O estudo morfológico de células sanguíneas é considerado como a base para diversas pesquisas, uma vez que a forma da célula, disposição do seu núcleo e o nível de condensação da cromatina são de fácil observação, além de detectar patologias que causam anormalidades no sangue. Assim, este estudo teve o objetivo de avaliar a morfologia das células sanguíneas encontradas na contagem qualitativa da espécie Piaractus brachypomus. Foram analisadas células de 43 peixes com peso médio de 1,34 Kg e comprimento total 39,23 cm, num total de 43000 células observadas. Assim, foi possível verificar a ocorrência de eritrócitos, trombócitos, e seis tipos de leucócitos: basófilo, eosinófilo, neutrófilo, heterófilo e monócito. Além disso, observou-se a presença de neutrófilos tóxicos, além de uma pequena quantidade de alterações morfológicas no núcleo das células como micronúcleos e invaginações. Durante o experimento, não houve morte de animais. No geral, as células sanguíneas de P. brachypomus apresentaram semelhanças morfológicas, quando comparada com a morfologia das células de peixes ósseos. Palavras chave: células sanguíneas, estudo morfológico, Piaractus brachypomus Morphological study of blood cells of Piaractus brachypomus (Cuvier, 1817)ABSTRACT. The morphological study of blood cells is considered as the basis of several studies, since the shape of the cell, its nucleus arrangement and the level of chromatin condensation are easy to note, as well as detecting pathologies that cause blood abnormalities. The aim of this study was to evaluate the morphology of blood cells found in the qualitative count of the species Piaractus brachypomus. There were analysed cells from 43 fishes, with an average weigth of 1.34 Kg and a mean length of 39.23 cm, in a total of 43000 cells were observed, thus it was possible to verify the ocurrence of erythrocyte, thrombocytes and six types of leukocytes: lymphocytes, basophils, eosinophils, neutrophils, heterophiles and monocytes. In addition, it was noticed toxic neutrophils and a small number of morphological nuclear changes such as micronuclei and invaginations In general the blood cells of P. brachypomus presented morphological similarities when compared to the morphology of the bone fish cells.

Genotoxicity studies in coastal ecosystems have been a priority in Environmental Risk Assessment (ERA). This research aimed to study the genotoxicity by the micronucleus test and comet assay in two Brazilian Amazon estuaries (anthropized and control) using Plagioscion squamosissimus as a biomonitor. Blood samples were collected from 54 specimens. No significant genotoxic effects were detected in the cells analyzed, although the highest occurrence (MN and DNA damages) was observed in anthropized site. The percentage of genomic damage differed between the sites studied, being always higher in anthropizes site as well. Of the nucleoids analyzed in this site, on average, 28 ± 14.42% of the cells were classified in the highest damage class. The fish analyzed in the present study are direct influenced of xenobiont agents capable of producing damage to the genetic material of aquatic organisms in both sites and, consequently, may bring consequences still little reported in studies of morphophysiological alterations in humans.

Genotoxicity studies in coastal ecosystems have been a priority in Environmental Risk Assessment (ERA). This research aimed to study the genotoxicity by the micronucleus test and comet assay in two Brazilian Amazon estuaries (anthropized and control) using Plagioscion squamosissimus as a bioindicator. Blood samples were collected from 54 specimens. No significant genotoxic effects were detected in the cells analyzed, although the highest occurrence was observed in anthropized site. The percentage of genomic damage differed between the sites studied, being always higher in anthropizes site as well. Of the nucleoids analyzed in this site, on average 28 ± 14.42% of the cells were classified in the highest damage class (4). The fish analyzed in the present study are direct influence of xenobiont agents capable of producing damage to the genetic material of aquatic organisms in both sites and, consequently, may bring consequences still little reported in studies of morphophysiological alterations in humans.

Corbicula fluminea is an Asian mussel that has aggressively invaded freshwater habitats worldwide, causing damage both economically and with the disappearance of native species. In Brazil, this species is present in almost all watersheds, including areas of Federal Conservation Units. In this context, the present work reported the first record of C. fluminea in the Carajás mosaic, Pará, Brazil, a Federal Conservation Area. Collections were made in September and February 2021 and May 2022. In total, 154 specimens of C. fluminea were collected. The size range of the specimens was 16 to 28 mm in shell length and 1.46 to 5.91 g in wet weight. This new record extends the distribution of this species in South America and in the tropical watersheds of Brazil and is the first record in federal protected areas, highlighting the need for large-scale knowledge of the environmental and economic changes that the species can cause.

Genotoxicity studies in coastal ecosystems have been a priority in Environmental Risk Assessment (ERA). This research aimed to study the genotoxicity by the micronucleus test and comet assay in two Brazilian Amazon estuaries (anthropized and control) using Plagioscion squamosissimus as a bioindicator. Blood samples were collected from 54 specimens. No significant genotoxic effects were detected in the cells analyzed, although the highest occurrence was observed in anthropized site. The percentage of genomic damage differed between the sites studied, being always higher in anthropizes site as well. Of the nucleoids analyzed in this site, on average 28±14.42% of the cells were classified in the highest damage class (4). The fish analyzed in the present study are direct influence of xenobiont agents capable of producing damage to the genetic material of aquatic organisms in both sites and, consequently, may bring consequences still little reported in studies of morphophysiological alterations in humans.