Misleading identification and subsequent publications on biological, molecular, and aquaculture data of mangrove mud crab (genus Scylla de Hann 1833) is a major concern in many countries. In this study, multiple molecular markers were used for genetic identification of all four known mud crab species under genus Scylla collected from India, Philippines, Myanmar, Malaysia and Indonesia. Internal Transcribed Spacer (ITS-1), Polymerase chain reaction (PCR)–Restriction Fragment Length Polymorphism (PCR–RFLP) and PCR-based species-specific markers were used to resolve taxonomic ambiguity. PCR–RFLP techniques using NlaIV and BsaJI restriction endonucleases were efficient to differentiate four different mud crab species under genus Scylla with specific fragment profile. The results also justified the use of ITS-1 and PCR-based species-specific markers to identify mud crab species available in many countries quite rapidly and effectively. Several new molecular markers generated during the study are reported here to resolve the taxonomic ambiguity of Scylla species and the results reconfirmed that India is only having two commonly available mud crab species which was reported by the authors earlier.

Abalone are among the most important fishery resources with high commercial values worldwide, with Haliotis asinina being the most in demand and widely studied species in the Philippines. Abalone culture in the country mainly depends on the red alga, Gracilariopsis heteroclada, as food for cultured stocks. This however, is not sustainable as this alga is also being farmed both for agar production and human consumption. Hence, other sources of natural food need to be explored for large-scale culture of abalone. This study investigated the viability of Ulva reticulata as food for abalone. This green alga is common in the intertidal zones of the Philippines but of no commercial value. H. asinina early juveniles (N = 60, shell length 2.12–3.07 cm, body weight 1.7–5.9 g) obtained from the Abalone Hatchery of SEAFDEC Aquaculture Department were randomly distributed (n = 10) in three replicate containers and fed with G. heteroclada and U. reticulata for 15 days. After 15 days, abalone fed with G. heteroclada were significantly larger and heavier (2.82 ± 0.04 cm and 4.64 ± 0.19 g) than those fed with U. reticulata (2.62 ± 0.03 cm and 3.45 ± 0.14 g). Abalone fed with U. reticulata also exhibited weakness, hardfoot, and easily detached from the walls of the culture containers. Based on these results, despite its availability in large quantities, U. reticulata could not be solely used as an alternative natural food to G. heteroclada for abalone culture. However, its potential as a partial substitute to G. heteroclada may be further examined.

The effects of dietary poly-β-hydroxybutyrate (PHB) on the lipid and fatty acids (FA) in crustaceans were investigated using Artemia as model species. Supplying PHB either in crystalline or amorphous form significantly increased the whole-body lipid contents of starved Artemia. Co-supplying dietary PHB with bacterial PHB degrader Comamonas testosteroni at 10⁶ cells ml⁻¹ for 24 hr also significantly increased this parameter. These findings have important implications on the lipid-saving effects of PHB in crustacean tissues. Dietary PHB, however, did not contribute to the increase in docosahexaenoic acid (DHA) of the naturally DHA-deprived Artemia. Alternative strategy of co-supplying dietary PHB with highly unsaturated fatty acid (HUFA)-rich emulsion for 24 hr effectively improved the nutritional contents of Artemia and at the same time assured efficient delivery of PHB to the larval predator. According to a ¹³C stable isotope tracer study, the significantly higher δ¹³C levels measured in Artemia 2 hr postfeeding with ¹³C-labelled R. eutropha DSM545 indicate that PHB offered in natural matrix is rapidly assimilated. Overall, this study demonstrated the lipid-saving effects of PHB in Artemia. PHB assimilation following gastrointestinal degradation could attribute to its reported beneficial effects in various aquatic farmed species.

The Philippine seaweed industry is affected by multiple but interrelated risks. Farmers mainly encountered environment-related risks (e.g. disease, pest infestations) which, if unmanaged, could result to production failure. Traders and processors considered volatility of seaweed supply and poor quality of raw materials as precursors of other risks such as increased competition among local traders and processing companies. Gender differences in awareness and knowledge of risks were more prominent among seaweed farmers but not among traders and processors as roles become more homogenous up the value chain. Poor governance resulted in the adoption of informal and market-driven strategies to prevent or minimise losses. However, this restricted farmers to participating in higher-income trading and processing activities and contributed to increased market inefficiency. The lack of government support has also curtailed the capacity of traders and processors to engage in product development and diversification. Gender and community experiences influence and shape people’s understanding of their situations and environment including their coping and adaptive strategies in sustaining livelihoods amidst recurring risk events. Embedding informal structures and the differential needs of the stakeholders in the national institutional framework is therefore essential for the promotion of resilient and sustainable seaweed industry.

Oyster farming is an important industry both in developed and developing countries. The high demand for oysters has caused overexploitation of natural stocks. This led to dwindling spat fall and unstable production. This study was conducted to compare growth and survival of wild and hatchery-bred spat of the oyster Crassostrea iredalei in grow-out culture. Results of the experiment revealed that both wild (n = 1450) and hatchery-bred spat (n = 1450) had comparable growth rates in grow-out culture. Growth rates of wild and hatchery-bred oysters did not differ significantly at 5.69 ± 0.88 mm shell length (SL) and 8.85 ± 1.07 g body weight (BW) mo⁻¹ and 6.88 ± 1.33 mm SL and 8.26 ± 1.15 g BW mo⁻¹, respectively. Growth rates, in terms of shell length, both for wild (p < 0.05, r = 0.74) and hatchery-bred oysters (p < 0.05, r = 0.76), showed strong positive correlation with salinity. Meat yield was almost the same at 16.41 ± 0.57% for wild oysters and 15.59 ± 0.37% for the hatchery-bred ones. Proximate composition of dried whole flesh oyster samples also showed the same amounts of crude protein, crude fat, crude fiber, nitrogen free extract, and ash in both wild and hatchery-bred oysters. The length-weight relationships of wild [W = 0.000492 L^2.6512 (R² = 86.8%, p < 0.001)] and hatchery-bred [W = 0.000052 L^3.1779 (R² = 92.6%, p < 0.001)] C. iredalei were also calculated from the length and weight data obtained during the duration of culture and revealed higher b for the smaller hatchery-bred oysters. Moreover, mean survival at harvest did not significantly differ at 85.03 ± 1.09% for wild oysters and 85.31 ± 1.40% for the hatchery-bred ones (Two-sample t-test, p > 0.05). The results of this study showed the potential of hatchery-bred oyster spat as seeds for grow-out culture to address the declining number of spat fall in natural oyster beds. Producing the same quality of oysters, it can be inferred that the hatchery-bred spat are just as competent as their wild conspecifics.

When searching for information in response to a query, their own library’s online public access catalog (OPAC) and databases remain the most preferred resource for most aquatic science librarians. This preference does not vary regardless of age, gender, educational degree, position or designation, country classification, or type of library. While the Internet acts as a supplement to the library collection, whenever the requested information is not available at the library, librarians prefer Googling instead of looking at other sources. Other than aquatic science-specific open access repositories and databases, some of the librarians have identified Google Scholar, DOAJ, ResearchGate, and Academia, among many others as valuable resources that help them fulfill their clientele’s query.

The Philippine milkfish industry has been dependent on the importation of juveniles for grow-out ever since the decline of wild fry catch and with inadequate supply from local hatcheries. However, self-sufficiency is required to address recent global uncertainties. Value chain analysis of the upstream stages of the milkfish aquaculture pathway reveals options for efficient utilization of coastal aquaculture resources, capital investments and workforce. This paper presents a value chain that starts in an integrated breeding and hatchery (IBH) facility that will produce the required juveniles to yield 7.7 thousand mt milkfish valued at PHP 692 million per year (1 USD = 50 PHP). The number of IBH needed annually were determined, such that the country should have 60 IBH in 2030 to produce 448 thousand mt milkfish worth PHP 61 billion for its 128 million projected population. Economic analysis showed that public-private partnership should fund high-investment but low-profit IBH, while private investors should operate profit-earning hatcheries, nurseries and 4-cage mariculture system to secure the milkfish industry.

As much as 78% of fish production is subject to international trade competition. While this may be positive for economic growth, it may be at odds with achieving food security. The purpose of this paper is to review the relationship between aquaculture and food security, focussing on trade and markets in some developing countries that account for more than 90% of aquaculture output. The international trade in fish products largely involves the movement of high value species from developing to developed countries and the opposite in reverse, which can contribute to food security. Countries where food security is not improving tend to rely on small-scale aquaculture production of species that are not desired in the main markets, themselves relying on imported fish to meet domestic demand. This suggests that an aquacultural revolution in these countries may contribute to food security, as well as economic growth.

The emergence of diseases such as Acute Hepatopancreatic Necrosis Disease and White Spot Syndrome has compelled researchers in shrimp aquaculture to develop more innovative methods in improving shrimp health management for the prevention of diseases. One of these methods involves the use of immunostimulants, which enhance the innate immunity of shrimp. Polysaccharides extracted from red seaweeds such as Gracilariopsis heteroclada, locally known as “Gulaman”, present a great source of immunostimulants. Thus, this study aimed to evaluate Gracilariopsis heteroclada as an immunostimulant for Litopenaeus vannamei, or Pacific white shrimp. Hot-water extracts of Gracilariopsis heteroclada were administered through immersion. Results showed no significant changes in total haemocyte count, ambiguous fluctuations in phenoloxidase activity, and a late temporary increase in respiratory burst activity. Overall, these indicate a lack of significant immunostimulation in Litopenaeus vannamei juveniles when immersed in Gracilariopsis heteroclada hot-water extract.

A shrimp grow-out trial was conducted in four 700 m² earthen ponds in Dumangas Brackishwater Station of SEAFDEC Aquaculture Department, in Iloilo, Philippines to evaluate the efficacy of a combination of immersion- and orally-administered formalin inactivated vaccine (FIV) as an antiviral strategy against WSSV. Purified virus prepared by sucrose gradient ultracentrifugation was inactivated by overnight incubation in 0.5% buffered formalin. PCR-screened Penaeus monodon postlarvae (PL14) obtained from a commercial hatchery were divided into two groups: 1) immersed in FIV solution for 2 h before stocking in ponds (VAC); and 2) unexposed control (CON). Both groups were stocked at a density of 15 m⁻² and grown for 115 d following recommended good practices. Pond water was aerated using two 20-HP electric blowers. Shrimp were given commercial feed following the manufacturer's protocol. They were booster-vaccinated by administering FIV-coated feed every 15 d until the termination of the trial. Shrimp samples were regularly collected to obtain estimates of growth, survival, and feed conversion ratio. In addition, shrimp and extraneous crustacean species were analyzed for the presence of WSSV and IHHNV by PCR. Water quality and bacterial load were monitored regularly. After 115 d of culture (DOC), shrimps grew to 12.93 ± 1.26 g in VAC and 8.54 ± 0.78 g in CON. Likewise, survival and yield was higher in VAC (71.2 ± 3.13% and 1311 ± 70.4 kg ha⁻¹, respectively) compared to CON (52.7 ± 5.05% and 640 ± 3.0 kg ha⁻¹, respectively). PCR analysis showed both shrimp and extraneous crustaceans to be lightly infected with WSSV and IHHNV. A few dead shrimp were noted during routine pond inspection as shrimp biomass increased towards the end of the trial. However, no mass mortalities occurred and shrimp were successfully harvested on 115 DOC. VAC and CON shrimp were also collected on day 70, 90, and 105 and experimentally infected with WSSV in tanks. Significant differences in survival rates (p < 0.05) between the groups were obtained 15 d post-challenge. Further studies in tanks and in ponds on prophylactic oral delivery of antiviral treatments with the use of protein vaccines and vectors/carriers are recommended.