Now showing items 1-8 of 8

    • Article

      Aeromonas hydrophila associated with ulcerative disease epizootic in Laguna de Bay, Philippines 

      AT Llobrera & RQ Gacutan - Aquaculture, 1987 - Elsevier
      Aeromonas hydrophila was consistently associated with necrotic ulcers and lesions in mudfish/snakehead (Ophiocephalus striatus), Thai catfish (Clarias batrachus), crucian carp (Carassius carassius) and goby (Glossogobius giurus) in Laguna de Bay, Philippines, during the months of December 1985 through February 1986. The bacterium was isolated from body lesions and ulcers of all fish examined and rarely from the kidney and liver of carp and catfish. The disease was characterized by hemorrhages, lesions and open necrotic ulcers on the body of the fish, particularly the head (just behind the eyes), the mandible and the maxilla, and the caudal peduncle regions. Erosion of the head bone tissues and the tails was observed in very severe cases. The presence of A. hydrophila is believed to be secondary to some predisposing factors existing in Laguna de Bay.
    • Conference paper

      Detoxification of Pyrodinium-generated paralytic shellfish poisoning toxin in Perna viridis from Western Samar, Philippines 

      RQ Gacutan, MY Tabbu, MTR de Castro, AB Gallego, ML Bulalacao, L Arafiles & F Icatlo Jr. - In AW White, M Anraku & KK Hooi (Eds.), Toxic Red Tides and Shellfish Toxicity in Southeast Asia. Proceedings of a Consultative Meeting, 11-14 September 1984, Singapore, 1984 - Marine Fisheries Research Department, Southeast Asian Fisheries Development Center; International Development Research Centre
      The results are presented of procedures for the detoxification of paralytic shellfish poisoning toxin using ozone, chlorine and PVP-iodine. Findings indicate ozone and PVP-iodine to effectively inactivate the toxins isolated from Perna viridis ; however, further investigations are recommended.
    • Conference paper

      Effects of coconut milk and brown sugar on crude toxins from mussels exposed to Pyrodinium bahamense var. compressa 

      RQ Gacutan - In JL Maclean, LB Dizon & LV Hosillos (Eds.), The First Asian Fisheries Forum: Proceedings of the First Asian Fisheries Forum, Manila, Philippines, 26-31 May 1986, 1986 - Asian Fisheries Society
      During a red tide episode caused by Pyrodinium bahamense var. compressa in Western Samar, Philippines in 1983, those who were taken ill after ingesting the green mussel, Perna viridis , resorted to drinking coconut milk (gata , Pilipino) with brown sugar or unpurified sugar lumps (tagapulot , Pilipino) as a temporary palliative, pending medical attention. Many victims felt relief after the drink. Crude toxins (CT) were extracted from P. viridis exposed to Pyrodinium using 0.1 N HCl and reacted with either or both 5% coconut milk (CM) and 5% brown sugar (BS) for an hour. The CT, CM, BS, CT + CM, CT + BS, and CT + CM + BS were assayed in duplicates for saxitoxin using the standard mouse toxicity test. CT with initial toxicity of 2,114 MU/100 g meat was substantially detoxified after a one-hour reaction. In CT + CM, the toxicity was 664 MU/100 g; in combined CT + CM + BS the toxicity was 1,005 MU/100 g. In medium- (436-563 MU/100 g) and low-toxicity extracts (160-231 MU/100 g) no deaths in mice were recorded within one hour of injection.
    • Article

      Paralytic shellfish poisoning due to Pyrodinium bahamense var. compressa in Mati, Davao Oriental, Philippines 

      RQ Gacutan, MY Tabbu, EJ Aujero & F Icatlo Jr. - Marine Biology, 1985 - Springer Verlag
      On 26 August 1983, a single case of paralytic shellfish-poisoning (PSP) was reported in Davao City, Philippines. The poisoning was traced to ingestion of the green mussel Perna viridis Linnaeus, gathered from Balete Bay, Mati, Davao Oriental. Phytoplankton and zooplankton analyses on 12 October 1983 (47 d later), revealed the presence of the dinoflagellate Pyrodinium bahamense var. compressa, a cause of a series of red tides in the early and middle 1970's in Papua New Guinea, Sabah, and Brunei, and more recently, in Palau, and Western Samar and Leyte, Philippines. The dinoflagellate was not dominant; in fact the enumeration showed greater numbers of Ceratium sp., another dinoflagellate. Quantification of the neurotoxin by the standard mouse assay revealed a very high potency. Mussels collected from a new raft (transplanted in May 1983) had a toxicity of 7 960 mouse units (MU) per 100 g-1 meat. Those from an old raft (transplanted in May 1982) had a toxicity of 9 620 MU per 100 g-1 meat.
    • Conference paper

      Post-harvest processing of oysters and mussels 

      RQ Gacutan - In Technical Consultation on Available Aquaculture Technology in the Philippines, February 8-11, 1979, 1979 - Aquaculture Department, Southeast Asian Fisheries Development Center
    • Article

      Preliminary results of feeding aquatic macrophytes to Penaeus monodon juveniles 

      JH Primavera & RQ Gacutan - Aquaculture, 1989 - Elsevier
      Penaeus monodon juveniles (PL50) were fed live and decaying aquatic macrophytes and a commercial grow-out pellet (40% crude protein) in 80-l glass tanks over a 30-day period. Growth and survival were significantly higher for juveniles fed some form of macrophyte compared to controls (pellets). Survival was highest with live Najas graminea (100%) compared to decaying Ruppia maritima (65.4%), live R. maritima (58.9%) and pellets (52.5%).

      Juveniles fed decaying N. graminea had the lowest survival rate (30.6%) but the best growth (7.8 mm carapace length (CL), 37.6 mm total length (TL), and 0.2587 g body weight (BW)). The latter body sizes were significantly greater than for juveniles fed pellets (6.2 mm CL, 0.2338 g BW) and other macrophyte treatments. Prawns fed with live R. maritima showed the poorest growth (4.5 mm CL, 24.7 mm TL and 0.1070 g BW).

      Aquatic plants are directly grazed by penaeid juveniles, or contribute to the detritus fed on by prawns and other benthic organisms. Aside from food, macrophytes also provide cover or shelter from predation and cannibalism.
    • Conference poster

      Ruppia maritima and Najas graminea as natural foods for Penaeus monodon juveniles. 

      RQ Gacutan & J Primavera - In Y Taki, JH Primavera & JA Llobrera (Eds.), Proceedings of the First International Conference on the Culture of Penaeid Prawns/Shrimps, 4-7 December 1984, Iloilo City, Philippines, 1985 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Ruppia maritima (kusay-kusay, Hiligaynon) and Najas graminea (digman, Hiligaynon) are macrophytes growing in local brackishwater ponds believed to provide food and shelter to prawns and fishes. Their effect on growth and survival of Penaeus monodon juveniles (PL50; carapace length, 4.01 mm; body weight, 0.053 g) were studied in 80-ℓ glass aquaria. The treatments were: (a) a commercial pellet (40% protein); (b) live Ruppia; (c) decaying Ruppia; (d) live Najas; and (e) decaying Najas. The pellet was offered to satiety (approx. 100% of body weight) twice daily. Live Ruppia and Najas were transplanted in the aquaria using pond soil a week prior to the experiment. Decaying Ruppia and Najas were transferred from ponds. Salinity was maintained at 15 ppt and 50% of the water was changed regularly.

      Highly significant differences (P < 0.01) in mean carapace length (CL) and mean body weight (BW) on the 10th, 20th and 30th days were observed among treatments. Increase in CL was fastest with decaying Najas and slowest in live Ruppia (14% vs. 17% after 30 days). Growth with decaying Ruppia was comparable to pellets on the 10th and 20th days but was faster after 30 days. Body weight on all sampling days was highest in decaying Najas and lowest in live Ruppia. Percentage increases were 122, 273 and 565% on the 10th, 20th and 30th days, respectively, with decaying Najas. Those given live Ruppia registered increases of 11, 67 and 94%, respectively. The rapid growth rate of animals on decaying Najas was compensated negatively by a low survival rate (31%), significantly lower than on live Najas (100%). Other survival percentages were: decaying Ruppia, 59% and pellet, 53%.
    • Conference paper

      A suctorean parasite of Penaeus monodon larvae 

      RQ Gacutan, AT Llobrera, CB Santiago, PJ Gutierrez & G Lio-Po - In Proceedings of the Second Biennial Crustacean Health Workshop, 1977 April 20-22, Galveston, Texas, 1979 - Sea Grant College Program, Texas A&M University
      A pathogenic suctorean, identified as Ephelota gemmipara was observed in P. monodon larvae spawned and reared in tanks. Commonly found to inhabit hydroid colonies, E. gemmipara has a stalked body with two types of tentacles, the sucking and piercing types, and was observed to reproduce by multiple exogenous budding.