cm shell length seemed to be underestimated by the flowmeter method. Future studies must investigate the size selectivity of the method used, for instance by conducting permanent belt, transect surveys of varied belt widths (e.g. 1, 1.5,2,2.5 m) and then comparing the recorded lengths of the most abundant clams. This will aid investigators to evaluate their data properly, and enable comparison of clam-stock estimates between surveys.
- Notes on the induced spawning and larval rearing of the Asian moon scallop, Amusium pleuronectes (Linné), in the laboratoryBelda, C. A.; Del Norte, A. G. C. (Elsevier, 1988-08)Sexual and chemical stimulations were effective in inducing the scallop, Amusium pleuronectes (Linné), to spawn sperm only, whereas thermal stimulation was not at all successful. Chemical stimulation consisted of serotonin injections into the ripe gonads. Fertilizable eggs were obtained by stripping gametes from the ovaries. Cleavage of zygotes (72.4 μm mean diameter) occured 1 h after fertilization. Trochophores (58.9–111.2 μm in length) and straight-hinge veligers or D-veligers (80.0–130.2 μm) were observed in less than 24 h. Five days after fertilization, the umbone stage (101.6–169.1 μm) was reached. Crawling pediveligers (174.0–250.0 μm) appeared after 9 days. Seawater in the culture vessels was changed 24 h after fertilization and every other day thereafter. The larvae were fed on Isochrysis galbana (Tahitian strain) at an initial concentration of 30 cells/gml.
- Temperature-influenced infection rates in the Chondrus crispus-Petersenia pollagaster pathosystem: A regression analysisMolina, F. I.; Hughes, G. C.; Craigie, J. S. (Springer, 1988-03)Cross-infection experiments were performed to determine the influence of temperature on infection rate in the Chondrus crispus Stackhouse-Petersenia pollagaster (Petersen) Sparrow pathosystem. C. crispus thalli were collected at Pubnico Harbor, Nova Scotia, Canada in the fall of 1981 to 1984. Infective zoospores were used to inoculate healthy thalli at five different temperatures. The highest infection rate was obtained at 20°C, while significantly lower rates were obtained at temperature extremes. The parasite's life cycle, consisting of infection of healthy thalli, endobiotic development, and release of zoospores, was completed in 48 to 72 h at 15° to 20°C.
- Status of giant clam resources of the PhilippinesJuinio, Marie Antoinette R.; Meñez, Lambert Anthony B.; Villanoy, Cesar L.; Gomez, Edgardo D. (Oxford University Press (OUP), 1989-11-01)Field surveys were conducted to determine distribution and abundance of giant dam resources in the Philippines. All seven known species of giant clams were recorded with Tridacna crocea, T. maxima and T. squamosa occurring the most frequently. The larger species T. derasa, T. gigas, Hippopus hippopus and H. porcellanus were relatively rare. The reduction of giant dam stocks in the Philippines is due to the uncontrolled exploitation of this resource which is primarily gathered for shellcraft and as supplementary diet in coastal villages.
- Growth rates and primary production of Enhalus acoroides (L.f.) royle from Lag-it, North Bais Bay, the PhilippinesEstacion, Janet S.; Fortes, Miguel D. (Elsevier, 1988-01)The growth rates and primary production of the leaves of Enhalus acoroides (L.f.) Royle at Lag-it, North Bais Bay, The Philippines, were studied from August 1982 to August 1983. Randomized complete block design showed that both rates are considerably influenced by the composite effect of spatial and temporal factors. Similarly, both are markedly bimodal. Mean growth rate was 0.93 cm day−1, with peaks in September–October and May, with lowest values in November–January. Mean production was 0.92 g C m−2 day−1, with peaks in October and March–May (Station 2) and December (Station 1) and lowest values in December (Station 2) and in June (Station 1). Growth rates significantly increased with a decrease in the percent of time the seagrass beds were exposed to air and sun in the daytime (r=−0.69), while it increased with the number of daylight hours (r=0.72). Production showed no significant correlation with either factor. Mean turnover time for the seagrass was 67 days, producing 5.5 crops annually.
- Electrophoretic evidence for extensive hybrid gene introgression into commercial Oreochromis niloticus (L.) stocks in the PhilippinesMacaranas, J. M.; Taniguchi, N.; Pante, M. J. R.; Capili, J. B.; Pullin, R. S. V. (Hindawi Limited, 1986-10)The usefulness of isozyme and protein markers in identifying tilapia species and their hybrids is demonstrated. Genetic characterization of Oreochromis niloticus populations from commercial farms, experimental stations, and government hatcheries in Luzon, Visayas and Mindanao in the Philippines indicates well-established introgression with O. mossambicus. Genetic differentiation of the O. niloticus stocks, measured by Nei's genetic distance, was highly correlated with O. mossambicus gene content. The implications of these results for tilapia genetic improvement are discussed.
- Indo-West Pacific affinities of Philippine seagrassesFortes, M. D. (Walter de Gruyter, 1988)A dendrograph was developed to depict the mutual relationships among 27 Indo-Pacific countries with similar seagrass floras. Hierarchical (cluster) analysis of the resulting affinities provides strong evidence that the countries could be partitioned into seven discrete provinces. The genus Halophila represents a major connection between most of these provinces, strongly influencing the clustering of the Seagrasses. The degree of species overlap (9.5 — 46.2%) between Province A (where Philippines belongs) and Province G (Western, Southern, and Southeastern portions of Australia) favors vicariance as an explanation. The separation of Kampuchea as a discrete unit within Province A appears to be an artifact of collection rather than a reflection of the true floral affinities in the region. The lack of sufficient basic floristic information remains as the most serious limitation in any attempt to describe the phytogeographic affinities of seagrasses in the Indo-Pacific region.