Natural infestation of an anchor worm, Lernaea sp. in cage culture of Asian Seabass, Lates calcarifer juveniles and its control using an anti-parasitic drug, emamectin benzoate

The persistence of emamectin benzoate in marine sediments with different organic matter regimes, temperature conditions, and antibiotic presence

The objectives of this 318-day study are to determine half-lives of the anti-sea lice medication emamectin benzoate (EMB) under conditions present in sediments at aquaculture sites and document the degradation of EMB into its main metabolite desmethyl emamectin benzoate (DES). Tested conditions include different matrix types (sand, mud), two temperatures (4, 10 degrees), organic matter presence (fish feed waste and feces), and the presence of oxytetracycline. We document a transformation ratio of EMB to DES of 0.16 to 4.4 % and show that the co-presence of oxytetracycline increases EMB calculated half-lives to values >6000 days for mud matrices. EMB incubated in high organic enrichment regimes was not observed to degrade at 4 degrees. Multivariate analyses show interactions between sediment conditions (matrix, temperature, organic matter [OM], oxytetracycline) influence EMB persistence and DES:EMB ratios. Ranges of EMB half-lives and information on metabolites can be used to anticipate potential effects on marine communities.

In vitro and in vivo action of turmeric oil (Curcuma longa L.) against Argulus spp. in goldfish (Carassius auratus)

Background

Argulus is a common and widespread ectoparasite that causes major parasitic diseases and is a virus and bacteria carrier in the ornamental fish trade.

Aim

The purpose of this study is to determine what types of phytochemicals are present in the essential oil extracted from turmeric rhizome (Curcuma longa L.) and to assess the efficacy of turmeric oil in eliminating Argulus spp. infestations in goldfish (Carassius auratus).

Methods

The chemical composition and quantity of the major substances in essential oils from fresh turmeric rhizome were detected by gas chromatography/mass spectrometry (GC-MS). The antiparasitic effect of turmeric oils on Argulus spp. was tested at 12.5, 25, 50, 100, and 200 ppm and compared to 0.25 ppm Neguvon® (the positive control). The percentage of Argulus spp. killed, the percentage of the mean mortality rate, and the effectiveness of each test were evaluated.

Results

By using GC-MS analysis, it was possible to identify the primary phytochemical component of turmeric essential oil as b-turmerone. The results obtained from the in vitro test indicated that there was a correlation between the concentration of turmeric essential oil and the average mortality rate of fish lice. The mean mortality of fish louse exposed to 200 ppm turmeric essential oil was higher than the mean mortality of fish louse exposed to Neguvon® (p < 0.05). In an in vivo study, the effectiveness of 12.5 ppm turmeric essential oil against parasites was 44.44%, 55.46%, and 62.83% at 24, 48, and 72 hours, respectively.

Conclusion

In summary, the efficacy of turmeric essential oil against fish louse has been shown both in vitro and in vivo studies.