Efeitos do tratamento com formalina e sulfato de cobre sobre os parâmetros hematológicos e parasitos monogenéticos em juvenis de Hemigrammus sp. (Osteichthyes: Characidae)

Abstract

RESUMOO objetivo deste trabalho foi avaliar a eficácia da formalina e sulfato de cobre no controle de monogenéticos em juvenis de Hemigrammus sp e seu efeito na contagem diferencial de leucócitos. Utilizou-se um delineamento inteiramente casualizado com 5 tratamentos e 3 repetições. Todos os tratamentos tiveram duração de três dias e corresponderam a: T1, controle; T2 e T3 banho por imersão de uma hora em formalina, em duas concentrações uma de 0,25 ml e outra 0,1 ml formalina L ). Após o período experimental observou-se que em T2 ocorreu 100% de mortalidade. O T3 e T5 proporcionaram eficácia de 100%, porém os peixes apresentaram intoxicação e mortalidades de 66 e 80%, respectivamente. T4 apresentou eficácia de 77,7% e diminuição dos índices parasitológicos: número total de parasitos de 11,3±9, intensidade média de infecção de 3,2±2 e prevalência de 47,1%. Quanto aos leucócitos observou-se que no T3, T4 e T5 ocorreram diferenças na proporção de linfócitos, monócitos e neutrófilos em relação ao controle. O CuSO 4 e a formalina reduzem a carga parasitária, mas apresentaram-se tóxicos nas maiores concentrações. PALAVRAS-CHAVE: CuSO 4 , formol, monogênias, tratamento Evaluation of formalin and copper sulfate on monogenetic parasite (Urocleidoides sp.) of Hemigrammus sp. (Osteichthyes: Characidae) juveniles ABSTRACTThe objective of this study was to evaluate the effectiveness of formalin and copper sulphate to control monogeneans in juvenile Hemigrammus sp and its effect on leukocyte count. We used a completely randomized design with five treatments and three replications. All treatments lasted for three days and consisted of: T1, control; T2 and T3 immersion bath for one hour in formalin, an of two concentrations of 0.25 ml formalin and the other 0.1 ml L ). After the experimental period was observed that T2, 100% mortality. The T3 and T5 provided 100% efficiency, however, fish presented mortalities and intoxication of the 66 and 80% respectively. T4 showed an efficacy of 77.7% and decrease in parasitological indices: total number of parasites of11, 3 ± 9, mean infection intensity of 3.2 ± 2 and a prevalence of 47.1%. As the leukocytes was observed that at T3, T4 and T5 occurred differences in the proportion of lymphocytes, monocytes and neutrophils as compared to control. The CuSO 4 and formalin reduce the parasite load, but presented to be toxic at higher concentrations.

Antiparasitic efficacy and blood effects of formalin on Arapaima gigas (Pisces: Arapaimidae)

“…In contrast, other studies reported that the use of formalin caused increased pH and reduced concentration of dissolved O 2 in the water (Treves-Brown, 2000;Martins, 2004). These changes were not found here, corroborating the findings of other studies (Fajer-Ávila et al, 2003;Sitjà-Bobadilla et al, 2006;Pahor-Filho et al, 2012;Paixão et al, 2013).…”

“…No mortality of A. gigas was observed whatsoever during the 1 h and 12 h therapeutic baths with formalin, since the lethal concentration for this fish was previously determined. In contrast, Paixão et al (2013) found 100% and 66.6% mortality for Hemigrammus sp. exposed to 275 and 110 mg L − 1 formalin during 1 h, respectively.…”

“…For Hemigrammus sp. exposed to 27.5 mg L − 1 formalin during 1 h, the efficacy was 77.7% (Paixão et al, 2013). In contrast, for Haliotrema abaddon in the gills of Glaucosoma hebraicum with 25 mg L − 1 formalin during 10 and 24 h, there was no antiparasitic efficacy (Stephens et al, 2003).…”

“…In aquaculture, one of the ways to control and treat diseases so as to minimize economic losses has been the use of chemical products such as formalin (Yildiz and Pulatsu, 1999;Fajer-Ávila et al, 2003;Stephens et al, 2003;Sharp et al, 2004;Sitjà-Bobadilla et al, 2006;Fujimoto et al, 2006;Pahor-Filho et al, 2012;Paixão et al, 2013;Andrade-Porto et al, 2017). Nevertheless, formaldehyde has been classified by the International Agency for Research on Cancer (IARC) as a human carcinogen.…”

Histopathological changes in the gills of zebrafish (Danio rerio) and bullfrog tadpoles (Lithobates catesbeianus) caused by the use of formaldehyde

“…According to Martins (2004), 37% formaldehyde can be used in the form of a short bath (up to 60 min) in the concentration of 55.5 mg/L to 92.5 mg/L and in long-term baths (24 h) at a concentration of 3.7 mg/L to 5.55 mg/L. However, Paixão et al (2013) working with these concentrations with the fish species Hemigrammus (a characid widely used in aquariums) using formaldehyde baths for 60 minutes reported 100% mortality. The authors suggest that this may have been due to the fact that wild fish are more susceptible to stress and less rustic than those in cultivation.…”