Search results for "Anguillidae"
showing 10 items of 16 documents
Sublethal Effects of an Organophosphate Insecticide on the European Eel,Anguilla anguilla
1997
The present communication deals with the effects of fenitrothion (0.02 mg/liter) on the energy metabolism of the European eel, Anguilla anguilla, and its recovery from intoxication. Various parameters such as glycogen, lactate, proteins, and glucose levels were measured in different eel tissues after 2, 8, 12, 24, 32, 48, 56, 72, and 96 hr of fenitrothion exposure. Subsequently, the fish were allowed recovery periods of 8, 12, 24, 48, 72, 96, 144, and 192 hr in clean water, and the same parameters were evaluated. Liver glycogen content showed no significant changes during the exposure time, while blood glucose levels increased markedly. Gill, liver, and blood lactate values increased during…
Cholinesterase Activity and Hematological Parameters as Biomarkers of Sublethal Molinate Exposure in Anguilla anguilla
2000
Cholinesterase (ChE) activity was measured in plasma, whole blood [using 5,5'-dithiobis(2-nitrobenzoic acid) and 2-PDS as chromophores], brain, and whole eyes of Anguilla anguilla exposed to a sublethal concentration of 11.15 mg/L (one-third of the 96-h LC(50)) of the carbamate herbicide molinate. ChE activity was evaluated after 6, 24, 48, 72, and 96 h of pesticide exposure. Results indicated that ChE activity in eel tissues decreased as time of exposure increased, especially in eel blood. Eels exposed to molinate were transferred to a pesticide-free water for a recovery period of 4 days and ChE activity was also evaluated. Results indicated that ChE activity for those animals with preexpo…
An approach to the diazinon toxicity in the European eel: bioaccumulation studies
1993
Abstract The acute toxicity effects of diazinon on European eel ( Anguilla anguilla ) were examined using short-term exposures in static conditions. In these conditions the 96-h median lethal concentration (LC 50 ) was 0.086 mg/1. In addition, the eels were exposed to two sublethal diazinon concentrations, 0.042 and 0.056 mg/1 (1/2 and 2/3 LC 50 96-h, respectively) for different exposure times, till a maximum of 96 h, and bioaccumulation and clearance of this insecticide in liver, muscle, gill and blood tissues were studied. BCF values of diazinon after 96 h exposure to 0.042 mg/l were 1850 in liver, 875 in gill and 775 in eel muscle. BCF values of diazinon over a 48-h exposure period to 0.…
Inhibition of Gill Na+,K+-ATPase Activity in the Eel,Anguilla anguilla,by Fenitrothion
1998
European eels (Anguilla anguilla) were exposed to sublethal fenitrothion concentrations (0.02 and 0.04 mg/liter) in a continuous flow-through system for 4 days. Gill Mg2+- and Na+,K+-ATPase activities were evaluated after 2, 8, 12, 24, 32, 48, 56, 72, and 96 h of pesticide exposure. Results indicated that ATPase activity in gill tissue decreased as concentration of fenitrothion increased. Pesticide induced significant inhibitory effects on the Na+, K+-ATPase activity of A. anguilla, ranging from >56% inhibition at a sublethal concentration of 0.02 ppm to >73% inhibition at a sublethal concentration of 0.04 ppm. Eels were exposed to both fenitrothion concentrations for 96 h and then allowed …
Eel ATPase activity as biomarker of thiobencarb exposure
2003
Abstract European eels ( Anguilla anguilla ) were exposed to a sublethal thiobencarb concentration of 0.22 mg/L in a flow-through system for 96 h. Mg 2+ and Na + –K + adenosine triphosphatase (ATPase) activities were evaluated in gill and muscle tissues at 2, 12, 24, 48, 72, and 96 h of thiobencarb exposure. Gill ATPase activities were rapidly inhibited from 2 h of contact onward. Highest inhibition was registered for Na + , K + -ATPase (85%) from 2 to 12 h. Both Mg 2+ and total ATPase were inhibited (>73%) during the first hours of toxicant exposure. At the end of the exposure period (96 h) ATPase activities were still different from those of the controls (>50%). Significant inhibition was…
Pesticide toxicokinetics in fish: accumulation and elimination.
1998
Bioaccumulation of fenitrothion in the European eel (Anguilla anguilla) was studied using two sublethal concentrations of this pesticide in a flow-through test system. The pesticide concentrations used were one-tenth (0.002 ppm) and one-fifth (0.04 ppm) the 96-h LC50 of fenitrothion in this species. Steady state was reached early (2 h) when the animals were exposed to 0.02 ppm of toxicant, and after 48 h when the animals were exposed to 0.04 ppm. Toxicokinetic parameters for fenitrothion in eel muscle (K1, K2, and T1/2) were calculated for both experiments. The highest bioconcentration factor was calculated for animals exposed to 0.04 ppm of toxicant, indicating the relationship between the…
Occurrence of Edwardsiella tarda in wild European eels Anguilla anguilla from Mediterranean Spain
2007
Pure cultures of Edwarsiella tarda were isolated from body ulcers and internal organs of wild European eels caught in a Mediterranean freshwater coastal lagoon (Albufera Lake, Valencia, Spain) over a 1 yr period. Overall, the E. tarda isolation rate from wild eels was 9%, but this increased to 22.8% in diseased individuals. All 22 E. tarda isolates belonged to the 'wild-type' biogroup of the species and were virulent for eels (lethal dose that kills 50% of exposed individuals [LD50 dose]: 10(4.85) to 10(6.83) CFU ind.(-1)), and therefore represented the aetiological agent of the haemorrhagic disease observed in wild European eels. The E. tarda isolates and E. tarda CECT 894T type strain wer…
Field testing of a vaccine against eel diseases caused by Vibrio vulnificus
2001
The field results of a vaccination programme against Vibrio vulnificus serovar E (biotype 2) in a Spanish eel farm are reported. A total of 9.5 million glass eels were vaccinated from January 1998 to March 2000 by prolonged immersion followed by 2 subsequent reimmunisations after 12 to 14 and 24 to 28 d, respectively. The acquired protection and the immune response against serovar E were estimated over a period of 6 mo after vaccination. A similar vaccination schedule was conducted with elvers in a Danish eel farm. In this case, the acquired protection and the immune response against serovar E and the new eel-pathogenic serovars, recently described in Denmark, were evaluated over a short te…
Isolation of a new serovar of Vibrio vulnificus pathogenic for eels cultured in freshwater farms
2003
The present work reports the isolation of a new serovar of Vibrio vulnificus pathogenic for eels cultured in freshwater farms. This serovar, named Serovar A, produced two outbreaks of low morbidity and mortality in one Spanish eel farm in September 2000 and March 2001. The vibriosis affected healthy eels, weighting between 10 and 100 g, that had been vaccinated against the serovar E of the species (formerly biotype 2) at least 6 months before. Some of the diseased eels showed symptoms different to those reported for the classical vibriosis due to serovar E. These symptoms included bleeding ventral ulcers together with haemorrhagic intestine. Bath experimental challenges demonstrated that (i…
Metal and metallothionein content in tissues from wild and farmed Anguilla anguilla at commercial size.
2007
Metallothionein and metal content (Cd, Zn, Hg, Cu, Fe, Pb and Mn) were determined in various organs of commercially available eel (Anguilla anguilla) of similar size obtained from a local farm and from The Albufera Lake in Valencia (Spain). Farmed fish showed statistically significant higher Cd concentrations in liver and kidney whereas wild individuals had higher levels of Pb in blood and Zn in kidney. Significant positive correlations were found between metallothionein and Cd in kidney of farmed eel and between metallothionein and Cu in liver of wild ones.No statistically significant differences were found between the two populations in the concentration of any of the metals analyzed in m…