Influence of Fish Capture Methods on Genotoxic Assessment in Different Tissues of Astyanax fasciatus (Osteichthyes, Characidae)

Abstract

ResumoEntre as abordagens para avaliar a genotoxicidade de ambientes aquáticos, peixes vêm sendo utilizados como biomonitores por reagirem sensivelmente a quaisquer alterações no meio, caracterizando-se como organismos sentinelas para biomonitoramento de rios e lagos. Os biomarcadores que refletem danos ao material genético dos peixes podem ser detectados pelo Ensaio Cometa (EC) e análise de Micronúcleos (MN), causados por diferentes agentes químicos e/ou fatores estressantes, como os originados por captura, manuseio e estocagem. Nesse estudo os métodos de tarrafa e pesca elétrica foram adotados para a captura, visando avaliar sua influência sobre a expressão dos biomarcadores utilizados em tecidos como sangue, brânquias e fígado. Indivíduos da espécie Astyanax fasciatus (Characidae) foram amostrados na lagoa dos Quadros -RS, considerada local livre de contaminação industrial, apresentando boa qualidade físico-química. Os resultados para o teste do MN, que reflete efeitos clastogênicos e aneugênicos, não mostraram diferença significante entre os métodos de captura avaliados, possivelmente por não haver tempo suficiente para a ocorrência de divisão celular, necessária para a formação de micronúcleos. Para o EC, que detecta quebras diretas ao DNA, houve diferença significante para Índice de Danos (ID) e Percentual de Danos (%D) entre os métodos de captura em todos os tecidos analisados (p ≤ 0.001), indicando efeito da eletricidade nos organismos coletados.Palavras-chave: pesca elétrica, pesca de tarrafa, estresse, genotoxicidade, micronúcleos, ensaio cometa. AbstRAct Influence of Fish Capture Methods on Genotoxic Assessment in Different Tissues of Astyanax fasciatus (Osteichthyes, Characidae)Among the approaches to evaluate genotoxicity of aquatic environments, fish are being used as biomonitors due to their sensitivity to any changes in the environment, characterizing it as sentinel organisms for the biomonitoring of rivers and lakes. Biomarkers that reflect damage to genetic material of fish are detected by the Comet Assay (EC) and through analysis of Micronucleus (MN) produced by different chemical agents and/or stressor factors due to capture, handling and keeping. Cast net and electric fishing were used for capture in this study, aiming to evaluate the influence of these methods on the analyzed biomarkers in different tissues, such as blood, gills and liver. Astyanax fasciatus (Characidae) individuals were captured in Quadros lagoon -RS, Brazil, site considered free on industrial contamination, showing a good physico-chemical quality. Results of MN test, which reflect clastogenic and aneugenic effects, presented no significant difference between the catch methods used, possibly because there was not enough time for cell division that is necessary for micronucleus forming. EC, which detects direct DNA brakeage, showed significant differences in Damage Index (ID) and Damage Percentage (%D) between capture methods in all tissues examined (p ≤ 0.001), indicating an effect of electricity on organisms collected.

Inhibition, Recovery and Field Responses of Astyanax fasciatus (Cuvier, 1819) Brain Cholinesterases Upon Exposure to Azinphos-methyl

“…The negative results of the micronuclei test appear to suggest that azinphos-methyl is not significantly genotoxic for A. fasciatus, which is in line with the WHO-FAO Datasheet on Pesticides Nº 59. The method is usually considered an useful genotoxicity indicator in fishes (Campana et al, 1999), although Moreira et al (2010) stated that the species used in our study commonly displays low micronuclei frequencies.…”

“…We were unable to find papers on Astyanax brain cholinesterases. Shulz & Martins-Junior (2000) recommended A. fasciatus for biomonitoring, and Moreira et al (2010) studied effects of capture methods on its genotoxicity biomarkers, but they did not analyzed its cholinesterases. In Asyanax sp.…”

“…The sentinel species should be abundant, widely distributed, non-migratory and, on the other hand, it must respond as linearly and predictably as possible, and in the widest possible range of concentrations, to the agent to be monitored (Valdez-Domingos et al, 2009). Astyanax fasciatus is an abundant teleost which appears to combine most of these features, and that has been already proposed as a possible bioindicator of anthropogenic pollution (Schulz & Martins-Junior, 2000;Carrasco-Letelier et al, 2006;Moreira et al, 2010). Moreover, it is widely distributed from Southern Central America to the Río de la Plata (River Plate) basin (Ringuelet et al, 1967;Castro & Casatti, 1997) and, importantly, is small, non-migratory, and pelagic and inhabits streams and rivers devoid of strong currents and lentic systems (Castro & Casatti, 1997).…”

Toxicity assessment on the waters from the Criciúma river (Criciúma, Santa Catarina, Brazil) using physico-chemical parameters and ecotoxicological approaches

“…Desta forma, o uso de biomarcadores de alterações bioquímicas, fisiológicas e morfológicas em organismos-teste vem ganhando espaço como mecanismo de avaliação de impacto ambiental (Streb et al, 2002). Dentre os biomarcadores, encontram-se os que indicam efeitos genotóxicos e, para tanto, podem ser empregados testes de fragmentação de DNA em células meristemáticas de Allium cepa L. e em tecidos de peixes Geophagus brasiliensis e em outras espécies (Bortolotto et al, 2009;Moreira et al, 2010;Hoshina & Marin-Morales, 2010).…”

Tissue levels of the antioxidant enzymes superoxide dismutase and catalase in fish Astyanax bimaculatus from the Una River Basin

“…Since fishes occupy an intermediate range in the food pyramid, they are ideally suited for bio-monitoring. Fishes of the genus Astyanax have been used to study the genotoxicity of the aquatic environments (Moreira et al, 2010), and their feasibility as biomarkers of pollution has been investigated (Trujillo-Jiménez et al, 2011).…”