Now showing items 3119-3138 of 3262

    • Article

      Uptake and elimination of iodine-131 by the freshwater clam Corbicula manilensis Philippi from water 

      MLA Cuvin & RC Umaly - Natural and Applied Science Bulletin, 1988 - College of Arts and Sciences, University of the Philippines
      Whole body uptake of Iodine-131 by the freshwater clam, Corbicula manilensis, from contaminated water was followed using NaI scintillation counter. The bioaccumulation factor (BF) exclusive of shell was 5.44. The degree of bioaccumulation of I-131 by the different tissues is as follows: visceral remains > gills > gut > gonads > mantle > muscle > foot. The specific activities of the different tissues corresponded with their BF values. The relative distribution of I-131 in the different tissues was generally proportional to the weight ratio of each tissue. Elimination studies gave the effective half-life, Te0.5, of 4.5 days. Estimation of Te0.5 in the different tissues gave the following values: 12 d (mantle), 3.9 d (gonad and muscle), 3.6 d (gut), 3.4 d (gills), 2.4 d (foot) and 1.9 d (visceral remains).
    • Article

      Uptake and some physiological effects of mercury on water hyacinth, Eichhornia crassipes (Mart) Solms. 

      RA Tabbada, PE Florendo & AE Santiago - Biotropia, 1990 - SEAMEO
      The uptake and growth effects of mercury (Hg) on Eichhornia crassipes under field conditions and with lakewater as cultural medium were investigated. Absorption of the heavy metal increase with higher levels of Hg in the culture solution. Roots of the heavy metal than the leaves. The addition of 1 and 2 ppm of Hg into the culture medium was not toxic but significantly reduce fresh matter production, root elongation, ramet formation and total chlorophyll content of mature leaf blades during a four-week culture period. The results strongly suggest a beneficial role of the plant, long considered as a noxious weed, as a bioaccumulator of Hg in polluted lakes.
    • Conference paper

      Urease activity in soybean meal: effect on its nutritional quality and on growth and survival of Penaeus monodon juveniles. 

      MN Bautista-Teruel & PF Subosa - In Aquaculture Research and Sustainable Development in Inland and Coastal Regions in South-East Asia, Proceedings of an IFS/EU Workshop, Can Tho, Vietnam, 18-22 March 1996, 1998 - International Foundation for Science
      Based on the results of a survey conducted on the urease activity (UA) in commercial shrimp feed containing soybean meal (SBM) (0.00-29. 70 ppm UA), a study was carried out to determine the effects of different heat treatments on the UA, and on the nutritional quality of SBM. The effect of these heat treated SBMs when incorporated into shrimp diet on the growth and survival of Penaeus monodon juveniles was likewise tested. Various levels of UA in SBM were obtained with different heat treatments. Six practical diets were formulated and contained 0.00 (SBM heated at !20°C for 20 min); 0.50 (SBM heated at 60°C for 160 min); 4.0 (SBM heated at 60°C for 80 min); 8.0 (SBM heated at 60°C for 40 min); 11.0 (SBM heated at 60°C for 20 min) and 22.0 ppm UA (without heating). These diets were fed to P. monodon (average weight = 4.24±0.10 g) juveniles for a period of 60 days. Results showed that protein quality in terms of amino acid content of SBM was not significantly affected by the different heat treatments. Weight gains of shrimps fed diets with 8.0, 11.0, 25.0 ppm UA were significantly lower than those fed other diets. Survival of shrimps was lowest with diets containing unheated SBM, but this was not significalltly different from those heated at 60°C. Heat treatment of SBM at 120°C is adequate to be an effective ingredient in shrimp diets.
    • Article

      The use of a Visual Implant tag to monitor the reproductive performance of individual milkfish Chanos chanos Forsskal 

      AC Emata & CL Marte - Journal of Applied Ichthyology, 1992 - Blackwell Publishing
      Nine-year old milkfish (3.8 kg., average body weight) were individually marked with Visible Implant (VI) tags to monitor their reproductive performance following hormonal induction. All tags were retained after one year; only 5 out of 64 tags were not readable due to improper implantation. The advantages of using VI tags include: less tagging time (less than one minute), high retention rate, longer retention, infection-free, and easily readable.
    • Article

      Use of Acadian marine plant extract powder from Ascophyllum nodosum in tissue culture of Kappaphycus varieties 

      AQ Hurtado, DA Yunque, K Tibubos & AT Critchley - Journal of Applied Phycology, 2009 - Springer Verlag
      Three varieties of Kappaphycus alvarezii (Kapilaran, KAP), Tambalang purple (PUR), Adik-adik (AA), and one variety of Kappaphycus striatum var. sacol (green sacol (GS) were used to determine the efficiency of Acadian marine plant extract powder (AMPEP) as a culture medium at different concentrations, for the regeneration of young plants of Kappaphycus varieties, using tissue culture techniques for the production of seed stock for nursery and outplanting purposes for the commercial cultivation of carrageenophytes. A shorter duration for shoot formation was observed when the explant was treated with AMPEP + Plant Growth Regulator (PGR = PAA + zeatin at 1 mg L−1) compared to AMPEP when used singly. However, four explants responded differently to the number of days required for shoot formation. The KAP variety took 46 days to form shoots at 3–4 mg L−1 AMPEP + PGR; while PUR required 21 days at 3–5 mg L−1 AMPEP and 3–4 mg L−1 AMPEP + PGR. AA required 17 days at 3–5 mg L−1 AMPEP and AMPEP + PGR; and GS 25 days at 1 mg L−1 AMPEP + PGR. It was observed that among the four explants used, PUR and AA initiated shoot formation with the use of AMPEP only at higher concentrations (3–5 mg L−1) after a shorter period. Only PUR responded positively to ESS/2 for shoot initiation. The use of AMPEP alone and/or in combination with PGR as a culture medium in the propagation of microplantlets using tissue culture technique is highly encouraging.
    • Article

      Use of agar-bound microparticulate diet as alternative food for tropical abalone, Haliotis asinina (Linnaeus 1758) post-larvae in large-scale cultures 

      MN Bautista-Teruel, JRH Maquirang, MR de la Peña & VT Balinas - Aquaculture International, 2017 - Springer Verlag
      The efficacy of using agar-bound microparticulate diet (A-MPD) as alternative food for abalone Haliotis asinina Linne post-larvae in large-scale culture was investigated. Larvae sourced from the hatchery-bred (HB) and wild-sourced (WS) broodstock were fed with either diatoms (TMT1-NF), agar-bound microparticulate diet (TMT2-A-MPD), or a combination of both feeds (TMT3-NF + A-MPD) in six 2-m3 tanks replicated over time. Three hundred thousand veliger larvae were stocked/tank containing 80 corrugated plates with mucus trails hanging on bamboo poles. Feeds were given at 0900 h starting at day 3 with seawater flow through introduced every 1400 h starting day 5. Two-way analysis of variance determined significant differences (p < 0.05) in survival and shell length between larval sources and feed types. Tukey’s post hoc test established differences among treatment means. At day 30, survival for HB- and WS-sourced larvae was significantly higher (42%) in TMT3 compared with TMT2 having 35% for HB and 38% for WS (p < 0.05). Larvae fed with TMT1 had significantly lowest survival among the three treatments. Survival at 60 and 90 days did not show significant difference for TMT2 and TMT3 regardless of broodstock source. Post-larval shell growth (90 days), from both sources fed with TMT2 and TMT3, was significantly higher than TMT1 (p < 0.05). Larval performance did not show any significant interactions between HB and WS broodstock. The use of A-MPD alone or in combination may elicit improvement in survival and shell length growth in abalone larvae regardless of larval sources. A-MPD may be used as full or partial replacements to diatoms as alternative food for abalone post-larvae in large-scale culture.
    • Conference paper

      The use of aquatic plants as feed for Tilapia nilotica in floating cages 

      SA Rifai - In Proceedings of the International Workshop on Pen Cage Culture of Fish, 11-22 February 1979, Tigbauan, Iloilo, Philippines, 1979 - Aquaculture Department, Southeast Asian Fisheries Development Center; International Development Research Centre
      Three kinds of aquatic plants, namely, Hydrilla verticillata, Lemna minor , and Chara sp. were used as feed for the T. nilotica reared in floating cages at three levels of stocking densities: 5, 15, and 45 fishes per cage. Results of the study showed that Lemna minor gave the best effect on growth rate of the fish in every level of stocking density. Feed conversion rate ranged from 19 to 33; Lemna minor was the lowest (33:1), while Chara sp. was the highest (19:1).
    • Book | Conference publication

      Use of Chemicals in Aquaculture in Asia : Proceedings of the Meeting on the Use of Chemicals in Aquaculture in Asia. 

      JR Arthur, CR Lavilla-Pitogo & RP Subasinghe (Eds.) - 2000 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The use of chemicals is common in various aquaculture systems, as it is in many agricultural practices. However, with growing worldwide awareness of the need for responsible practices in aquaculture, governments and aquaculturists are increasingly concerned with the effects of the use of chemicals in aquaculture, especially those which appear likely to be hazardous to man, cultured stock and/or the environment. The need to synthesize and disseminate information on the use and management of double prime aquachemicals double prime was recognized by the Fishery Resources Division of the Food and Agriculture Organization of the United Nations (FAO) and the Southeast Asian Fisheries Development Center (SEAFDEC) Aquaculture Department, who convened double prime The Expert Meeting on the Use of Chemicals in Aquaculture in Asia, double prime which was held 20-22 May 1996 at the SEAFDEC facilities in Tigbauan, Iloilo, the Philippines. Support was provided by FAO, SEAFDEC and the Canadian International Development Agency s (CIDA) ASEAN Fund. The World Health Organization (WHO) supported the participation of a human health expert. The meeting was attended by 27 participants and more than 70 observers from the public and private sectors of 20 countries. Among the attendees were representatives from the Network of Aquaculture Centres in Asia-Pacific (NACA), the Fish Health Section of the Asian Fisheries Society (FHS/AFS), the Japan International Research Center for Agricultural Sciences (JIRCAS), the GESAMP Working Group on Environmental Impacts of Coastal Aquaculture, and the ICES Working Group on Environmental Interactions of Mariculture. The results of this expert workshop are presented in this volume. They include the texts of presentations on a wide range of topics (thematic reviews) related to the use of chemicals in aquaculture, with emphasis on the Asian Region, as well as country overview papers summarizing the use of aquachemicals in Asian countries. The contributions of the selected participants during the meeting are contained in this volume.
    • Conference paper

      The use of chemicals in aquaculture in India 

      SC Pathak, SK Ghosh & K Palanisamy - In JR Arthur, CR Lavilla-Pitogo & RP Subasinghe (Eds.), Use of Chemicals in Aquaculture in Asia : Proceedings of the Meeting on the Use of Chemicals in Aquaculture in Asia 20-22 May 1996, Tigbauan, Iloilo, Philippines, 2000 - Aquaculture Department, Southeast Asian Fisheries Development Center
      A review of the use of chemotherapeutants and other chemicals and drugs in Indian aquaculture is presented. A large number of products are used for various purposes such as soil and water treatments, disinfectants, piscicides, herbicides, organic and inorganic fertilizers, feed additives, therapeutants, and anesthetics. Farm management techniques for the use of chemicals are discussed, as are the hazards posed by, and impacts resulting from chemical use. Other approaches to disease prevention (crop holiday, pond preparation, regulating stocking density, effluent treatment systems) are considered, and national regulations on the use of chemicals in aquaculture and current research being conducted in India are summarized. Recommendations for the improved use of chemicals in Indian aquaculture are provided for farmers, government and aquaculture institutions, the chemical industry, regional and international agencies, and research institutions.
    • Conference paper

      The use of chemicals in aquaculture in Indonesia 

      H Supriyadi & A Rukyani - In JR Arthur, CR Lavilla-Pitogo & RP Subasinghe (Eds.), Use of Chemicals in Aquaculture in Asia : Proceedings of the Meeting on the Use of Chemicals in Aquaculture in Asia 20-22 May 1996, Tigbauan, Iloilo, Philippines, 2000 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Aquaculture systems in Indonesia have developed toward intensive culture. As a result of intensification of fish culture, increased outbreaks of disease have occurred. Various chemotherapeutic agents like antibiotics and other chemicals have been widely used for treatment and prevention of infectious diseases in fish and shrimp farms. Antibiotics such as oxytetracycline, chloramphenicol, neomycin, streptomycin, erythromycin, prefuran and enrofloxacin are used in the treatment of bacterial diseases. Other chemicals such as malachite green oxalate, potassium permanganate, formalin, methylene blue, chlorine and teaseed have been used for the treatment of various diseases. Organic fertilizers, such as chicken manure, and inorganic fertilizers like urea and trisodium phosphate are often applied by shrimp farmers to improve primary productivity in ponds. Bacterial products with trade names like “Multi bacter,” “Enviro star” and “Super NB” have recently been used by shrimp farmers to decompose organic matter resulting from excessive feeding. Feed additives such as vitamin C, “Protec Plus,” and “Super Embak” are used for disease prevention.
    • Conference paper

      The use of chemicals in aquaculture in Malaysia and Singapore 

      S Mohamed, G Nagaraj, FHC Chua & YG Wang - In JR Arthur, CR Lavilla-Pitogo & RP Subasinghe (Eds.), Use of Chemicals in Aquaculture in Asia : Proceedings of the Meeting on the Use of Chemicals in Aquaculture in Asia 20-22 May 1996, Tigbauan, Iloilo, Philippines, 2000 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Aquaculture is an increasingly important force in both the Malaysian as well as the Singaporean economies. In recent years, Singapore has focused on the aquarium fish trade, making it one of the largest ornamental fish production and transhipment centers in the world. Similarly, the Malaysian aquaculture industry has made rapid strides in the last few years and is poised to become a major contributor to the national fish supply by the early part of the next century. A significant trend in both countries has been the growing intensification of culture systems to achieve higher production per unit area. This has led to a greater occurrence of disease, particularly among aquarium fish, shrimp and marine fish farms. To obviate and control these diseases, there has been a concurrent increase in the use of chemotherapeutants. The three major groups of commonly used chemotherapeutants are: topical disinfectants, antimicrobials and probiotics. There is a wide range of topical disinfectants used by aquafarmers. The most common of these include lime, teaseed cake, formalin, benzalkonium chloride, acriflavine, malachite green, hypochlorite and poly-vinyl pyrrolidine. Of these, lime and teaseed cake are used exclusively in ponds, and acriflavine and malachite green only in hatcheries, while the others are used in both systems. Antimicrobials being used include sulfonamides, tetracyclines, nitrofurans, chloramphenicol, oxolinic acid and virginiamycin. A number of other chemotherapeutants are also used, albeit on a limited basis. The current concerns surrounding the use of chemotherapeutants and the legislative framework surrounding their sale and distribution are also discussed.
    • Conference paper

      The use of chemicals in aquaculture in Taiwan, Province of China 

      IC Liao, JJ Guo & MS Su - In JR Arthur, CR Lavilla-Pitogo & RP Subasinghe (Eds.), Use of Chemicals in Aquaculture in Asia : Proceedings of the Meeting on the Use of Chemicals in Aquaculture in Asia 20-22 May 1996, Tigbauan, Iloilo, Philippines, 2000 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Aquaculture in Taiwan has a history of more than three centuries. To satisfy consumer preferences, a wide variety of aquatic species, 71 in 1993, are being cultured in Taiwan. It is difficult to control diseases when many species are cultured and stocking densities are high. At present, it is important to manage the use and application of chemotherapeutants effectively. Many aquatic animal diseases fall under the category of potentially curable illnesses. These include diseases of bacterial, protozoan, fungal, and environmental etiologies. This paper summarizes the chemicals used in aquaculture, farm management practices, alternative disease prevention methods, national regulations, and the current research on chemical use for aquaculture in Taiwan.
    • Conference paper

      The use of chemicals in aquaculture in Thailand 

      K Tonguthai - In JR Arthur, CR Lavilla-Pitogo & RP Subasinghe (Eds.), Use of Chemicals in Aquaculture in Asia : Proceedings of the Meeting on the Use of Chemicals in Aquaculture in Asia 20-22 May 1996, Tigbauan, Iloilo, Philippines, 2000 - Aquaculture Department, Southeast Asian Fisheries Development Center
      In Thailand, many chemicals are used to treat diseases of cultured aquatic animals and to improve water quality in culture facilities. Along with the intensification of aquaculture practices that has occurred in recent years in Thailand, chemical use has also increased, particularly in marine shrimp culture. This paper summarizes information on the types of chemotherapeutants commonly used in Thailand, their sources and costs, the treatment regimes used, the adverse impacts that have resulted and the hazards posed. Also included is information on national regulations, a summary of on-going research, and recommendations to aquaculturists, producers and suppliers of chemicals, government agencies and scientists. It is concluded that although chemicals and drugs will continue to play an important role in the development of Thai aquaculture, they must be used with caution to avoid adverse effects such as environmental damage and the development of resistant strains of pathogens. To minimize chemical usage, additional emphasis needs to be placed on developing good management practices for aquaculture systems.
    • Conference paper

      The use of chemicals in aquaculture in the People's Republic of China. 

      J Yulin - In Use of Chemicals in Aquaculture in Asia : Proceedings of the Meeting on the Use of Chemicals in Aquaculture in Asia 20-22 May 1996, Tigbauan, Iloilo, Philippines, 2000 - Aquaculture Department, SEAFDEC
      Aquaculture in China has developed very rapidly in recent years. Chemicals have become important tools in the control of disease and prevention of losses in various culture systems. The occurrence of diseases stimulated the development and production of drugs for aquatic culture systems, and promoted research on chemicals and their applications. Meanwhile, there exist some problems in the application of chemicals; and there are some potential risks in their usage in aquaculture which should not be neglected.

      This paper describes the use of chemicals for the prevention and control of diseases in aquaculture in China. Their production, marketing, and usage, as well as associated problems and adverse impacts are also discussed. Approaches and practices to prevent diseases are also given. National regulations, on-going research and other aspects of the use of chemicals in aquaculture in China are also highlighted.
    • Conference paper

      The use of chemicals in aquaculture in the Philippines. 

      ER Cruz-Lacierda, L De la Peña & S Lumanlan-Mayo - In Use of Chemicals in Aquaculture in Asia : Proceedings of the Meeting on the Use of Chemicals in Aquaculture in Asia 20-22 May 1996, Tigbauan, Iloilo, Philippines, 2000 - Aquaculture Department, SEAFDEC
      The intensification of aquaculture in the Philippines has made the use of chemicals and biological products inevitable. A recent survey conducted nation wide among shrimp and milkfish culture facilities revealed the use of more than 100 products for rearing, prophylaxis, and treatment purposes. The most commonly applied chemicals are disinfectants, soil and water conditioners, plankton growth promoters, organic matter decomposers, pesticides, feed supplements, and antimicrobials. All of these are readily available in the market. The dosages, purposes, patterns of use, origins, and manufacturers of these chemicals and biological products are discussed in this paper.

      The indiscriminate use of chemicals has caused mortalities and morphological deformities in the host and development of antibiotic-resistant bacterial strains. The use of chemicals in aquaculture also poses dangers to public health. Government policies regulating or prohibiting the use ofcertain chemicals for aquaculture have helped curtail the destructive consequences of chemotherapy. Moreover, research institutions have geared their studies towards discovering environmentally safe drugs and other alternatives to disease control. However, these efforts will be futile unless a strong and aggressive campaign on the cautious and restricted use of drugs in aquaculture is conducted among shrimp and fish farmers, drug manufacturers and suppliers.
    • Conference paper

      The use of chemicals in aquafeed. 

      M Boonyaratpalin - In Use of Chemicals in Aquaculture in Asia : Proceedings of the Meeting on the Use of Chemicals in Aquaculture in Asia 20-22 May 1996, Tigbauan, Iloilo, Philippines, 2000 - Aquaculture Department, SEAFDEC
      Various chemicals and additives used in fish and shrimp feeds may have impacts on animal health, product quality and the environment. This paper reviews the use and effects of vitamins (vitamins C and E), essential fatty acids, carotenoids, immunostimulants, hormones and attractants added to feeds for cultured fish and shellfish.
    • Conference paper

      The use of chemicals in carp and shrimp aquaculture in Bangladesh, Cambodia, Lao PDR, Nepal, Pakistan, Sri Lanka and Viet Nam. 

      M Phillips - In Use of Chemicals in Aquaculture in Asia : Proceedings of the Meeting on the Use of Chemicals in Aquaculture in Asia 20-22 May 1996, Tigbauan, Iloilo, Philippines, 2000 - Aquaculture Department, SEAFDEC
      This paper provides an overview on the use of chemicals in seven countries in Asia (Bangladesh, Cambodia, Nepal, Laos PDR, Pakistan, Sri Lanka and Viet Nam), with an emphasis on coastal shrimp aquaculture and inland carp farming systems. The data come primarily from a recently completed survey of aquaculture farms in Asian countries conducted under the ADB/NACA Regional Study and Workshop on Aquaculture Sustainability and Environment. The issues discussed include the types and uses of chemicals in shrimp and carp culture, farm management practices and use of chemicals, hazards and adverse impacts associated with chemical use, alternative approaches to chemical use, and research recommendations. In inland carp farming, apart from lime and fertilizers, which are unlikely to give rise to any significant negative environmental impact, the overall use of chemicals is extremely low. Piscicides are used in some countries to control predators prior to stocking of ponds, but the use of antimicrobials and disease-control chemicals is limited to a small percentage (<5%) of producers. Most small-scale producers, who dominate aquaculture production in these countries, simply do not have the resources or need for such chemicals. The situation is similar in shrimp culture, with lime and fertilizers, followed by piscicides, being the most common chemicals used. The use of antimicrobials increases with intensification in shrimp culture, and these chemicals are mostly used in more intensive shrimp farming. In both shrimp and carp culture, promotion of “primary” health management practices probably offers greatest scope for prevention of aquatic animal disease outbreaks and the need for chemical use.
    • Conference paper

      The use of chemotherapeutic agents in aquaculture in the Philippines 

      MCL Baticados & JO Paclibare - In M Shariff & RP Subasinghe (Eds.), Diseases in Asian Aquaculture I. Proceedings of the First Symposium on Diseases in Asian Aquaculture, 26-29 November 1990, Bali, Indonesia, 1992 - Asian Fisheries Society, Fish Health Section
      Chemotherapeutants are widely used to treat diseases of fish, specifically shrimp and aquarium fishes in the Philippines. The most commonly treated diseases are luminous vibriosis, filamentous bacterial disease, shell disease, larval mycosis and protozoan infections in shrimp and white spot, velvet disease, fin and tail rot, crustacean and monogenean infections, fungal infections and dropsy in finfishes. These chemicals include chloramphenicol, erythromycin, oxytetracycline, nitrofurans, formalin, malachite green, potassium permanganate, copper sulfate and Neguvon. The indiscriminate use may cause mortalities and morphological deformities in the host, development of resistant strains of bacteria and public health hazards. The Philippine government has embarked on regulating the use of these chemicals. Initially, use of chloramphenicol has been banned in food producing animals. In the near future, rules and regulations on the registration and labelling of these chemicals will be implemented. While these are a welcome development, much still needs to be done. It is recommended that medically important drugs be excluded from aquaculture. The campaign on the careful and restricted use of drugs should be intensified in both drug and aquaculture industries. Further research must be done on the screening of other drugs which are effective and environmentally safe. Lastly, funds should be allocated for research, extension and manpower development in fish health management, specifically, in chemotherapy.
    • Conference paper

      The use of chemotherapeutic agents in shrimp hatcheries in Sri Lanka. 

      PKM Wijegoonawardena & PPGSN Siriwardena - In Use of Chemicals in Aquaculture in Asia : Proceedings of the Meeting on the Use of Chemicals in Aquaculture in Asia 20-22 May 1996, Tigbauan, Iloilo, Philippines, 2000 - Aquaculture Department, SEAFDEC
      In Sri Lanka, the active promotion of chemical products to prevent disease in shrimp hatcheries has led to an increase in the use of drugs and chemicals without much emphasis on understanding their efficacies. A survey was carried out to evaluate trends in the use of drugs and chemicals as therapeutic treatments for shrimp-hatchery diseases. A wide range of chemicals and drugs are being used, both for prophylactic treatment and to prevent or control parasitic, fungal and bacterial diseases in hatcheries. Without proper scientific investigation into treatment regimes, there has been a tendency for individual hatcheries to select their own treatment regimes and to do their own experimentation. Little knowledge exists among hatchery operators as to the hazardous effects of the chemicals in use. Lack of legislation on the use of chemotherapeutants in aquaculture has led to the uncontrolled use and improper selection of chemicals for use in shrimp hatcheries.
    • Article

      Use of copepod nauplii during early feeding stage of grouper Epinephelus coioides 

      JD Toledo, MS Golez, M Doi & A Ohno - Fisheries Science, 1999 - Japanese Society of Fisheries Science
      Newly-hatched Epinephelus coioides larvae were stocked in five 5-ton tanks at an initial density of 25, 000 ind/tank. Copepod nauplii were propagated in four of these tanks by inoculating various densities (20 to 80 ind/l) of mixed copepodids of Acartia tsuensis, Pseudodiaptomus spp., and Oithona sp. three days before stocking larvae. Rotifers were added in these tanks on Day 7 at an initial density of 5, 000 ind/l. Larvae in the remaining tank were fed rotifers (only) starting Day 2 at 5, 000 ind/l. The feeding incidence, gut content, growth, and survival of larvae were better in tanks with higher density of copepodids (60-80 ind/l). These indices were lowest in larvae given rotifers only. Total n-3 HUFA of copepods was 2 to 3 times higher than rotifers. High percentages of 22:6n-3 (DHA) were detected in the fatty acid composition of Pseudodiaptomus (13%) and Acartia (24%) with DHA/EPA (20:5n-3) values of 1.4 and 2.6, respectively. By providing nauplii of copepods at the early feeding stage, an average survival of 3.4% at harvest (Day 36) was obtained in a pilot scale grouper seed production trial in three 10-ton tanks.