Browsing by Author "Catap, Elena S."
Development of a method for reproducing epizootic ulcerative syndrome using controlled doses of Aphanomyces invadans in species with different salinity requirements Lesions typical of epizootic ulcerative syndrome (EUS) were induced in three-spot gourami, Trichogaster trichopterus, and sand whiting, Sillago ciliata, injected intramuscularly with controlled doses of Aphanomyces invadans zoospores, the fungal pathogen associated with the disease. Both species of fish exhibited chronic granulomatous response and inflammatory cells, predominantly macrophages and lymphocytes, infiltrated the muscle and skin tissues, at days 6–8 post-inoculation of 65 to 85 spores/fish. Based on the comparative granuloma counts and percentage of cellular infiltration in a sampled lesion area using image analysis, it was shown that the three-spot gouramis mounted a more vigorous response than the sand whiting. It was also observed that lesions in three-spot gouramis exhibited early signs of resolution than those in sand whiting. However, fish mortality was greater in EUS-affected three-spot gourami than in EUS-affected sand whiting. With this technique, we were able to describe and compare the sequential histopathology of EUS lesions in a freshwater (three-spot gourami) and an estuarine (sand whiting) fish species.
Experimental transmission of hepatopancreatic parvovirus (HPV) infection in Penaeus monodon postlarvae ES Catap & RD Traviña - In Diseases in Asian Aquaculture V : Proceedings of the Fifth Symposium on Diseases in Asian Aquaculture 24-28 November 2002, Queensland, Australia, 2005 - Fish Health Section, Asian Fisheries SocietyHepatopancreatic parvovirus (HPV) infection in penaeid shrimps was first reported in various countries of the Asia-Pacific region in mid-1980. The virus affects the hepatopancreas of postlarvae and juveniles, usually leading to slow growth and mortality during the early stage of culture. At present, there is no established experimental model of infection in Penaeus monodon, a susceptible species, since there has not been any report of successful HPV transmission under laboratory conditions. Therefore, experiments were undertaken to induce HPV infection by feeding P. monodon postlarvae (PL) with virusinfected PL. Postlarval P. monodon (PL-16), initially examined to be free from HPV, were found HPV-positive 24 hours after they were fed with the infected material. Percentage of infection was from 30% (day 1) to 100% (day 7) based on the examination of wet mounts of hepatopancreas (squashed tissue) stained with malachite green and through histopathology. This is the first report of a successful horizontal transmission of HPV in P. monodon PL. This infection model could be used to study the pathogen further and would permit controlled experiments to be undertaken in order to identify methods of prevention and control.
Book chapterES Catap & GD Lio-Po - In K Nagasawa & ER Cruz-Lacierda (Eds.), Diseases of cultured groupers, 2004 - Aquaculture Department, Southeast Asian Fisheries Development CenterThe incidence of ichthyophoniosis in groupers (Epinephelus) has been reported in Plectropomus sp. in Singapore and Cromileptes altivelis in Indonesia. It has also been known to infect at least 80 other species of teleost fish from marine, estuarine and freshwater habitats in both temperate and tropical regions (e.g., rainbow trout, yellowtail, mackerel, herring, flounder and cod). The etiologic agent of this disease is reportedly of uncertain taxonomic affinity but is often described as a fungus.
Book chapterES Catap & ER Cruz-Lacierda - In GD Lio-Po & Y Inui (Eds.), Health Management in Aquaculture, 2010 - Aquaculture Department, Southeast Asian Fisheries Development CenterHistology is an important tool in fish disease diagnosis as it affords the comparison of normal structures or morphology of tissues against those from diseased fish. However, correct diagnosis and confirmation of changes associated with diseases require proper specimen processing and some degree of expertise in histopathology. The four basic types of tissues are: epithelial, connective, muscular and nervous. An organ is usually a combination of these four tissue types. It is important to remember that the histology or structure of an organ is always related to the function it performs.