Status of grouper research in the Philippines
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Marte, C. (1998). Status of grouper research in the Philippines. In M. A. Rimmer, K. C. Williams, & M. J. Philipps (Eds.), Proceedings of the Grouper Aquaculture Research Workshop, 7-8 April 1998, Bangkok, Thailand (pp. 82-86). Canberra, Australia: Australian Centre for International Agricultural Research.
PublisherAustralian Centre for International Agricultural Research
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Changes in the gastrointestinal tract and associated organs during early development of the grouper (Epinephelus coioides) GF Quinitio, AC Sa-an, JD Toledo & JD Tan-Fermin - In MA Rimmer, S McBride & KC Williams (Eds.), Advances in grouper aquaculture, 2004 - Australian Centre for International Agricultural Research
Series: ACIAR Monograph 110The histomorphological changes in the gastrointestinal tract of Epinephelus coioides and associated organs during its early development were studied. Larvae of E. coioides were reared in 5-tonne tanks using the semi-intensive culture system. Larval samples were collected at days 0, 2, 4, 6, 8, 10, 12, 14, 16, 20, 25, 30, 35, 40, 45 and 60. The total length (TL) of about 10-20 larvae per sampling was measured. At least 3 samples were examined from each stage for longitudinal sections using light microscopy. The digestive tract of day 0 larvae was a straight, undifferentiated tube composed of simple cuboidal cells. At day 2, cellular differentiation was observed in the pharynx, oesophagus, primordial stomach and intestine. The primordial stomach broadened into a voluminous pouch at day 10. The gastric gland was observed in the stomach from day 20. Day 35 seemed to be the proper time to feed larvae with minced fish when using the semi-intensive rearing system. Insignificant histomorphological changes in the metamorphosing grouper larvae were observed from days 40-60.
Localisation of enzymes in the digestive system during early development of the grouper (Epinephelus coioides) GF Quinitio, AC Sa-an, JD Toledo & JD Tan-Fermin - In MA Rimmer, S McBride & KC Williams (Eds.), Advances in grouper aquaculture, 2004 - Australian Centre for International Agricultural Research
Series: ACIAR Monograph 110This study was undertaken to investigate the occurrence of some digestive enzymes in the gastrointestinal tract during early development in the grouper. This work was conducted to provide information on formulating an appropriate feeding scheme and an artificial diet for the early development of the grouper, Epinephelus coioides. Larvae of E. coioides were reared in 5 tonne rectangular concrete tanks. The digestive enzymes localized were acid phosphatase (ACP), alkaline phosphatase (ALP), nonspecific esterase (NSE), aminopeptidase (AMP), trypsin (TRP), maltase (MAL) and lipase (LIP). Weak enzyme activity occurred during the yolk sac stage. High AMP activity started at day 14 prior to Artemia feeding at day 16. Fluctuations in TRP activity might be related to stomach formation. Occurrence of MAL during early development demonstrated a capacity to digest carbohydrates. An increase in LIP activity coincided with the occurrence of gastric glands. Insignificant changes in digestive enzymes were observed in the metamorphosing grouper larvae from day 40 to 60.
Book chapter | Article
Viral nervous necrosis (VNN) as a critical infectious disease of orange-spotted grouper, Epinephelus coioides, in the Philippines I Kiryu, LD de la Peña, Y Yoshiura, M Ototake & Y Maeno - In K Nakamura (Ed.), Sustainable Production Systems of Aquatic Animals in Brackish Mangrove Areas, 2007 - Japan International Research Center for Agricultural SciencesOrange-spotted grouper, Epinephelus coioides, is a valuable commodity in the Philippines. In 2001, mass mortality occurred in the grouper larvae at Aquaculture Department, Southeast Asian Fisheries Development Center (SEAFDEC/AQD) and the disease was identified as viral nervous necrosis (VNN). Since then, the disease has been observed every year and the grouper hatcheries have been devastated. In this paper, recent studies of VNN which were conducted at the SEAFDEC/AQD from 2001 to 2006 are reviewed. 1) Susceptibility to the VNN virus was tested among fish species that were cultured in mangrove brackish are. Five representative cultured fish species including orange-spotted grouper, Asian sea bass (Lates calcarifer), mangrove red snapper (Lutjanus argentimaculatus), milkfish (Chanos chanos) and rabbitfish (Siganus guttatus) were used in the test where the virus was intraperitoneally injected into the juveniles. Although low or no mortality occurred in the challenge test, histopathological changes were observed in the brain and retina where the virus was re-isolated. The results were the same among the species except for rabbitfish which had no evidence for the infection. It was verified that the virus has a wide host range. 2) To estimate the possible risk of viral spread by vertical transmission, virus distribution was determined in asymptomatic groupers including 7 broodstock and 17 juveniles with body weights ranging from 4 to 12 kg and 2 to 9 respectively. The virus was detected by PCR method. The highest detection rate was in the brain, and the virus was also detectable in other organs such as the gills, heart, spleen, kidney, blood, esophagus, stomach, intestine, liver, gonad, swim bladder and/or skin. 3) As a possible VNN vaccine, a DNA p;asmid encoding the capsid protein of the virus was evaluated. After the challenge, the mortalities between the native and DNA-injected fish appeared significantly different (P<0.05).