The effects of teflubenzuron on mortality, physiology and accumulation in Capitella sp

• Published in: Ecotoxicology and environmental safety Vol. 203; p. 111029
• Main Authors: Fang, Jinghui, Samuelsen, Ole B., Strand, Øivind, Hansen, Pia Kupka, Jansen, Henrice
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 15-10-2020
• Subjects: Aquaculture; Growth; Mortality; Polychaete; Salmon lice; Teflubenzuron; Teflubenzuron; Polychaete; Growth; Mortality; Salmon lice; Aquaculture
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2020.111029

The chitin synthesis inhibitor teflubenzuron (TFB) is a feed antiparasitic agents used to impede molting of the salmon lice, an ecto-parasite that severely affects the salmon industry. Low absorption of oral administered TFB may cause elevated concentrations in the feces discharged from the salmon into the benthic environment. The polychaete Capitella sp. are often dominant in such habitats and consume organic waste deposited on the sediment. In the present study, Capitella sp. were exposed to doses of TFB in salmon feed of 1, 2 and 4 g TFB kg−1 (0 g TFB kg−1 in control group) over an experimental period of 32 days. Cumulative mortality was 12%–15% in both treatment groups with 1 and 2 g TFB kg−1 and reached 27% in the group with 4 g TFB kg−1. Only the highest dose (4 g TFB kg−1) negatively affected feed intake, growth and respiration of the polychaetes while food conversion efficiency was not affected. At the end of the experiment, the concentrations of TFB in the Capitella sp. were high, in the range of 9.24–10.32 μg g−1 for the three treatment groups. It was suggested that a maximum level of absorption rate was reached, also for the lowest dose. High concentrations of TFB in the Capitella sp. might pose a risk to crustaceans that forage for polychaetes in the vicinity of fish farms. We conclude that the effects of TFB on Capitella sp. may therefore primarily be to the predators rather than the Capitella sp.
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•TFB is readily absorbed by Capitella and reaches high tissue concentrations.•12%–27% cumulative mortalities were recorded after 32 days of exposure to TFB.•Feed with 4 g kg−1 TFB negatively affected FI, SGR and respiration but not FCE.•Due to high concentrations of TFB the Capitella sp. may be a risk to predators.