Effect of nutraceuticals on acanthocephalan Neoechinorhynchus buttnerae and its toxicity to the host tambaqui Colossoma macropomum

Abstract

The production of tambaqui Colossoma macropomum has been undergoing financial losses due to parasitic infection by the acanthocephalan Neoechinorhynchus buttnerae, raising an alert for aquaculture in South America. The lack of adequate treatment and use of unlicensed chemicals encourages research for alternative solutions with minimal side effects. The objectives of this study were to evaluate the in vitro antiparasitic potential of commercial nutraceutical products (Natumix® and BioFish®) against N. buttnerae and to assess the respective in vivo toxic effects on the host tambaqui. For in vitro assays, parasitized fish were necropsied for acanthocephalans sampling. The parasites were exposed to three concentrations (0.078, 0.313 and 1.25 mg/ml) of each product, as well as controls (one without product and another with a solubilizer). For the in vivo acute toxicity test, juvenile fish (<0.1 g) were exposed to five increasing concentrations of each product. Mortality of tambaqui was recorded at 24, 48, 72 and 96 h. The estimated lethal concentration (LC) for 10, 50, 90 and 99% of fish was determined to classify the toxicity of the products on the target species. After in vitro efficacy tests, the highest concentrations (1.25 mg/ml) caused 100% mortality of the parasites in both products, but only Natumix® caused 100% mortality using the intermediate concentration (0.313 mg/ml) after 24 h. According to the acute toxicity result, the LC50 classified the nutraceutical products as slightly toxic for tambaqui. The tested products had a parasiticidal effect on N. buttnerae, and the toxicity test showed that both products have therapeutic potential when added to the diet.

The farming and husbandry ofColossoma macropomum: From Amazonian waters to sustainable production

“…Recent in vitro studies have reported the potential of natural plant extracts 315 organic acids, essential oils 316 and oleoresins 317 to kill the acanthocephalan, and in vivo studies have shown that a commercial phytobiotic 318 and plant essential oils 319 have reduced the burden of parasitism at different levels. Recent in vitro studies have reported the potential of natural plant extracts, 315 organic acids, essential oils 316 and oleoresins 317 to kill the acanthocephalan, and in vivo studies have shown that a commercial phytobiotic 318 and plant essential oils 319 have reduced the burden of parasitism at different levels.…”

Acanthocephalans parasites in farmed fish in Brazil: A review

“…The only study of an industrialized natural compound was carried out by Seixas et al (2019) in which they found that Natumix ® killed 100% of parasites in 24 h at 0.313 mg ml −1 . By contrast, at the highest concentration tested (1.25 mg ml −1 ), BioFish ® and Natumix ® displayed strong anti‐parasite (100% mortality) activity.…”

Ovicidal effect of essential oils of Lippia alba, Lippia sidoides and Lippia gracilis on the acanthocephalan Neoechinorhynchus buttnerae (Eoacanthocephala: Neoechinorhynchidae)

“…The indiscriminate use of these drugs may lead to a selection of drug‐resistant organisms, and consequently, risks to handlers, contamination of natural water bodies where they are usually discharged, and residual accumulation in the meat of farmed fish. Therefore, herbal medicines have also been widely explored as an alternative in the control of N. buttnerae and be potentially effective against this parasite (Costa et al., 2020; Santos et al., 2018; Seixas et al., 2020).…”