Exposure effects of the UV-filter 4-MBC to "Solea senegalensis" metamorphosis

Abstract Many personal care products integrate UV-filters, such as 4-methylbenzylidene camphor (4-MBC) which has been detected in aquatic habitats. Possible effects of 4-MBC to aquatic organisms have been poorly studied. Therefore, the main objective of this work is to study the effects of 4-MBC exposure to Solea senegalensis during metamorphosis, a sensitive life stage of this flatfish. To achieve this, at the beginning of metamorphosis (13 days after hatching, dah) fish were exposed to 4-MBC (0.2–2.0 mg L− 1) for 48 h. After this period, fish were transferred to clean medium and were fed and maintained until more than 80% of fish in control group completed the metamorphosis (24 dah). Mortality, malformations and metamorphosis progression were studied on a daily basis. In addition, growth, behavior and biochemical markers of neurotransmission (acetylcholinesterase, AChE), oxidative stress (catalase, CAT; glutathione S-transferase, GST, and lipid peroxidation, LPO) and anaerobic metabolism (lactate dehydrogenase, LDH) were determined at the end of the experiment. An acceleration of metamorphosis progression was observed during and 2 days after the 4-MBC exposure in all concentrations tested. In addition, decreased length, inhibition of CAT activity and induction of oxidative damage (LOEC = 0.928 mg L− 1 4-MBC for length, CAT and LPO) were observed. A short-term exposure to 4-MBC at the onset of metamorphosis, a critical period of development, affected S. senegalensis at several levels of organization, even after nine days in clean medium, including growth and metamorphosis progression, suggesting possible long-term adverse effects to this species.