SEAFDEC/AQDINSTITUTIONAL REPOSITORY
    • Login
    View Item 
    •   SEAFDEC/AQD Institutional Repository Home
    • 02 SEAFDEC/AQD Collaborative Publications
    • SEAFDEC/AQD-Government of Japan-Trust Fund (GOJ-TF)
    • Recent Advances in Diagnosis and Prevention of Fish and Shrimp Diseases in Southeast Asia
    • View Item
    •   SEAFDEC/AQD Institutional Repository Home
    • 02 SEAFDEC/AQD Collaborative Publications
    • SEAFDEC/AQD-Government of Japan-Trust Fund (GOJ-TF)
    • Recent Advances in Diagnosis and Prevention of Fish and Shrimp Diseases in Southeast Asia
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Biology and pathogenicity of the gill monogenean of grouper (Epinephelus coioides) cultured in the Philippines

    • Global styles
    • APA
    • Elsevier - Harvard
    • Vancouver
    • MLA
    • Help
    Thumbnail
    View/Open
    Erazo-PagadorG2005.pdf (403.0Kb) AQD Access AQD Access
    Downloads: 2
    Date
    2005-03
    Author
    Erazo-Pagador, Gregoria
    Page views
    575
    Metadata
    Show full item record
    
    Share 
     
    Abstract
    The diplectanid monogenean Pseudorhabdosynochus lantauensis was the most abundant parasite recovered from the gills of cultured orange-spotted grouper (Epinephelus coioides) in the Philippines. The morphology of P. lantauensis is described. Morphometric analysis showed this species has smaller measurements when compared with other related species previously reported from Hong Kong, Malaysia and Indonesia. This species is characterized by having an overlapping dorsal bar and a short copulatory organ.

    The life cycle of this gill monogenean is also described. One mature parasite lays at least 10-22 eggs/day. Eggs are oval in shape (0.021-0.120 mm) with a spiral filament attached to one end. Eggs hatch into free-swimming larvae (oncomiracidia) within 2-6 days at 30°C and 30 ppt. The rate of development of various eggs of one hatch is not uniform, that is, some hatch in 2 days while others take 6 days. The oncomiracidium can attach to the grouper host within 2 hr. Upon attachment, the oncomiracidium metamorphoses to an adult parasite in 4-7 days. The parasite becomes fully mature and lays eggs in 7 days. Without a host, the oncomiracidium dies in 4-8 hr. The life cycle is completed in 13-20 days (egg to oncomiracidium in 2-6 days; oncomiracidium to adult parasite in 4-7 days; and adult to fully mature and egg laying parasite in 7 days).

    The effects of salinity and temperature on the hatching rate of eggs were investigated to estimate biological characteristics of the gill monogenean. Results showed that at 30°C the rate of egg hatching was 85% at 10 ppt, 92% at 20 ppt and 98% at 30 ppt. No hatching was observed at 0 and 60 ppt. Egg hatching was 75% at 25°C, 86% at 30°C and 67% at 35°C in seawater (30 ppt).

    The pathogenicity of the gill monogenean on healthy grouper juveniles was studied. Results showed that a level of 5,000 parasite eggs placed in aquarium with 20 fish resulted in 85% mortality of the fish, 2,000 eggs/20 fish caused 60% mortality, 1,000 eggs/20 fish resulted in 50% mortality and 500 eggs/20 fish resulted in 35% mortality. No mortality was observed at the control (0 egg/20 fish) group. The hematocrit level of the highest infection group (5,000 eggs/20 fish) was lower than those of the other treatment groups. Histopathological analysis revealed that the gills filaments of infected grouper challenged with 5,000 eggs/20 fish showed extensive hyperplasia and hypertrophy.
    URI
    http://hdl.handle.net/10862/5935
    Suggested Citation
    Erazo-Pagador, G. (2005). Biology and pathogenicity of the gill monogenean of grouper (Epinephelus coioides) cultured in the Philippines. In K. Nagasawa (Ed.), Recent Advances in Diagnosis and Prevention of Fish and Shrimp Diseases in Southeast Asia (pp. 295–308). Tigbauan, Iloilo, Philippines: Aquaculture Department, Southeast Asian Fisheries Development Center.
    Type
    Book chapter
    ISBN
    9718511732
    Subject
    Pathogens; Grouper culture; Parasites; Salinity; Temperature; Gills; Life cycle; Hatching; Water temperature; Statistical analysis; Fish eggs; Pseudorhabdosynochus lantauensis; Epinephelus coioides; Pathogenicity; Groupers; Philippines; Morphology; Monogenea
    Collections
    • Recent Advances in Diagnosis and Prevention of Fish and Shrimp Diseases in Southeast Asia [43]


    © SEAFDEC/AQD  2021
    Contact Us | Send Feedback
     

     

    Browse

    All of SAIRCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsKeywordsThis CollectionBy Issue DateAuthorsTitlesSubjectsKeywords

    My Account

    LoginRegister

    Statistics

    View Usage Statistics
    SEAFDEC/AQD Library

    © SEAFDEC/AQD  2021
    Contact Us | Send Feedback
     

     

    Export citations

    Export the current results of the search query as a citation list. Select one of the available citation styles, or add a new one using the "Citations format" option present in the "My account" section.

    The list of citations that can be exported is limited to items.

    Export citations

    Export the current item as a citation. Select one of the available citation styles, or add a new one using the "Citations format" option present in the "My account" section.

    Export Citations

    EXTERNAL LINKS DISCLAIMER

    This link is being provided as a convenience and for informational purposes only. SEAFDEC/AQD bears no responsibility for the accuracy, legality or content of the external site or for that of subsequent links. Contact the external site for answers to questions regarding its content.

    If you come across any external links that don't work, we would be grateful if you could report them to the repository administrators.

    Click DOWNLOAD to open/view the file. Request a copy in case the link we provided don't work.

    Download

    DOCUMENT REQUEST NOT AVAILABLE

    This publication is still available (in PRINT) and for sale at AQD bookstore. The library is currently restricted to send PDF of publications that are still for sale.

    You may contact bookstore@seafdec.org.ph or visit AQD bookstore for orders.

    FILE UNDER EMBARGO

    This file associated with this publication is currently under embargo. This will be available for download after the embargo date.