The hematological changes in snakehead (Ophicephalus striatus) affected by epizootic ulcerative syndrome
View/
Date
1994Page views
2,477ASFA keyword
AGROVOC keyword
Taxonomic term
Metadata
Show full item recordShare
Abstract
Selected hematological parameters were studied in snakehead from Laguna de Bay (Philippines) affected with different stages of epizootic ulcerative syndrome (EUS). For comparison, normal (from a non-endemic area) and apparently normal fish were also studied. The hematocrit values of normal and apparently normal fish, 45.04 ± 0.71 and 47.20 ± 1.03%, respectively, were significantly higher (P<0.05) than severely affected fish (29.30 ± 2.34%). The same trend was observed for serum protein (7.09 ± 0.11 and 6.35 ± 0.27 g/100 ml for normal and apparently normal fish, respectively, against 4.68 ± 0.42 g/100 ml for severely affected fish) and hemoglobin (9.80 ± 0.26 and 9.70 ± 0.26 g/100 ml against 4.67 ± 0.42 g/100 ml) concentrations. The granulocyte counts of normal and apparently normal fish, 26.2 and 60.3, respectively were significantly lower than severely affected fish (210.0). This general hemodilution could be attributed to loss of body fluids and depression of hematopoietic tissues in the spleen and kidney.
Type
Conference paperCollections
- Conference Proceedings [300]
Related items
Showing items related by title, author, creator and subject.
-
Seaweed research at SEAFDEC Aquaculture Department
(Seaweed Industry Association of the Philippines, 2003)Seaweed research at the Aquaculture Department of SEAFDEC focuses mainly on 2 genera of agarophytes (Gracilaria and Gracilariopsis) and carrageenophytes (Eucheuma and Kappaphycus). From 1988 to 1998, research works were mainly on Gracilaria and Gracilariopsis along these areas: (1) refinement of culture technique, (2) basic biology, production ecology, and corp management, (3) product utilization, (4) screening and characterization of natural products, and (5) economics of farming system. Four years ago, the Seaweed Program of the Department re-focused its thrust on Advanced Aquaculture Technologies (Biotechnology) to include also Eucheuma and Kappaphycus in answer to the needs of the industry. This paper briefly describes the highlights of the different studies done on biotechnology. -
Experimental transmission of epizootic ulcerative syndrome (EUS) in snakehead, Ophicephalus striatus
(Fish Health Section, Asian Fisheries Society, 1995)Two separate experiments on transmission of epizootic ulcerative syndrome (EUS) to naive snakehead (Ophicephalus striatus) by cohabitation with EUS-positive snakehead in EUS-enzootic environment and exposure to EUS-enzootic environment alone were conducted in Laguna, Philippines. Under unfed conditions, initial signs of EUS were observed after 9 d of cohabitation and progressed into advanced stages in 10 tol6 d, whereas in exposure to EUS-enzootic environment alone, initial signs were observed in 10 d and developed into advanced stages in 15 to 20 d post-exposure. When food was given, initial signs of the disease were observed after 14 d of cohabitation and progressed into advanced stages in 17 to 20 d, whereas in fish exposed to EUS-enzootic environment alone, onset of EUS was 44 d post-exposure developing into advanced stages in 50 to 55 d post-exposure. Transmission of the disease was 100% in all treatments. -
Pathogenicity of the epizootic ulcerative syndrome (EUS)-associated rhabdovirus to snakehead Ophicephalus striatus
(Japanese Society of Fish Pathology, 2001)The rhabdoviruses isolated from EUS-affected snakeheads in the Philippines was tested for pathogenicity to healthy, naive snakehead Ophicephalus striatus fry, fingerlings and juveniles. Virus exposure of naive snakehead fry and fingerlings by bath at 20-22.5°C resulted in significant mortalities (p<0.01) with no apparent lesions. Naive snakehead juveniles when injected intramuscularly (IM) with the EUS-associated rhabdovirus at ambient water temperature (28-32°C) did not develop any lesion. However, similarly treated snakehead juveniles at 20-22.5°C developed dermal lesions 3-5 days following treatment. The lesions progressed from slight to moderately advanced lesions by days 10-12 but not to deep ulcers as exhibited by naturally EUS-affected snakeheads. Mean mortalities were higher in the virus-injected fish (72%) compared to those in controls (33%). Moreover, the virus was reisolated from fish in the 20-22.5°C treatment but not from fish in the 28-32°C treatment. Virus from infected tissue filtrate and the virus passaged 3 or 4 times induced similar dermal lesions if the rhabdovirus concentration was 103 TCID50/fish or higher. When administered orally, by bath, by intraperitoneal (IP), IM and subdermal injections to snakehead juveniles, only the latter two viral routes induced dermal lesions. However, IP injection of the rhabdovirus caused 75% mortalities but none in control fish. The results demonstrate the pathogenicity of the rhabdovirus isolates to naive snakeheads at low (20-22.5°C) rearing water temperatures.
