Selected hematological parameters were studied in snakehead from Laguna de Bay (Philippines) affected with different stages of epizootic ulcerative syndrome (EUS). For comparison, normal (from a non-endemic area) and apparently normal fish were also studied. The hematocrit values of normal and apparently normal fish, 45.04 ± 0.71 and 47.20 ± 1.03%, respectively, were significantly higher (P<0.05) than severely affected fish (29.30 ± 2.34%). The same trend was observed for serum protein (7.09 ± 0.11 and 6.35 ± 0.27 g/100 ml for normal and apparently normal fish, respectively, against 4.68 ± 0.42 g/100 ml for severely affected fish) and hemoglobin (9.80 ± 0.26 and 9.70 ± 0.26 g/100 ml against 4.67 ± 0.42 g/100 ml) concentrations. The granulocyte counts of normal and apparently normal fish, 26.2 and 60.3, respectively were significantly lower than severely affected fish (210.0). This general hemodilution could be attributed to loss of body fluids and depression of hematopoietic tissues in the spleen and kidney.

This paper aims to determine the optimum NaOH pretreatment strength and duration and also the monthly variations in gel strength, agar yield and sulfate content of agar from Gracilariopsis heteroclada (Zhang et Xia) Zhang et Xia. Samples collected from Leganes, Iloilo, Philippines were pretreated with NaOH at different strengths (1,3 and 5%) and duration (30 min and 60 min) at 85-90°C. Agar extractions were done by the method of Nelson et al. (1983) Agar yield was calculated based on Santos (1980). Gel strength and sulfate content were determined using the methods of Aguilar-Santos and Doty (1978) and Jackson and McCandless (1978), respectively. Agar gelling and melting temperatures were analyzed in triplicate (Whyte and Englar, 1976). Viscosity in cps, moisture and ash contents in per percent, were determined using standard methods. Analysis of variance and Duncan’s multiple range test were used to compare the gel strength for the NaOH pretreatment experiment and the different monthly samples. Correlation analysis was carried out to determine the relationship between the different parameters analyzed. Highest gel strength (641 gm cm^-2 ) and lowest sulfate content (7.66 gm/mg SO₄) were obtained following alkaline pre-treatment with 5% NaOH for 30 min with agar yield of 32.4 per cent. Gelling and melting temperatures of agar with the highest gel strength were 40°C and 80°C, respectively, while specific viscosity, moisture and ash contents were 7.5 cps, 12.2% and 4.32%, respectively. Agar yield was negatively correlated with NaOH pre-treatment (P<0.05). Sulfate content was negatively correlated with gel strength (P<0.05). Gel strength, agar yield and sulfate content showed monthly variation. Sulfate was highly correlated with gel strength (P<0.05). Agar yield was positively correlated with month, while it is negatively correlated with gel strength (P<0.05). The results showed that agar from Gracilariopsis heteroclada has a very good potential for use as raw material for the production of food, drug and industrial grades of agar because of its superior gel strength.

The protencial of partial replacement of fish meal protein with protein indigenous leaf meals in practical diets for milkfish, Chanos chanos (Forsskal) was studied. Five isocaloric (375 kcal/100 g diet), isonitrogenous (40% protein), and isolipidic (10%) diets were formulated to contain leaf meals from either swamp cabbage (kangkong, Ipomea reptans), sweet potato (kamote, Ipomea batatas), ipil-ipil (Leucaena leucocephala), and cassava (kamorng kahoy, Manihot esculenta), or a combination of swamp cabbage, sweet potato and cassava. The control diet contained fish meal and soybean meal as sources of protein while thw test diets contained fish meal, soybean meal, and leaf meals erplacing 15% of the fish meal protein. The protein sources were incorporated in levels that gives optimal essential amino acid patterns to the diets. Each diet was fed to reiplcate groups of fish (about 0.3 g) maintained at 20 ppt salinity and 29^oC in a recirculating system for twelve weeks. Growth, feed conversion ratio (FCR), protein efficiency ratio (PER), and survival of fish fed the diet contaning cassava leaf meal showed the best groth FCR, PER and survival. the data sugest that these leaf meals can be used to partially replace fish meal in a diet for juvenile milkfish if the requirments for essential amino acids are met.

The problems confronting the fishery sector have received varying degree of attention from the government sector over time. In the past two decades the main thrust was to increase productivity through technology generation. In the late 1980s, however, the worsening problem of inequity in fisheries shifted the concern to the socioeconomic issues of sustainability and equity. This reorientation in emphasis is largely attributable to the contribution of social scientists. The study reviews completed and ongoing socioeconomic research in the fishery sector. This relates the focus of the studies in the sector. Research gaps and researchable areas were determined to identify future research directions. Moreover, this review aims to find out whether social scientists have responded to the needs and urgent issues of the sector.

One of the mandates of the SEAFDEC Aquaculture Department is the development of human resources and dissemination and exchange of information in aquaculture to promote the aquaculture industry in Southeast Asia. The Department receives trainees from SEAFDEC Member Countries (Thailand, Malaysia, Singapore) and other countries for short-term training programs. AQD also disseminates and exchanges information on aquaculture research and technology through symposia, seminars, workshops, video programs, and publications.

Broodstock management and seed production techniques have evolved from laboratory and verification tests that are conducted to increase survival and growth rates of cultured fish species. The present methods of induced maturation and hatchery rearing of shrimp (Penaeus monodon) used at the SEAFDEC Aquaculture Department are examples.

During the past two decades, many investigators have assumed that the major locus of regulation of cysteine catabolism is the partitioning of cysteinesulfinate between its decarboxylation and transamination pathways. Hepatic cysteinesulfinate decarboxylase activity correlates well with the capacity of animals to synthesize taurine1–4, and low cysteinesulfinate decarboxylase activity in the cat has been associated with its nutritional requirement for dietary taurine5. More recent studies in our laboratory have indicated that cysteinesulfinate-independent pathways also play a major role in cysteine metabolism6,7. In contrast to cysteinesulfinate-dependent metabolism of cysteine, which leads to both taurine and sulfate production, the cysteinesulfinate-independent pathways all result in release of reduced inorganic sulfur and its subsequent oxidation to sulfate. This evidence revealing a contribution of cysteinesulfinate-independent pathways to cysteine catabolism suggested that partitioning of cysteine between cysteinesulfinate formation and metabolism by cysteinesulfinate-independent pathways may also be important in the regulation of cysteine metabolism to taurine.

The study compares the profitability of mud crab pond culture with existing crab fattening practices in Iloilo, Philippines. Monoculture of Scylla serrata at stocking densities of 5,000, 10,000, 15,000 and 20,000 pcs/ha are compared for economic feasibility. Highest return on investment, return to equity, and shortest payback period were obtained from a stocking density of 5,000/ha. Production cost ranged from 35.78/kg at 5,000/ha stocking density to 55.05 P/kg at 20,000 stocking density. Partial budgeting showed that no incremental benefit accrued from increasing the stocking density to 10,000/ha. Discounted economic indicators, such as net present value, benefit-cost ratio and internal rate of return, were also highest at 5,000/ha stocking density.