Assessment of the Toxicological Effects of Pesticides and Detergent Mixtures on Zebrafish Gills: a Histological Study

Abstract Pesticides, as Temephos and Roundup, and surfactants, like Sodium Dodecyl Sulfate (SDS), when discharged into the environment, are harmful to non-target wildlife, especially fish. To evaluate the effects of those chemicals alone and their binary combinations, we assessed the histological alterations in Danio rerio gills after 15 days of exposure to Temephos (1ppm), Roundup (10ppm), SDS (2ppm), SDS plus Temephos (2ppm+1ppm), SDS plus Roundup (2ppm+10ppm) and Temephos plus Roundup (1ppm+10ppm). Hyperplasia, a regressive change, was significant in all exposed groups. The progressive change, complete fusion of lamellae, was significantly intensive in Roundup plus Temephos group. Regarding circulatory disturbances, vascular congestion was significant intensive in SDS group, while severe aneurysm was observed in Roundup group. Although xenobiotics in the blend are biologically complex, mainly for long periods, combinatorial exposure incremented only complete fusion of lamellae. Our results reinforce the rationalization of indiscriminate use of those compounds alone or in combination.

Biomarcadores histológicos em Sciades herzbergii (Pisces, Ariidae) para avaliação de impactos em ambientes estuarinos da Baía de São Marcos, Maranhão / [Biomarkers histological in Sciades herzbergii (Pisces, Ariidae) for impact assessment in estuarine environments of São Marcos Bay, Maranhão]

Neste estudo, objetivou-se avaliar o impacto ambiental em áreas estuarinas da Baía de São Marcos, Maranhão, utilizando-se alterações histológicas nas brânquias e no fígado de Sciades herzbergii como biomarcadores de contaminação aquática. Foram realizadas coletas no período chuvoso (março de 2018) e de estiagem (julho de 2018), em que foram capturados 40 exemplares de S. herzbergii em duas regiões distintas da Baía de São Marcos: A1) Ilha dos Caranguejos (área referência); A2) Terminal de Pesca Industrial de Porto Grande (área potencialmente contaminada). As estações foram georreferenciadas por GPS e, em cada local de captura dos peixes, registraram-se as seguintes variáveis abióticas: temperatura, salinidade, pH e oxigênio dissolvido. Em campo, os organismos foram pesados e medidos, as brânquias e os fígados foram retirados e fixados. Posteriormente, foram mantidos em álcool a 70% até o procedimento histológico padrão. Resultados indicam que as duas áreas são semelhantes em termos de características físico-químicas da água e do sedimento. Todavia, a análise semiquantitativa das alterações histológicas observadas revelou que as brânquias foram o órgão mais afetado nos peixes de A2, indicando que os peixes desse local apresentam danos teciduais maiores resultantes de estresse acentuado por impactos antrópicos.(AU)

This study aimed to evaluate the environmental impact in estuarine areas of São Marcos Bay, Maranhão, using histological changes in the gills and liver of Sciades herzbergii as biomarkers of aquatic contamination. Samples were collected during the rainy (March 2018) and dry (July 2018) seasons, in which 40 specimens of S. herzbergii were captured in two distinct regions of São Marcos Bay: A1) Crab Island (reference area); A2) Porto Grande Industrial Fishing Terminal (potentially contaminated area). The stations were georeferenced by GPS and at each fish capture site the following abiotic variables were recorded: temperature, salinity, pH and dissolved oxygen. In the field, the organisms were weighed and measured and the gills and livers removed and fixed. Afterwards, they were kept in 70% alcohol until the standard histological procedure. Results indicate that the two areas are similar in terms of physicochemical characteristics of water and sediment. However, the semi-quantitative analysis of the observed histological alterations revealed that the gills were the most affected organ in A2 fish, indicating that the fish in this site have greater tissue damage resulting from stress accentuated by anthropic impacts.(AU)

A new species of Tereancistrum (Monogenea: Dactylogyridae), parasite of Prochilodus lineatus (Characiformes: Prochilodontidae) from southeast Brazil / Uma nova espécie de Tereancistrum (Monogenea: Dactylogyridae), parasito de Prochilodus lineatus (Characiformes: Prochilodontidae) do sudeste do Brasil

Abstract A new species of Tereancistrum Kritsky, Thatcher & Kayton, 1980 collected of Prochilodus lineatus gills from the Batalha River, Tietê-Batalha basin, São Paulo State, Brazil is described. The new species can be distinguished from its congeners mainly by the configuration of the ventral bar, which has an anvil-shaped characteristic with corrugated anterior projection. Tereancistrum takemotoi n. sp. is morphologically similar to T. toksonum Lizama, Takemoto & Pavanelli, 2004 in terms of their dorsal bars (Y-shaped), their dorsal anchors with divergent roots (superficial and deep) wherein their deep root rather elongated, and by the fact that they both have the male copulatory organ counterclockwise. However, only T. takemotoi n. sp. presents the male copulatory organ with 2» rings and shows undulations in the anterior margin of the dorsal bar. These undulations are absent in T. toksonum (which only has 1» rings). This is the fourth Tereancistrum species described for P. lineatus and the first described for the region from the Tietê-Batalha basin.

Resumo É descrita uma nova espécie de Tereancistrum Kritsky, Thatcher & Kayton, 1980, coletada das brânquias de Prochilodus lineatus do rio Batalha, bacia do Tietê-Batalha, estado de São Paulo, Brasil. A nova espécie pode ser diferenciada de seus congêneres, principalmente pela configuração da barra ventral, que tem o formato de bigorna e apresenta uma projeção anterior com ondulações. Tereancistrum takemotoi n. sp. é morfologicamente semelhante a T. toksonum Lizama, Takemoto & Pavanelli, 2004, em termos de suas barras dorsais (em forma de Y), suas âncoras dorsais com raízes divergentes (superficiais e profundas) sendo que a raiz profunda é bastante alongada, e pelo fato de ambos terem o órgão copulatório masculino no sentido anti-horário. No entanto, apenas T. takemotoi n. sp. apresenta o órgão copulatório masculino com 2» anéis e também exibe ondulações na margem anterior da barra dorsal, diferentemente do T. toksonum (que possui apenas 1» anel em seu órgão copulatório masculino). Essa é a quarta espécie de Tereancistrum descrita para P. lineatus e a primeira descrita para a região da bacia do Tietê-Batalha.

Evaluation of aquatic contamination in an urban lagoon environment in a coastal region in the north of Brazil / Avaliação da contaminação aquática em uma laguna costeira urbana no norte do Brasil

The quality of water is related to how it is used and how its physical, chemical and biological conditions are evaluated. The use of different evaluation tools can therefore provide accurate data about the environmental quality of aquatic ecosystems. The objective of the present study was to evaluate the aquatic contamination of the Laguna da Jansen Ecological Park in São Luís, in the state of Maranhão, Brazil, using different tools (physical variables, microbiological analysis and erythrocytic and gill alterations in Oreochromis niloticus). The microbiological analysis of the water was based on the identification of the most probable number (MPN) of total and thermotolerant coliforms using a chromogenic and fluorogenic enzymatic substrate test (MUG), while the physical-chemical parameters determined were temperature, pH, turbidity and dissolved oxygen. The fish were captured and then anaesthetized for the blood collect by gill puncture. Blood smear slides were prepared and stained with modified Rosenfeld staining for the evaluation of erythrocyte alterations. For histopathological analysis of the gills, the second left branchial arch was removed from each specimen and fixed in 10% formaldehyde for 24 hours. These were subsequently decalcified in 10% nitric acid and histological protocols in paraffin. Large numbers of erythrocyte alterations, notably micronuclei, were identified. Among the most common branchial alterations were lamellar epithelium lifting, blood capillary dilation, aneurysms, and total and partial lamella fusion. The result of the microbiological analysis of the water revealed a quantity of thermotolerant coliforms than is permitted under current legislation. These results indicate that the health of the animals has been damaged, pointing out the poor quality of the water in the Laguna da Jansen.

A qualidade da água está relacionada ao tipo de uso da água e à avaliação de suas condições físicas, químicas e biológicas. O uso de diferentes ferramentas pode, portanto, fornecer dados precisos sobre a qualidade ambiental dos ecossistemas aquáticos. O objetivo do presente estudo foi avaliar a contaminação aquática do Parque Ecológico Laguna da Jansen, em São Luís, no estado do Maranhão, utilizando diferentes ferramentas (variáveis físicas, análises microbiológicas e alterações eritrocíticas e branquiais em Oreochromis niloticus). A análise microbiológica da água envolveu a identificação do número mais provável (NMP) de coliformes totais e termotolerantes utilizando um teste enzimático cromogênico e fluorogênico (MUG), enquanto a análise dos parâmetros físico-químicos determinou temperatura, pH, turbidez e oxigênio dissolvido. Os peixes foram capturados e em seguida anestesiados para coletada do sangue por punção branquial. As lâminas de esfregaço de sangue foram preparadas e coradas com coloração de Rosenfeld modificado para a avaliação das alterações eritrocitárias. Para análise histopatológica das brânquias, o segundo arco branquial esquerdo foi removido de cada espécime e fixado em formaldeído a 10% por 24 horas. Esses foram subsequentemente descalcificados em ácido nítrico a 10% e foram realizados protocolos histológicos em parafina. Alterações eritrocitárias, notadamente micronúcleos, foram identificadas em grandes quantidades. Entre as alterações branquiais mais comuns foram a elevação do epitélio lamelar, dilatação capilar sanguínea, aneurismas e fusão total e parcial da lamela. O resultado da análise microbiológica da água revelou uma quantidade de coliformes termotolerantes maior do que é permitido pela legislação vigente. Esses resultados indicam que a saúde dos animais foi danificada, apontando a má qualidade da água na Laguna da Jansen.

Analysis of histopathological abnormalities in the gills of Astyanax jacuhiensis (Characidae) for assessment of water quality in the Ijuí River, southern Brazil / Análisis de anormalidades histopatológicas en las branquias de Astyanax jacuhiensis (Characidae) para la evaluación de la calidad del agua del Río Ijuí, sur de Brasil

The aim of this study was to assess histopathological alterations in the gills of Astyanax jacuhiensis from different points along the Ijuí River and to determine if these abnormalities can be used as biomarkers in biomonitoring studies. Fish specimens were collected from three sites on the Ijuí River in winter and summer and examined histologically for abnormalities of the secondary lamellae of their gills. For each fish, estimates were made of the frequencies of lamellae with edema, hyperplasia, hypertrophy, epithelium lifting, lamellar fusion or deformation, in addition to the overall frequency of abnormal lamellae and the number of abnormalities per lamella. No differences were observed between sampling points during the winter. In summer the frequency of lamellae with hypertrophy was significantly higher at site 3 (Pirapó) than at site 2 (Santo Ângelo) and the frequency of abnormal lamellae was increased at site 1 (Ijuí) in comparison to site 3. Additionally, all three sample points had a significantly higher value in the winter than in the summer for one of the histological parameters analyzed. These results indicate temporal and spatial variation in the level of contamination of the Ijuí River and also shows that fish gill histopathology can be used for in situ biomonitoring studies.

El agua de la cuenca del río Ijuí, en el sur de Brasil, se utiliza principalmente para irrigar los cultivos y para el abastecimiento público de agua. El objetivo del presente estudio fue evaluar alteraciones histopatológicas en las branquias de Astyanax jacuhiensis en diferentes puntos del Río Ijuí y determinar si tales anormalidades pueden ser usadas como biomarcadores en estudios de biomonitoramiento. Los especímenes fueron recolectados en tres puntos del río durante el invierno y el verano y luego las lamelas secundarias de las branquias fueron examinadas histológicamente para la presencia de anormalidades. Para cada pez se estimaron las frecuencias de lamelas con edema, hiperplasia, hipertrofia, desprendimiento del epitelio, fusión y deformación lamelar. Además, se obtuvieron las frecuencias de lamelas alteradas, así como el número medio de cambios por lamela. No se observaron diferencias entre los puntos de recolección durante el invierno. En el verano, la frecuencia de lamelas con hipertrofia fue significativamente mayor en el punto 3 (Pirapó) que en el punto 2 (Santo Angelo), y el punto 1 (Ijuí) presentó mayor frecuencia de lamelas alteradas que el punto 3. Además, en los tres puntos muestreados, el período de invierno presentó valores superiores para uno de los parámetros histológicos analizados. Estos resultados indican variación espacial y temporal en los niveles de contaminación del Río Ijuí y demuestran que el análisis histológico de las branquias de peces puede ser utilizado en estudios de monitoreo in situ.

Infecção das brânquias de tilápia do Nilo (Oreochromis niloticus) por Myxosporea / Infection of the gills of Nile tilapia (Oreochromis niloticus) by Myxosporea

Neste estudo, 85 tilápias do Nilo (Oreochromis niloticus Linnaeus, 1758) foram coletadas em um lago de pesca recreativa (n = 35) e no lago do parque do Ibirapuera (n = 50), ambos localizados na cidade de São Paulo. Após a eutanásia, as brânquias dos peixes foram examinadas a fresco e por técnicas histológicas para identificar mixosporídeos. Foram observados mixosporídeos somente nos peixes capturados no lago de pesca recreativa com prevalência de 45,7% (16/35). Os esporos de Henneguya sp. foram encontrados em esfregaços a fresco (11,4%, 4/35). A prevalência de Myxobolus sp. foi de 34,3% (12/35), sendo os plasmódios deste gênero identificados de acordo com a localização nas brânquias, no epitélio (75%, 9/12), nos vasos sanguíneos (16,2%, 2/12), e na musculatura branquial (0,8%, 1/12). A presença de mixosporídeos estava relacionada com hiperplasia epitelial, fusão das lamelas, hiperplasia de células mucosas, reação inflamatória e outras alterações patológicas. Assim conclui-se que as prevalências de Myxobolus sp. e Henneguya sp. nas brânquias de O. niloticus foram altas e estavam associadas à lesões histopatológicas significantes, o que evidencia a importância desses cnidários patogênicos para as culturas peixes.(AU)

In this study, 85 Nile tilapia (Oreochromis niloticus Linnaeus, 1758) were collected in recreational fishing lake (n=35) and Lake Ibirapuera Park (n=50), both located in the city of São Paulo. After euthanasia, the fish gills were examined fresh and after histological techniques for the presence of myxosporea. Myxosporeans were observed only in recreational fishing lake with a prevalence of 45.7% (16/35). Henneguya sp. (11.4%, 4/35) and Myxobolus sp. (34.3%, 12/35) were myxosporeans observed in this study. Spores of Henneguya sp. were found in smears fresh gills. The plasmodium of Myxobolus found was of the types epithelial (75%, 9/12), vascular (16.2%, 2/12), and muscle, muscle located in the gills (0.8%; 1/12). The presence of myxosporea was related to epithelial hyperplasia, fusion of lamellae, hyperplasia of mucous cells, inflammation and other pathological changes. Thus it is concluded that prevalence of Myxobolus sp. and Henneguya sp. in gills of O. niloticus was high and was associated with significant histopathological lesions, which highlights the importance of these protozoa to fish cultures.(AU)

Mitochondria-rich cells changes induced by nitrite exposure in tambaqui (Colossoma macropomum Cuvier, 1818)

ABSTRACT The gill mitochondria-rich cells of the juvenile Amazonian fish Colossoma macropomum were analyzed using light and scanning and transmission electron microscopy after 96 h exposure to 0.04 and 0.2 mM nitrite. Although the number of mitochondria-rich cells decreased significantly in the lamellar epithelium, no decrease was found in the interlamellar region of the gill filament. Nitrite exposure caused significant reduction on the apical surface area of individual mitochondria-rich cells (p < 0.05), with a resulting reduction of the fractional area of these cells in both the lamellar and filament epithelium. Swelling of endoplasmic reticulum cisternae, nuclear envelope and mitochondria were the main changes found in the mitochondria-rich cells. Cristae lysis and matrix vacuolization characterized the mitochondrial changes. The overall ultrastructural changes indicated cellular functional disruption caused by exposure to nitrite. The changes observed in the gill indicate that the cellular structures involved in the process of energy production become severely damaged by exposure to nitrite indicating irreversible damage conducting to cell death.

Comparative transcriptome and potential antiviral signaling pathways analysis of the gills in the red swamp crayfish, Procambarus clarkii infected with White Spot Syndrome Virus (WSSV)

Abstract Red swamp crayfish is an important model organism for research of the invertebrate innate immunity mechanism. Its excellent disease resistance against bacteria, fungi, and viruses is well-known. However, the antiviral mechanisms of crayfish remain unclear. In this study, we obtained high-quality sequence reads from normal and white spot syndrome virus (WSSV)-challenged crayfish gills. For group normal (GN), 39,390,280 high-quality clean reads were randomly assembled to produce 172,591 contigs; whereas, 34,011,488 high-quality clean reads were randomly assembled to produce 182,176 contigs for group WSSV-challenged (GW). After GO annotations analysis, a total of 35,539 (90.01%), 14,931 (37.82%), 28,221 (71.48%), 25,290 (64.05%), 15,595 (39.50%), and 13,848 (35.07%) unigenes had significant matches with sequences in the Nr, Nt, Swiss-Prot, KEGG, COG and GO databases, respectively. Through the comparative analysis between GN and GW, 12,868 genes were identified as differentially up-regulated DEGs, and 9,194 genes were identified as differentially down-regulated DEGs. Ultimately, these DEGs were mapped into different signaling pathways, including three important signaling pathways related to innate immunity responses. These results could provide new insights into crayfish antiviral immunity mechanism.

Morphological Studies on the Gills of Puffer Fish (Lagocephalus sceleratus, Gmelin, 1789) / Estudios Morfológicos en Branquias del Pez Globo (Lagocephalus sceleratus, Gmelin, 1789)

In the present study, we focused on the morphology of L. sceleratus gills using gross anatomy, scanning electron microscopy as well as light microscopy. Results of this study revealed that the gill openings appeared as simple slits anterior to the pectoral fin without distinct opercular cover. The gill system consisted of three pairs of gill arches carrying two rows of gill rakers on its concave border and gill filaments on its convex border. SEM showed that all surfaces of the gill arch were characterized by the presence of the longitudinal ridges with many taste buds in addition to many spines around the rakers. Histologically, the gill arch was composed of curved bar of hyaline cartilage with slightly elevated area corresponding to the sites of gill rakers. Each filament was formed of a thin central cartilaginous core surrounded by peripheral cartilaginous matrix and covered by primary epithelial layer with abundant mucous cells. The chloride cells appeared mainly near to the base of secondary lamellae. Each gill filament gave rise to a very large number of secondary lamellae on both sides. The epithelial lining of the secondary lamellae comprised epithelial pavement cells, few mucous cells and pillar cells. The latter interposed the enriched blood capillaries. These findings suggest that L. sceleratus gills have characteristic morphological features that are related to adaptive functions for feeding habits, osmoregulation and respiratory mechanism with in their living environment.

El objetivo fue estudiar la morfología de las branquias de Sceleratus L. desde la anatomía macroscópica, microscopía electrónica de barrido, así como la microscopía de luz. Los resultados revelaron que las aberturas branquiales aparecían como simples rendijas por delante de la aleta pectoral sin una cubierta opercular distinta. El sistema branquial consistió en tres pares de arcos branquiales con dos filas de branquiespinas en sus filamentos branquiales frontales y cóncavos en el margen. La microscopía de barrido mostró que todas las superficies del arco branquial se caracterizaron por la presencia de crestas longitudinales con muchas papilas gustativas, además de una cantidad importante de espinas alrededor de los rastrillos. Histológicamente, el arco branquial se compone de una barra curva de cartílago hialino con una zona ligeramente elevada, correspondiente a los sitios de branquiespinas. Cada filamento se formó por un delgado núcleo central cartilaginoso rodeado de matriz cartilaginosa periférica y cubierto por una capa epitelial primaria con abundantes células mucosas. Las células de cloruro aparecieron principalmente cerca a la base de laminillas secundaria. Cada filamento de las branquias en ambos lados dio origen a un gran número de laminillas secundarias. El revestimiento epitelial de laminillas secundarias estaba formado de células epiteliales, algunas células mucosas y células sostenedoras. Estos hallazgos sugieren que las branquias de L. sceleratus tienen características morfológicas que están relacionadas con las funciones de adaptación de los hábitos de alimentación, la osmorregulación y el mecanismo respiratorio de acuerdo a su entorno.

Histological Alterations in Common Carp (Cyprinus carpio Linnaeus, 1758) Gills as Potential Biomarkers for Fungicide Contamination

ABSTRACTThe present study aimed to investigate the histological alterations in common carp gills caused by a fosetyl-Al and fenamidone based fungicide tested in laboratory conditions at 30, 38 and 50 mg/L concentration. In general, all the tested concentrations activated compensatory-adaptive mechanisms, which caused pathological changes in the fish gills. Results showed different histological alterations in the gill structure, which included lamellar lifting, edema, proliferation of the glandular cells and epithelium, covering the gill filament, fusion and degenerative alterations. Blood circulatory system showed vasodilatation of the secondary lamellae and aneurysms. Overall, there was enhancement of the gill histological changes, which was dose-dependent, i.e., proportional to the increasing fungicide concentrations. Thus, based on the results, it was concluded that the histological alterations in common carp gills could be applied as possible biomarkers in risk assessment and monitoring programs for pesticide contamination of aquatic ecosystems.

Histopathological Alterations in Common Carp (Cyprinus carpio L.) Gills Caused by Thiamethoxam

This work aimed to study the effect of new neonicotinoid thiamethoxam on the histological structure of common carp (Cyprinus carpio, L.) gills. Three experimental groups of fish were treated with 6.6, 10 and 20 mg/l thiamethoxam in laboratory conditions. Results showed different histological changes in the gill epithelium, which included lamellar lifting, edema, proliferation of the glandular cells and epithelium, covering the gill filament, fusion and degenerative alterations. The blood circulatory system showed mainly vasodilatation. All thiamethoxam concentrations activated compensatory-adaptive mechanisms, which caused pathological changes in the gills. Moreover, there was a tendency towards the enhancement of the gill histological changes, whose degree of expression was proportional to the increasing thiamethoxam concentrations.

Acute copper toxicity in juvenile fat snook Centropomus parallelus (Teleostei: Centropomidae) in sea water

Three experiments were designed to assess the accumulation and acute toxicity of copper (Cu) in juvenile fat snook Centropomus parallelus. The first experiment was performed to determine the 96-h lethal concentration (LC50) of Cu. The second experiment was designed to assess the effects of sublethal concentrations of Cu (0.47 and 0.94 mg/L), while the third one allowed us to test the recovery capacity of fish exposed to the sublethal concentrations Cu and kept in sea water without Cu addition. The LC50 value for Cu was found to be 1.88 mg/L Cu. Fish exposed to the sublethal concentrations of Cu showed a significant accumulation of Cu in gills at 96 h respect to the control ones (0.43 µg/g Cu). No significant difference was observed in the accumulation of Cu in gills between fish exposed to 0.47 mg/L (1.09 µg/g Cu) and 0.94 mg/L (1.26 µg/g Cu). Exposure (24 and 96 h) to the sublethal concentrations of Cu tested induced DNA damage in the erythrocytes. The results show that acute exposure to sublethal concentrations induces Cu accumulation and DNA damage in fish, these effects being recovered after 240 h in sea water without Cu addition.

Três experimentos foram realizados para avaliar o acúmulo e toxicidade aguda do cobre (Cu) em juvenis de robalo-peva Centropomus parallelus. O primeiro experimento foi realizado para determinar a concentração letal (96h-CL50) de Cu. O segundo experimento foi realizado para avaliar os efeitos de concentrações subletais de Cu (0,47 e 0,94 mg/L), enquanto o terceiro permitiu testar a capacidade de recuperação dos peixes expostos a concentrações subletais do Cu e posteriormente mantidos em água do mar sem acréscimo de Cu. O valor de LC50 encontrado para o Cu foi de 1,88 mg/L. Os peixes expostos as concentrações subletais de Cu mostraram um acúmulo significativo nas brânquias em relação ao controle em 96 h de exposição (0,43 µg/g Cu). Nenhuma diferença significativa foi observada entre os peixes expostos a 0,47 mg/L de Cu (1,09 µg/g) e 0,94 mg/L de Cu (1,26 µg/g). A exposição (24 e 96 h) para as concentrações subletais de Cu induziram danos no DNA. Os resultados mostram que a exposição aguda a concentrações subletais induz o acúmulo de Cu e danos ao DNA nas brânquias dos peixes, onde estes efeitos são recuperados após 240 h em água do mar sem adição de Cu.

Surface ultrastructure of the gills of Odontesthes bonariensis (Valenciennes, 1835)(Teleostei: Atheriniformes) from a temperate shallow lake / Estudio ultraestructural de las branquias de Odontesthes bonariensis (Valenciennes, 1835) (Teleostei: Atheriniformes) de un lago somero templado

We studied the gill epithelium of juveniles of Odontesthes bonariensis using scanning electron microscopy with a particular interest in the relationship between cell morphology and the different functional aspects of gills. The specimens used were collected in Laguna de los Padres, Buenos Aires Province, Argentina. The gill filaments or primary lamellae are arranged in two rows along the convex outer face of the gill arch forming the anterior and posterior hemibranchiae. On its concave inner face, each arch supports two rows of gill rakers forming the pharyngeal region wall. The primary lamellae are lined by a stratified epithelium made up of polygonal cells with well-defined outlines and cell membrane microfolds. Several mucous and chloride cells were observed in the primary lamellae. The epithelial cells of the secondary lamellae have ill-defined outlines and few microfolds. Both the arches and gill rakers are covered by a stratified epithelium of polygonal cells, among which mucous cells and taste corpuscles are abundant. The ultrastructural analysis of gills of O. bonariensis contributes to the advancement of knowledge of the organ histophysiology and of future histopathological studies.

Se estudió el epitelio branquial de juveniles de Odontesthes bonariensis utilizando microscopía electrónica de barrido con un interés particular en la relación entre la morfología celular y los distintos aspectos funcionales de las branquias. Los ejemplares utilizados fueron colectados en la Laguna de los Padres, Provincia de Buenos Aires, Argentina. Los filamentos branquiales o laminillas primarias están dispuestos en dos filas a lo largo de la cara exterior convexa del arco branquial formando las hemibranquias anterior y posterior. En su cara interior cóncava, cada arco sostiene dos hileras de branquiespinas que forman la pared de la región faríngea. Las laminillas primarias están revestidas por un epitelio estratificado constituido por células poligonales con contornos bien definidos y micropliegues de la membrana celular. Se observaron numerosas células clorhídricas y mucosas en las laminillas primarias. Las células epiteliales de las laminillas secundarias tienen contornos poco definidos y escasos micropliegues. Tanto los arcos como las branquiespinas están cubiertos por un epitelio estratificado de células poligonales, entre las cuales hay abundantes células mucosas y corpúsculos gustativos. El análisis ultraestructural de las branquias de O. bonariensis proporciona información para avanzar en el conocimiento de la histofisiología del órgano y para realizar futuros estudios histopatológicos.

Alterações morfológicas em brânquias de Oreochromis niloticus (Pisces, cichlidae) como biomarcadores de poluição aquática na Laguna da Jansen, São Luís-MA (Brasil) / Morphological changes in fish gills of Oreochromis niloticus (pisces, cichlidae) as biomarkers of aquatic pollution in the lagoon of Jansen, São Luís, State Of Maranhão (Brazil)

Uma investigação de biomarcadores histológicos pode ser uma ferramenta de baixo custo para determinar a saúde das populações de peixes, refletindo a saúde de um ecossistema aquático inteiro. Na presente pesquisa objetivou-se estudar as alterações histológicas nas brânquias de Oreochromis niloticus como biomarcadores em combinação com a análise microbiológica da água a partir de dois diferentes locais da "Laguna da Jansen" (São Luís, Brasil). As amostras de água e tecidos de peixes (brânquias) foram coletadas em duas estações de amostragem. Amostras de brânquias para análise histológica (arcos branquiais completos) foram dissecadas e fixadas por 24 horas. Notáveis mudanças estruturais foram detectadas nos tecidos dos peixes amostrados. As principais lesões moderadas observadas foram descolamento do epitélio lamelar, fusão de lamelas primárias e fusão das lamelas secundárias. As lesões mais graves foram infiltrado heterofilico, hemorragia, necrose e eritrofagocitose. O exame microbiológico da água indicou contaminação por coliformes totais, Escherichia coli e bactérias heteroróficas. Esses resultados indicam que as lesões branquiais são respostas adaptativas dos peixes à baixa qualidade microbiológica, da água do ambiente analisado.

A histological biomarker investigation may be a cost effective tool to determine the health of fish populations, reflecting the health of an entire aquatic ecosystem. The present research aimed to study the histological changes on the gills of the Oreochromis niloticus as biomarkers in combination with microbiological analysis of the water from two different sites of the Laguna da Jansen (São Luís, Brazil). Water and gills samples were collected from two sampling stations. Gill samples for histological analysis (complete gill arches) were dissected and fixed for 24 hours. Remarkable structural changes were detected in the tissues of the fishes sampled. The main moderate lesions observed were lamellar epithelium lifting, fusion of primary lamellae and fusion of secondary lamellae. The severe lesions were heterophilic inflammatory infiltrate, hemorrhage, necrosis and erythrophagocytosis. Microbiological water analysis indicated contamination by total coliforms, Escherichia coli and heterotrophic bacteria. These results indicate that the gill lesions are adaptive responses of fish to poor water quality of the environment analyzed.

Haematological and parasitological assessment of silver catfish Rhamdia quelen farmed in Southern Brazil / Monitoramento hematológico e parasitológico em jundiá Rhamdia quelen criado no Sul do Brasil

This study evaluated for two years the haematological parameters and the occurrence of gill parasites in silver catfish Rhamdia quelen, farmed in the state of Santa Catarina, southern Brazil. Between March 2010 and January 2012, a total of 137 fish were caught in a fish farm to compare the haematological and parasitological analysis, during hot and cold seasons. Simultaneously, water quality parameters were measured in the pond to analyze the relationship between environmental conditions and haematology and parasitism. During the hot season, there was an increase in water temperature, electrical conductivity and ammonia followed by a decrease in dissolved oxygen, pH, transparency and alkalinity. Two species of Monogenea were observed in the gills, Aphanoblastella mastigatus (Dactylogyridae) and Scleroductus sp. (Gyrodactylidae). Additionally, during this season, there was a significant increase (p<0.05) in the mean intensity of infection by Monogenea, as well as total leukocytes number, thrombocytes and lymphocytes, and a reduction in monocytes. The changes might be caused by parasitism and/or environmental variations between seasons.

O presente estudo avaliou, durante dois anos, os parâmetros hematológicos e a ocorrência de parasitos branquiais em jundiá Rhamdia quelen, cultivado no Estado de Santa Catarina, Sul do Brasil. Entre março de 2010 e janeiro de 2012, um total de 137 jundiás foi coletado de uma piscicultura para comparar os parâmetros hematológicos e parasitológicos durante as estações quente e fria. Simultaneamente, foram medidos os parâmetros de qualidade da água do viveiro, para relacionar as condições ambientais com a hematologia e o parasitismo. Na estação quente, houve aumento da temperatura, condutividade elétrica e amônia, e redução do oxigênio dissolvido, pH, transparência e alcalinidade. Duas espécies de Monogenea foram observadas nas brânquias, Aphanoblastella mastigatus (Dactylogyridae) e Scleroductus sp. (Gyrodactylidae). Na estação quente, houve aumento significativo (p<0,05) da intensidade média de infecção por Monogenea, bem como dos valores de leucócitos totais, trombócitos e linfócitos, e redução significativa dos monócitos. As diferenças observadas podem ter sido causadas pelas variações ambientais entre as estações.

Parasites in Curimata cyprinoides (Characiformes: Curimatidae) from eastern Amazon, Brazil - doi: 10.4025/actascibiolsci.v35i4.19649

This work is the first study on parasitic fauna of Curimata cyprinoides Linnaeus, 1766 (Curimatidae) and the host-parasite relationship. The total of 154,740 parasites such as Ichthyophthirius multifiliis (Ciliophora), trophozoite of Spironucleus sp. (Hexamitidae), Urocleidoides sp. (Monogenoidea), Digenea gen. sp. and Polymorphus sp. (Polymorphidae) were collected. The component community showed low diversity (HB = 0.004 ± 0.020) and parasite species richness (1.4 ± 0.6). However, I. multifiliis and Urocleidoides sp. were prevalent and with higher intensity on the host population and also aggregated the distribution pattern. The occurrence of these ectoparasites in C. cyprinoides may be a consequence of its alimentary diet. Positive correlation between the abundance and size of I. multifiliis and the relative condition factor of the host were observed and discussed. These data represent increased knowledge of the biology of these parasites. Furthermore, this study expanded the geographic distribution of some parasite species for this new host from Brazil.

Parasites in Curimata cyprinoides (Characiformes: Curimatidae) from eastern Amazon, Brazil / Parasitos em Curimata cyprinoides (Pisces, Curimatidae) da Amazônia oriental, Brasil

This work is the first study on parasitic fauna of Curimata cyprinoides Linnaeus, 1766 (Curimatidae) and the host-parasite relationship. The total of 154,740 parasites such as Ichthyophthirius multifiliis (Ciliophora), trophozoite of Spironucleus sp. (Hexamitidae), Urocleidoides sp. (Monogenoidea), Digenea gen. sp. and Polymorphus sp. (Polymorphidae) were collected. The component community showed low diversity (HB = 0.004 ± 0.020) and parasite species richness (1.4 ± 0.6). However, I. multifiliis and Urocleidoides sp. were prevalent and with higher intensity on the host population and also aggregated the distribution pattern. The occurrence of these ectoparasites in C. cyprinoides may be a consequence of its alimentary diet. Positive correlation between the abundance and size of I. multifiliis and the relative condition factor of the host were observed and discussed. These data represent increased knowledge of the biology of these parasites. Furthermore, this study expanded the geographic distribution of some parasite species for this new host from Brazil.

Este trabalho providenciou o primeiro estudo sobre a fauna parasitaria de Curimata cyprinoides Linnaeus, 1766 (Curimatidae) e relação hospedeiro-parasito. Foram coletados 154.740 parasitos, tais como Ichthyophthirius multifiliis (Ciliophora); trofozoíto de Spironucleus sp. (Hexamitidae); Urocleidoides sp. (Monogenoidea); Digenea gen. sp. e Polymorphus sp. (Polymorphidae). A comunidade componente apresentou baixa diversidade (HB = 0,004 ± 0,020) e riqueza de parasitos (1,4 ± 0,6). Ichthyophthirius multifiliis e Urocleidoides sp. apresentaram a maior prevalência e intensidade na população de hospedeiro e tiveram padrão de distribuição agregado. Em C. cyprinoides, a ocorrência desses ectoparasitos pode ser uma consequência da ampla variedade de sua dieta alimentar. Correlação positiva da abundância de I. multifiliis como o tamanho e fator de condição relativo dos hospedeiros foi observada e discutida. Estes dados representam um aumento do conhecimento sobre a biologia desses parasitos. Além disso, este estudo ampliou a distribuição geográfica de algumas espécies de parasitos para este novo hospedeiro no Brasil.

Pseudobrânquia do guaru Poecilia reticulata (Peter, 1859): análise estrutural, morfométrica e histoquímica para detecção de glicoconjugados / Pseudo-gill of guppy, Poecilia reticulata (Peter, 1859): structural, morphometric, and histochemical analyses for the detection of glycoconjugates

A morfologia, os parâmetros citomorfométricos e os glicoconjugados presentes na pseudobrânquia de guaru, Poecilia reticulata Peter, 1859 (Cyprinodontiformes: Poeciliidae), foram investigados por microscopia de luz acoplada ao sistema de captura e análise de imagens, juntamente por histoquímica com lectinas. A anatomia microscópica indicou que P. reticulata possui pseudobrânquia glandular formada por dois lóbulos, a qual se localiza abaixo do epitélio faringiano. O órgão é constituído por parênquima vascularizado e rico em células pseudobranquiais. Esse tipo celular exibe estado citofisiológico ativo, com abundante sistema de biomembranas e ausência de óstio na superfície apical,que por sua vez é encontrado nas células ricas em mitocôndrias das holobrânquias. Assim, indica-se que as células da pseudobrânquia se distinguem das células das holobrânquias em relação à morfologia, histoquímica e fisiologia. Em decorrência dessas características intrínsecas, a pseudobrânquia de alevinos do guaru pode desempenhar funções não respiratórias nas fases iniciais do desenvolvimento. Além disso, a caracterização da pseudobrânquia do guaru possibilitará estudos futuros sobre o efeito de poluentes aquáticos em espécies biomonitoras, como P. reticulata.

The morphology, cytomorphometric parameters, and glycoconjugates present in the pseudo-gill of guppy, Poecilia reticulata Peter, 1859 (Cyprinodontiformes: Poeciliidae), were investigated by light microscopy coupled to image capture and analysis system, and also by lectin histochemistry. The microscopic anatomy indicates that P. reticulata has a glandular pseudo-gill formed by two lobes, located underneath the pharynx epithelium. The organ is formed by vascularized parenchyma rich in pseudo-gill cells. This cell type exhibits active cytophysiological state with an abundant system of biomembranes and lacking of ostium in apical surface, which in turn is found in the mitochondria-rich cells of the holobranch. This indicates that the pseudo-gill cells distinguishe from the holobranch cells in their morphology, histochemistry and physiology. Due to these intrinsic characteristics, the pseudo-gill of guppy fingerlings may have non-respiratory function in the initial phase of their development. The characterization of guppy's pseudo-gill could facilitate further studies about the effect of water pollutants on biomonitor species, such as P. reticulata.

Refractive Changes after Removal of Anterior IOLs in Temporary Piggyback IOL Implantation for Congenital Cataracts

PURPOSE: To assess the refractive change and prediction error after temporary intraocular lens (IOL) removal in temporary polypseudophakic eyes using IOL power calculation formulas and Gills' formula. METHODS: Four consecutive patients (7 eyes) who underwent temporary IOL explantation were enrolled. Postoperative refractions calculated using IOL power calculation formulas (SRK-II, SRK-T, Hoffer-Q, Holladay, and the modified Gills' formula for residual myopia and residual hyperopia) were compared to the manifest spherical equivalents checked at 1 month postoperatively. RESULTS: The mean ages of temporary piggyback IOL implantation and IOL removal were 6.71 +/- 3.68 months (range, 3 to 12 months) and 51.14 +/- 18.38 months (range, 29 to 74 months), respectively. The average refractive error was -13.11 +/- 3.10 diopters (D) just before IOL removal, and improved to -1.99 +/- 1.04 D after surgery. SRK-T showed the best prediction error of 1.17 +/- 1.00 D. The modified Gills' formula for myopia yielded a relatively good result of 1.47 +/- 1.27 D, with only the variable being axial length. CONCLUSIONS: Formulas to predict refractive change after temporary IOL removal in pediatric polypseudophakia were not as accurate as those used for single IOL implantation in adult eyes. Nonetheless, this study will be helpful in predicting postoperative refraction after temporary IOL removal.

Refractive Changes after Removal of Anterior IOLs in Temporary Piggyback IOL Implantation for Congenital Cataracts

PURPOSE: To assess the refractive change and prediction error after temporary intraocular lens (IOL) removal in temporary polypseudophakic eyes using IOL power calculation formulas and Gills' formula. METHODS: Four consecutive patients (7 eyes) who underwent temporary IOL explantation were enrolled. Postoperative refractions calculated using IOL power calculation formulas (SRK-II, SRK-T, Hoffer-Q, Holladay, and the modified Gills' formula for residual myopia and residual hyperopia) were compared to the manifest spherical equivalents checked at 1 month postoperatively. RESULTS: The mean ages of temporary piggyback IOL implantation and IOL removal were 6.71 +/- 3.68 months (range, 3 to 12 months) and 51.14 +/- 18.38 months (range, 29 to 74 months), respectively. The average refractive error was -13.11 +/- 3.10 diopters (D) just before IOL removal, and improved to -1.99 +/- 1.04 D after surgery. SRK-T showed the best prediction error of 1.17 +/- 1.00 D. The modified Gills' formula for myopia yielded a relatively good result of 1.47 +/- 1.27 D, with only the variable being axial length. CONCLUSIONS: Formulas to predict refractive change after temporary IOL removal in pediatric polypseudophakia were not as accurate as those used for single IOL implantation in adult eyes. Nonetheless, this study will be helpful in predicting postoperative refraction after temporary IOL removal.