The silver therapon, Leiopotherapon plumbeus, is being promoted as a new species for aquaculture. However, information on the optimal conditions for the transport of this species for grow-out culture needs to be established to avoid stress and unnecessary mortalities. This study examined the effects of duration of transport and loading density on survival and water quality during simulated transport of silver therapon (Leiopotherapon plumbeus). Hatchery-produced fingerlings [1.30±0.34 g body weight (BW); 44.30±3.77 mm total length (TL)] were held in double-layered oxygenated plastic bags at three transport durations (6 h, 9 h, and 12 h) and densities (40 fish bag^-1, 80 fish bag^-1, and 120 fish bag^-1) in triplicates. Mean survival rates were not significantly affected by both duration of transport (P=0.321) and loading density (P=0.345). However, a highly significant effect of duration of transport on dissolved oxygen (DO) and pH (P=0.000), and a significant effect on Total Ammonia Nitrogen (TAN; P=0.039) and total bacterial count (TBC; P=0.034) were evident. Similarly, water quality parameters were significantly influenced by loading density (P=0.000), with lower DO and pH levels, and higher TAN and TBC recorded at 120 fish bag^-1 density. Since a very high survival rate (>99%) is achieved at the highest loading density of 120 fish bag^-1 up to 12 h transport, this density can be recommended to transport silver therapon fingerlings. However, chemical treatments using either salt, methylene blue, or tropical almond leaf extract in transport water may be used to reduce the high bacterial count during transport.

The present invention is a culture process for the larval rearing of mud polychaete Marphysa iloiloensis (from 1 DAH to 30 DAH). The process involves the use of fresh bioflocs as the first food source and settlement substrate of the polychaete larvae. Larval rearing was located in a shady area (0 to 50 lux) and aerated, UV-treated seawater was recirculated in the larval rearing tanks. Using this invention, 83.29 ± 3.79% of the larvae survived with 21± 1 segments after 30 days of larval rearing.

Since the first occurrence of White Spot Disease (WSD) in 1992, it is still listed as one of the crustacean diseases by the World Organisation for Animal Health in 2022. Horizontal transmission in co-culture systems is one of the usual modes in the spread of the disease. WSD outbreak was recorded during the experimental run of the co-culture of black tiger prawn (Penaeus monodon) and sandfish (Holothuria scabra) in the grow-out phase. In this study, artificial infection through two cohabitation experiments were conducted to determine if H. scabra is a potential non-crustacean vector or reservoir of WSSV. Samples were checked using one-step and nested PCR for increased readout sensitivity of virus infection to investigate the horizontal transmission between prawn and sandfish. During the first cohabitation (5 days) where WSSV (+) prawn were cohabited with WSSV (-) sandfish, 100% of the prawn were one-step PCR positive for WSSV while 100% of the sandfish were nested PCR positive. Subsequently, WSSV (+) sandfish from the first cohabitation were transferred to another tank to be cohabited with WSSV (-) prawn. Sampling of both prawn and sandfish was done every 6 days post-infection (dpi). At 6 to 18 dpi, prawn and sandfish were nested PCR positive. At 25 dpi, there were no prawns left due to mortality and 1 of the 3 remaining sandfish was nested PCR positive. Based on the results, it elucidates the ability of sandfish to bioaccumulate the viral particles when cohabited with WSSV (+) prawn. Results suggest that WSSV is viable in the sandfish confirming its potential as a vector or reservoir due to the consistent nested PCR positive results of the prawn during the second cohabitation. Hence, it can be inferred that sandfish can be a potential non-crustacean vector or reservoir of WSSV for a limited period of time.

We announce the complete genome sequence of Vibrio parahaemolyticus strain PH1273. This strain was collected from a Penaeus vannamei pond in the Philippines in 2015. Genome analysis revealed that it lacks the gene pirAB responsible for causing acute hepatopancreatic necrosis disease but encode multiple secretion systems and the associated effectors.

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 preference of females for male body size was examined in an experimental environment where direct interference between males was eliminated. In this environment, females preferred to spawn with larger males. To understand the preference of females for larger males, paternal care and egg defence abilities and paternal cannibalism intensity were further tested with respect to the body size of males. The dead egg rate for an egg mass during the paternal care period was not related to the body size of the paternal males. However, larger males could defend their egg masses more successfully against nest intruders than smaller ones. During the paternal egg care period, paternal males often consumed eggs in their nests. In particular, smaller males compared to females caused paternal brood cannibalism. High egg defence ability and low paternal cannibalism intensity are the most plausible reasons for females to choose larger males.

Growth performance (specific growth rate [SGR] and biomass yield), carrageenan properties (yield, viscosity, and gel strength), and disease and pest incidence were compared between Kappaphycus alvarezii var. tambalang (brown) tissue-cultured (TC) plantlets and farm-sourced (FS) seedlings. Seedlings used in the trials were propagules (4‒19 g pieces) and these were deployed on lines in sea cages over three separate runs of 60 days. The highest growth rate was recorded in TC plantlets and the SGRs were significantly higher (1.5‒6.5x) in TC than FS after Day of Culture (DOC) 15 (i.e., measurements taken every 15 days in each cycle). The carrageenan properties did not differ between treatments, with the exception of viscosity at DOC 45, where TC was higher than FS. “Ice-ice” disease (IID) was observed in both FS and TC in May‒June and August‒October at DOC 45 to 60, coinciding with changes in environmental conditions (i.e., dry‒wet and wet seasons). IID in FS had a moderate to very high incidence (31.2‒86.2%), while TC IID had a lower range of incidence (12.8‒60.6%). On the other hand, epiphytic filamentous algae (EFA) were observed only in August‒October with a low incidence (≤25%). However, EFA appeared earlier in FS than in TC. Taken together, these results highlight that tissue-cultured seaweeds had higher growth performance without compromising carrageenan quality and may be more resistant to health problems than farm-sourced seedlings. Studies should now assess the long-term viability of using tissue-cultured seaweeds over farm-sourced seedlings scaling to allow testing in standard farm settings, including the size of the initial seed.

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).

A greater focus on governance is needed to facilitate effective and substantive progress toward sustainability transformations in the aquaculture sector. Concerted governance efforts can help move the sector beyond fragmented technical questions associated with intensification and expansion, social and environmental impacts, and toward system-based approaches that address interconnected sustainability issues. Through a review and expert-elicitation process, we identify five engagement arenas to advance a governance agenda for aquaculture sustainability transformation: (1) setting sustainability transformation goals, (2) cross-sectoral linkages, (3) land–water–sea connectivity, (4) knowledge and innovation, and (5) value chains. We then outline the roles different actors and modes of governance can play in fostering sustainability transformations, and discuss action items for researchers, practitioners, and policymakers to operationalize activities within their engagement arenas.