Now showing items 717-736 of 1065

    • Article

      Observation on the host-parasite relationship of Epipenaeon ingens Nobili (Epicaridea: Bopyridae) and Penaeus semisulcatus De Haan. 

      FJ Palisoc - Philippine Journal of Science, 1987 - Science and Technology Information Institute
      Sample of Penaus semisulcatus or Tiger Shrimp ("hipong bulik") from Manila Bay and Tayabas bay, and from waters off Palawan, Cebu, Samar and Capiz were obtained from Navotas Fishery Port during the period from March, 1978 to Febuary, 1979. The prevalence of Epipenaeon ingens in P. semisulcatus is 4.83/1000. No significant difference (P>0.05) in the prevelence of infection between the sezes was found. The parasites (E. ingens) was lodged on either side of the host's carapace and there was no significant difference in the regression analyses of the tumor size on carapace length wheter tumor is on the left or right side of the carapace of either male or female host. Despite the homogenity of regression lines in the comparative analyses of length-weight relationship of infected and uninfected P. semisulcatus, the slope of the regression of the infected sample are always higher than the value for the uninfected ones.
    • Article

      Observations on artificial fertilization of eggs and embryonic and larval development of milkfish, Chanos chanos (Forskal) 

      H Chaudhuri, JV Juario, JH Primavera, R Samson & R Mateo - Aquaculture, 1978 - Elsevier
      Hydrated eggs obtained from a female milkfish, Chanos chanos, were artificially fertilized with the milt collected from a male injected with acetone-dried pituitaries of salmon. The fertilized eggs (1.1–1.25 mm in diameter) developed normally in seawater in basins and petri dishes at a salinity of 30–34‰, and successfully hatched in 25–28.5 hours at a temperature of 26.4–29.9°C. The yolk was completely absorbed in about 2.5 days and during this period many postlarvae died. A few larvae were reared up to 5 days but all died on the 6th day. Attempts were made to feed the postlarvae with freshly hatched trochophore larvae of oysters obtained from eggs artificially fertilized in the laboratory.
    • Article

      Occurrence and distribution of milkfish larvae, Chanos chanos off the western coast of Panay Island, Philippines 

      T Bagarinao & S Kumagai - Environmental Biology of Fishes, 1987 - Springer Verlag
      The occurence and distribution of milkfish larvae (∼3–17 mm TL) off western Panay Island, Philippines are reported based on 594 plankton net tows made in April and May 1980. Forty-two tows yielded 44 larvae, together with 1149 milkfish eggs by 98 tows. About 70% of the larvae of all stages came from stations less than 100 m deep and 1–2 km from land. Younger larvae up to 6 mm and about 1 week old occurred at stations of various distances from shore, while older larvae occurred only near shore. About 48% of larvae of all stages were caught by surface tows; younger larvae occurred also in deeper layers (20 and 30 m). Larval abundance increased towards May. Younger larvae tended to occur during the quarter moon periods and older ones during the full and new moon periods.
    • Article

      Occurrence and histopathogenesis of a didymozoid trematode (Gonapodasmius epinepheli) in pond-reared orange-spotted grouper, Epinephelus coioides 

      ER Cruz-Lacierda, RJG Lester, PS Eusebio, HS Marcial & SAG Pedrajas - Aquaculture, 2001 - Elsevier
      A didymozoid trematode encapsulated in the gills of orange-spotted grouper, Epinephelus coioides Hamilton, was observed in October 1997 and September 1999 among pond-reared fish in the Philippines. Capsule prevalence was 33% and 18% and mean intensity 2 and 1, respectively. The opaque-white and yellowish capsules were found only on the first gill arch and were attached lengthwise along the posterior surface of the primary gill filaments. When the capsules were opened, long thread-like worms were revealed, which were identified as Gonapodasmius epinepheli Abdul-Salam, Sreelatha and Farah. The parasites were encapsulated between the basement membrane of the epithelium and the efferent artery of the gill filament. The response of the host included mild hyperplasia of the interlamellar epithelium and an increase in the number of mucous cells.
    • Article

      Occurrence and pathology of an Amyloodinium-like protozoan parasite on gills of grey mullet, Mugil cephalus 

      MCL Baticados & GF Quinitio - Helgolander Meeresuntersuchungen, 1984 - Biologische Anstalt Helgoland
      In cultured grey mullets, Mugil cephalus L., mortalities caused by a dinoflagellate-like parasite were observed under normal rearing conditions. Moribund fish were abnormally swimming near the water surface and exhibited haemorrhagic areas on the head, around the mouth and on the body surfaces. Their gills displayed whitish spots as well as haemorrhagic areas and showed excessive mucus production. Microscopic examination of these whitish spots revealed structures highly resembling the trophonts of Amyloodinium attached to the gill filaments. The most consistent feature of this parasitic infestation was lamellar disintegration or degeneration. Early stages of the infestation showed epithelial lifting and lamellar detachment, eventually leading to the disruption of the lamellae and lamellar tissue degeneration. The parasites were associated with large necrotic areas in the gills and caused degeneration of the gill ray tissues. Hyperplasia of the gill epithelium and lamellar fusion were also observed, with the parasites enclosed by the fused lamellae. These structural alteration may have caused osmoregulatory and respiratory difficulties which ultimately led to the observed mortalities.
    • Article

      Occurrence and pathology of Penaeus monodon baculovirus infection in hatcheries and ponds in the Philippines. 

      MCL Baticados, CL Pitogo, MG Paner, LD de la Peña & EA Tendencia - The Israeli Journal of Aquaculture-Bamidgeh, 1991 - Society of Israeli Aquaculture and Marine Biotechnology
      Samples from Penaeus monodon hatcheries (2-3 day old larvae or Zoea 1 to 34 day old post larvae or PL34) and ponds (15 to 159 days old in the pond) were histologically examined for the presence of eosinophilic occlusion bodies in hypertrophied nuclei of the hepatopancreas which is indicative of P. monodon baculovirus infection. The earliest stage found infected in the hatcheries was PL3. Infected shrimp from ponds had slow growth rates and generally pale yellow to reddish brown hepatopancreata. The infection was also characterized by the necrosis and degeneration of the hepatopancreatic tubules with secondary bacterial invasion.
    • Article

      Occurrence of luminous bacterial disease of Penaeus monodon larvae in the Philippines 

      CR Lavilla-Pitogo, MCL Baticados, ER Cruz-Lacierda & LD de la Peña - Aquaculture, 1990 - Elsevier
      Larval mortalities associated with luminescence have been observed in epizootic proportions in black tiger prawn (Penaeus monodon) hatcheries in Panay Island, Philippines. Luminescent vibrios, identified as Vibrio harveyi and V. splendidus, were isolated from infected larvae but not from uninfected ones. These bacteria were also recovered readily from seawater samples from nearshore areas, the main source of hatchery rearing water. Thus, it is possible that the nearshore seawater is one major source of infection. Pathogenicity tests resulted in significant mortalities of larvae and postlarvae of P. monodon within 48 h of immersion challenge. Scanning electron microscopic observations show that colonization by the bacteria occurred specifically on the feeding apparatus and oral cavity of the larvae, suggesting an oral route of entry for the initiation of infection.
    • Article

      Occurrence of milkfish, Chanos chanos (Forsskal) eggs around Panay Island, Philippines 

      T Senta, S Kumagai & NM Castillo - Bulletin of the Faculty of Fisheries, Nagasaki University, 1980 - The Faculty of Fisheries, Nagasaki University
      A total of 551 milkfish eggs was collected by horizontal tows with a fish larval net in the waters around Panay island during the period from April 1976 to June 1979. The maximum number obtained by a single tow was 33 eggs. Most of the eggs were collected from Cuyo East Pass, with some from the waters around the Cagayan Islands and a single egg from the Sibuyan Sea. Almost all the eggs were collected during the period frim March to June, with a peak in April, one month ahead of the peak of fry occurrence.

      Very often milkfish eggs occurred in shallow waters around islands or close to the coasts, while they were sometimes found at locations remote from land and as deep as 900 m. Water temperatures and salinities at locations shere milkfish eggs were found ranged from 26.7 to 30.8°C and from 32.9 to 34.5 ppt. The eggs were rather evenly distributed from the surface to at least 20 m down. The eggs found in the early morning collections were in the early stages of development; those found later in the day were more advanced. It seems that spawning of mikfish takes place at midnight, and that the incubation period of eggs in the wild is about 20 hours.
    • Article

      Occurrence of Polysiphonia epiphytes in Kappaphycus farms at Calaguas Is., Camarines Norte, Phillippines 

      AQ Hurtado, AT Critchley, A Trespoey & GB Lhonneur - Journal of Applied Phycology, 2006 - Springer Verlag
      This paper describes the occurrence of an epiphyte infestation of Kappaphycus farms in Calaguas Is. Camarines Norte, Philippines. In particular, percentage cover of ‘goose bump’-Polysiphonia and ‘ice-ice’ disease, and some environmental parameters that influence the thallus condition of Kappaphycus alvarezii in Calaguas Is. were assessed during 3 separate visits and are discussed.

      Commercial cultivation of Kappaphycus at Calaguas Is. began in the early 1990s. After five years of farming, the stock was destroyed by a strong typhoon. The area was re-planted the following year and production increased annually and reached its peak in 1998–1999. However, the following year, the first occurrence of a Polysiphonia epiphyte infestation occurred concurrently with an ‘ice-ice’ disease. Consequently, annual production and the number of seaweed planters declined rapidly, and this situation persists to the present time. This paper highlights the etiological factors and their consequences.

      Results show that farm-site selection is critical for the success of Kappaphycus production. Characteristics of water movement and light intensity in farming areas contributed to the occurrence and detrimental effect of the phenomenon described as ‘goose bumps’: a morphological distortion of the host seaweed due to the presence of a Polysiphonia sp. epiphyte. A strong inverse correlation was observed between the occurrence of Polysiphonia and water movement: areas with low water motion registered a higher % cover (65%) of Polysiphonia than those in more exposed areas (17%). Although ‘goose bump’-Polysiphonia infestation and ‘ice-ice’ disease pose a tremendous problem to the seaweed farmers, the results of this limited assessment provide a useful baseline for future work.
    • Article

      Occurrence of Vibrio sp. infection in grouper, Epinephelus suillus 

      CR Lavilla-Pitogo, AR Castillo & MC de la Cruz - Journal of Applied Ichthyology, 1992 - Blackwell Publishing
      Vibrio sp., was consistently isolated from grouper, Epinephelus suillus, with bacterial infection. Fingerlings, which were challenged with the bacterium by injection, were highly susceptible. Immersion challenge resulted in 100% mortality within 48 hrs in fish subjected to combination of injury and exposure to the bacterium. Mortality in uninjured fish was observed in the long bath subgroup, but not in the short bath subgroup. These results are correlated with the present practices in the grouper fingerling industry in the Philippines.
    • Article

      Occurrence, characterisation and detection of potential virulence determinants of emerging aquatic bacterial pathogens from the Philippines and Thailand 

      RP Maluping, CR Lavilla-Pitogo, A DePaola, JM Janda & K Krovacek - The New Microbiologica, 2004 - Luigi Ponzio e Figlio Editori
      Strains of Aeromonas spp., 'non-cholera vibrios' (NCVs) and Plesiomonas shigelloides isolated from aquatic environments, fish and human diarrhoeal cases in the Philippines and Thailand were characterised for potential virulence markers. Thus, the production of cytotoxin, cell-associated and cell-free haemolysin and their capacity to adhere to human intestinal (Henle 407) cells in vitro was investigated. In addition, the occurrence of tlh and tdh haemolysin genes and urease activity among V. parahaemolyticus strains was investigated. The results showed that strains recovered from clinical sources (human and fish) produced these virulence factors, whereas these are absent in environmental strains.
    • Article

      Occurrence, histopathology and experimental transmission of hepatopancreatic parvovirus infection in Penaeus monodon postlarvae 

      ES Catap, CR Lavilla-Pitogo, Y Maeno & RD Traviña - Diseases of Aquatic Organisms, 2003 - Inter-Research
      Hepatopancreatic parvovirus (HPV) was detected in samples of Penaeus monodon postlarvae (PL-13, PL-18, PL-19, PL-26) from 2 hatcheries in 2 provinces (Samar and Iloilo) in the Philippines. The percentage of infection was 20 to 100% in postlarvae obtained from the hatchery in Samar in August 2001. Postlarvae from the hatchery in Iloilo, sampled in October and November 2001, had 70 to 99% HPV infection. Wet mounts of squashed hepatopancreatic tissue stained with malachite green (wet-mount technique) and histopathology revealed the presence of large, usually single, basophilic intranuclear inclusion bodies in the distal tubules, which led to displacement of the nucleoli. Light microscopy showed ovoid to spherical inclusion bodies, 5 to 11 µm in diameter. Transmission electron microscopy revealed that the inclusion bodies were composed of electron-dense granular material and virions. The virions appeared roughly spherical and averaged 18 to 22 nm in diameter. An experiment was undertaken to induce HPV infection by feeding P. monodon postlarvae with virus-infected postlarvae. P. monodon postlarvae (PL-16), initially determined as free from HPV, were found HPV-positive 24 h after being fed with infected material. The percentage of infection ranged from 30% at Day 1 post-infection (p.i.) to 100% at Day 7 p.i. determined by the wet-mount technique and by histopathology. This is the first report of a successful horizontal transmission of HPV in P. monodon postlarvae.
    • 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

      On a new species of Trachypenaeus (Crustacea, Decapoda: Penaeidae) from the Philippines, with notes on related species 

      MS Muthu & H Motoh - Researches on Crustacea, 1979 - Carcinological Society of Japan
      Trachypenaeus villaluzi a new species of penaeid prawn from the Philippines is described in detail and compared with the related species. The new species is characterized by the following features : Mastigobranchia are present on the 2nd and 3rd pereiopods, but absent on the first ; anterior plate of thelycum is deeply concave ; the lower margin of the distolateral projections of the petasma is concave. It is also suggested that Trachypenaeus asper Alcock Should be considered as a valid species instead of being treated as a synonym of T. curvirostris (Stimpson).
    • Article

      On predicting the setting season of the oyster Crassostrea iredalei in Himamaylan River, Negros Occidental 

      AL Young & R Traviña - Kalikasan, The Journal of Philippine Biology, 1983 - University of the Philippines at Los Baños
      A spatfall forecasting program in April-November 1981 suggests that daily counts of larvae in plankton samples may be used to forecast spatfall of C. iredalei . Counts of at least five ready-to-settle larvae per 100-liter sample for three to five days indicate that spatfall will occur very soon and that collector materials should be put out immediately.

      Oyster spatfall was good in the months of July, August, and September. Highest larval count was 247 ready-to-settle larvae per 100-liter plankton sample; this led to a record set of 2,423 oyster spat on a string of thirteen shell cultch between August 24 and 31.
    • Article

      On publishing scientific papers in peer reviewed ISI-covered journals 

      T Bagarinao - The Philippine Scientist, 1994 - San Carlos Publications, University of San Carlos
      This article exhorts university graduate students and researchers everywhere to publish their scientific papers in peer-reviewed journals, preferably those covered by the Institute for Scientific Information (ISI), rather than in the gray literature – technical reports, conference proceedings, and books. Philippine journals are also used to work for stringent peer review, frequent and prompt issues, wide circulation, high standards, and ISI coverage – so that Filipino scientists contribute to, and benefit from, the mainstream literature of the international scientific community.
    • 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

      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.
    • Article

      On the visual feeding of milkfish larvae and juveniles in captivity 

      G Kawamura & S Hara - Nippon Suisan Gakkai Shi. Bulletin Of The Japanese Society Of Scientific Fisheries, 1980 - The Japanese Society of Scientific Fisheries
      Feeding of milkfish (Chanos chanos) larvae and juveniles on Artemia nauplii in captivity was observed. The retinae of the larvae were observed histologically. Milkfish larvae could not take food in the dark. The juveniles could take food in the dark although less efficiently than in the lighted condition. Vision thus seems to be the most important sense for the milkfish larvae since feding depends very much on it. The larvae were found to have already well-developed regionally differentated retinae with all elements present. Vision, evidently, is developed foremost among the senses.
    • Article

      Ontogeny of feeding apparatus and foregut of mud crab Scylla serrata Forsskål larvae 

      GJ Lumasag, ET Quinitio, RO Aguilar, RB Baldevarona & CA Saclauso - Aquaculture Research, 2007 - Blackwell Publishing
      The development of the feeding apparatus of the mud crab Scylla serrata larvae was studied using electron microscopy for mandibles and light microscopy for other paired mouthparts and the foregut. The six paired mouthparts, which consisted of the mandibles, maxillules, maxillae, first maxillipeds, second maxillipeds and third maxillipeds, were dissected from specimens representing each larval stage. The first five paired appendages were already present in newly hatched larvae while third maxillipeds appeared only at the megalopa stage. Mandibles displayed complex incisor and molar processes at early zoeal stages, which became simple in morphology at megalopa. Mandibular palp buds were observed at the zoea 5 stage and these became fully developed as three-segmented mandibular palps at the megalopa stage. Endopods of other paired mouthparts exhibited increased number of setae and size as the individual metamorphosed from zoeal stages to megalopa and crab instar. The foregut appeared as a continuous cavity at zoea 1 where the cardiopyloric valve was indistinct while the filter gland was clearly identifiable. Zoea 2 and succeeding zoeal stages exhibited a setose foregut; the gastric mill and its lateral and median teeth were prominent at zoea 3 stage. The significance of these morphological changes is discussed in terms of its implication in larval feeding management.