Deo, Ashutosh Dharmendra (2000) Ichthyocrinotoxicity of marine catfishes of Mumbai coast. PhD thesis, Central Institute of Fisheries Education, Versova.
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Epidennal secretions of two marine catfishes Arius dussumieri and Osteogeneiosus militaris from Mumbai waters were studied for their blotoxic properties. Crude mucus extract obtained by scrapping was lyophilized for use as crude toxin. This crude toxin was further fractionated using DEAE Cellulose column chromatography. Bioassays involving Kausauli strain male albino mice of 20±2 g weight revealed lethal activity in crude mucus extract of both the species, with MLD values of 0.25 ml (A. dussumien) and 0.50 ml (0. militariSj per mouse. 24 Hr LOsa values were calculated to be 20.06 mg/kg and 25.86 mg/kg for A. dussumieri and O. militaris respectively. Potent hemolytic activity upto 16 HU (A. dussumien) and upto 8 HU (0. militariSj were exhibited while hemagglutnation was only partial. Crude extracts also exhibited edematic activity, upto 154% ER in A. dussumieri and 137% ER in O. militaris. Partially purified toxin of both the fish had pronounced hemagglutination activity of 32 HAU. In case of the partially purified fractions, 2 lethal factors were discernible in each species. All lethal factors had a parallel hemolytic or edematic activity. In addition to these, fractions of both fishes each had 3 hemolysins and 2 edema factors. Avil ® and Dolonex ® blocked the edematic acivity, the latter being more effective than the fonner; Atropine ®, on the other hand, enhanced the edematic activity. These toxic fractions were further separated on HPLC that indicated a compound resembling Cytochrome C to be the toxic factor. SDS-PAGE revealed the presence of at least 18 proteins In A. dussumieri and 16 proteins in O. militaris crude mucus, with their molecular weights ranging between 10 and 100 kD. Gas Chromatography of the lipid fractions indicated predominance of Palmitic acid, Oleic add, Stearic acid, Palmitoleic acid, Myristic add, Lauric add and Unoleic aCid, a precursor of prostaglandins. The crude mucus extract of both species exhibited wound healing activities in a CAM model with marked angiogenic activity. Area of wound decreased by 22.5% and 30.0% while hydroxyproline Increased by 24.93% (A. dussumierl) and 25.52 % (0. militJriSj and Iysyloxidase by 9.09% (A. dussumien) and 9.17% (0. militJriSj in 7 days when 20.0 III of crude extract was applied topically to each of the punched wounds in guinea pig. Envenomated mice, upon autopsy revealed gross anatomical changes in the liver and lungs. Histopathological investigations revealed distended sinusoids, pycnotic and karyorrhectic nuclei and karyolysis in liver, and thickening of alveolar walls in the lungs as also blood clots in both the tissues. Damage to kidney and heart was negligible. Histology revealed, in both the species, specialized glands to be absent in the skin while a mucus aggregation around, and glycoprotein-like substances, inside the lumen of the spines and might have a role in the toxicity. Toxicity was not correlated with food of the fish but with season and the Condition Factor (Kn) of the fish indicating stress do the causative factor for increased epidermal secretions. Possibilities exist that Stress Proteins (SP) (=Heat Shock Proteins, HSP) 68 and 70 might be involved in the toxidty, wound healing and other bioactivities. A primary role of defence can be attributed to the mucus and the lethality couid be a synergistic effect of the different bioactivities.
|Item Type:||Thesis (PhD)|
|Supervisor(s):||Devaraj, M and Venkateshvaran, K|
|Uncontrolled Keywords:||Ichthyocrinotoxicity; marine catfishes; Mumbai coast|
|Subjects:||Fish and Fisheries > Fish Toxicology|
Demersal Fisheries > Catfish
|Divisions:||CMFRI-Cochin > Marine Capture > Demersal Fisheries|
|Deposited By:||Geetha P Mrs|
|Deposited On:||28 Jan 2011 10:51|
|Last Modified:||09 Mar 2011 11:53|
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