Aims: To determine bacterial diversity in milkfish culture ponds that contain different life-cycle stages of the milkfish (pond A: fry, pond B: juveniles and pond C: adults) by DNA sequence analysis of organisms and compare that microbial diversity to organisms found in soil adjacent to the ponds. Study Design: Comparative metagenomic study of aquatic and terrestrial biodiversity based on DNA sequence analysis of water and soil DNA. Place and Duration of Study: SEADEC milkfish ponds in Tigbauan, Iloilo, Philippines. All water and soil samples were collected over a three-day period. Methodology: DNA sequence analysis of nucleic acids extracted from water samples collected from the three types of milkfish ponds along with soil adjacent to the ponds. DNA was extracted and PCR was performed using the 11F-1492R primer pair to amplify 16S rRNA gene. Purified 16S rDNA amplicons were cloned in using the TOPO-TA cloning kit for DNA sequencing. 16s rRNA gene sequences were analyzed with the use of software tools at the National Center for Biotechnology Information website and imported into the ARB phylogenetic analysis software. Distance matrices were exported using the neighbor-joining algorithm in ARB, in the form of PHYLIP-formatted lower triangular matrices. The distance matrices were then used to calculate Shannon-Weaver and Simpson diversity indices to evaluate the richness and evenness of the sampled populations. Rarefaction curves were determined to evaluate sampling efficiency. Results: Rarefaction curves indicated that the sampling effort was sufficient to reveal the majority of phyla present in the sample. Shannon-Weaver and Simpson indices suggested that the diversities of all the groups were statistically different from each other. It was observed that pond A was least diverse, followed by pond C and pond B. The soil was most diverse. DNA sequence analysis identified the various species of bacteria in soil and water. Conclusion: All three pond communities were significantly different in diversity. This study did not identify any significant human pathogens such as Vibrios, Salmonella or Shigella. Bacterial diversity of sites decreased in the following order: soil > fry pond > fingerling pond > adult pond.

Food colour preference is a fundamental aspect of food recognition and has practical application in the formulation of artificial diets and the design of visual baits. Food colour affects growth performance and feed efficiency in captive fishes. This study determined the food colour preference of the juveniles of the African catfish Clarias gariepinus under natural light in a roofed hatchery. A group of 20 juveniles were held in a transparent aquarium whose background colour was made white, blue, green, red, or black. The test food was diced shrimp flesh dyed blue, green, red, and yellow, with non-dyed natural flesh as the white control. In the food colour preference test, the catfish were presented the shrimp flesh in a pair of different colours at a time. The colour of the food that was first approached and ingested, i.e., the first response, was recorded. All the 10 possible food colour pairs were tested against five background colours. Quantitative analysis of the frequency of first response was done by χ2 test and Thurstone’s law of comparative judgment. The juveniles exhibited clear food colour preference that varied with the background colours. Against the black background, the first response was significantly biased to red shrimp flesh. Against the red and blue backgrounds, red and blue shrimp flesh were significantly preferred. Against the white and green backgrounds, no significant color preference was detected. Overall, juvenile African catfish preferred red and blue coloured shrimp flesh. This distinct preference for red and blue food could not be explained by associative learning (brown feed in the hatchery) and seemed innate.

The nutritive value of four leguminous plant seeds: pigeonpea (Cajanus cajan), mungo (Phaseolus radiatus), kidneybean (Phaseolus vulgaris) and soybean (Glycine max), were evaluated as protein sources for milkfish (Chanos chanos) juveniles in isonitrogenous and isocaloric diets containing 40% protein. The legumes were heat-treated and added at different levels so that their protein contributed 25% of total dietary protein; peruvian fishmeal supplied the remaining portion. A diet with all protein contributed by fishmeal was used as a control. Substitution of 25% of the total 40% animal protein in the control diet by mungo and soybean meal did not adversely affect (P > 0.05) fish growth and the efficiency of feed conversion. Diets with 25% of protein contributed by pigeonpea and kidneybean meal resulted in significantly depressed (P ≤ 0.05) growth and efficiency of feed conversion. Milkfish survival rate was more than 97% throughout the six-week experimental period. We conclude that mungo and soybean meal, contributing at least 25% of dietary protein, can be used to replace fishmeal to reduce the cost of feed without adverse effect on the growth, survival and efficiency of feed conversion of juvenile milkfish.

The COVID-19 global pandemic has had severe, unpredictable and synchronous impacts on all levels of perishable food supply chains (PFSC), across multiple sectors and spatial scales. Aquaculture plays a vital and rapidly expanding role in food security, in some cases overtaking wild caught fisheries in the production of high-quality animal protein in this PFSC. We performed a rapid global assessment to evaluate the effects of the COVID-19 pandemic and related emerging control measures on the aquaculture supply chain. Socio-economic effects of the pandemic were analysed by surveying the perceptions of stakeholders, who were asked to describe potential supply-side disruption, vulnerabilities and resilience patterns along the production pipeline with four main supply chain components: a) hatchery, b) production/processing, c) distribution/logistics and d) market. We also assessed different farming strategies, comparing land- vs. sea-based systems; extensive vs. intensive methods; and with and without integrated multi-trophic aquaculture, IMTA. In addition to evaluating levels and sources of economic distress, interviewees were asked to identify mitigation solutions adopted at local / internal (i.e., farm-site) scales, and to express their preference on national / external scale mitigation measures among a set of a priori options. Survey responses identified the potential causes of disruption, ripple effects, sources of food insecurity, and socio-economic conflicts. They also pointed to various levels of mitigation strategies. The collated evidence represents a first baseline useful to address future disaster-driven responses, to reinforce the resilience of the sector and to facilitate the design reconstruction plans and mitigation measures, such as financial aid strategies.

Thirty-five specimens of Glossogobius giurus (TL = 10.8-23.4 cm, wt. = 8.8-66.3 g) collected from Naujan Lake, Oriental Mindoro from May 1991 to February 1992 were examined for metazoan parasites. The parasite species recovered (their organ location in the host, prevalence (%) and intensity of infection range and mean number of parasites per infected fish) were Neochasmus microvatus (Tubangui, 1928) Tubangui and Masilungan, 1944, (Digenea: Cryptogonimidae), stomach and intestine, 48.6, 1-279 (45.1); Opegaster minima (Tubangui, 1928) Yamaguti, 1934, (Digenea: Opecoelidae), stomach and intestine, 37.1, 1-33 (8.7); larval Diplostomulum sp. Hughes, 1929 (Digenea: Diplostomidae), eyes, 25.7, 1-5 (1.8); and Lernaea cyprinacea L. (Crustacea: Copepoda), skin and muscle, 8.6, 1-2 (13).

The manual discusses tilapia culture methods in concrete tanks, net cages, and fishponds. It details the species of tilapia cultured in the Philippines, which include Oreochromis niloticus, O. mossambicus, O. aureus. It covers the following: site selection; construction of netcages and its modules; fishpond construction and pond preparation; criteria for fry selection; stocking; netcage and pond management including water quality management; and harvest. The manual also lists the agencies involved in tilapia research and development in the Philippines; defines some technical terms in a glossary, and lists some useful references.

Following a brief account of the biology of the green mussel (Perna viridis), a review is made of mussel farming techniques in the Philippines. The basic principles behind mussel farming are described, considering spatfall, site selection, and selection of suitable collector material. Farm construction and operation procedures are also described, and an examination is made of the economic aspects of mussel farming.

A sampling of the protandric shrimp, Pandalus latirostris, was conducted at fixed sites from July 2015 to March 2020 in Akkeshi Bay and the connecting Lake Akkeshi on the Pacific coast of eastern Hokkaido. Based on the occurrence pattern of P. latirostris, most individuals begin mating as males at Age-1, followed by a sex change to females, spawn eggs as females at Age-2, and hatch their eggs in the spring of Age-3. Pre-hatching ovigerous females were mainly found in eelgrass beds near and in Lake Akkeshi, where the water temperature was relatively high. The females probably migrate there to hatch their eggs, making sure of the high survival and growth of the hatched larvae. Juveniles and small males were also abundant in near and in Lake Akkeshi, indicating that many larvae remained in the eelgrass beds where they hatched. These eelgrass beds play an important role in the maintenance of the shrimp population as a major egg-hatching site and nursery habitat in Akkeshi waters. With ontogenetic development, the occurrence rate of P. latirostris gradually increased on the offshore side of Akkeshi Bay, with its body size being larger. As P. latirostris grow, they will probably disperse to the offshore side of Akkeshi Bay. However, the density of P. latirostris in the eelgrass bed in the bay near the lake was extremely high, with its strong preference at all ontogenetic stages. This eelgrass bed would help maintain the shrimp population as a “key habitat” for the shrimp. The site-specific environmental characteristics of vegetation beds influence the distribution and abundance of individuals within a population of P. latirostris through their growth and the associated change in habitat preference. In this study, the importance of maintaining the diverse habitats of P. latirostris will be discussed as part of the shrimp stock management measures.