Ecotoxicological assessment of UV filters benzophenone-3 and TiO2 nanoparticles, isolated and in a mixture, in developing zebrafish (Danio rerio).

The increasing use of UV filters, such as benzophenone-3 (BP-3) and titanium dioxide nanoparticles (TiO2 NPs), has raised concerns regarding their ecotoxicological effects on the aquatic environment. The aim of the present study was to examine the embryo-larval toxicity attributed to BP-3 or TiO2 NPs, either alone or in a mixture, utilizing zebrafish (Danio rerio) as a model after exposure to environmentally relevant concentrations of these compounds. Zebrafish embryos were exposed to BP-3 (10, 100, or 1000 ng/L) or TiO2 NPs (1000 ng/L) alone or in a mixture (BP-3 10, 100, or 1000 ng/L plus 1000 ng/L of TiO2 NPs) under static conditions for 144 hr. After exposure, BP-3 levels were determined by high-performance liquid chromatography (HPLC). BP-3 levels increased in the presence of TiO2 NPs, indicating that the BP-3 degradation decreased in the presence of the NPs. In addition, in the presence of zebrafish, BP-3 levels in water decreased, indicating that zebrafish embryos and larvae might absorb BP-3. Data demonstrated that, in general, environmentally relevant concentrations of BP-3 and TiO2 NPs, either alone or in a mixture, did not significantly induce changes in heart and spontaneous contractions frequencies, levels of reactive oxygen species (ROS), morphological and morphometric parameters as well as mortality rates during 144 hr exposure. However, the groups exposed to TiO2 NPs alone and in a mixture with BP-3 at 10 ng/L exhibited an earlier significant hatching rate than the controls. Altogether, the data indicates that a potential ecotoxicological impact on the aquatic environment exists.

Environmentally relevant concentrations of benzophenone-3 induce differential histopathological responses in gills and liver of freshwater fish.

BP-3 is one of the most used organic UV filters. However, its widespread use and release into aquatic environment can induce ecotoxicological impact on aquatic organisms. Thus, the aim of the current study is to evaluate the gills and liver of freshwater fish Poecilia reticulata subjected to acute exposure (96 h) to BP-3 at environmentally relevant concentrations (10-1000 ng L-1). The study was based on adopting qualitative and semi-quantitative approach to assess histopathological changes and integrated the biomarker response in order to investigate organ-specific responses to BP-3 exposure. BP-3 has induced high histopathological index associated with circulatory disturbances, as well as with regressive and immunological changes in gills, whereas the hepatic histopathological index was associated with circulatory disturbances. Moreover, lower BP-3 concentrations were mostly associated with changes in gills, whereas higher BP-3 concentration was mostly linked to hepatic changes. In conclusion, acute exposure to BP-3 at environmentally relevant concentrations had stronger impact on gills than on the liver of P. reticulata, which confirmed organ-specific responses to UV filters.

Ovary histology and quantification of hemolymph proteins of Rhipicephalus (Boophilus)microplus treated with Melia azedarach

This study aimed to analyze ovary histology and quantify total protein in the hemolymph of Rhipicephalus (Boophilus)microplus females treated with hexane extracts from green fruits of Melia azedarach. Eight engorged females were immersed in the extract at 0.25% concentration, and eight in water containing 5% acetone (control). The females were dissected 72 hours after treatment, and the ovaries were weighed and subjected to standard histological techniques. The total protein concentration was measured in the hemolymph of 200 females, of which 100 were treated as described above and 100 served as a control. In the treated group, ovary weight reduction and predominance of immature oocytes were observed. In addition, there were decreases in the diameters of the cytoplasm and germ vesicle of the oocytes in the treated group, compared with the controls. The protein concentration in the hemolymph was higher in the treated group than in the controls. The morphological changes observed in the treated ovaries included: presence of vacuolization; alteration of oocyte morphology, which changed from rounded to elongated; deformation of the chorion; and disorganization of the yolk granules. These results demonstrate the action ofM. azedarach fruit extracts on R.(B.) microplus oogenesis.

Este estudo foi desenvolvido, visando analisar a histologia do ovário e quantificar as proteínas totais na hemolinfa de fêmeas deRhipicephalus (Boophilus)microplus tratadas com extrato hexânico de frutos verdes deMelia azedarach. Oito fêmeas ingurgitadas foram tratadas por imersão com o extrato na concentração de 0,25%, e oito com água contendo 5% de acetona (controle). As fêmeas foram dissecadas 72 horas após o tratamento e os ovários foram pesados e submetidos a técnicas histológicas padrões. A concentração total de proteína foi mensurada na hemolinfa de 200 fêmeas, sendo 100 tratadas como descrito anteriormente e 100 como controle. Foi observada redução do peso dos ovários, predomínio de ovócitos imaturos e houve diminuição nos diâmetros do citoplasma e da vesícula germinal dos ovócitos do grupo tratado em comparação ao controle. A concentração de proteína na hemolinfa foi mais alta no grupo tratado que no controle. As alterações morfológicas observadas nos ovários tratados foram a presença de vacuolizações, alteração da morfologia dos ovócitos que mudaram de redondos para alongados, deformação do córion e desorganização dos grânulos de vitelo. Estes resultados demonstram a ação do extrato de M. azedarach na ovogênese de R.(B.) microplus.

MYOGENESIS OF GILL MUSCLE TISSUE OF THE EURYHALINE FISH Poecilia vivípara (Cyprinodontiformes, Poeciliidae) EXPOSED TO SALINITY / MIOGÊNESE DO TECIDO MUSCULAR BRANQUIAL DO PEIXE EURIALINO Poecilia vivipara (Cyprinodontiformes, Poeciliidae) EXPOSTO À SALINIDADE

The teleost Poecilia vivipara are characterized as euryhaline, in other words, they modulate gill cell behavior to survive in environments with varying salinity. P.vivipara gills have a set of striated skeletal muscles, abductor and adductor muscles, which plays an important role in the respiration process. This study aimed to describe the morphology of gill muscles during the early stages of development and perform an initial morphological characterization of adults P.vivipara. Moreover, it aimed to analyze the effects of different concentrations of salinity on the morphological characteristics of muscle fibers in fingerlings´ gills. Results showed that the muscle fibers are formed between phases 2 and 3 of embryonic development. At this stage of development, gill muscles are inserted into the basal portion of gill filament, possibly in the bulkhead of cartilage that supports the gills, and organized in muscle bundles located along the gill filament. This morphological organization remains in adults. An increase in the diameter of the fibers and muscle bundles was observed in fingerlings exposed to concentrations of sea salt, which allows relating the body size of P.vivipara with the degree of salinity of the environment where they live.KEYWORDS: guppy; gill muscle; ontogeny; salinity.

Os teleósteos Poecilia vivipara, conhecidos popularmente como guarus, são caracterizados como eurialinos, ou seja, eles modulam o comportamento celular branquial para sobreviver em ambientes com variações de salinidade. As brânquias do P.vivipara possuem um conjunto de músculos estriados esqueléticos, os músculos adutores e abdutores, que têm papel importante no processo de respiração. O presente trabalho teve como objetivos principais descrever a morfologia das estruturas musculares branquiais durante os estágios iniciais do seu desenvolvimento e realizar uma caracterização morfológica inicial em guarus adultos. Além disso, visou-se analisar os efeitos das diferentes concentrações de salinidade nas características morfológicas das fibras musculares branquiais de alevinos. Como resultados das investigações, observou-se que as fibras musculares são formadas entre a fase 2 e 3 do desenvolvimento embrionário. Nesse estágio de desenvolvimento, os músculos branquiais estão inseridos na porção basal do filamento branquial, possivelmente no tabique de cartilagens que suporta as brânquias, e organizados em feixes musculares localizados ao longo do filamento branquial. Essa organização morfológica permanece nos adultos. Detectou-se um aumento no diâmetro das fibras e dos feixes musculares em alevinos expostos a concentrações de sal marinho, o que permite relacionar o tamanho corporal do

MYOGENESIS OF GILL MUSCLE TISSUE OF THE EURYHALINE FISH Poecilia vivípara (Cyprinodontiformes, Poeciliidae) EXPOSED TO SALINITY / MIOGÊNESE DO TECIDO MUSCULAR BRANQUIAL DO PEIXE EURIALINO Poecilia vivipara (Cyprinodontiformes, Poeciliidae) EXPOSTO À SALINIDADE

The teleost Poecilia vivipara are characterized as euryhaline, in other words, they modulate gill cell behavior to survive in environments with varying salinity. P.vivipara gills have a set of striated skeletal muscles, abductor and adductor muscles, which plays an important role in the respiration process. This study aimed to describe the morphology of gill muscles during the early stages of development and perform an initial morphological characterization of adults P.vivipara. Moreover, it aimed to analyze the effects of different concentrations of salinity on the morphological characteristics of muscle fibers in fingerlings´ gills. Results showed that the muscle fibers are formed between phases 2 and 3 of embryonic development. At this stage of development, gill muscles are inserted into the basal portion of gill filament, possibly in the bulkhead of cartilage that supports the gills, and organized in muscle bundles located along the gill filament. This morphological organization remains in adults. An increase in the diameter of the fibers and muscle bundles was observed in fingerlings exposed to concentrations of sea salt, which allows relating the body size of P.vivipara with the degree of salinity of the environment where they live.KEYWORDS: guppy; gill muscle; ontogeny; salinity.

Os teleósteos Poecilia vivipara, conhecidos popularmente como guarus, são caracterizados como eurialinos, ou seja, eles modulam o comportamento celular branquial para sobreviver em ambientes com variações de salinidade. As brânquias do P.vivipara possuem um conjunto de músculos estriados esqueléticos, os músculos adutores e abdutores, que têm papel importante no processo de respiração. O presente trabalho teve como objetivos principais descrever a morfologia das estruturas musculares branquiais durante os estágios iniciais do seu desenvolvimento e realizar uma caracterização morfológica inicial em guarus adultos. Além disso, visou-se analisar os efeitos das diferentes concentrações de salinidade nas características morfológicas das fibras musculares branquiais de alevinos. Como resultados das investigações, observou-se que as fibras musculares são formadas entre a fase 2 e 3 do desenvolvimento embrionário. Nesse estágio de desenvolvimento, os músculos branquiais estão inseridos na porção basal do filamento branquial, possivelmente no tabique de cartilagens que suporta as brânquias, e organizados em feixes musculares localizados ao longo do filamento branquial. Essa organização morfológica permanece nos adultos. Detectou-se um aumento no diâmetro das fibras e dos feixes musculares em alevinos expostos a concentrações de sal marinho, o que permite relacionar o tamanho corporal do