Now showing items 21-40 of 1064

    • Article

      Toxicity of malachite green to the larvae of Penaeus monodon. 

      GD Lio-po, CR Lavilla & A Trillo-Llobrera - Kalikasan: The Philippine Journal of Biology, 1978 - University of the Philippines at Los Baños
      The toxicity of malachite green to the larvae of the jumbo tiger prawn Penaeus monodon was determined in a static bioassay. Daily larval death was directly proportional to the chemical concentration of and exposure time to the dye. Estimates of the TL50 in 24, 48, 72, and 96 h are as follows: 112.80, 30.61, 18.91 and 2.27 micrograms/l for the zoeae; 2502.65, 1105.63, 610.09 and 139.01 micrograms/l for the myses; and 2900.17, 339.28, 70.85, and 66.60 micrograms/l for the postlarvae. No adverse effects on the development and moulting of larvae were noted.
    • Article

      Present prawn culture in the Philippines. 

      H Mochizuki - The Philippine Journal of Fisheries, 1978 - Bureau of Fisheries and Aquatic Resources
      This paper discusses present prawn culture practices in the Philippines, as well as the experiments which are conducted at the SEAFDEC Aquaculture Department by reviewing production of fry, production of juveniles in nursery ponds, growing prawn in rearing ponds, and present problems of prawn culture in the Philippines.
    • Article

      The lancelets [Cephalochordata, Amphioxi] of Lucena Anchorage, Quezon, Philippines 

      NC Carandang - Kalikasan: The Philippine Journal of Biology, 1978 - University of the Philippines at Los Baños
      Two species of lancelets (amphioxi) are described from Philippine waters: Branchiostoma belcheri and Epigonichthys cultellus. The characters suited for numerical evaluation in both species were examined statistically.

      Epigonichthys cultellus is reported for the first time from the Philippines. The specimens examined differ by the presence of a dark band behind the rostrum and anterior to the first myotome, the greater number of myotomes in the preatrioporal region, and the numerous sense papillae on the buccal cirri.
    • Article

      Notes on the construction of 12 cu m ferrocement tank for prawn broodstock 

      RT Tolosa - Journal of Ferrocement, 1978 - International Ferrocement Information Center
      One of the important research studies at the Aquaculture Department of SEAFDEC is the maturation of Penaeus monodon females in captivity. Equal numbers of male and female prawns are stocked in tanks. Ovarian maturation is induced using the eyestalk ablation method.

      Initial successes in obtaining gravid female prawns by ablation in wooden and concrete tanks led to the attempt at mass production of spawners. This significant in view of the high cost of procuring prawn spawners from the wild and of their seasonal spawning.

      This paper is an offshoot of such an attempt. Its aim is to develop an economical, rational and easy method of constructing ferrocement tanks suitable for Penaeus monodon maturation.
    • Article

      Preliminary studies on growth and survival of Penaeus japonicus postlarvae fed with Tapes philippinarum and commercial formula feed. 

      CT Villegas - Fisheries Research Journal of the Philippines, 1978 - Fisheries Research Society of the Philippines
      The postlarvae were maintained in 5-l round plastic aquaria and provided with aeration for a 28-day feeding period. Highest survival rate of 100% was obtained when the postlarvae were fed with Diet-B. Growth, in terms of weight and length was highest in postlarvae fed with Kyowa Hakko and mysid feeds. Using T. philippinarum as control, this experiment showed that feeding with Diet-B, Kyowa Hakko and mysid feeds resulted in similar or better growth and survival rates of P. japonicus postlarvae.
    • Article

      A study on certain aspects on the biology and control of Caligus sp., an ectoparasite of the adult milkfish Chanos chanos (Forskal) 

      EM Laviña - Fisheries Research Journal of the Philippines, 1978 - Fisheries Research Society of the Philippines
      One unidentified species of copepod belonging to the genus Caligus was found to infest the adult milkfish broodstock kept in canvas tanks at the SEAFDEC research station in Mag-aba, Pandan, Antique, Philippines. This report describes the morphology of the adult and early larval stages of this copepod. A highly effective method of control using the chemical Neguvon (2,2,2-trichloro-1-hydroxyl-phosphoric acid-dimethylethol) at a concentration of 0.25 ppm is recommended.
    • Article

      Induced maturation and spawning in five-month-old Penaeus monodon Fabricius by eyestalk ablation 

      JH Primavera - Aquaculture, 1978 - Elsevier
      Pond-reared sugpo (Penaeus monodon Fabricius) females from coastal fry harvested after 4 months were unilaterally ablated and stocked in an indoor concrete tank with an equal number of males. The first two spawnings were obtained 22 d after ablation with the eggs hatching into viable nauplii. Five months (12–15 d from spawning to first postlarva, 14–16 d from first postlarva to coastal fry, and 4 months rearing in ponds) is the shortest age on record at which P. monodon females can be successfully ablated.
    • Article

      On a new species of Metapenaeus (Crustacea, Decapoda: Penaeidae) from the Philippines 

      H Motoh & MS Muthu - Nippon Suisan Gakkai Shi. Bulletin Of The Japanese Society Of Scientific Fisheries, 1979 - The Japanese Society of Fisheries Science
      A new species of penaeid prawn, Metapenaeus philippinensis from the Philippines is described in detail and compared with the closely related species, M. ensis. The petasma of the new species which superficially resembles that of M. ensis is markedly different in details; the distomedian lobes have rounded postern-lateral comers and the denticles are borne on a crescentic ridge on the disto-medial aspect of the lobes. The thelycum is also distinctive, with lateral tufts of setae and two conical pillar like prominences at the posterior end of the lateral plates and a characteristic median plate which is broader posteriorly than anteriorly. The new species is devoid of dorsal carina on the first three abdominal segments.
    • Article

      Ferrocement bouys for mussel culture 

      RT Tolosa - Journal of Ferrocement, 1979 - International Ferrocement Information Center
      This paper describes a method of constructing 12 mm thick ferocement buoys used as a floatation system in the culture of green mussels (Mytilus smaragdinus).
    • Article

      Larvae of decapod crustacea of the Philippines. III. Larval development of the giant tiger prawn, Penaeus monodon reared in the laboratory 

      H Motoh - Nippon Suisan Gakkai Shi. Bulletin Of The Japanese Society Of Scientific Fisheries, 1979 - The Japanese Society of Scientific Fisheries
      The egg, larval stages and the first postlarva of the giant tiger prawn, Penaeus monodon Fabricius, reared from egg in the laboratory are described and illustrated.

      Six naupliar, three protozoeal and three mysis stages are recognized. The larvae of P. monodon are morphologically similar to those of P. japonicus described by Hudinaga except for the following characters: 1) number of setae on first antenna of fourth and fifth nauplii is 5 or 6 in P. monodon, but it is 7 in P. japonicus; 2) supra-orbital spine of second protozoea is bifurcated at base in P. monodon, but at tip in P. japonicus; 3) number of segments of endopod of second maxilliped of second mysis is 5 in P. monodon, but it is 4 in P. japonicus; 4) number of rostral spines in second and third myses is 0 and 0 or 1 respectively in P. monodon, but it is 1 and 2 respectively in P. japonicus.
    • Article

      Mass-production of Tetraselmis chuii in seawater 

      RQ Gacutan & MCL Baticados - Kalikasan: The Philippine Journal of Biology, 1979 - University of the Philippines at Los Baños
    • Article

      Evaluation of various protein sources for Penaeus monodon postlarvae 

      C Lim, P Suraniranat & RR Platon - Kalikasan, The Philippine Journal of Biology, 1979 - University of the Philippines, Los Baños
      Penaeus monodon postlarvae with an average weight of 15.61 mg each were fed fresh brown mussel meat and artificial diets containing casein, shrimp meal, squid meal and Spirulina as protein sources at a daily rate of 20 per cent of their biomass for 10 days. Results indicate that squid meal is best for growth based on weight gain, diet conversion, and protein efficiency ratio. Fresh brown mussel meat was essentiallly comparable to shrimp meal for growth but was inferior based on protein efficiency ratio and survival rate. Both squid meal and shrimp meal appeared to be good protein sources for P. monodon postlarvae.
    • Article

      Studies on the fungal diseases in crustaceans. I. Lagenidium scyllae sp. nov. isolated from cultivated ova and larvae of the mangrove crab (Scylla serrata) 

      BZ Bian, K Hatai, GL Po & S Egusa - Transactions of the Mycological Society of Japan, 1979 - Mycological Society of Japan
      Lagenidium scyllae , a marine mastigomycete from the ova and larvae of the mangrove crab, is described and illustrated as new. The fungus grew at a temperature range of 16-42 C, with an optimum at 22.5-31.8 C. It grew well in peptone-yeast-glucose (PYG) broth containing 2-3% NaCl. In PYG-sea water medium, it grew at a pH range of 5-11.
    • Article

      Growth of chaetoceros-calcitrans in seawater fortified with fertilizers 

      RQ Gacutan, M Rosales & F Sunez - Kalikasan: The Philippine Journal of Biology, 1979 - University of the Philippines at Los Baños
    • Article

      Larval mycosis in Penaeus monodon 

      MCL Baticados, GL Po, CR Lavilla & RQ Gacutan - Kalikasan: The Philippine Journal of Biology, 1979 - University of the Philippines, Los Baños
      A phycomycetous fungus, presumably a Lagenidium, was observed to infect Penaeus monodon larvae. Monitoring of the hatchery in 1976 and 1977 showed that it occurred in 35 out of 51 and 22 out of 37 runs, respectively. So devastating was the infection that whole tank populations had to be discarded after 48 hr.

      Extramatrical tubes are sent out profusely; a discharge vesicle is formed from each tube. The cytoplasmic contents of the hypha then flow into the vesicle, and zoospore formation occurs. Zoospore release is facilitated by rupture of the vesicle after continuous movement of the zoospores. The hyphae in infected larvae measure 2.5-6.3 microns wide. The discharge vesicles are 14.5-25.0 microns in diameter; each one releases 14-32 zoospores 3.8-6.3 microns wide by 5.0-6.3 microns long.
    • Article

      Larvae of decapod crustacea of the Philippines. IV. Larval development of the banana prawn, Penaeus merguiensis reared in the laboratory. 

      H Motoh & P Buri - Nippon Suisan Gakkai Shi. Bulletin Of The Japanese Society Of Scientific Fisheries, 1979 - The Japanese Society of Scientific Fisheries
      The eggs, the larval stages and the first postlarva of the banana prawn, Penaeus merguiensis, from Philippine waters are described and illustrated.

      The complete larval stage consisting of six naupliar, three protozoeal and three mysis sub-stages were reared from egg spawned in the laboratory. The larval and postlarval stages of the present materials are compared with those of P. merguiensis from India, P. monodon from the Philippines and P. japonicus from Japan. The morphological characteristics of P. merguiensis are identical with those of genus Penaeus in Gulf of Mexico, except for the absence of the dorso-median spine on the third abdominal segment in the mysis stage of. P. merguiensis.
    • Article

      A preliminary study on the protein requirements of Chanos chanos (Forskal) fry in a controlled environment 

      C Lim, S Sukhawongs & FP Pascual - Aquaculture, 1979 - Elsevier
      Milkfish (Chanos chanos) fry with an average weight of 40 mg per fish were stocked in 60-l wooden-glass aquaria filled with 30 l of filtered sea water with a salinity of 32–34 p.p.t. and a temperature of 25–28°C. They were fed diets containing 20, 30, 40, 50 and 60% protein and 2740 kcal of digestible energy per kg at a daily rate of 10% of the biomass for a period of 30 days. Fish which were fed the diet containing 40% protein had the highest weight gain which was significantly higher (P < 0.05) than those of fish receiving the lower dietary levels of protein. Slightly lower weight gains were obtained when fish were fed diets containing 50 and 60% protein. Although feed conversion values were not statistically different (P < 0.05) among all treatments, the value for the 40% protein diet (1.96) was the best. The mean survival rates were low for all treatments but was highest for the 40% protein diet. No significant difference (P < 0.05) was found in the survival rates of fish receiving different treatments. Results show that a dietary level of 40% protein was required by milkfish fry for maximum growth, efficient feed conversion and high survival rate.
    • Article

      On the induced spawning and larval rearing of milkfish, Chanos chanos (Forskal) 

      IC Liao, JV Juario, S Kumagai, H Nakajima, M Natividad & P Buri - Aquaculture, 1979 - Elsevier
      A female milkfish, captured at sea, was injected with two hormonal injections of acetone-dried salmon pituitary powder and human chorionic gonadotropin, plus Vitamin B complex. It was stripped, and produced 128,000 ripe eggs with an average diameter of 1.15 mm. Fertilization rate was 38% following artificial fertilization with milt from an uninjected male. A total of 36,000 larvae hatched (74% of fertile eggs) after 26–32 h at 34 ‰ salinity and 27–32°C. The newly hatched larvae measured 3.4 mm in mean total length and possessed a large yolk sac. The mouth of the larvae opened about 54 h after hatching. The larvae were fed with fertilized oyster eggs, rotifers, copepods, brine shrimp, flour and prepared feed, together with Chlorella. A critical period was between the 4th and 6th days with mortality over 80%. The larvae started increasing in length by Day 8, and had the appearance of the wild fry by Day 11. On Day 13 a pigmentation pattern developed and the biggest larva measured 10.0 mm. By Day 18 the larvae measured 12.5 mm, and 14.5 mm by Day 21. A total of 2,859 fry was obtained; the highest larval survival rate obtained from different experimental groups was 46.8%.
    • Article

      Results of drift card experiments and considerations on the movement of milkfish eggs and larvae in the northern Sulu Sea 

      S Kumagai & TU Bagarinao - Fisheries Research Journal of the Philippines, 1979 - Fisheries Research Society of the Philippines
      For a period of one year beginning December 1977, drift card experiments were conducted off the western and southwestern coasts of Panay Island to determine the surface currents in the area.

      Of a total 2,384 drift cards released during the study, 382 (16.02%) were recovered, 92% of them within 30 days following dispatch. The surface currents in the study area are strongly influenced, in direction and speed, by the prevailing monsoon winds. During the NE monsoon period, the surface currents move away from the coast; during the SW monsoon, toward and/or parallel to the coast. Based on the results, the probable movement and transport of milkfish eggs and larvae from the spawning ground to the fry collection ground are also discussed.
    • Article

      On the new species of Penaeus (Crustacea, Decapoda: Penaeidae) from North Borneo 

      MS Muthu & H Motoh - Researches on Crustacea, 1979 - Carcinological Society of Japan
      A new species of penaeid prawn, Penaeus silasi from North Borneo is described in detail and compared with the closely related species such as P. indicus, P. merguiensis and P. penicillatus. The new species is characterized by the following features : The 3rd maxilliped of the adult male has a dactylus as long as or slightly shorter than the propodus which has only a rudimentary tuft of hair instead of a long tuft of bristles as in P. indicus; the anterior plate of the thelycum is triangular and relatively prominent.