Now showing items 1-20 of 3117

    • 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

      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.
    • Book

      Annual report 1975 

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

      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

      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

      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

      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

      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

      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

      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.
    • 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.
    • 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.
    • Technical Report

      An annotated list of scientific and english common names of commercially important penaeid prawns and shrimps. 

      H Motoh - 1977 - SEAFDEC Aquaculture Department
      Series: Technical report / SEAFDEC. Aquaculture Department; No. 2
      There are 318 species of penaeid shrimps (Family Penaeidae) recorded in the world, of which about 80 species are placed under exploitation in fishing industry and/or cultivated artificially. The species under the genus Penaeus are particularly favored for human consumption because of their larger size and palatability and are therefore exposed to extensive capture by fishing boats. The shrimp fishing industry has developed in various parts of coastal waters worldwide extending from the temperate to tropical zones in both hemispheres. The nations engaged in shrimp fishing are numerous; Japan, U.S.A., Mexico, Thailand, India, lead in terms of volume of catch. Japan, for instance one of the large shrimp consuming nations in the world, has been dispatching shrimp fishing boats to many countries whether on her own capital or in joint ventures. Japan annually imports some 100,000 tons of frozen shrimp of which penaeids rank first in quantity. Meanwhile, the demand for shrimp is expected to rise in the years to come.

      The shrimp fishing industry and its operation are conducted and managed naturally, as indicated above, under international agreement. However, confusions arise particularly regarding the common names of shrimp caught or the products. It is evident that many commercial species of penaeids are given common names which differ from one country to another. For instance, the so-called "white shrimp" adopted by commercial circles includes nine different species. Understandably, these nine species, aside form being closely related biologically, are characterized by whitish coloration of the body.

      The present list was compiled to show the status of shrimp nomenclature, based on available literature, giving scientific names and English common names adopted or applied. The present article is written in the hope that the common names of penaeid shrimp shall be standardized internationally at least in English. Needless to say, the standardization will contribute greatly to world trading, as well as to scientific studies.
    • Article

      The biology and control of Caligus sp., an ectoparasite of the adult milkfish Chanos chanos Forskal 

      EM Laviña - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - SEAFDEC Aquaculture Department
      One unidentified species of copepod belonging to the genus Caligus of the family Caligidae was found to infest the adult milkfish broodstock. To control the parasites infesting the adult milkfish, tests were made using the chemical (2,2,2-trichloro-1-hydroxyl)-phosphonic acid-dimethylethol (Neguvon) at a concentration of 0.25 ppm. It is noted that a concentration of 0.25 ppm of Neguvon maintained for 12-24 hours in the sabalo-containing tanks in a closed water system but with aeration is effective in controlling the parasites. Fish mortality during the experiment was due to inadequate aeration in the tanks.
    • Article

      The propagation of the mud crab Scylla serrata (F.) de Haan 

      AFD Laviña & AS Buling - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - SEAFDEC Aquaculture Department
      The mud crab Scylla serrata is an important commercial species found in many brackish areas in the Philippines. During spawning and hatching, the berried females migrate to the sea. Seeds for pond stocking are obtained from the wild. Because of the unpredictability of seed supply, there is a need to propagate the species artificially. Thus, spawning, larval rearing, maturation, and rematuration of the species are being studied. The first attempts at hatching S. serrata were successful with rates varying between 75% and 90%. Two out of three trials on larval rearing yielded a few megalops. The first zoeal stages were fed diatoms, rotifers, Artemia salina, and bread yeast. Overfeeding programs were implemented during the critical premolting periods to prevent weakening of the larvae and lessen cannibalism. Larval weakening during the premolt makes them susceptible to attacks by fungi like Lagenidium and ciliates like Vorticella. S. serrata larvae survived salinity levels as low as 15 ppt until the 14th day of rearing. Other larvae were able to survive in salinities of 30-32 ppt for 8 to 13 days. Zoeal molting was hastened by lowering the salinity to 25-27 ppt. Artificial broodstocking of juveniles and adult crabs has been made possible using a simple refuge system made of three-compartmented hollow blocks. This system has been helpful in minimizing fighting among crabs. Remarkable growth rates have been observed with feeds like mussel meat and trash fish. Average growth increments of 11 mm carapace length and 20 . 35 g body weight have been observed every fortnight. A newly spent spawner could gain additional weight of 22.5 g in only 6 days. Feeding rates of juveniles and adult crabs have been established based on the average body weight from an experiment using mussel meat. Crabs feed more at night. In another experiment, eyestalk ablation was found to be effective in inducing growth and mating. Aside from hastening the molting process, copulation is induced even among the small crabs (average carapace length = 55 mm). Natural mating lasts about 26 hr. A copulation which lasted for seven days with a break in between was observed.
    • 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

      Organic pollution in culture water resulting from excess feed and metabolite buildup 

      OM Millamena & RR Platon - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - SEAFDEC Aquaculture Department
      Penaeus monodon postlarvae were subjected to increasing feed concentrations and their growth and survival rates were recorded. Measurements were made of dissolved organic matter, and ammonia and nitrite-nitrogen concentrations. Survival was highest at the lowest feeding level and decreased as feed concentration increased. It is concluded that although organic matter enriches the food supply for P. monodon postlarvae, at higher concentration levels it can pollute the culture water, which in turn leads to mass mortality of the postlarvae. Secondly, the survival rate of P. monodon postlarvae is directly related to dissolved organic matter concentration, oxygen tension, and ammonia-nitrogen concentrations in the culture water. Even at sublethal levels these adverse environmental conditions decrease the survival rate.
    • 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.