1,721,040 research outputs found
The status of seed production of grouper and other coral reef fishes in the Philippines
No full textInitial work on seed production of grouper in the Philippines was first reported in 1986. Most of the work has been undertaken by the SEAFDEC Aquaculture Department (SEAFDEC/AQD), which concentrated on Epinephelus coioides. The achievements and results of SEAFDEC/AQD on breeding and larval rearing of grouper which including studies on sex inversion will be discussed. Directions for future research directions are also presented
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Milkfish, rabbitfish and mullet
Full text linkThis paper reviews studies conducted on milkfish (Chanos chanos), rabbitfish (Siganus guttatus), and mullet (Mugil cephalus) at the SEAFDEC Aquaculture Department from 1968 to 1991. Milkfish studies focused on hormonal induction of off-season gonadal maturation, dietary manipulation of milkfish broodstock to improve egg and larval quality, improvement of larval rearing techniques for mass fry production and technology transfer to the private sector, and search for a low-cost, practical diet for milkfish and a supplemental diet to increase pond production. Preliminary success on alternate feed for larval rearing and spontaneous maturation of milkfish in concrete tanks may help alleviate milkfish fry supply in the future. Studies on rabbitfish centered on improvement of larval survival and search for the optimum diet for growth of rabbitfish fry and juveniles reared in ponds. The difficulty in rearing rabbitfish larvae due to high mortality at first week after hatching hinders the development of the rabbitfish industry. Research involving mullet was solely on the establishment of broodstock for fish propagation
Seaweed: Gracilaria
Full text linkThis paper reviews the studies on Gracilaria/Gracilariopsis conducted from 1988 to 1991 by the Aquaculture Department, Southeast Asian Fisheries Development Center. It includes 114 species of macrobenthic algae collected in Panay, the nomenclature of Gracilariopsis heteroclada previously described as Gracilaria sp., and the biology, ecology, and farming systems of Gracilariopsis. Agar quality of the different species of Gracilaria and the effect of seasonal variation on the quality and quantity of agar produced from Gracilariopsis heteroclada were also studied
Prospects of seafarming through the Fisheries Sector Program (Philippines)
Full text linkThe status and problems confronting the fisheries sector are discussed. An exploratory discussion of the five-year Fisheries Sector Program addressed on aquatic resources regeneration, conservation, and sustained management of coastal fisheries, production intensification in aquaculture within limits of ecological balance, and commercial fishing away from over-fished areas into the deeper water is made. Seafarming as one of the alternative livelihood for a large number of coastal subsistence fishermen is emphasized particularly in the 12 priority bays under the program to uplift their economic condition. Rapid resources assessment in the 3 priority bays during the first year of the program implementation pinpointed existing aquaculture practices, potential sites for Seafarming and recommended species for culture. The credit, extension services, and training components of the program are envisioned to enhance Seafarming development in the country
Influence of LHRHa and methyltestosterone on milt production of sea bass Lates calcarifer (Bloch)
Full text linkAbstract only.Milt volume, sperm density, and number of spermatozoa were determined to quantify milt production of mature sea bass after a single injection of LHRHa [(D-Ala6,Pro9-N-ethylamiide)LHRH] in saline solution and 17α-methyltestosterone in corn oil (MT). Two measures of sperm density, sperm count and spermatocrit, were highly correlated (r=0.85). Compared with control, milt volume and the number of spermatozoa collected increased but sperm count decreased (24% at 24 h) after a LHRHa (20 µg/kg body weight treatment, suggesting a stimulation of spermatozoa production and not merely milt dilution. Further milt dilution (44%) was induced by 80 µg/kg LHRHa (LHRHa80) at 12 h post-treatment but not by 200 µg/kg MT (MT200) alone. A milt dilution of only 27% at 12 h after simultaneous injections of LHRHa80 and MT200 may indicate some inhibitory effect of MT on the efficiency of LHRHa. These results demonstrate that the stimulation of milt production by LHRHa involves testicular hydration resulting in milt dilution
Growth and survival of milkfish (Chanos chanos) larvae reared on artificial diets
Full text linkA preliminary feeding experiment was conducted to determine growth and survival of milkfish larvae reared on various feeding regimes involving the use of artificial diets. Two larval diets (Feed A and Feed B) containing 45% protein and 10% lipid were fed either alone or in combination with Brachionus from day 8 to day 21. The feed in the control treatment were Brachionus (10 ind/ml) from day 8 to day 14 and Artemia (2-3 ind/ml) from day 15 to day 21. Larvae in all treatments were fed Brachionus (10 ind/ml) from day 2 to day 7.
No significant differences were observed in survival rates, total length, wet weight and dry weight among fish fed combination of Brachionus and Feed B and the control feed (Brachionus and Artemia). These promising results indicate the possibility of using Feed B as partial replacement or supplement to live food. However, lowest survival rates, total length, and weight were obtained in fish fed either Feed A or Feed B alone, indicating that the test artificial diets given solely to milkfish larvae starting from day 8 can not support good growth and survival. Further studies on the development of improved artificial diets for larval milkfish need to be done
Artificial incubation for intensive fry production of Nile tilapia Oreochromis niloticus (L.)
Full text linkTwo experiments were conducted to evaluate and compare the production, quality, and survival of eggs and the subsequent growth and survival of fry in two small scale production systems: (i) natural incubation (NI), and (ii) egg collection followed by artificial incubation in upwelling glass funnels (AI). Cost benefits analysis was applied to the production figures to compare the economic viability of the two methods. The results were used to design a fry production system for the intensive production of Genetically Male Tilapia (GMT) from limited numbers of novel YY-male broodstock
Seafarming and searanching development in the Philippines
Full text linkThe paper reviews developments in Seafarming and searanching in the Philippines. Seafarming activities concentrated on seaweeds and molluscs, technology for which are already widely practiced. In Seafarming of oysters and mussels, technology is mature but only applied in traditional sites. As such, the quality of products and consumption is low due to known pollution of oyster and mussel farming areas. Seafarming of giant clams is just beginning. Hatchery techniques of producing juveniles are being refined for mass production and seeding of reef areas to enhance giant clam population. Seafarming of marine fishes is also practiced but constrained by the lack of seed stock. Sea cage fanning operators mainly depend on wild-caught fry and juveniles although the hatchery technology for sea bass has been developed. There is more research work to be done to mass-produce fry and juveniles for Seafarming of other fish species.
Seafarming and searanching appear to be the future major means of supplementing the production of animal protein by year 2000 as arable land continues to dwindle. Declining arable land area would not be sufficient to produce the food needs of the increasing population.
There is great potential for Seafarming and searanching to enhance coastal resources and produce more food. However, there is a need to provide stronger legal and institutional support for these activities to sustain development efforts
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