National Committee on Marine Sciences (NCMS)
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- Latitudinal variation in growth and survival of juvenile corals in the West and South PacificNozawa, Yoko; Villanueva, Ronald D.; Munasik, Munasik; Roeroe, Kakaskasen Andreas; Mezaki, Takuma; Kawai, Takashi; Guest, James; Arakaki, Seiji; Suzuki, Go; Tanangonan, Jean J. B.; Ang, Put O.; Edmunds, Peter J. (Springer, 2021-08-18)Reef-building corals are found across > 30° of latitude from tropical to temperate regions, where they occupy habitats greatly differing in seawater temperature and light regimes. It remains largely unknown, however, how the demography of corals differs across this gradient of environmental conditions. Variation in coral growth is especially important to coral populations, because aspects of coral demography are dependent on colony size, with both fecundity and survivorship increasing with larger colonies. Here we tested for latitudinal variation in annual growth rate and survival of juvenile corals, using 11 study locations extending from 17° S to 33° N in the West and South Pacific. Regression analyses revealed a significant decline in annual growth rates with increasing latitude, whereas no significant latitudinal pattern was detected in annual survival. Seawater temperature showed a significant and positive association with annual growth rates. Growth rates varied among the four common genera, allowing them to be ranked Acropora > Pocillopora > Porites > Dipsastraea. Acropora and Pocillopora showed more variation in growth rates across latitudes than Porites and Dipsastraea. Although the present data have limitations with regard to difference in depths, survey periods, and replication among locations, they provide evidence that a higher capacity for growth of individual colonies may facilitate population growth, and hence population recovery following disturbances, at lower latitudes. These trends are likely to be best developed in Acropora and Pocillopora, which have high rates of colony growth.We appreciate volunteers, students, and assistants for data collection. Y.N. especially thank H.-S. Hsieh and C.-H. Liu for data measurement, and V. Denis for his comments on the manuscript. Comments from two anonymous reviewers improve our manuscript greatly. The study was funded by the thematic research grant of Academia Sinica (23-2g) and an internal research grant of Biodiversity Research Center, Academia Sinica to Y.N. The Okinawa survey was partly supported by the Japan Society for the Promotion of Science through NEXT Program #GR083. Temperature data for the Okinawa site were provided by the coral reef survey of Monitoring Sites 1000 Project, operated by the Ministry of the Environment, Japan. Temperature data for Moorea were provided by the Moorea Coral Reef LTER, funded by the US National Science Foundation (OCE-0417412).
- Transcriptome analysis of growth variation in early juvenile stage sandfish Holothuria scabraOrdoñez, June Feliciano F.; Galindez, Gihanna Gaye S.T.; Gulay, Karina Therese; Ravago-Gotanco, Rachel (Elsevier, 2021-12)The sandfish Holothuria scabra is a high-value tropical sea cucumber species representing a major mariculture prospect across the Indo-Pacific. Advancements in culture technology, rearing, and processing present options for augmenting capture production, stock restoration, and sustainable livelihood activities from hatchery-produced sandfish. Further improvements in mariculture production may be gained from the application of genomic technologies to improve performance traits such as growth. In this study, we performed de novo transcriptome assembly and characterization of fast- and slow-growing juvenile H. scabra from three Philippine populations. Analyses revealed 66 unigenes that were consistently differentially regulated in fast-growing sandfish and found to be associated with immune response and metabolism. Further, we identified microsatellite and single nucleotide polymorphism markers potentially associated with fast growth. These findings provide insight on potential genomic determinants underlying growth regulation in early juvenile sandfish which will be useful for further functional studies.The authors are grateful to the following individuals and institutions for providing samples and facilitating their collection: D. Ticao of (Finfish Hatcheries, Inc.); Dr. M.A. Juinio-Menez, ˜ J.R. Gorospe, C. Edullantes, B. Rodriguez, A. Rioja, T. Catbagan, and G. Peralta of Bolinao Marine Laboratory, University of the Philippines Marine Science Institute; and E. Tech (Palawan Aquaculture Corp.).
- Age, growth, and population structure of Conomurex luhunuasSanchez-Escalona, Katherine; Aliño, Porfirio (National Fisheries Research and Development Institute, 2022-12)Age and growth dynamics of Conomurex luhuanus were investigated to determine the population structure. Age-specific change in shell shape determined with geometric morphometrics revealed discrimination of shape between 0-3 years old at 99–100% while 3–4 years old can be separated with 81% certainty. Using the age discrimination data, K and L∞ were estimated at 1.00 year and 7.28 cm, respectively. Recruitment is bimodal with natural mortality (M) of 0.71 and fishing mortality (F) approximated at 3.92 year. The exploitation rate (E) is 0.85 year, indicating probable overharvesting of the population under study. The presence of a deep-water population, age-specific burying behavior, and bimodal recruitment pattern are possible resilience factors.The study was supported by a grant from PCAARRD-DOST.
- Associated effects of shading on the behavior, growth, and survival of Stichopus cf. horrens juvenilesRioja, Rose Angeli; Palomar-Abesamis, Nadia; Juinio–Meñez, Marie Antonette (Springer Science and Business Media LLC, 2021-07-07)Stichopus cf. horrens is an emergent culture species. It is known to be nocturnal and negatively phototactic; hence, determining its behavioral and growth responses to different light regimes is essential in optimizing culture protocols. This study examined the interactive effects of shading and relative food availability on the feeding pattern, absolute growth rates, and survival of juvenile S. cf. horrens. Six-month-old juveniles (4.27 to 19.41 g) were reared in replicate aquaria with three different shading treatments (covered, exposed, and half-covered aquaria) under ambient light conditions for 30 days. Juveniles in the exposed treatment with high microalgal biomass (13.44 ± 4.57 mg/g) had the highest growth rates (0.10 ± 0.05 g/day) but also the highest mortality (50%). In contrast, juveniles in the covered treatment had the lowest growth (−0.07 ± 0.03 g/day) but the highest survival (100%). Growth rates in the half-covered treatment were comparable with the exposed, and survival was higher than in the covered treatment. These indicate a trade-off between growth associated with more food and mortality risks due to light-induced stress. Juveniles in the half-covered treatment showed a significant preference to stay in the shaded portion whenever they were inactive during the day, suggesting avoidance to high light intensities (4726.51 ± 1582.43 Lux). Results of this study suggest that careful calibration of light intensities in nursery systems may help enhance juvenile growth. For indoor systems that may have limited space or surfaces for microalgal growth, cultured benthic diatom can be added to the partially covered tanks to increase the food available for the juveniles.
- The genus Sargassum (Phaeophyta, Sargassaceae) from Balibago, Calatagan, PhilippinesAng, P. O.; Trono, G. C. (Walter de Gruyter GmbH, 1987)Eight species of Sargassum: S. baccularia (Mertens) C. Agardh, S. cinctum J. Agardh, S. crassifolium J. A-gardh, S. ilicifolium (Turner) C. Agardh, S. notarisii Zanardini, S. oligocystum Montagne, S. paniculatum J. Agardh, and S. siliquosum J. Agardh are reported from Balibago, Calatagan, Philippines. Growth and changes in the morphology of the two most common species, S. paniculatum and S. siliquosum, were noted throughout their different growth phases over 1 1/2 years. Collections of material representing growth stages of the other species were made at periodic intervals. The more consistent morphological characters for each species were recognized and their utility in taxonomic work was discussed. These characters include outline and length/width ratio of the leaves characteristic of each branching order of laterals, shape and size of the vesicles, muricatous nature of the terminal branchlets, branching pattern of the receptacles, morphology of the female receptacles and the type of holdfast.
- Laboratory and field growth studies of commercial strains of Eucheuma denticulatum and Kappaphycus alvarezii in the PhilippinesDawes, Clinton J.; Lluisma, A. O.; Trono, G. C. (Springer, 1994-02)Daily growth rates of 0.1 to 8.4% d-1 for the brown form and 0.2 to 6.3% d-1 of the green form were measured for 3 to 5-cm long branches of the tropical red seaweed Kappaphycus alvarezii cultured in the laboratory. Highest growth rates were found using inexpensive enrichments such as soil water and coconut water supplemented with 0.7 mM N and 13 µM P and with a liquid fertilizer, Algafer, produced from seaweeds in the Philippines. Laboratory grown branches of both K. alvarezii and Eucheuma denticulatum transplanted to rafts in the field showed daily growth rates of 4.4 to 8.9% d-1, as high or higher than other reported growth rates. The studies, carried out in the Philippines, demonstrate the viability and high yield of laboratory cultivars and methods to keep laboratory culture costs low.
- Survival, growth and food conversion efficiency of Panulirus ornatus following eyestalk ablationJuinio–Meñez, Marie Antonette; Ruinata, Jesselita (Elsevier BV, 1996-11)The viability of eyestalk ablation as a means to enhance the growth of juvenile spiny lobsters in commercial growout cultures was investigated in a 4-month experiment. Three replicate groups of small-sized (86.3–94.4 g total weight; 44.1–46.6 mm carapace length (CL)) Panulirus ornatus were subjected to three experimental treatments: unablated/control, unilateral and bilateral eyestalk ablation. Only animals which were initially at the intermolt stage were used in the experiments. The average food conversion efficiency (12–17%) and monthly growth rates of bilaterally ablated lobsters, based on both total weight (42.0–64.0 g) and carapace length (6.7–7.0 mm CL) increments, were significantly higher than lobsters in the two other treatments during the first 2 months of the experiment but declined thereafter. At the end of the experiment, only 6% of the bilaterally ablated lobsters (n = 48) survived compared with 73% and 75% for unilaterally ablated and unablated lobsters, respectively. The extreme sensitivity of bilaterally ablated lobsters to water quality and diet renders bilateral ablation impractical for commercial growout culture. The high survivorship and generally higher growth rates of unilaterally ablated lobsters compared with unablated lobsters resulted in the highest gross yield among the three treatments. The results indicate that unilateral ablation may be a viable option to consider in accelerating the growth of small juvenile P. ornatus to a marketable size of 200–300 g.
- Metamorphic success and production cost of Holothuria scabra reared on microalgae concentrates compared with live microalgaeGarpa, Tomilyn Jan; Caasi, Olivier Josh C.; Juinio–Meñez, Marie Antonette (Bureau of Fisheries and Aquatic Resources, 2024-03-07)The production of live microalgae poses challenges for the expansion of sandfish hatcheries, hindered by high costs and limited technical resources. In relation to this, the use of three imported commercial concentrates (Instant Algae®) - TW1200 (Thalassiosira weisflogii), TISO1800 (Isochrysis sp.), and Shellfish1800 (mixed diatom) - were compared with live Chaetoceros calcitrans (CC). The diet efficacy was evaluated based on larval development, growth, and survival to late auricularia (LA) with hyaline spheres (HS), and the number of post-settled juveniles. Larvae reared with TW did not progress beyond LA, while those fed CC exhibited earlier LA development, larger sizes (1028.43 ± 19.38 µm), and significantly more post–settled juveniles (9,268 ± 2,183.79) compared to SHELL and TISO. Although TISO larvae reached a larger size during LA (855.7 ± 62.67 µm), SHELL resulted in a higher number of post-settled juveniles. The better performance of CC and SHELL may be attributed to their higher carbohydrate content. Despite SHELL and TISO having lower juvenile yields and longer feeding durations, the estimated cost per juvenile using SHELL, TISO, and CC were PHP 2.00, PHP 11.77, and PHP 0.52, respectively. Results showed that microalgae concentrates are not a cost-effective option under the studied conditions. The potential use of microalgae concentrates as supplemental feeds and further research to develop the use of local microalgae concentrates to sandfish larval culture are discussed.This study was funded by Australian Centre for International Agricultural Research (ACIAR) through the project FIS/2016/122 “Increasing technical skills supporting community-based sea cucumber production in Vietnam and the Philippines” and administrative support from the Marine Environment and Resources Foundation (MERF), Inc. We would also like to thank the Bolinao Marine Laboratory of the University of the Philippines Marine Science Institute for the use of facilities and equipment. We are grateful to our collaborators, Jon Altamirano and Roselyn Noran, and SEAFDEC AQD for guidance on the methods used for preparation and protocols of microalgae concentrate feeding regimen. Special thanks to JayR Gorospe for comments on the earlier draft and Jerwin Baure for copyediting this manuscript. The assistance of Mr. Tirso Catbagan in the culture of larvae and maintenance of the experimental tanks was invaluable during the experiment.
- Escudero: Prioritize growth of local fishing industry over importationCasayuran, Mario (Manila Bulletin Publishing Corporation, 2022-01-22)Sorsogon Governor Francis ‘’Chiz’’ Escudero has said helping the local fishing industry grow and making it competitive should be the priority of the government over importation to address a projected shortage, if it wants to ensure a steady stream of fish supply in the country. Escudero, a senatorial candidate, said a recent announcement by the Department of Agriculture (DA) to import 60,000 metric tons of fish due to its projected supply shortfall of 119,000 metric tons from January to March is worrisome.