Now showing items 1-20 of 3152

    • Book

      First annual report of the Aquaculture Department of the Southeast Asian Fisheries Development Center (SEAFDEC) for the fiscal year ending December 31, 1973. 

      SEAFDEC Aquaculture Department - 1974 - SEAFDEC Aquaculture Department
      An illustrated account is presented, covering background (establishment of the department), plan of operation (functions; activities), project site development (Leganes Station, Tigbauan Station, construction of buildings, infrastructure development), research (prawn fry stocking, collection of prawn spawners, research staffing, research tie-up with Mindanao State University, Japanese fisheries experts), equipment (preparation of the list of Japanese donated equipment), organization of the department, funding.
    • Book

      Annual report 1974 

      Southeast Asian Fisheries Development Center, Aquaculture Department - 1975 - SEAFDEC Aquaculture Department
      The 1974 report describes the development of project sites at Tigbauan and Leganes, where new ponds and labs have been established. The facilities of these labs include covered and open ponds, wet and field labs, a food preparation building, as well as dormitories and housing units. A substation is now operating at Nueva Valencia, investigating the life cycle of tiger prawn, Penaeus monodon, and 5 further substations also exist. Organisational aspects are described, covering scientific staff, equipment, funding etc. The Department s activities are described in detail; these are mainly concerned with shellfish culture and the associated problems. Notes are included on the First Aquaculture Research Conference (April 1974)and 7th SEAFDEC Council Meeting (Dec 1974). Finally, the new and continuing research projects to be conducted during 1975 are listed.
    • Book

      Annual report 1975 

      Anon. - 1976 - Aquaculture Department, Southeast Asian Fisheries Development Center
    • Book

      Manual of operations : sugpo pond culture 

      JH Primavera & FD Apud - 1976 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Series: Aquaculture extension manual; No. 2
      This manual is intended for fish farmers, extension workers and others in their initial efforts to produce marketable sugpo (Penaeus monodon) for local consumption or export. Information is presented on pond preparation, stocking, transfer from nursery to rearing pond, rearing, harvesting, processing and transport. Appendices deal with the control of pests and predators, diseases, fertilization, and the estimation of rate of supplementary feeding.
    • Article

      Effect of different stocking densities on survival and growth of sugpo (Penaeus monodon Fabricius) in a milkfish-rearing pond 

      JH Primavera, FD Apud & C Usigan - Philippine Journal of Science, 1976 - STII-DOST
      Employing a direct stocking monoculture method, postlarval P. monodon were stocked in 8 compartments of a shallow milkfish rearing pond at densities of 1, 2, 3 and 4/sq m with replicates. Feeding was exclusively natural (microbenthic lablab and plankton); Chanos fingerlings were later introduced to control excessive growth of lablab. Measurements of temperature, DO, pH, salinity and alkalinity were taken daily; stock sampling of length and weight was done every 30 days. Halfway through the culture period, the nylon net separating the compartments was accidentally lifted thereby invalidating data for 5 of the compartments. The prawns were harvested after 5.5 months. Survival was approximately the same for all stocking rates (51.76% at 4/sq m; 50.20% at 2/sq m; 42.54% at 1/sq m and 49.75% for the five remaining compartments treated as one). Growth rates are less conclusive due to the paucity of data. Effects of such physiochemical conditions as high and shallow depth are discussed.
    • Article

      A simple method of tagging prawns 

      LM Rodriguez - Natural and Applied Science Bulletin, 1976 - University of the Philippines
      The recognition of individual animals is crucial to many aspects of research. Prawns present unique difficulties in this respect since they molt regularly. Thus almost all tagging and marking methods developed for prawns so far have proven inadequate. Some are lost during molting; others cause injury to the prawns. A new and efficient method has been developed at the Igang Sea Farming Station of the Aquaculture Department.

      Brass tags measuring 5 mm by 20 mm and numbered consecutively are encircled around the eyestalk like a small bracelet. The prawn is gently held at the base of the carapace by the left hand while the right hand slips the brass tag over the eye. The tag is gently pressed around the eyestalk to prevent its slipping out. All tagging is done under water to avoid stress.
    • Article

      Survival rates of different Penaeus monodon Fabricius postlarval stages 

      JH Primavera - Philippine Journal of Science, 1976 - National Science Development Board
      Four different postlarval stages (P11, P15 , P21, and P25) of P. monodon were stocked in suspension nets at the rate of 200 fry/sq m with 3 nets for each postlarval stage. Pond bottom was simulated by filling each net with a 15 cm layer of mud; dried twigs were provided for protection of the fry. Feeding with lablab and determination of temperature, dissolved oxygen, pH, salinity and alkalinity were regularly undertaken. Results show higher survival rates for P15 and P18 compared to the other stages.
    • Article

      Pond culture of sugpo, P. monodon (Fabricius). 

      JH Primavera & FD Apud - The Philippine Journal of Fisheries, 1976 - BFAR
      A resume is presented of the practical considerations involved in establishing a sugpo pond culture operation, as a guide to fish farmers, extension workers and others interested in producing marketable sugpo in the Philippines. In addition to outlining the general biology of P.monodon , information is given for pond preparation, stocking, transfer from nursery pond to rearing pond, rearing, harvesting, processing and transport. A large appendix deals with the control of pests, predators and diseases, fertilisation and supplementary feeding, and incorporates an illustrated manual of operations.
    • Article

      Induction of maturity and spawning in Penaeus monodon Fabricius, 1798, by unilateral eyestalk ablation (Decapoda, Natantia) 

      RG Wear & AC Santiago Jr. - Crustaceana, 1976 - Brill Academic Publishers
      Preliminary experiments carried out at the Aquaculture Department of the Southeast Asian Fisheries Development Centre in the Philippines have achieved success in the rearing of viable F1 postlarvae of Penaeus monodon from pond reared stocks. Unilateral eyestalk ablation was carried out on 100 female. 7 of these had successfully spawned at 23-months. Egg numbers up to 355,000 per female and successful hatch rates of up to 81% wee obtained. Bilaterally ablated female suffered total mortality by 196 days from eyestalk removal without 1 recorded spawning. Similarly, no spawnings were obtained from unablated controls. It is difficult to determine whether success can be solely attributed to unilateral ablation, or whether a fortuitous choice of experimental site played some major role. In any case, the data obtained are a valuable guide for future work aimed at propagating P.monodon commercially under fully controlled conditions.
    • Article

      Note: larvae of decapod crustacea of the Philippines. II. Laboratory-hatched first zoea of box crab 

      H Motoh - The Philippine Agriculturist, 1976 - College of Agriculture and Central Experiment Station, University of the Philippines at Los Baños
      This is the first report in the world on the characters of the first zoea of Calappa philargius under laboratory conditions. The zoea has a rostral, a dorsal and a pair of lateral spines on the carapace. The average length of larvae from tip of rostral to tip of dorsal spine is 1.26 mm, width, including both lateral spines, 0.74 mm and that of distance between outer margins of eyes, 0.47 mm. There are a pair of lateral hooks on the second and third abdominal segments. There are four natatory hairs on the first and second maxillipeds. Spinal arrangements on the endopodites of the first and second maxillipeds from proximal to distal segment are 2-1-0-2-5 (or 4) and 1-1-4 (or 3), respectively. The number of inner setae on the telson is six (3+3).
    • Article

      Larvae of decapod crustacea of the Philippines - I. The zoeal stages of a swimming crab, Charybdis cruciata (Herbst) reared in the laboratory 

      H Motoh & AC Villaluz - Nippon Suisan Gakkai Shi. Bulletin Of The Japanese Society Of Scientific Fisheries, 1976 - The Japanese Society of Scientific Fisheries
      Six zoeal stages of Charybdis cruciata (Herbst) which are reared in the laboratory, are described. The zoea has a rostral, a dorsal and a pair of laterial spines. There are a pair of lateral hooks on the 2nd and 3rd abdominal segments. The number of natatory hairs on the rirst and second maxillipeds increased by one pair at each molt, being 4, 6, 8, 10, 12 and 14, in the 1st to 6th zoea, respectively. The number of inner setae on the telson are 3+3 in stage 1; 4+4 in stages 2 and 3, 4+1+4 in stage 4, and 5+5 in stages 5 and 6. Spinal arrangement form proximal to distal segment of the endopodite of the first maxillipeds are 2-2-0-2-5 in stages 1-3 and 2-2-1-2-6 in stages 4-6 and that of the second maxillipeds are 1-1-4 in stages 1 and 2 and 1-1-5 in stages 3-6.
    • Article

      The larval stages of benizuwai-gani, Chinoecetes japonicus Rathbun reared in the laboratory 

      H Motoh - Nippon Suisan Gakkai Shi. Bulletin Of The Japanese Society Of Scientific Fisheries, 1976 - The Japanese Society of Fisheries Science
      This study deals with the larval stages of C. japonicus, and with the comparison with those of Zuwaigani, C. opilio. There are 2 zoneae and 1 megalopa. The larval stages of C. japonicus are morphologically similar to those of C. opilio excepting some characters as follows: (1) Chromatophores of Zoeae and megalopa are vermillion or crimson in C. japonicus and brown or reddish in C. opilio. (2) C. japonicus is generally bigger than C. opilio in zoeae and megalopa. (3) Length of postero-lateral spine on 3rd abdominal segment is>1.3times the length of the 4th abdominal segment in C. japonicus, but is shorter than (rarely equal to) that in C. opilio. (4) Ischiopodite of cheliped has no spine in C. japonicus, but it has a spine in C. opilio, in megalopa.
    • Article

      Notes on the external sex characters of Chanos chanos (Forskal) spawners 

      H Chaudhuri, JV Juario, R Samson & LB Tiro - Fisheries Research Journal of the Philippines, 1976 - Fisheries Research Society of the Philippines
      In the present study, no visible differences between the sexes of C. chanos with reference to external features such as colouration, shape of head, snout and operculum, presence of tubercles or nasal pores, length, size and shape as well as any roughness in the various fins, could be found. However, the anal region of the mature milkfish (sabalo) exhibits discernible anatomical differences in the male and female. The male has two main openings visible externally: the anterior anus and the posterior urogenital opening at the tip of the urogenital papilla. The female has three main openings instead of two: the anteriormost anus, followed by the genital pore and the urinary pore located posterior to the genital pore at the tip of the urogenital papilla. Internal examinations were also made on both sexes. In ripe sabalo, it is easier to distinguish the sexes since milk oozes out of the urogenital pore by pressing the abdomen of the ripe male fish. Gravid females are identified by their distended abdomens.
    • Technical Report

      Development of a brood stock of the jumbo tiger prawn, Penaeus monodon Fabricius 

      AC Santiago Jr., L Rodriguez, R Mateo & R Obregon - 1976 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Series: Technical report / SEAFDEC. Aquaculture Department; No. 1
      The full-scale cultivation of sugpo, P. monodon Fabricius, could only be realized if there is an assurance of continuous supply of fry. Obviously, a steady supply will depend largely on the availability of spawners. In December 1975, roughly after 2 1/2 years of intensive study, for the first time in the world, SEAFDEC Aquaculture Department has succeeded in inducing P. monodon to mature and produce normally the first generation of postlarval fry, thereby successfully effecting the completion of P. monodon's life cycle while in captivity. Another significant study the Department has initially carried out which could help augment and stabilize the supply of spawners and eventually stimulate the establishment of more prawn hatcheries and the development of ponds for prawn culture as a major export-oriented, dollar-earning industry, is the possible development of ovarian rematuration of spent spawners.
    • Article

      Successful spawning of cultured Penaeus monodon Fabricius after eyestalk ablation 

      AC Santiago Jr. - Aquaculture, 1977 - Elsevier
      Preliminary experiments resulted in successful spawning of captive stock of the prawn Penaeus monodon, or “sugpo”, to complete the life cycle and produce a viable F1 generation of larvae. Gonadal development was induced using eyestalk ablation techniques on sexually mature females. Removal of one eyestalk was found to be sufficient to induce gonadal development, whereas bilateral ablation indirectly resulted in high mortality of the treated females. By comparison, successful spawning had not occurred in unablated animals after 9 months.

      Fry hatched from wild adult stock and reared to 25-day postlarvae were further impounded in brackishwater experimental ponds and reared for 4 months. A transfer of 1 500 animals were then made to marine pens. After a further 10 months, 600 animals were selected for the experiment; healthy females were ablated unilaterally and placed with 100 males for a further 9 months. Of the remaining 400 specimens, 200 were used as controls and the remainder ablated bilaterally, Seven of the 23-month old females with one eyestalk removed had spawned successfully by January 27, 1976.

      Egg numbers, hatching rate and larval survival compared favorably with data obtained from females of oceanic origin. It is not known if the success of the experiment was entirely due to the effect of ablation or to the choice of a suitable environment. Work is continuing to induce gonadal development under more closely controlled conditions to overcome the inadequate and unreliable supply of spawners.
    • Article

      Bacteria from seawater used in Penaeus monodon larval cultures 

      AT Llobrera & RQ Gacutan - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - SEAFDEC Aquaculture Department
      Bacteria in the seawater used in P. monodon hatchery operations were isolated on Bachmann's agar. The total plate counts in 25 isolations ranged from 1.0 - 5.0 x 102 to 5.1 -10.0 x 105 cells per ml. Out of 124 isolates, 98 (79 percent) were Gram-positive and 26 (21 percent) were Gram-negative. Micrococcus and Staphylococcus were dominant in the former group, while Acinetobacter, Moraxella, Flavobacterium and Alcaligenes were most numerous in the latter. Twenty-nine of the Gram-positive isolates closely resembled Peptostreptococcus, Planococcus, and Pediococcus.
    • Article

      Reduction in Chaetoceros populations by furanace 

      MCL Baticados & RQ Gacutan - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - SEAFDEC Aquaculture Department
      One of the most promising prophylactic agents being tested to control Penaeus monodon larval diseases is furanace (6-hydroxymethyl-2 2(5-nitro-2-furyl) vinyl pyridine). To evaluate further its suitability as a chemotherapeutic agent, its effects on the population growth of Chaetoceros calcitrans, the diatom used as feed for the zoeal stages, was examined. Chaetoceros populations of uniform density (initial density in all runs: 130-141x10 -3 cells /ml) were placed in nine white, circular (382 sq cm), plastic basins. The physio-chemical characteristics of the culture water were as follows: salinity, 28 . 5-30 . 0 ppt; pH, 8 . 62-8 . 72; temperature, 23-25 . 5 degree C; dissolved oxygen, 7 . 1-9 . 3 ppm; nitrate, 0 . 03-0 . 07 ppm; and ammonia, 0 . 005-0 . 03 ppm. Preweighed furanace granules were dissolved in the culture water, with resulting concentrations of 1 and 2 mg/l (3 replicates each). A set of replicates without furanace served as the control. Population counts of the diatom were taken after 2, 4, 6, 8, and 10 hr exposures. After 4 hr, the population decreased in all three levels. The population in 2 mg/l furanace showed the lowest count and that in control the highest. The population means are not statistically different from one another. The results of the study show that the furanace causes reductions in Chaetoceros population at all durations of exposure.
    • Article

      A simple method of tagging prawns 

      LM Rodriguez - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - SEAFDEC Aquaculture Department
      The recognition of individual animals is crucial to many aspects of research. Prawns (Penaeus monodon) present unique difficulties in this respect since they molt regularly. Thus, almost all tagging and marking methods developed for prawns so far have proven inadequate. Some tags or marks are lost during molting; others cause injury to the prawns. A new and efficient method has been developed at the Igang Seafarming Station of the Aquaculture Department.

      Rectangular brass tags measuring 5 mm by 20 mm and numbered consecutively are used. The prawn is held gently but firmly at the base of the carapace with the left hand while the right hand slips the brass tag around the stalk of the unablated eye and presses the tag gently. All tagging must be made under water to avoid stress.

      From May 29 to September 7 to a total of 348 unilaterally-ablated adult female prawns were tagged on the unablated eyestalk in 5 batches to enable individual observations on gonadal maturation, molting, and growth. Periodic examinations were made four times a month to coincide with the different phases of the lunar cycle. On each examination, survival and recovery rates were recorded. The data included death due to immediate mortality during ablation and loss to cannibalism for the duration of the experiments.

      In all five tagging experiments, most of the prawns recovered had their tags intact. These included even dead and molting animals.

      The eyestalk tagging method is suitable for prawns because the tags can be attached without causing injury and has no effect on the rate of growth, maturity, molting and behavior of the animal. The tags are identifiable and permanent; they remain attached to the animal even after death.
    • Article

      Survival rates of different postlarval stages of Penaeus monodon Fabricius 

      JH Primavera - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - SEAFDEC Aquaculture Department
      The objective of this study is to determine survival rates of different postlarval stages upon stocking in the Leganes ponds. Twelve 3m x 2m x 2m suspension nets made of nylon cloth (mesh size = 0.1 mm) were set up in a Leganes Station pond (ave. water depth = 1 m) by means of 3-m long poles stacked at distances approximating the area of each net. The net bottom was filled with topsoil at least 15 cm thick to stimulate the pond bottom. At least 60 cm of the upper edge of each net was above the water level to prevent mixing of water inside and outside the net. P. monodon of stages P11, P15, P21 (from the hatchery) and P25 (from the wet lab) were stocked in the nets at 200/sq m or 1,200 fry/net. Due to lack of fry, only one P25 net was stocked. Each net had two large dried miapi branches as shelter from predation and cannibalism for the young sugpo fry. Fresh lablab was fed at the rate of one pail (approximately 5 kg) every four days per net. Harvest data show relatively higher survival rates for P15 and P18 compared to P11 and P25 with no significant difference between these two stages. The results for P25 may not be valid because the stock came from the wet lab in comparison to the other postlarval stages which were reared in the hatchery. Moreover, the P25 stock had no replicates and the net itself (no. 10) was discovered to have many holes. These preliminary results point to P15 as the best stage for harvest from the hatchery in terms of high pond recovery and lesser expense in rearing compared to older postlarvae.
    • Article

      Notes on the external sex characters of Chanos chanos Forskal spawners 

      H Chaudhuri, J Juario, Samson R. & R Mateo - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - SEAFDEC Aquaculture Department
      In this study, the authors did not find any visible differences between the sexes with reference to external features such as coloration, shape of head, snout and operculum, presence of tubercles or nasal pores, length, size and shape as well as any roughness in the various fins. However, the anal region of the mature milkfish exhibits discernible anatomical differences in the male and female. In the males, there are 2 main openings visible externally. These are the anterior anus and the posterior urogenital opening at the tip of the urogenital papilla. Internally, the vasa deferentia (male genital ducts) from the testes join into a common duct about 5-10 mm from the urogenital pore. The urinary pore opens into this common duct from the dorsal side. In addition, there are 2 small pores situated on each side of the base of the urogenital papilla opening ventrally into the coelom. In the females, there are 3 main openings in the anal region instead of 2 as found in the males. The anteriormost opening is the anus followed by the genital pore. The third opening is the urinary pore which is posterior to the genital pore located at the tip of the urogenital papilla.