Evaluation of oregano essential oil as a growth promoter and resistance stimulator against Ichthyophthirius multifiliis (Protozoa, Ciliophora) in silver catfish juveniles, Rhamdia sp. (Siluriformes, Heptapteridae)

Lippia alba essential oil promotes survival of silver catfish (Rhamdia quelen) infected with Aeromonas sp.

In vitro and in vivo activity of the Lippia alba essential oil (EO) against Aeromonas sp. was evaluated. In the in vitro assay the minimum inhibitory concentration (MIC) and a minimum bactericidal concentration (MBC) of EO for Aeromonas cells were determined using the microdilution method. Twenty five strains of Aeromonas sp. isolated from infected fish obtained from local fish farms were used....

Occurrence of natural triploidy in Rhamdia quelen (Siluriformes, Heptapteridae).

Five specimens of Rhamdia quelen collected from the Lindóia Stream, PR, Brazil, were cytogenetically analyzed. The diploid chromosome number found was 58, including 30 metacentric, 16 submetacentric, 10 subtelocentric, and 2 acrocentric chromosomes. Supernumerary or B chromosomes, frequently observed in this fish group, were not detected. One of the individuals was triploid, with 3n = 87. A sil...

Triploidy in the hematology of jundia juveniles (Siluriformes: Heptapteridae).

This study compared the hematological characteristics of diploid and triploid of jundia, Rhamdia quelen juveniles, an important freshwater fish cultured in south Brazil. Hematological morphometry of erythrocytes were determined in blood smears under a light microscope. The blood was used to measure the number of red blood cells (RBC) with a hemocytometer Neubauer chamber, and the numbers of whi...

Susceptibility of channel catfish, blue catfish and channel×blue catfish hybrid to Ichthyophthirius multifiliis

Ichthyophthirius multifiliis as a potential vector of Edwardsiella ictaluri in channel catfish.

There is limited information on whether parasites act as vectors to transmit bacteria in fish. In this trial, we used Ichthyophthirius multifiliis and fluorescent Edwardsiella ictaluri as a model to study the interaction between parasite, bacterium, and fish. The percentage (23-39%) of theronts fluorescing after exposure to E. ictaluri was significantly higher than control theronts (~ 6%) using...