The Elongate surgeonfish Acanthurus mata caught from the sea and feeding in the milkfish’s net cages separated from wild fish were measured for their otolith strontium (Sr) concentration using an wave-length dispersive electron probe micro analyzer. The analysis showed three types of Sr distributions in the otolith of wild fish, but the type from artificially fed fish caught in cages was unchanged. The Sr concentration in the otolith could be influence by the water chemistry and/or food composition, and other factors. In conclusion, if you try understand the Elongate surgeonfish life-history based on it’s Sr concentration variation, one should take great care.

An eight-week feeding trial was conducted to evaluate the contribution of biofloc on dietary lipid requirement in whiteleg shrimp Litopenaeus vannamei. Five diets with graded levels of dietary lipid (45, 60, 90, 120 and 150 g/kg) were fed to juvenile shrimp. Final weight, weight gain and specific growth rate of shrimp fed diets with 60, 90 and 120 g/kg lipid levels were significantly higher than those of shrimp fed diets with lipid levels 45 and 150 g/kg (p < .05). Feed efficiency and protein efficiency ratio of shrimp fed 60, 90 and 120 g/kg were higher than those fed 150 g/kg diet. Plasma total cholesterol and triglyceride levels were lower in shrimp fed 45 g/kg compared with those fed the 90 g/kg (p < .05). Also, lysozyme activity for 90 g/kg group was higher than the 15 g/kg group. Hepatopancreas lipase and amylase activities of shrimp fed 90 and 120 g/kg diets were significantly higher than those of shrimp fed 45 and 150 g/kg diets. Broken-line regression analysis for weight gain indicated that the dietary lipid requirement of whiteleg shrimp juveniles reared in a biofloc system was estimated to be higher than 56 g/kg but <60 g/kg.

The hatchery protocol for silver therapon (Leiopotherapon plumbeus, Kner 1864) in outdoor tanks is disclosed. The process includes timed provision of preferred natural food commensurate with the age of larvae, pre-conditioning of rearing water, utilizing ambient lake water and the addition of fresh tropical almond leaves Terminalia catappa to enhance natural food supply in tanks. A stocking density of 0.1 to 1 larvae /L was used to enhance survival and growth. Survival of larvae increased to 35.41 ± 15.32 per cent using the invention.

In the Philippines, cage culture of milkfish in marine environments is increasing. The practice uses high stocking densities, with significantly greater inputs of artificial feeds which more often than not, has led to excessive feeding and consequently excessive nutrient loading in receiving waters, exacerbating problems with pollution. These could have contributed to occurrence of periodic fish kills in areas of marine milkfish culture clusters. Sixty percent of milkfish farming expenses are attributable to feed costs. A series of experiments were conducted in an attempt to develop alternative feeding strategies that will reduce feed inputs without compromising growth and resulting production. In the first experiment, growth was compared in milkfish fed daily, on alternate days and on alternate 2-week or 4-week starvation and refeeding cycles in a tank environment provided with flow-through water system. Results show, that milkfish fed on alternate days do not grow as well as milkfish that are fed daily. Feed restriction for 2 weeks followed by 2 weeks of refeeding elicited a compensatory growth response such that average body weight (ABW) of fish was not significantly different from ABW of fish fed daily. Another experiment compared growth of fish given a ration equivalent to 10% of BW (usual practice) or 7.5% of BW. Results show no significant effect on growth or final ABW or biomass in fish fed daily or on 2-week cycles of feed restriction and refeeding. Thus, a lower feeding ration can be given to milkfish without compromising yield. Results of the tank experiments were verified in actual marine cage and brackishwater pond production systems using an initial feeding rate of 7.5% rather than 10% ABW. In the experiment in cages, survival rates between the control fish and the groups subjected to cycles of 2-week starvation followed by 2 weeks of normal feeding were comparable, except for one replicate of the starved-refed group where survival rate was very low (38.78%). After 3 cycles of starvation and refeeding, weight gain in the starved-refed groups were generally lower than in the control groups, which may suggest that small-sized fish cannot adapt very well to periodic starvation. In brackishwater ponds, growth, survival and total biomass at harvest was comparable between milkfish fed daily and those fed on alternate days. Hence, FCR was lower in the milkfish fed on alternate days compared to fish fed daily. On the other hand, survival was very low in fish subjected to 2 cycles of 2 weeks starvation followed by 4 weeks of normal feeding. These results suggest that as in tilapia, alternate day feeding can be adopted to milkfish culture in brackishwater ponds without compromising production while at the same time lowering production cost and environmental impact. Overall, these studies provide two practical strategies, reduced ration size and alternate day feeding, to improve production efficiency of milkfish, the largest finfish aquaculture industry in the Philippines.

The potential of enriched Ulva pertusa meal as feed ingredient in abalone juveniles, Haliotis asinina was evaluated. Four isonitrogenous and isolipidic diets were formulated which contain 27% protein and 5% lipid. Enriched U. pertusa meal replaced 0% (control), 10%, 20%, and 30% of protein from fish and soybean meals in the formulated diets. Thirty randomly selected abalone juveniles with average weight and shell length of 0.45 g ± 0.01 and 12.71 mm ± 0.01, respectively, were placed in each of the twelve 60-L oval fiberglass tanks equipped with a flow-through seawater system. Abalone were given diets at 3–5% body weight daily for 120 days in three replicate samples. Results showed no significant differences (p > 0.05) in percent weight gain, shell length, specific growth rate, feed conversion ratio, and protein efficiency ratio even up to 30% replacement level. Apparent dry matter digestibility of U. pertusa meal in abalone diet was 92%. Crude protein content of the abalone fed diets 1 (10% enriched U. pertusa meal) and 3 (30% enriched U. pertusa meal) was significantly (p < 0.05) higher than those fed on basal diet. Enriched U. pertusa meal can partially replace fish and soybean meals as protein source in formulated diets for abalone, Haliotis asinina juveniles.

Seaweeds have been used as a food for centuries in Asia and are increasingly exploited as a source for dietary supplements, animal feed, chemicals, and biofuels. In recent years, there has been an increase in the prevalence of diseases and pests in these aquaculture crops, with a subsequent reduction in their quantity and commercial value. In this article, we review diseases that have been reported in the scientific literature for species of red and brown seaweeds. We have focused on the major seaweed crops grown in Asia, where much of this production is centered. We also provide information on disease management and biosecurity and some observations on future directions.

The Atlantic Bluefin Tuna (ABFT, Thunnus thynnus) is one of the most intensely exploited fisheries resources in the world. In spite of the years of studies on ABFT, basic aspects of its reproductive biology remain uncertain. To gain insight regarding the seasonal changes of the reproductive characteristics of the eastern stock of ABFT, blood and tissue samples were collected from mature specimens caught in the Mediterranean basin during the reproductive (May-June) and non-reproductive season (Oct-Nov). Histological analysis of the gonads of May-June samples indicated that there were females which were actively spawning (contained post-ovulatory follicles) and females that were not actively spawning that had previtellogenic and fully vitellogenic oocytes. In males, testis were at early or late stage of spermatogenesis during the reproductive season. In Oct-Nov, ovaries contained mostly previtellogenic oocytes as well as β and α atretic follicles while the testis predominantly contained spermatogonia and few cysts with spermatocytes and spermatozoa. Gonadosomatic index (GSI) in females was highest among the actively spawning individuals while in males GSI was higher in early and late spermatogenic individuals compared to those that were spent. Plasma sex steroids levels varied with the reproductive season. In females, estradiol (E2), was higher in May-June while testosterone (T) and progesterone (P) did not vary. In males, E2 and T were higher in May-June while P levels were similar at the two sampling points. Circulating follicle stimulating hormone (FSH) was higher in Oct-Nov than in May-June both in males and females. Vitellogenin (VTG) was detected in plasma from both males and females during the reproductive season with levels in females significantly higher than in males. VTG was undetected in Oct-Nov samples. Since choriogenesis is an important event during follicle growth, the expression of three genes involved in vitelline envelope formation and hardening was measured and results showed significantly higher levels in ovaries in fish caught in May-June with respect to those sampled in Oct-Nov. In addition, a set of genes encoding for ion channels that are responsible for oocyte hydration and buoyancy, as well as sperm viability, were characterized at the two time points, and these were found to be more highly expressed in females during the reproductive season. Finally, the expression level of three mRNAs encoding for different lipid-binding proteins was analyzed with significantly higher levels detected in males, suggesting sex-specific expression. Our findings provide additional information on the reproductive biology of ABFT, particularly on biomarkers for the assessment of the state of maturation of the gonad, highlighting gender-specific signals and seasonal differences.

Ontogenetic niche shifts in diet are a consequence of changes in body size or resource partitioning between age classes. To better resolve the feeding patterns of the Japanese scallop Mizuhopecten yessoensis, we examined the relative importance of age and size in the diet of this species using stable isotope ratios of carbon (δ¹³C) and nitrogen (δ¹⁵N) from 2006 to 2009. Contribution of food sources was quantified using an isotope mixing model by comparing the muscle tissue isotope ratios to those of suspended particulate organic matter (SPOM) and their zooplankton prey (e.g. micro- and meso-zooplankton). Unlike the δ¹³C values, which remained constant with age and size, muscle δ¹⁵N values were more positively correlated with age accounting for 69 % of variations than size with only 46 %. Increasing ¹⁵N values with age suggested that shifts in diet from SPOM to micro- and meso-zooplankton occurred during ontogeny in M. yessoensis. Results of the isotope mixing model indicated that SPOM contribution to scallop’s diet decreased from 68 to 8 % while those of zooplankton increased from 15 to 50 % with increasing age. This study concludes that age-related dietary shift explains the enrichment of ¹⁵N, as a result of predation on zooplankton by M. yessoensis.

Gonad development of the silver therapon Leiopotherapon plumbeus in two volcanic crater lake habitats (Sampaloc Lake, Taal Lake) in south Luzon, Philippines was examined during the annual reproductive cycle. The minimum body size‐at‐maturity of fish in these two lake habitats was also compared. Four gonad development stages were characterized as basis for the classification of ovarian (immature, maturing, mature, spawned) and testicular maturation (immature, maturing, mature) phases. The occurrence of all development stages in individual gonads suggest an asynchronous development whereby advanced stages are recruited continuously from a pool of younger stage germ cells to result in elevated female and male GSI throughout the annual cycle due to active gonadogenesis. Together with the increasing occurrence of advanced stage oocytes and spermatozoa from March until October, the elevated GSI of fish may indicate peak gonadal growth during the onset of the dry season (December–January) for eventual spawning from the beginning (May–June) until the end of the wet season (October–November). In both lake habitats, male fish were smaller than females but, regardless of sex, the minimum size‐at‐maturity of fish in Sampaloc Lake was significantly smaller than fish in Taal Lake. Overall, asynchronous development during oogenesis and spermatogenesis allows for year‐round reproduction of silver therapon, with elevated gonad growth in the dry season in preparation for spawning during the wet season. Compared with fish in Taal Lake, a smaller size‐at‐maturity of fish in Sampaloc Lake may be a response of the wild fishery stock to long‐term high fishing mortality and degradation of the lake habitat.

The academic libraries in Marawi City, Lanao del Sur, Philippines are vulnerable to disasters. In the last ten years, the majority of the 13 respondent libraries have sustained at least one disaster that may have been caused by civil unrest, war or terrorism, flood, earthquake, or fire. The majority were unprepared to face such disasters, may it be small-scale or catastrophic, and only one library has a disaster management plan. The lack of significant holdings of rare books, shortage of financial resources, no perceived risk, and the unavailability of staff to write a disaster management plan, are the reasons why most libraries do not have a plan. Moreover, the majority lacked staff that has undergone training in disaster preparedness and management. On the other hand, all of the libraries have disaster management practices that although not enough, will still enable them to lessen the effects of the disaster and save their library and parts of their collection when necessary. The respondents identified management support as an essential factor in their success in disaster management. The results of the study provide valuable information on the current state of the libraries in the Philippines with regards to disaster preparedness and management. Therefore, it is an essential addition to the literature on disaster management in the Philippines, which is very scarce as of the moment.