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    Histopathology of the gill, abdomen, and lymphoid organ of giant black tiger shrimp (Penaeus monodon) infected with white spot syndrome virus (WSSV)
    Apines, John S. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2004-03)
    Histological changes in giant black tiger shrimp, Penaeus monodon, were investigated at various time intervals after injection with white spot syndrome virus (WSSV). After infection with the virus, mortalities were observed. Gills, abdomen, and lymphoid organ (LO) were then dissected and subjected to histological examination. The study revealed that the lymphoid organ was the most severely damaged compared to the gills and abdomen. The abdomen, although low in prevalence, was one of the target organs of the virus. Light microscopy showed the aggregation of hemocytes in the abdominal muscles of the shrimp. The infected shrimp were found to have a high prevalence of apoptotic cells. The results of this study supported the earlier findings that cell death in viral infection may have resulted mainly from apoptosis and that increasing numbers of apoptotic cells probably caused the death in WSSV-infected shrimp. Moribund shrimp had extensive deterioration of vital tissues such as the gills and lymphoid organs, thus affecting vital processes in the shrimp body. Gross signs of lethargy and weakness were observed in the moribund shrimps. Hemocyte aggregation, as well as formation of spheroids, were observed in the hemal sinuses of the LO, the abdominal region and the gills. The results are discussed in relation to the hypotheses of acquired tolerance and quasi-immune response in shrimp.
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    Temperature tolerance of adult seahorse Hippocampus barbouri
    Araneta, Aira Joy T. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2010-03)
    Two experiments were carried out to determine the temperatures that could be tolerated by the adult seahorse Hippocampus barbouri (1 year and 4 months old). The low temperature levels tested were 16, 19, and 22 °C. The high temperature levels tested were 32, 35, and 38 °C. Ambient water temperature of 25-28°C served as the control. Seahorses were acclimatized for one hour prior to transfer to various experimental temperatures. The experiment was conducted in 10 L plastic containers with 10 seahorses per container. The experimental containers were floated in a 1 tonne fiber glass tank filled with 18cm of water, which served as water bath, to maintain the desired water temperature inside the containers. There were three replicates per treatment. Survival of the seahorses was monitored every hour for 96 hours. For the low-temperature tolerance experiment, only 57% survival was observed after 96 hours of exposure to 16°C, while 100% survival was obtained on seahorses reared in 19 and 22°C. Significantly decreasing percentage survival correlated closely with decreasing temperature. For the high-temperature tolerance experiment, H. barbouri tolerated a temperature of 32°C with 100% survival. However, no seahorse survived water temperatures of 35°C. Similarly all seahorses succumbed within an hour of exposure to water with a temperature of 38°C. No death occurred in seahorses at a temperature of 25-28°C (control). The results of the present study show that adult H. barbouri could tolerate temperatures as low as 16°C and as high as 32 °C.