Reproductive and morphological analysis of the trairão Hoplias intermedius in the São Francisco River, downstream from a large reservoir.

Hoplias intermedius, of the Characiformes order and Erytrinidae family, is widely distributed across South America. This commercially interesting species can reach a length of 100 cm and a weight of 15-20 kg. To evaluate the reproductive biology of H. intermedius in the São Francisco River, Brazil, 154 males and 190 females were captured bi-monthly between September 2018 and August 2019 from the downstream regions of the Três Marias dam. Gillnets with differently sized meshes were deployed at distances of 34-54 km after the confluence with the Abaeté River (18°00'49″ S, 45°10'51″ W). Biometric data, gonadosomatic index (GSI), Fulton condition factor (K) and absolute fecundity (AF) were determined for each specimen. Gonad maturation stages and the spawning season were also established. The biometric data, GSI and K average values were relatively higher in females than in males. The reproductive peak for both sexes was reached around January/February. The mean AF was 4300.5 ± 1451.2 follicles per female. Fully developed vitellogenic follicles had a mean diameter of 1014.8 ± 250.7 µm, which is characteristic of fish with moderate fecundity. Fish of all maturation stages, from mature, spawned and spermed, occurred in all bimesters, indicating that this species reproduced throughout the year. The high frequency of spawning females throughout the year and the histological characteristics of spawned ovaries indicated that trairão H. intermedius' spawning type is partial.

Morphological analysis of the reproductive activity of Curimatella lepidura (Characiformes: Curimatidae).

Curimatella lepidura, commonly known as the manjuba, belongs to the Curimatidae family. To assess the reproductive activity of this species, fish were collected from three sections of the São Francisco River: section 1 = the Três Marias reservoir (TMR), section 2 = the SFR immediately downstream of the TMR, and section 3 = the SFR 54 km downstream from the TMR after the confluence of the SFR with the Abaeté River. Fish were collected bimonthly from January to December 2012. From this, the gonadosomatic index (GSI), Fulton condition factor (K), gonadal maturation stages in females and males, and diameters of vitellogenic follicles were determined. That is, this study employed histological and histometrical techniques to study the ovaries and testes of collected fish. The Fulton condition factor was statistically higher in section 1 than in the other sections, indicating that C. lepidura presents better health conditions in this section. Fish in the maturation/mature gonadal stage were collected in the November/December and January/February bimesters, coinciding with high temperatures, a long photoperiod, and abundant rainfall in this region. The mean vitellogenic follicle diameter was statistically lowest for sections 2 and 3, with a better impact on reproduction than in section 1. Overall, the results show that C. lepidura has reproductive success in lentic environments, such as in section 1, the TMR.

The importance of the temporomandibular joint in the differential diagnosis of primary headaches and recurrent primary headaches / A importância da articulação temporomandibular no diagnóstico diferencial de cefaleias primárias e cefaleias primárias recorrentes

Introduction: he present article aims to popularize the temporomandibular disorder as a possible diagnosis when the phisician is facing a primary headache that was first thought to be a migraine headache or tension type headache, specially when they are not responsible to the treatment. Methodology:This study focused on the clinical manifestation of the headache caused by temporomandibular disorder, with data searched in the National Library of Medicine, Scielo and PubMed libraries, from 2002 to 2022; also the 3rd edition of the International Classification of Headache Disorders (2018) and the Continuum Headache (2021). The aspects of the clinical manifestation chosen for comparison were location of the pain, type of pain, crisis duration, improvement and worsening factors and associated symptoms. Results:27 articles were found and 3 were included and used to create a table comparing migraine, tension type and TMD headache. Some manifestations were similar, like bilateral location of headache (tension type and TMD headache) and many manifestations were distinct, like the type of pain (pulsatile for migraine, tight for tension type and rigidity or stabbing for TMD headache). In face of these results, it is clear that there are many aspects of the differential diagnosis between these three types of headache that can be investigated so that we can distinguish them. This study also reiterates the need for further studies regarding this topic. Conclusion:It is very reasonable to consider TMD headache as a first diagnosis when the complaint is a primary headache, as much as it is reasonable to consider this diagnosis when the refractoriness is the complaint. Also, considering the TMD as a trigger to the other headaches.

Introdução: o presente artigo tem como objetivo popularizar a disfunção temporomandibular como um possível diagnóstico quando o médico se depara com uma cefaleia primária que inicialmente se pensava ser uma enxaqueca ou cefaleia do tipo tensional, principalmente quando não são responsáveis ​​pelo tratamento. Metodologia:Este estudo teve como foco a manifestação clínica da cefaleia causada pela disfunção temporomandibular, com dados pesquisados ​​nas bibliotecas National Library of Medicine, Scielo e PubMed, de 2002 a 2022; também a 3ª edição da Classificação Internacional de Cefaleias (2018) e da Cefaleia Contínua (2021). Os aspectos da manifestação clínica escolhidos para comparação foram localização da dor, tipo de dor, duração da crise, fatores de melhora e piora e sintomas associados. Resultados: foram encontrados 27 artigos e 3 foram incluídos e utilizados para criar uma tabela comparando enxaqueca, tipo tensional e cefaleia por DTM. Algumas manifestações foram semelhantes, como localização bilateral da cefaleia (tipo tensional e cefaléia por DTM) e muitas manifestações foram distintas, como o tipo de dor (pulsátil para enxaqueca, tensa para tipo tensional e rigidez ou pontada para cefaléia por DTM). Diante desses resultados, fica claro que existem muitos aspectos do diagnóstico diferencial entre esses três tipos de cefaleia que podem ser investigados para que possamos distingui-los. Este estudo também reitera a necessidade de mais estudos sobre esse tema. Conclusão: É muito razoável considerar a cefaleia por DTM como primeiro diagnóstico quando a queixa é uma cefaleia primária, assim como é razoável considerar este diagnóstico quando a refratariedade é a queixa. Além disso, considerar a DTM como gatilho para as demais dores de cabeça.

Evaluation of the Quality of Life of Patients Using Circular External Fixator in a Trauma Hospital.

Objective To evaluate the quality of life of patients using an Ilizarov type external fixator for the treatment of complicated fractures and their sequelae. Method This is an observational and cross-sectional study, in which the 36-item short form survey (SF-36) questionnaire (translated into Portuguese) was applied during outpatient consultations in 2 periods, in the months of July 2018 and January 2019. The patients who participated in the study underwent their surgical procedures between January and June 2018. Results We evaluated 36 patients using an external Ilizarov fixator. We observed a predominance of male patients, with a mean age of 37.9 years. Fractures of leg bones and their complications represented half of the sample. Improvement in functional capacity and emotional aspects of the patients was observed throughout the treatment. Conclusion The use of the circular external fixator is an important and effective method for the surgical treatment of complex fractures and their sequelae. This study allowed us to conclude that, after treatment, patients achieved functional return to daily activities with adequate quality of life.

Reproduction of saguiru Steindachnerina elegans (Steindachner, 1874) (Pisces: Curimatidae) in the São Francisco River, downstream from a large reservoir in south-eastern Brazil.

The gametogenesis and reproduction of S. elegans from the São Francisco River at Três Marias, Minas Gerais, were analyzed in this study. Steindachrina elegans is a species abundant in the São Francisco River basin and an important fish in the food chain. The size at first gonadal maturation (indicated by the total length of the shortest spermatid male and spawned female) was 10.5 cm and 15.0 cm, respectively. Reproduction occurred more frequently from September to April. This period had high water temperature values. A high frequency of females was observed at the mature and spawned stages and height gonadosomatic index (GSI). Meanwhile, in males, the reproductive peak was from November to February. The long spawning period and the histological characteristics of the spawned ovaries that contained oocytes at different stages of development along with post-ovulatory and atretic oocytes indicates that the spawning of S. elegans is of the partial type.

Evaluation of the Quality of Life of Patients Using Circular External Fixator in a Trauma Hospital / Avaliação da qualidade de vida dos pacientes em uso de fixador externo circular em um hospital de trauma

Abstract Objective To evaluate the quality of life of patients using an Ilizarov type external fixator for the treatment of complicated fractures and their sequelae. Method This is an observational and cross-sectional study, in which the 36-item short form survey (SF-36) questionnaire (translated into Portuguese) was applied during outpatient consultations in 2 periods, in the months of July 2018 and January 2019. The patients who participated in the study underwent their surgical procedures between January and June 2018. Results We evaluated 36 patients using an external Ilizarov fixator. We observed a predominance of male patients, with a mean age of 37.9 years. Fractures of leg bones and their complications represented half of the sample. Improvement in functional capacity and emotional aspects of the patients was observed throughout the treatment. Conclusion The use of the circular external fixator is an important and effective method for the surgical treatment of complex fractures and their sequelae. This study allowed us to conclude that, after treatment, patients achieved functional return to daily activities with adequate quality of life.

Resumo Objetivo Avaliar a qualidade de vida dos pacientes em uso do fixador externo do tipo Ilizarov para tratamento de fraturas complexas e de suas sequelas Método Trata-se de um estudo observacional e transversal, em que foi aplicado o questionário 36-item short form survey (SF-36) (traduzido para a língua portuguesa) durante as consultas ambulatoriais em 2 períodos, nos meses de julho de 2018 e janeiro de 2019. Os pacientes que participaram do estudo realizaram seus procedimentos cirúrgicos no período de janeiro a junho de 2018. Resultados Foram avaliados 36 pacientes em uso de fixador externo do tipo Ilizarov. Foi observado predomínio do sexo masculino e idade média de 37,9 anos. As fraturas de ossos da perna e suas complicações representaram metade da amostra. Foi observada melhora na capacidade funcional e nos aspectos emocionais dos pacientes ao longo do tratamento. Conclusão O uso do fixador externo circular constitui um método importante e eficaz para o tratamento cirúrgico de fraturas complexas e de suas sequelas. Este trabalho permitiu concluir que, após o tratamento, os pacientes alcançaram retorno funcional às atividades diárias com adequada qualidade de vida.

Comparative analysis of the reproductive activity of Leporinus piau (Characiformes: Anostomidae) in lentic and lotic environments

In this study, we determined the main reproductive parameters of piau gordura, Leporinus piau, in two sections of the São Francisco River basin. Between May 2015 and April 2016, a total of 573 specimens were captured from a lentic environment (section 1), the Três Marias Reservoir (TMR), and a lotic environment (section 2), downstream of the TMR at the confluence of the São Francisco River (SFR) with the Abaeté River. Analysis of reproductive activity showed that L. piau from both sections reproduced, but females and males from section 1 exhibited higher total length, body weight, Fulton condition factor, and gonadosomatic index values, as compared to section 2. Sexual dimorphism was evident in the species, with females being larger than males. Moreover, males reached first gonadal maturation at a smaller size than females. The peak maturation/mature stage was observed in November/April for females and males in section 1 and in November/December in section 2, coinciding with high temperatures and precipitation in the region. In both sections of the river, L. piau exhibited the typical characteristics of partial spawning, with a prolonged spawning period, and preferential reproduction in lentic environments.(AU)

Neste estudo, determinamos os principais parâmetros reprodutivos do piau gordura, Leporinus piau, em duas seções da bacia do rio São Francisco. Entre maio de 2015 e abril de 2016, um total de 573 espécimes foram capturados de um ambiente lêntico (seção 1), o reservatório de Três Marias (RTM), e um ambiente lótico (seção 2), à jusante da RTM na confluência do rio São Francisco (RSF) com o rio Abaeté. A análise da atividade reprodutiva mostrou que L. piau se reproduz nas duas seções, mas fêmeas e machos da seção 1 apresentaram maiores valores de comprimento total, peso corporal, fator de condição de Fulton e índice gonadossomático em comparação com a seção 2. O dimorfismo sexual foi evidente na espécie com as fêmeas sendo maiores do que os machos. Além disso, os machos atingiram a primeira maturação gonadal em tamanho menor do que as fêmeas. O pico do estágio de maturação/maduro foi observado em novembro/abril para fêmeas e machos na seção 1 e em novembro/dezembro na seção 2, coincidindo com altas temperaturas e precipitação na região. Em ambas as seções do rio, L. piau apresentou características típicas de desova parcelada com período de desova prolongada e reproduz preferencialmente em ambientes lênticos.(AU)

Reproductive biology of the Neotropical catfish Iheringichthys labrosus (Siluriformes: Pimelodidae), with anatomical and morphometric analysis of gonadal tissues.

The reproduction of Iheringichthys labrosus (Lütken, 1874) from the Turvo River, Brazil, was studied using anatomical, biometric, histological, and ultrastructural techniques. Between April 2014 and March 2015, a total of 278 males and 512 females were captured bimonthly. The testes of Iheringichthys labrosus are fringed and possess a cranial spermatogenic region and an exclusively secretory caudal region. Histologically, the cranial region is composed of seminiferous tubules with spermatogenesis being completed in cysts. The spermatozoa are of the primitive type with a spherical head and have a rudimentary intermediate piece and a long tail with an axonemic arrangement of 9 + 2. The caudal region does not form an individualized gland, and cells in this testis area have characteristics of protein secretion. A variable density electron-dense secretion accumulates in the cisternae of the rough endoplasmic reticulum in the lumen of the seminiferous tubules and in the testicular ducts during maturation. The cortical alveoli are discontinuous, and the zona pellucida consists of three layers crossed by pore canals, and the follicular cells are squamous in the early stages of oogenesis and cuboidal in advanced stages. The gonadosomatic index was associated with the maturation of the gonads while the condition factor indicated that the fish feed less and utilize adipose reserves during the reproductive period. Males and females reproductively functional throughout the year with spawning being partial or multiple, similar to that reported in studies of the species in lentic environments.

The influence of a large reservoir on the reproductive activity of the white piranha, Serrasalmus brandtii (Lütken, 1875) in Southeast Brazil / A influência de um grande reservatório na atividade reprodutiva da piranha branca, Serrasalmus brandtii (Lütken, 1875) no sudeste do Brasil

Abstract: In order to assess the influence of the Três Marias dam on the reproduction of the white piranha, Serrasalmus brandtii, 1569 specimens captured from June 2011 to May 2012 in three sections of the São Francisco River basin were analyzed: section 1 = Três Marias reservoir (TMR); section 2 = São Francisco River (SFR) segment immediately downstream of TMR; and section 3 = SFR segment at the confluence with the Abaeté River. Total length (TL), body weight (BW), gonadosomatic index (GSI), and gonadal maturation stages were determined for each specimen, while vitellogenic follicle diameter, and absolute (AF) and relative (RF) fecundities were also determined for females. Reproductive activity, including spawned females and spermed males, was recorded throughout the year in the three river segments. Higher frequencies of females and males at the maturing/mature stage were found in the November/December and January/February, which coincided with the period of higher temperature, rainfall, and dissolved oxygen concentration. Mean GSI and vitellogenic follicle diameter were higher in sections 1 and 3 than in section 2 (P <0.05), while AF and RF were higher in section 1 (P <0.05) than in sections 2 and 3. The results of the present study showed that S. brandtii had lower reproductive performance in section 2, probably due to thermal disturbances caused by the dam, thus confirming the influence of dams on the reproduction of fish downstream from hydroelectric plant reservoirs.

Resumo: Com o objetivo de avaliar a influência da barragem de Três Marias na reprodução da piranha branca, Serrasalmus brandtii, foram analisados 1569 exemplares capturados de junho de 2011 a maio de 2012 em três trechos da bacia do rio São Francisco: seção 1 = reservatório de Três Marias (RTM); seção 2 = segmento do rio São Francisco (SRF) imediatamente a jusante do RTM; e seção 3 = segmento RSF na confluência com o rio Abaeté. O comprimento total (CT), peso corpóreo (PC), índice de gonadossomático (IGS) e estágio de maturação gonadal foram determinados para cada amostra, enquanto o diâmetro do folículo vitelogênico, fecundidade absoluta (FA) e relativa (FR) foram determinadas para fêmeas. Nas três seções estudadas, a atividade reprodutiva foi registrada ao longo do ano, incluindo fêmeas desovadas e machos espermiados. Maiores frequências de fêmeas e machos na fase de maturação/maduro foram encontradas nos meses de novembro/dezembro e janeiro/fevereiro, coincidindo com o período de maior temperatura, precipitação e concentração de oxigênio dissolvido. O IGS médio e o diâmetro do folículo vitelogênico foram maiores nas seções 1 e 3 do que na seção 2 (P <0,05), enquanto FA e FR foram maiores na seção 1 (P <0,05) do que nas seções 2 e 3. Os resultados do presente estudo mostraram que S. brandtii teve menor desempenho reprodutivo na seção 2, provavelmente devido a perturbações térmicas causadas pela barragem, confirmando a influência das barragens na reprodução de peixes a jusante de reservatórios de usinas hidrelétricas.

Growth hormone on ovarian morphology of lambaris (Astyanax bimaculatus) after induced spawning / Hormônio de crescimento sobre a morfologia ovariana de lambaris (Astyanax bimaculatus) após desova induzida

ABSTRACT: Lambari, Astyanax bimaculatus, is an oviparous, multiple-spawning fish that is reproductively active throughout the year, which makes it promising for cultivation and research. This research histologically evaluates the ovaries of lambari that have undergone artificial spawning induced with pituitary extract (control group), and the effect of growth hormone at a dose of 2 mg/g body weight (treatment group) on the subsequent process of ovarian recovery. Ovaries of fish in both the control and treatments groups were collected at 120 hours after spawning and analyzed using optical microscopy to characterize the average quantities of: follicles in different stages of development, post-ovulatory follicles, follicular atresia and granulocytes. Quantity and morphology of early and advanced primary follicles did not differ between the treatment and control groups; an important and necessary factor for ovarian recovery for subsequent spawning. There was a greater amount of granulocytes in initial atresia in the group treated with growth hormone. These results demonstrated that the administration of growth hormone may potentiate the process of ovarian recovery after induced spawning.

RESUMO: O Lambari Astyanax bimaculatus é um peixe ovíparo de desova múltipla que é reprodutivamente ativo durante todo o ano, o que o torna promissor para cultivo e pesquisa. Este trabalho avalia histologicamente os ovários de lambaris submetidos à desova artificial, induzida pelo extrato hipofisário (grupo controle) e o efeito do hormônio de crescimento na concentração de 2 μg/g de massa corporal (grupo tratamento) no subsequente processo de recuperação ovariana. Os ovários dos peixes dos grupos controle e tratamento foram coletados às 120 horas após a desova e analisados em microscopia óptica para caracterizar as quantidades médias de: folículos em diferentes estágios de desenvolvimento, folículos pós-ovulatórios, atresia folicular e granulócitos. A quantidade e a morfologia dos folículos primários iniciais e avançados não diferiram entre os grupos tratamento e controle; um fator importante e necessário para a recuperação dos ovários para posterior desova. Houve maior quantidade de granulócitos na atresia inicial no grupo tratado com hormônio de crescimento. Esses resultados demonstram que a administração do hormônio do crescimento pode potencializar o processo de recuperação ovariana após a desova induzida.

Downstream effects of a large reservoir on the reproductive activity of Prochilodus hartii (Pisces: Prochilodontidae).

To analyze the effect of the Irapé reservoir on the reproduction of "curimba", Prochilodus hartii, a migratory species, 503 specimens were collected during the reproductive period from February 2012 to January 2013. Specimens were collected from two river sections within the Jequitinhonha River Basin: Site 1 - a section of the Itacambiruçu River, a tributary of the Jequitinhonha River upstream of the Irapé reservoir; and Site 2 - a section of the Jequitinhonha River immediately downstream from the Irapé dam. Specimens (n = 270) were captured at Site 1 (160 males and 110 females), and 233 specimens at Site 2 (136 males and 97 females). The following were determined for each specimen: gonadosomatic index (GSI), hepatosomatic index (HSI), stomach repletion index (SRI), coelomic fat index (CFI) and condition factor (K). Both male and female fish were captured at all stages of gonadal maturation at Site 1, whereas only fish in the inactive and initial maturation stages were captured at Site 2. Length and mean GSI were greater (P < .05) at Site 1. Mean HSI and SRI of females was less in the advanced maturation stage. There were lesser values ​​for temperature and dissolved oxygen at Site 2 than 1. It is possible that the lesser values ​​for the physical and chemical characteristics of the water at Site 2 failed to promote advanced gonadal maturation, spawning, and spermiation of P. hartii, thus there are associations that are indicative of a negative effect of the Irapé reservoir on the reproduction of this migratory species.

Immunohistochemical, morphological and histometrical analyses of follicular development in Astyanax bimaculatus (Teleostei: Characidae) exposed to an organochlorine insecticide.

Thiodan® is an organochlorine insecticide used in agriculture that can reach aquatic ecosystems where it can affect fish reproduction. This research aimed to evaluate follicular development and the expression of integrin ß1, collagen type IV and caspase 3 by morphological, histometrical and immunohistochemical analyses of Astyanax bimaculatus exposed to Thiodan®. Treatments included three sublethal concentrations of Thiodan® (1.15, 2.30, and 5.60µgL-1) for 96h and a control without the insecticide. Mature females with ovaries in advanced follicular development were chosen for study (average weight: 11.52 ± 2.0g; average total length: 9.12 ± 0.64cm). The follicles of A. bimaculatus exhibited normal morphology, while the diameters of secondary follicles showed an increase (P< 0.05) in all concentrations when compared to the control group; a characteristic of follicles undergoing the initial stages of intoxication. Immunohistochemical analysis revealed secondary follicles with greater expression of integrin ß1 and collagen type IV in cytoplasm of follicular cells than in the primary follicles in all treatments and in the control. Immunolocalization of caspase 3 was detected in follicular cells during secondary development in all tested concentrations of Thiodan® and the control. These analyses demonstrate positive immunolocalization throughout the course of follicular development, even in fish exposed to varying concentrations of Thiodan® for 96h, demonstrating that follicular cells retain their physiological integrity.

Pathological and histometric analysis of the gills of female Hyphessobrycon eques (Teleostei:Characidae) exposed to different concentrations of the insecticide Dimilin(®).

Female individuals of Hyphessobrycon eques were exposed to Diflubenzuron (Dimilin(®)) in order to determine whether exposure to sublethal levels of this insecticide causes changes in gill morphology. Fish were exposed to 0.01, 0.1 and 1.0mgL(-1) for 96h and 17 days and then submitted to pathological and histometric evaluation. Pathological lesions, such as hyperplasia, lamellar fusion, vascular congestion, secondary lamellar disarray, vasodilatation, hemorrhage and increased lamellar epithelium, were significantly more common in the gills of fish exposed to Dimilin(®) than the control. Histometric analysis documented significant changes in blood vessel diameter, primary lamellae width and secondary lamellae length, and the appearance of hemorrhage foci in all concentrations tested. Even at low Dimilin(®) concentrations, the histopathological alteration index was mild to moderate, thereby indicating that the function of this tissue was compromised. These findings indicate that indiscriminate use of Dimilin(®) can adversely affect the structural integrity of the gills of H. eques, which can cause numerous problems for fish farming systems.

Histological and Histometric Evaluation of the Liver in Astyanax Bimaculatus (Teleostei: Characidae), Exposed to Different Concentrations of an Organochlorine Insecticide.

To investigate possible morphological changes to the liver tissue of lambaris, Astyanax bimaculatus (Linnaeus, 1758), females were exposed to treatments of sublethal concentrations of the insecticide Thiodan(®) for 96 hr. Treatments included three sublethal concentrations of 1.15, 2.3, and 5.6 µg L(-1) of Thiodan(®) and a control group without insecticide. The action of Thiodan(®) at sublethal concentrations did not affect the morphological structure of the liver as a whole, but changes in isolated locations of the hepatic parenchyma were observed. Glycogen depletion, nuclear and cytoplasmic deformation, nuclear and cytoplasmic hypertrophy, hyperemia, and cellular degeneration in liver cells at the different concentrations studied were recorded. These observed changes in the livers were greater in groups exposed to Thiodan(®) in comparison to the control group. Furthermore, there was a change in the diameter of the nuclei and cytoplasm of hepatocytes in the different treatments. The groups exposed to Thiodan(®) also exhibited a larger number of hepatocyte nuclei and a reduction in the amount of cytoplasm. We conclude that for the exposure period and concentrations of Thiodan(®) analyzed, the morphology of hepatic tissue had a cellular adaptive response.

O inseticida Thiodan® sobre o desenvolvimento folicular de lambaris / Thiodan® insecticide on the follicular development of lambaris

O Thiodan(r) é um organoclorado a base de endosulfan que pode causar alterações morfológicas nos tecidos de peixes, dependendo da concentração e tempo de exposição. Este estudo teve como objetivo determinar a CL50-96h do Thiodan(r) (endosulfan 350g L-1) para fêmeas de lambaris Astyanax bimaculatus em período de reprodução e analisar a morfologia do desenvolvimento folicular em diferentes concentrações do agrotóxico. Foram feitos quatro experimentos: 1) sem aclimatação e sem alimentação; 2) sem aclimatação e alimentados; 3) com aclimatação de 10 dias e sem alimentação; 4) com aclimatação de 10 dias e alimentados. A CL50-96h determinada foi de 13,6µg L-1, com intervalo de confiança de 10,1 a 18,4µg L-1 (P<0,05). Em todos os experimentos, foram utilizadas três concentrações diferentes do Thiodan(r) inferiores à CL50-96h pré-determinada em laboratório de acordo com a NBR 15088 (ABNT, 2007). Os lambaris foram expostos ao Thiodan(r) por 96 horas em três concentrações subletais de 1,15; 2,3 e 5,6µg L-1 e um grupo controle, livre de agrotóxico. Morfologicamente, percebeu-se que a ação do Thiodan(r) nas concentrações subletais não alterou a morfologia do desenvolvimento folicular. Porém, o diâmetro folicular nos folículos secundários no experimento com aclimatação/com alimentação expostos ao Thiodan(r) foi maior em relação ao grupo controle (P<0,05). Esses dados sugerem que a reprodução pode ser afetada pelo produto químico e pode causar comprometimento no desenvolvimento folicular.

Thiodan(r) is an organochlorine based in endosulfan which can cause morphological changes in fish tissues exposed to it depending on the concentration and exposure time. This study aimed to determine the LC50-96h of Thiodan(r) (350g L-1 endosulfan) for lambaris females of Astyanax bimaculatus in a reproduction period and analyze the morphology of follicular development in different experiments. Four experiments were performed: without adaptation and no feeding, feeding without adaptation, with adaptation and without feeding, with adaptation and feeding. The LC50-96h determined was 13.6µg L-1, with a confidence interval from 10.1 to 18.4µg L-1 (P<0.05). The lambaris were exposed to Thiodan(r) for 96 hours in three sub-lethal concentrations of 1.15, 2.3 and 5.6µg L-1 and without pesticides control group. Morphologically, it was noted that the action of Thiodan(r) in sub-lethal concentrations did not alter the morphology of follicular development. However, the follicular diameter in secondary follicles in the experiment with adaptation and feeding exposed to Thiodan(r) was higher relative to the control group (P<0.05). These data suggest that reproduction may be affected by chemical and can cause impairment in the follicular development.