Now showing items 1-10 of 10

    • Article

      Developmental stages of a microsporidian parasite of the white prawn, Penaeus merguiensis de Man 1888 

      MCL Baticados & GL Enriquez - Natural and Applied Science Bulletin, 1982 - University of the Philippines
      A microsporidian parasite found to invade the ovaries of the white prawn, Penaeus merguiensis de Man, 1888, causes the whitening of the mature female gonads. Ultrastructure examination of the white ovaries reveal the presence of spores and other developmental stages of the parasite.

      The earliest stage observed is the schizont which contains a few cisternae of endoplasmic reticulum, many ribosomes and a thin plasma membrane. The next stage is the sporont characterized by a pansporoblast membrane, an increase in the amount of endoplasmic reticulum, appearance of more vesicles and of polar filament precursors. Diplokaryotic schizonts and sporonts are also found. Division of the sporonts gives rise to uninucleate sporoblasts. At this stage, the spore organelles start to form and the cell acquires a degree of plarity. The polar filament and the polar sao appear and the sporont membrane complex develops into a sporoblast wall. The sporoblast is transformed into a spore with a polar cap, posterior vacuole, polaroplast, and two laters of spore wall, the exospore and the endospore. The polar filament is a tubular structure consisting of seven coils which after the second coil taper abruptly distally.

      All these stages of development of the parasite are observed in the infected ovaries within which its life cycle is completed. A probable mode of transmission and life cycle of the parasite is presented.
    • Article

      Effects of furanace on Brachionus 

      MC Baticados, RQ Gacutan & PJ Gutierrez - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Tiger prawn P.monodon) larvae utilize Brachionus a rotifer, as food in the Zoea 3 and mysis stages when they change from an herbivorous to an omnivorous diet. The present work aims to show the effects of furanace on the population growth of Brachionus. Cultures of Brachionus were obtained and fed with Chlorella at a density of 1-2x10 SUP-6 cells/ml. Five liters of the culture water were placed in each of 4 white, circular, 152x304 mm plastic basins. The mean initial densities of the rotifer ranged from 26 . 5 to 38 . 5 individuals/ml. The concentrations of furanace were 0, 1, 2 and 3 mg /l. The cultures were vigorously aerated. Population growth was observed after 3, 6, and 9 hours of exposure. The cultures were thoroughly mixed before samples were taken to ensure an almost equal distribution of the rotifers in the water. To facilitate the counting of the rotifer, one drop of Lugol s solution was added to each sample. This immobilizes the rotifer as well as stops further reproduction. Individuals with only the lorica left or with badly deformed lorica were considered dead. Population counts were done using a Sedgwick-Rafter counting chamber. Among the different durations of exposure, the percentage survival of the populations in the furanace baths were highest after 3 hr. There were slight increases in the control and 2 mg/l and slight decreases in 1 and 3 mg/l. The differences in the mean densities are statistically insignificant at . 01 significance level. After a 6-hr exposure, the control population reached its peak density with a survival of 89%. Populations in furanace baths decreased to 88 . 5% in both 2 and 3 mg /l followed closely by 87% in 1 mg/l. Again, no statistical differences exist among all the levels. The mean percentage survival in 1 and 2 mg/l increased (89% and 91%, respectively) after a 9-hr expsoure, while those in the control and 3 mg/l decreased to 86 . 5% and 88 . 25%, respectively. There were no marked differences in appearance noted among the individuals in furanace baths and those in the control.
    • Conference paper

      Effects of furanace on the development of larval stages of Penaeus monodon Fabricius 

      RQ Gacutan, AT Llobrera & MCL Baticados - In Proceedings of the Second Biennial Crustacean Health Workshop, 1977 April 20-22, Galveston, Texas, 1979 - Sea Grant College Program, Texas A&M University
      Successful molts and morphological defects in P. monodon zoeae (Z1, Z2, Z3) resulting from a 24-h exposure to 1.0 and 2.0 mg/L furanace in baths of 1.0 and 2.0 mg/L were quantified. Molting was delayed in Z1, but not in Z2 and Z3 at 1.0 mg/L; considerably delayed in all sub-stages at 2.0 mg/L. Morphological defects in the telson, carapace, uropods and pereiopods were observed in high frequency in Z3 after the exposure. These abnormalities did not result in 1.0 mg/L. In Z2, a 6-h exposure is deemed optimum for bath in 1.0 mg/L as gauged from higher survival of larvae after 96 h.
    • Article

      Effects of Gusathion A on the survival and shell quality of juvenile Penaeus monodon 

      MCL Baticados & EA Tendencia - Aquaculture, 1991 - Elsevier
      Juvenile Penaeus monodon (body weight=10–20 g) were exposed to a commonly used organophosphate pesticide, Gusathion A, in ponds for 96 h. Prawns exposed to 1.5–150 ppb Gusathion A had 27–53% shell softening, with a 96 h LC50 of 120 ppb. Histopathological changes in the gills and hepatopancreas included slight hyperplasia of the gill epithelium, delamination of the hepatopancreatocytes, and general necrosis and degeneration of these tissues.
    • Article

      Isolation and culture in artificial media of Lagenidium from Penaeus monodon larvae 

      MCL Baticados, GL Po, CR Lavilla & RQ Gacutan - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Fungal infection of P. monodon larvae is a problem in hatchery operations. The fungus, which attacks the nauplius to postlarval stages and causes up to 100% mortality, has been tentatively identified as belonging to the genus Lagenidium. This pathogenic organism has recently been isolated and cultured. A description is given of the fungus, and features of its biology and pathology are discussed.
    • Conference paper

      New developments in marine prawn disease research in south east Asia. 

      MCL Baticados - In SH Cheah & S Thalathiah (Eds.), New Technologies in Aquaculture. Proceedings of a Seminar Organized by the Malaysian Fisheries Society and the Ministry of Science, Technology and the Environment, 17 August 1989, Kuala Lumpur, 1992 - Malaysian Fisheries Society. Occasional Publication No. 6
      Researches on marine shrimp diseases for the past three years centered primarily on the diagnosis and control of viral and bacterial infections as well as nutritional, toxic and environmental diseases. Diagnostic techniques developed or adopted recently for prawn viruses include the ELISA technique for detecting baculoviruses, acridine orange fluorescence, eosin flourescence and in vitro culture of the Penaeus monodon-type baculovirus (MBV) on lymphoid organ-derived monolayer culture. Studies have been conducted on the identification, pathogenicity and chemical control of bacteria causing luminous vibriosis and shell disease. Investigations on non-infections diseases such as the chronic soft-shell syndrome, blue shrimp disease and aflatoxicosis elucidated the factors responsible for the development of these diseases. Current research on marine shrimp diseases, other related problems and recommendations are discussed.
    • 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

      Reduction in Chaetoceros populations by furanace 

      MCL Baticados & RQ Gacutan - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - Aquaculture Department, Southeast Asian Fisheries Development Center
      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

      Studies on the chemical control of luminous bacteria Vibrio harveyi and V. splendidus isolated from diseased Penaeus monodon larvae and rearing water 

      MCL Baticados, CR Lavilla-Pitogo, ER Cruz-Lacierda, LD de la Peña & NA Suñaz - Diseases of Aquatic Organisms, 1990 - Inter Research
      The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of 24 drugs for luminous bacteria Vibrio harveyi and V. splendidus were determined. Only chloramphenicol, sodium nifurstyrenate and the nitrofurans (furazolidone, nitrofurazone, nitrofurantoin and Prefuran) showed relatively low MICs and MBCs (<25 µg/ml-1). The bacteria showed varied responses to chloramphenicol and Prefuran and low sensitivity to oxytetracycline. Chloramphenicol, oxytetracycline and Prefuran are commonly used in shrimp hatcheries. Shrimp larvae showed high survival rates and active swimming movement after 24 h exposure to in vivo bactericidal doses of chloramphenicol, Furacin, nitrofurantoin (protozoa only), oxytetracycline (nauplius only), Prefuran (mysis only) and sodium nifurstyrenate, but the drugs caused deformities in the carapace, rostrum, and setae. Chemical control of luminous vibriosis among shrimp larvae appears limited, based on the efficacy of existing and readily available drugs, because of the possible development of resistant strains of bacteria and the limited tolerance of the shrimp larvae to the drugs.
    • Book chapter

      Typical prawn diseases - causes, prevention, and treatment 

      MCL Baticados - In YN Chiu, LM Santos & RO Juliano (Eds.), Technical Considerations for the Management and Operation of Intensive Prawn Farms, 1988 - U.P. Aquaculture Society
      Diseases of prawn in ponds are caused by microorganisn like viruses, bacteria fungi and protozoans as well as factors such as nutritional deficiency, poor pond conditions and environmental pollutants. Most of these may be controlled by environmental and dietary manipulation. Control of transfers or introduction of new prawn species may also reduce the risk of disease occurrence. Chemotherapy is considered only as alast resort in the control of diseases in prawn ponds. The basic features of prawn diseases with emphasis on causative agents and methods of preventio and treatment are discussed.