Protium heptaphyllum essential oil from the fruit as a sedative and anesthetic in Rhamdia quelen: influence in cardiac frequency, biochemical, and oxidative parameters.

This study aimed to evaluate the effects of Protium heptaphyllum fruit essential oil (PHEO) on the physiology of silver catfish (Rhamdia quelen) during anesthesia and recovery, through studying echocardiograms, oxidative status, and metabolic parameters. Three experiments were performed: (1) 50 silver catfish juveniles were submitted to anesthesia and recovery tests with 300, 400, 500, 600, and 700 mg L-1 of PHEO. (2) Echocardiogram analysis was performed in anesthetized and non-anesthetized fish. (3) Biochemical parameters were evaluated at 0, 30, 60, and 120 min of recovery after being anesthetized for 3 min with 600 mg L-1 PHEO. Times to sedation and deep anesthesia were reduced with PHEO increasing concentrations. The echocardiogram showed a higher cardiac rate in anesthetized fish. Plasma glucose levels increased in control fish through recovery time, but anesthetized fish showed lower levels than controls at 120 min of recovery. Metabolic parameters such as plasma and hepatic glucose did not show changes considering the recovery time of up to 120 min. Hepatic glycogen, lactate, and triglycerides reduced their levels over recovery times. Fish anesthetized enhanced superoxide dismutase activity and thiobarbituric acid reactive substances levels but decreased reduced glutathione (GSH) levels at 30 min compared to controls. After 60 min, GSH values were significantly higher in anesthetized fish than in controls. These results suggest that PHEO at 600 mg L-1 is an effective anesthetic for the rapid handling of silver catfish, providing stable metabolic parameters and enhanced antioxidant responses during recovery. Echocardiogram analysis confirms the anesthetic effect, supporting PHEO as a viable and efficient option for fish anesthesia in aquaculture. The use of PHEO in aquaculture can enhance fish welfare by reducing stress during handling and transportation, potentially leading to improved growth, health, and survival rates.

Histological biomarkers and microbiological parameters of an estuarine fish from the Brazilian Amazon coast as potential indicators of risk to human health.

This study aimed to isolate and identify pathogenic bacteria in the intestinal tract, skin, and muscles of Sciades herzbergii; detect histopathological changes in the gill and liver; and use these biomarkers for the assessment of potential risks to human health. Fish were sampled during the rainy and dry seasons at two points in São Marcos Bay, Maranhão, Brazil: Ilha dos Caranguejos (IC) and Porto Grande (PG). Isolation and quantification were carried out using COLItest®. Colonies were subjected to identification and phenotypic investigation of antimicrobial resistance using Vitek®. Gill and liver samples were subjected to routine histological examination. The results indicated the presence of Klebsiella pneumoniae and Escherichia coli, the latter of which showed phenotypic resistance to norfloxacin and gentamicin. Fish caught at PG exhibited more extensive gill and liver damage than fish caught at IC. The findings suggest that histological changes in target organs of S. herzbergii may be influenced by infection with pathogenic bacteria.

Physiological strategies of acute thermal conditions of Rhamdia voulezi collected in the Iguaçu river watershed, Paraná, Brazil: biochemical markers of metabolic and oxidative stress.

Thermal pollution creates substantial challenges that alter energy demand and produce reactive oxygen species that damage fish DNA, proteins, and lipids. Rhamdia voulezi is a species of fish native to the Iguaçu river, Paraná, Brazil, that does not have scientific records of minimum (CTmin) and maximum (CTmax) temperatures required for survival. As it is a top predator species in the food chain and lives at temperatures below 22 °C, the loss of the species can cause functional problems in controlling the ecosystem and energy flow. The study evaluated the tissue metabolism of the brain, heart, and muscle of R. voulezi (n = 72) subjected to acute thermal stress of 31 °C for 2, 6, 12, 24, and 96 h after acclimatization to 21 °C. The biochemical markers SOD, GPx, MDH, HK, and CK of the brain, PCO of the heart and CAT, glycogen, G6PDH, and ALT of muscle were significant. PCA, IBR, thermal sensitive, and condition factor suggested that R. voulezi has different physiological strategies for acclimatization to 31 °C to mobilize and sustain the metabolic needs of oxygenation and energy allocation/utilization for tissue ATP production.

The barcode trap-Description of a new species of Microglanis, with a review of the status of Microglanis cibelae (Siluriformes: Pseudopimelodidae).

In a recent study based on the generalized mixed Yule coalescent method for delimiting species, a threshold of 2% genetic distance using cytochrome c oxidase subunit I sequences was used to delimit the species of Microglanis. That action resulted in assembling several populations of Microglanis from Atlantic coastal rivers between Rio Grande do Sul and São Paulo states as a single species, Microglanis cottoides, including Microglanis cibelae as a junior synonym. We reexamined these populations and found three species diagnosed by their morphology and that constitute separate mtDNA lineages, including a new species. The synonym of M. cibelae and M. cottoides is reviewed and refuted based on morphological and molecular evidence. M. cibelae and the new species are sympatric and occasionally syntopic in the Tramandaí, Mampituba, and Araranguá river basins. The new species is distinguished from M. cibelae and M. cottoides by the anterior margin of the posttemporosupracleitrum narrow articulated with the epioccipital, the short mental and maxillary barbels, and depressed head and body.

Molecular Evidence Reveals Taxonomic Uncertainties and Cryptic Diversity in the Neotropical Catfish of the Genus Pimelodus (Siluriformes: Pimelodidae).

Pimelodus is the most speciose genus of the family Pimelodidae, and is amply distributed in the Neotropical region. The species-level taxonomy and phylogenetic relationships within this genus are still poorly resolved, however. These taxonomic problems and the general lack of data have generated major uncertainties with regard to the identification of specimens from different localities. In the present study, we applied a single-locus species delimitation approach to identify the MOTUs found within the genus Pimelodus and provide sound evidence for the evaluation of the species richness of this genus in the different river basins of the Neotropical region. The study was based on the analysis of sequences of the mitochondrial COI gene of 13 nominal species, which resulted in the identification of 24 consensus MOTUs. Only six nominal species were recovered as well-defined molecular entities by both the traditional barcoding analysis and the molecular delimitation methods, while the other seven presented cryptic diversity or persistent taxonomic uncertainties. The lineages identified from the Parnaíba ecoregions, Amazonas Estuary and Coastal Drainages may represent a much greater diversity of Pimelodus species than that recognized currently, although a more detailed study of this diversity will be necessary to provide a more definitive classification of the genus.

Assessing physiological responses and oxidative stress effects in Rhamdia voulezi exposed to high temperatures.

Exposure to high temperatures induces changes in fish respiration, resulting in an increased production of reactive oxygen species. This, in turn, affects the enzymatic and non-enzymatic components of antioxidant defenses, which are essential for mitigating cellular stress. Rhamdia voulezi, an economically important fish species endemic to Brazil's Iguaçu River, served as the subject of our study. Our goal was to assess enzymatic antioxidant biomarkers (superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase, glutathione reductase, glucose-6-phosphate dehydrogenase), non-protein thiol levels (reduced glutathione), and markers of oxidative damage (lipoperoxidation and carbonylation) in the liver, gills, and kidneys of R. voulezi after acute exposure to high temperatures (31°C) for 2, 6, 12, 24, and 96 h. Control groups were maintained at 21°C. Our findings revealed that the liver exhibited increased superoxide dismutase levels up to 12 h and elevated glutathione S-transferase levels at 12 and 96 h at 31°C. In the gills, superoxide dismutase levels increased up to 24 h, along with increased lipoperoxidation at 2, 6, 12, and 96 h of exposure to high temperatures. The kidneys responded to heat stress at 12 h, with an increase in superoxide dismutase and catalase activity, and lipid peroxidation was observed at 2 and 6 h at 31°C. The three tissues evaluated responded differently to heat stress, with the liver demonstrating greater physiological adjustment to high temperatures. The intricate interplay of various antioxidant defense biomarkers and oxidative damage suggests the presence of oxidative stress in R. voulezi when exposed to high temperatures.

Microsatellite DNA markers for the commercially important fish Hypophthalmus donascimientoi (Pisces: Siluriformes: Pimelodidae) in the Amazon basin: isolation, characterization and amplification in congeneric species.

BACKGROUND: The genus Hypophthalmus comprises six species (H. edentatus, H. marginatus, H. fimbriatus, and H. oremaculatus), and the recently described: H. donascimientoi and H. celiae. The popular name for Hypophthalmus spp. in Brazil is mapará, this name refers to the six species. This group of fish has commercial importance for the states of Amazonas and Pará and, for this reason, requires studies to identify fish stocks. One approach is to use molecular markers, which have been very useful in studies with identification and population analysis of fish. Microsatellite molecular markers (SSRs) are one of the most informative markers for this purpose. There is little populations study of Hypophthalmus using SSRs, and there are less than six loci for the species Hypophthalmus marginatus available in the literature. With the construction of a genomic library of H. donascimientoi, we aimed to isolate and characterize SSRS markers and evaluate the extent of interspecific amplification. METHODS AND RESULTS: A genomic library was constructed with regions enriched of microsatellite for Hypophthalmus donascimientoi. A total of 126 contigs with 42 SSRs were used to design flanking primers for 39 microsatellites. Fifteen loci were characterized in three locations of the Solimões/Amazonas Rivers. The number of alleles ranged from one to 17 with a total of 126 alleles. The mean observed heterozygosity (HO) and expected heterozygosity (HE) were 0.721-0.692, respectively (S.d. HO 0.061 and HE 0.060). Two loci showed significant deviation in the HWE. The PIC ranged from 0.375 to 0.908. Such identified, 12 highly informative loci, and two moderately informative loci. Among the fifteen loci characterized, seven were successfully amplified in four other species of the genus. CONCLUSIONS: The microsatellite showed promise for estimating the genetic variability of H. donascimientoi and can be used as an efficient tool in population analyses of this species and in congeneric species analyzed.

Genetic population structure of Pseudoplatystoma corruscans (Siluriformes: Pimelodidae) and evidence of temporal variation in structure.

Surubim (Pseudoplatystoma corruscans, Pimelodidae) are migratory catfish native to the rivers in the La Plata and São Francisco basins. They are piscivores that attain considerable body sizes and are a valuable economic resource. Surubim exhibits extensive migrations during its life cycle that may affect the population structure at vast geographic scales. The authors examined the genetic diversity and population genetic structure of P. corruscans using microsatellite markers from a comprehensive sampling of 260 individuals from the Upper and Lower Paraná River. They identified two well-differentiated genetic clusters corresponding to a natural geographic barrier historically separating Upper and Lower Paraná regions. They also demonstrated temporal variation in population genetic structure at a site in Lower Paraná close to the confluence with the Paraguay River, most likely explained by the influx of migrant fishes at certain times of the year.

Sublethal effects of the herbicides atrazine and glyphosate at environmentally relevant concentrations on South American catfish (Rhamdia quelen) embryos.

The objective of this work was to evaluate the effects following exposure (96 h) of South American catfish (R. quelen) embryos to active ingredients and commercial formulations from atrazine and glyphosate, isolated and in mixtures, at environmentally relevant concentrations. While the survival rates were not affected, sublethal effects were evidenced after exposure. The most frequent deformities were fin damage and axial and thoracic damage. The mixture of active ingredients caused an increase in SOD and GST, differing from the treatment with the mixture of commercial formulations. The activity of AChE was significantly reduced following the treatment with the active ingredient atrazine and in the mixture of active ingredients. In general, herbicide mixtures were responsible for causing more toxic effects to R. quelen embryos. Therefore, these responses showed to be suitable biomarkers of herbicides' exposure, in addition to generating more environmentally relevant baseline data for re-stablishing safety levels of these substances in aquatic bodies.

Gill and hepatic histological alterations in Sciades herzbergii resulting from trace element contamination in the Port of São Luiz, Brazil / Alterações histológicas branquiais e hepáticas em Sciades herzbergii resultantes da contaminação por elementos traços no Porto de São Luís, Brasil

Abstract The objective of this study was to evaluate, through changes in the gills and livers of Sciades herzbergii, the environmental contamination to which estuarine organisms are exposed in two areas in São Marcos Bay - MA. Two collection areas located in São Marcos Bay were selected for this study: A1, an area close to the Port Complex, and A2, an area on Caranguejos Island (included in the Environmental Protection Area of Baixada Maranhense). Collections were carried out during rainy and dry periods. Sediments (for trace element analyses), surface water (for physico-chemical analyses), and specimens of S. herzbergii (for biometric measurements and identification of branchial and hepatic histopathology) were collected. Physico-chemical parameters (pH, dissolved oxygen, temperature and salinity) were within limits established by Brazilian legislation. Arsenic (in A1) and nickel (in A1 and A2) were above the legal standards in both periods. The highest percentage of histological alterations in the gills (aneurysms, lamellar fusion and detachment of the epithelium) occurred in the port area, in the rainy (93%) and dry (74%) periods. Liver alterations (melanomacrophage centers and necrosis) occurred only in specimens from the same area, in the rainy (41%) and dry (36%) periods. The highest histological indices of gill and liver changes were recorded in A1. This result was further supported by the total HI value of the lesions, which was higher in the port area compared to A2 (less impacted area), suggesting that the environmental conditions in that location are less favorable for the well-being of these organisms. Permanent environmental monitoring of the area is necessary to control environmental impacts efficiently.

Resumo O objetivo deste estudo foi avaliar, por meio de alterações nas brânquias e fígados de Sciades herzbergii, a contaminação ambiental a que os organismos estuarinos estão expostos em duas áreas da Baía de São Marcos - MA. Para este estudo foram selecionadas duas áreas de coleta localizadas na Baía de São Marcos: A1, área próxima ao Complexo Portuário, e A2, área na Ilha dos Caranguejos (incluída na Área de Proteção Ambiental da Baixada Maranhense). As coletas foram realizadas nos períodos chuvoso e seco. Foram coletados sedimentos (para análises de elementos traço), águas superficiais (para análises físico-químicas) e espécimes de S. herzbergii (para medidas biométricas e identificação de histopatologia branquial e hepática). Os parâmetros físico-químicos (pH, oxigênio dissolvido, temperatura e salinidade) estiveram dentro dos limites estabelecidos pela legislação brasileira. Arsênio (em A1) e níquel (em A1 e A2) estiveram acima dos padrões legais em ambos os períodos. A maior porcentagem de alterações histológicas nas brânquias (aneurismas, fusão lamelar e descolamento do epítélio) ocorreu na área portuária, nos períodos chuvoso (93%) e seco (74%). As alterações hepáticas (centros de melanomacrófagos e necrose) ocorreram apenas nos espécimes dessa mesma área, nos períodos chuvoso (41%) e seco (36%). Os maiores índices histológicos de alterações branquiais e hepáticas foram registrados em A1. Esse resultado foi ainda corroborado pelo valor de IH total das lesões, que foi maior na área portuária em comparação com A2 (área menos impactada), sugerindo que as condições ambientais naquele local são menos favoráveis ao bem-estar desses organismos. O monitoramento ambiental permanente da área é necessário para controlar os impactos ambientais de forma eficiente.

New species of Rhyacoglanis (Siluriformes: Pseudopimelodidae) from the upper rio Tocantins basin

A new species of Rhyacoglanis from the upper rio Tocantins basin is described based on morphological and molecular data. The new species differs from the congeners by its color pattern, caudal fin shape, hypural bones fusion pattern, pectoral-fin spine shape, and barcode sequence of cytochrome oxidase subunit I (COI). In this study, two putative monophyletic groups of Rhyacoglanis are proposed based on morphology, one consisting of species with a short post-cleithral process and caudal fin with rounded lobes, Rhyacoglanis epiblepsis and R. rapppydanielae, and the other with a longer post-cleithral process and caudal fin with pointed lobes, R. annulatus, R. paranensis, R. pulcher, R. seminiger, and the new species described herein.(AU)

Uma nova espécie de Rhyacoglanis da bacia do alto rio Tocantins é descrita com base em dados morfológicos e moleculares. A nova espécie difere das congêneres por seu padrão de colorido, forma da nadadeira caudal, padrão de fusão dos ossos hipurais, forma do espinho da nadadeira peitoral e sequência de código de barras do citocromo oxidase subunidade I (COI). Neste estudo, dois possíveis grupos monofiléticos de Rhyacoglanis são propostos com base na morfologia, constituídos por espécies com o processo pós-cleithral curto e nadadeira caudal com lóbulos arredondados, Rhyacoglanis epiblepsis e R. rapppydanielae, e o outro com o processo pós-cleithral mais alongado e nadadeira caudal com lóbulos pontiagudos, R. annulatus, R. paranensis, R. pulcher, R. seminiger, e a nova espécie aqui descrita.(AU)

New species of Farlowella (Siluriformes: Loricariidae) from the rio Tapajós basin, Pará, Brazil

A new species of stick-catfish Farlowella is described from streams of the lower rio Tapajós drainage, in Pará State, northern Brazil. The new species is distinguished from all congeners by a naked gular region (vs. gular region with plates) and from most congeners by the presence of five lateral series of plate rows on anterior region of body (vs. four). The new species shows variation in the series of abdominal plates and a discussion on the variation of abdominal plates within Farlowella is made and comments on synapomorphic characters in Farlowellini.(AU)

Uma nova espécie de cascudo-graveto Farlowella é descrita de pequenos igarapés do baixo rio Tapajós, no Estado do Pará, norte do Brasil. A nova espécie é distinta de todas as suas congêneres por uma região gular nua (vs. região gular com placas) e de muitas congêneres pela presença de cinco fileiras de placas laterais na região anterior do corpo (vs. quatro). A nova espécie apresenta variação na série de placas abdominais e é feita uma discussão sobre a variação das placas abdominais dentro de Farlowella e comentários sobre caracteres sinapomórficos em Farlowellini.(AU)

Redescription and expansion of the geographic distribution of Phenacorhamdia nigrolineata (Siluriformes: Heptapteridae)

Phenacorhamdia nigrolineata is redescribed, and the expansion of its geographic distribution is presented based on abundant new records. Morphological analysis, meristic comparison and osteological description were performed. No one autapomorphy was identified for P. nigrolineata, but the species is identified by an exclusive combination of characters of coloration of the body, morphometric and meristic data (snout length, maxillary and outer mental barbels length; number of vertebrae). A discussion of its geographic distribution, coloration pattern of the body, the putative relationships among some species of the genus, and its conservation status are presented.(AU)

Phenacorhamdia nigrolineata é redescrita e a expansão de sua distribuição geográfica é apresentada com base em abundantes novos registros. Foram realizadas análises morfológicas, comparação merística e descrição osteológica. Nenhuma autapomorfia foi identificada para P. nigrolineata, mas a espécie é identificada por uma combinação exclusiva de caracteres de colorido do corpo, dados morfométricos e merísticos (comprimento do focinho, comprimento dos barbilhões maxilares e mentais externos; número de vértebras). Uma discussão dessa distribuição geográfica, padrão de coloração do corpo, as supostas relações entre algumas espécies do gênero e seu estado de conservação são apresentados.(AU)

Impacted estuaries on the Brazilian Amazon coast near port regions influence histological and enzymatic changes in Sciades herzbergii (Ariidae, Bloch, 1794) / Estuários impactados na costa amazônica brasileira próximos a regiões portuárias influenciam mudanças histológicas e enzimáticas em Sciades herzbergii (Ariidae, Bloch, 1794)

Enzymatic (glutathione S-transferase, GST and catalase, CAT) and histological biomarkers in S. herzbergii are important for the analysis of impacted estuaries in port regions of the Brazilian Amazon coast. Fish specimens were collected in two areas in the rainy and dry seasons: Porto Grande (potentially impacted region) and Ilha dos Caranguejos (less impacted region). Sediment samples were collected for chemical analysis. Morphometric, histological, and enzymatic biomarker analyzes were performed. The analysis of the sediments collected in the potentially impacted region showed levels of iron, aluminum and polycyclic aromatic hydrocarbons above the limits allowed by CONAMA legislation. Histological changes in the gills and liver, as well as GST and CAT activities, were high in fish collected at the port. Analyzes suggest that fish in the potentially impacted region are subject to pollutants that compromise their health.

Biomarcadores enzimáticos (glutationa S-transferase, GST e catalase, CAT) e histológicos em S. herzbergii são importantes para a análise de estuários impactados em regiões portuárias da costa amazônica brasileira. Espécimes de peixes foram coletados em duas áreas nas estações chuvosa e seca: Porto Grande (região potencialmente impactada) e Ilha dos Caranguejos (região menos impactada). Amostras de sedimento foram coletadas para análise química. Análises morfométricas, histológicas e de biomarcadores enzimáticos foram realizadas. A análise dos sedimentos coletados na região potencialmente impactada mostrou teores de ferro, alumínio e hidrocarbonetos aromáticos policíclicos acima dos limites permitidos pela legislação do CONAMA. As alterações histológicas nas brânquias e no fígado, bem como as atividades de GST e CAT, foram elevadas nos peixes coletados no porto. As análises sugerem que os peixes da região potencialmente impactada estão sujeitos a poluentes que comprometem sua saúde.

Effect of amla and ginger powders on quality criteria of African catfish (Clarias gariepinus) fingers / Efeito da amla e do gengibre em pó nos critérios de qualidade dos palitos de bagre-africano (Clarias gariepinus)

Catfish (Clarias gariepinus) meat isn't preferred by consumers in compared to other fish species meat, thus to enhance the use of catfish meat, ready to eat catfish fingers were prepared with some plants additives (amla and ginger powder). The mean objective of this study was to assess the impact of amla and ginger powder on catfish finger qualities in terms of physical, chemical, microbiological, and sensorial parameters under stored at a low temperature (5 ± 1 °C). The obtained results were compared with those of a control sample (basic formula) and a sample containing the synthetic antioxidant. During the storage period, the levels of pH, thiobarbituric acid, total volatile basic nitrogen, trimethylamine, total bacteria count, psychrophilic bacteria, molds and yeasts counts increased dramatically, although the values remained within acceptable ranges. The findings also revealed, that amla and ginger powder considerably (p < 0.05) reduced the changes in quality parameters, as well as there was a considerable increase in the quality parameter in all treated samples than in the control. Finally, amla and ginger powder can be a substitute for synthetic antioxidants and antimicrobials. These findings suggest that the powder of amla and ginger are suitable for use as a natural antioxidants and antimicrobials to extend the shelf-life of animal products.

Catfish (Clarias gariepinus) meat isn't preferred by consumers in compared to other fish species meat, thus to enhance the use of catfish meat, ready to eat catfish fingers were prepared with some plants additives (amla and ginger powder). The mean objective of this study was to assess the impact of amla and ginger powder on catfish finger qualities in terms of physical, chemical, microbiological, and sensorial parameters under stored at a low temperature (5 ± 1 °C). The obtained results were compared with those of a control sample (basic formula) and a sample containing the synthetic antioxidant. During the storage period, the levels of pH, thiobarbituric acid, total volatile basic nitrogen, trimethylamine, total bacteria count, psychrophilic bacteria, molds and yeasts counts increased dramatically, although the values remained within acceptable ranges. The findings also revealed, that amla and ginger powder considerably (p < 0.05) reduced the changes in quality parameters, as well as there was a considerable increase in the quality parameter in all treated samples than in the control. Finally, amla and ginger powder can be a substitute for synthetic antioxidants and antimicrobials. These findings suggest that the powder of amla and ginger are suitable for use as a natural antioxidants and antimicrobials to extend the shelf-life of animal products.

Camellia sinensis extract delays microbiological and oxidative changes in striped catfish fillets during frozen storage / Extrato de chá verde age sobre a qualidade de filés de pescado durante o armazenamento por congelamento

This study investigated the effects of tea leaf (Camellia sinensis) extract on the quality of striped catfish (Pangasianodon hypophthalmus) fillets during 18-months of frozen storage (-20 ± 2 °C). Fillet samples were submitted to the treatments Control (cold tap water), CS 7.63 (C. sinensis extract solution 7.63 µg / mL) and CS 625 (C. sinensis extract 625 µg / mL) and stored for 18 months, with collections performed at 0, 1, 3, 6, 9, 12 and 18 months. Total viable count, physicochemical parameters (water holding capacity, total volatile basic nitrogen, peroxide value, thiobarbituric acid reactive substances, moisture and pH), sensory properties and color measurement were evaluated. Results showed that fillets treated with C.a sinensis extracts slightly reduced lipid oxidation, inhibited bacterial growth and improved sensory properties compared to untreated samples, without causing significant changes in the other quality indicators. The findings indicated that the green tea leaf extract immersion treatments, contributed to the improved quality preservation of striped catfish fillets during frozen storage.

O objetivo deste estudo foi investigar os efeitos do extrato de folhas de chá verde (Camellia sinensis) na qualidade de filés de bagre listrado (Pangasianodon hypophthalmus) durante 18 meses de armazenamento congelado (-20 ± 2 ° C). O estudo incluiu três tratamentos: imersão dos filés de bagre listrado em água fria da torneira como um tratamento de controle, em solução de extrato de Camellia sinensis 7,63 µg / mL e em solução de extrato de Camellia sinensis 625 µg / mL. As amostras foram armazenadas por 18 meses e as coletas foram feitas aos zero, um, três, seis, nove, 12 e 18 meses. Os parâmetros avaliados incluíram contagem viável total, parâmetros físico-químicos (capacidade de retenção de água, nitrogênio básico volátil total, valor de peróxido, substâncias reativas ao ácido tiobarbitúrico, umidade e pH), propriedades sensoriais e medição de cor. Os resultados mostraram que os filés de bagre listrado tratados com extratos de Camellia sinensis reduziram ligeiramente a oxidação de lipídios, inibiram o crescimento de bactérias e aumentaram as propriedades sensoriais em comparação com as amostras não tratadas. Além disso, o tratamento do extrato de Camellia sinensis não afetou o pH, a umidade, a capacidade de retenção de água, o nitrogênio básico volátil total e a cor do filé durante o armazenamento congelado. Com base na contagem viável total, parâmetros físico-químicos e qualidade sensorial, pode-se concluir que filés de bagre listrados não tratados ou tratados com extratos de Camellia sinensis (7,63 e 625 µg / mL) podem ser usados ​​por até 18 meses.

Camellia sinensis extract delays microbiological and oxidative changes in striped catfish fillets during frozen storage / Extrato de chá verde age sobre a qualidade de filés de pescado durante o armazenamento por congelamento

ABSTRACT: This study investigated the effects of tea leaf (Camellia sinensis) extract on the quality of striped catfish (Pangasianodon hypophthalmus) fillets during 18-months of frozen storage (-20 ± 2 °C). Fillet samples were submitted to the treatments Control (cold tap water), CS 7.63 (C. sinensis extract solution 7.63 µg / mL) and CS 625 (C. sinensis extract 625 µg / mL) and stored for 18 months, with collections performed at 0, 1, 3, 6, 9, 12 and 18 months. Total viable count, physicochemical parameters (water holding capacity, total volatile basic nitrogen, peroxide value, thiobarbituric acid reactive substances, moisture and pH), sensory properties and color measurement were evaluated. Results showed that fillets treated with C.a sinensis extracts slightly reduced lipid oxidation, inhibited bacterial growth and improved sensory properties compared to untreated samples, without causing significant changes in the other quality indicators. The findings indicated that the green tea leaf extract immersion treatments, contributed to the improved quality preservation of striped catfish fillets during frozen storage.

RESUMO: O objetivo deste estudo foi investigar os efeitos do extrato de folhas de chá verde (Camellia sinensis) na qualidade de filés de bagre listrado (Pangasianodon hypophthalmus) durante 18 meses de armazenamento congelado (-20 ± 2 ° C). O estudo incluiu três tratamentos: imersão dos filés de bagre listrado em água fria da torneira como um tratamento de controle, em solução de extrato de Camellia sinensis 7,63 µg / mL e em solução de extrato de Camellia sinensis 625 µg / mL. As amostras foram armazenadas por 18 meses e as coletas foram feitas aos zero, um, três, seis, nove, 12 e 18 meses. Os parâmetros avaliados incluíram contagem viável total, parâmetros físico-químicos (capacidade de retenção de água, nitrogênio básico volátil total, valor de peróxido, substâncias reativas ao ácido tiobarbitúrico, umidade e pH), propriedades sensoriais e medição de cor. Os resultados mostraram que os filés de bagre listrado tratados com extratos de Camellia sinensis reduziram ligeiramente a oxidação de lipídios, inibiram o crescimento de bactérias e aumentaram as propriedades sensoriais em comparação com as amostras não tratadas. Além disso, o tratamento do extrato de Camellia sinensis não afetou o pH, a umidade, a capacidade de retenção de água, o nitrogênio básico volátil total e a cor do filé durante o armazenamento congelado. Com base na contagem viável total, parâmetros físico-químicos e qualidade sensorial, pode-se concluir que filés de bagre listrados não tratados ou tratados com extratos de Camellia sinensis (7,63 e 625 µg / mL) podem ser usados ​​por até 18 meses.

Envenomations caused by fish in Brazil: an evolutionary, morphological, and clinical vision of a neglected problem

Venomous fish are commonly found in Brazilian waters. The most important marine venomous fish species are stingrays (Dasyatidae, Gimnuridae, Myliobatidae, and Rhinopteridae families), catfish (Ariidae family), scorpionfish and lionfish (both Scorpaenidae family), and toadfish (Batrachoididae family). Meanwhile, Potamotrygonidae stingrays and Pimelodidae catfish are the most important venomous freshwater fish. The mechanisms of envenomation vary and involve various venomous apparatuses and glands. Despite not being highly developed, these venomous apparatuses in fish appear rudimentary, using structures such as fins and rays to inoculate toxins and rarely presenting with specialized structures. Toxins are produced by glandular tissue made up of proteinaceous cells, lacking true glands, and are positioned along the inoculation structures. However, systemic manifestations are rare. No antivenom serum has been developed for any species of American venomous fish. Brazilian venomous fish and their venoms have only recently attracted attention, leading to new studies not only addressing clinical issues in humans, but also exploring the discovery of new active substances with immense pharmacological potential.

Description of eight new mitochondrial genomes for the genus Neoarius and phylogenetic considerations for the family Ariidae (Siluriformes).

The genus Neoarius, known as marine catfish, is a group of the family Ariidae, composed of 10 species found in Oceania. None of the species in this genus have their mitochondrial genome described, which is highly valuable in phylogenetic and molecular evolution studies. For the present work, eight species from the Neoarius genus were selected: Neoarius utarus, Neoarius midgleyi, Neoarius graeffei, Neoarius leptaspis, Neoarius berenyi, Neoarius paucus, Neoarius pectoralis, and Neoarius aff. graeffei. DNA sequences of the eight species were obtained through the NCBI Sequence Read Archive (SRA) database, and the mitochondrial genomes were assembled using the NOVOplasty tool on the Galaxy platform, subsequently annotated with the MitoAnnotator tool. We then utilized the protein-coding genes from the mitogenomes to estimate the phylogenetic relationships within the group, including seven additional mitogenomes available in the NCBI. In all species, the mitochondrial genomes presented 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and 1 D-loop.

Envenomations caused by fish in Brazil: an evolutionary, morphological, and clinical vision of a neglected problem

ABSTRACT Venomous fish are commonly found in Brazilian waters. The most important marine venomous fish species are stingrays (Dasyatidae, Gimnuridae, Myliobatidae, and Rhinopteridae families), catfish (Ariidae family), scorpionfish and lionfish (both Scorpaenidae family), and toadfish (Batrachoididae family). Meanwhile, Potamotrygonidae stingrays and Pimelodidae catfish are the most important venomous freshwater fish. The mechanisms of envenomation vary and involve various venomous apparatuses and glands. Despite not being highly developed, these venomous apparatuses in fish appear rudimentary, using structures such as fins and rays to inoculate toxins and rarely presenting with specialized structures. Toxins are produced by glandular tissue made up of proteinaceous cells, lacking true glands, and are positioned along the inoculation structures. However, systemic manifestations are rare. No antivenom serum has been developed for any species of American venomous fish. Brazilian venomous fish and their venoms have only recently attracted attention, leading to new studies not only addressing clinical issues in humans, but also exploring the discovery of new active substances with immense pharmacological potential.