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1.
An Acad Bras Cienc ; 92(2): e20180610, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32556046

RESUMO

Eighty-one Hoplias malabaricus specimens were collected between February 2014 and June 2016. A total of 29 species of metazoan parasites were found, 13 of which were identified as monogeneans, seven were digenean species, seven of which were nematodes, and two of which were from the subclass Hirudinea. The highest prevalence values ​​were presented by Contracaecum sp. and Tylodelphys sp. The highest mean abundance and mean intensity was recorded by Tylodelphys sp.; the values were ​​36.7 ± 61.8 and 55.65 ± 69.1, respectively. The abundance of the monogenean Urocleidoides cuiabai was found to be positively correlated with host weight. The abundance of Bucephalidae gen. sp. exhibited significant positive correlations with host weight and length. For Contracaecum sp., a significant negative correlation was found between its abundance and host length and weight. No significant differences between the diversity indexes (Margalef, Pielou and Shannon) of the parasites collected in the two points were found. The Sorensen similarity index, with a value of 0.82 between the two sampling points revealed that the parasitic diversity between them is similar. The findings from this study represent new records of occurrence of H. malabaricus, as well as of Urocleidoides margolisi, Scleroductus sp. and Helobdella sp.


Assuntos
Biodiversidade , Caraciformes/parasitologia , Doenças dos Peixes/parasitologia , Parasitos/isolamento & purificação , Animais , Brasil , Parasitos/classificação , Densidade Demográfica , Rios
2.
An Acad Bras Cienc ; 92(2): e20181165, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32556047

RESUMO

This study describes the histological characteristics and distribution of gastrointestinal tract endocrine cells (ECs) of Prochilodus lineatus (detritivorous fish) using immunohistochemical procedures. The digestive tract of P. lineatus was divided into seven portions: stomach (cardial and pyloric), pyloric caeca, and intestine (anterior, glandular, middle and posterior). A pool of specific antisera against cholecystokinin (CCK-8), -neuropeptide Y (NPY), -ghrelin (Ghre) and -leu-enkephalin (Leu-ENK) to identify ECs were used. According to the morphological characteristics of ECs, two different types were identified and classified as open or closed-type. The number of ECs varied throughout the gastrointestinal tract, though a high abundance was found in the anterior intestine and pyloric caeca. A large number of ECs immunoreactive to CCK-8 and NPY were recorded in the anterior, glandular and middle intestine. ECs immunopositive to Leu-ENK were distributed in the stomach and pyloric caeca. For Ghre, immunopositive ECs were restricted to the glandular intestine. The results of the present study indicate that P. lineatus presents an ECs distribution pattern with species-specific particularities. However, CCK showed a distribution similar to that of omnivores, which is possibly related to local signaling functions in order to achieve the correct digestion of the various organisms found in the detritus.


Assuntos
Caraciformes/classificação , Encefalina Leucina/análise , Trato Gastrointestinal/química , Grelina/análise , Neuropeptídeos/análise , Sincalida/análise , Animais , Imuno-Histoquímica
3.
Rev Bras Parasitol Vet ; 29(2): e017019, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32428185

RESUMO

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.


Assuntos
Caraciformes/parasitologia , Trematódeos/classificação , Animais , Brasil , Brânquias/parasitologia , Rios , Trematódeos/anatomia & histologia
4.
Zootaxa ; 4747(3): zootaxa.4747.3.10, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32230104

RESUMO

A new species of Knodus is described from the rio Cupari drainage, a tributary from the right margin of the lower rio Tapajós, Pará State, Brazil. The new species differs from its congeners, except K. geryi, by having a dark basal blotch on each caudal fin lobe (vs. caudal fin lobes with sparse chromatophores, lacking basal blotches) and, with the exception of K. borki, K. heteresthes, and K. pasco, by having 10-12 scales around the caudal peduncle (vs. 13-15).


Assuntos
Characidae , Caraciformes , Animais , Brasil , Rios
5.
Zootaxa ; 4755(2): zootaxa.4755.2.10, 2020 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-32230188

RESUMO

A new species of Creagrutus is described from the Amazonian Piedmont, Colombia. The new species can be distinguished from congeners by presenting the following unique combination of characters: a dark mid-lateral stripe starting at anteriormost scale of lateral line, a vertically elongated humeral blotch, absence of dark blotches on dorsal fin and at base of middle caudal-fin rays, a triangular dentigerous surface of the premaxilla, 5-6 dentary teeth, and 11-12 predorsal scales. Comparisons with congeners distributed in the piedmont region of Río Caquetá basin are presented and its relationships among species of Creagrutus is inferred from the available phylogenetic framework.


Assuntos
Characidae , Caraciformes , Animais , Brasil , Colômbia , Filogenia , Rios
6.
Zootaxa ; 4751(3): zootaxa.4751.3.1, 2020 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-32230403

RESUMO

A taxonomic review of the Hyphessobrycon panamensis species-group is presented, with recognition of six valid species. In Central America, H. panamensis was restricted to the drainages of both Atlantic and Pacific coasts of Panama; H. savagei was recorded at the río Pírris and río Térraba, Pacific coast of Costa Rica, and Hyphessobrycon bussingi, new species, described from the río Sixaola basin, Atlantic coast of Costa Rica, and from the río Changuinola, río Guarumo and río San San, Atlantic coast of Panama. At trans-andean South America, H. columbianus was recorded at the río Acandí, Colombia, and its geographical distribution was extended into the coastal drainages in San Blas province, Panama; H. condotensis was recorded at the río Atrato, río Baudó, lower río Magdalena and río San Juan basins, Colombia, while H. sebastiani was considered as its junior synonym. Hyphessobrycon daguae was revalidated, erected to the specific level, considered as senior synonym of H. chocoensis, and recorded from the río Dagua, río Patía and río Telembí basins, in Colombia, the río Mira, at the border between Colombia and Ecuador, and the río Cayapas, río Mataje, and río Santiago, in Ecuador. Color pattern and secondary sexual characters (e.g. number, arrangement and shape of hooks in mature males) suggest that the Hyphessobrycon panamensis species-group is a putatively monophyletic lineage.


Assuntos
Characidae , Caraciformes , Animais , Brasil , Masculino , Rios
7.
Zootaxa ; 4751(1): zootaxa.4751.1.11, 2020 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-32230439

RESUMO

A new species of Hemiodus is described from the Rio Xingu basin, Pará, Brazil. It is distinguished from congeners by the combination of presence of a dark longitudinal stripe extending from head to tip of lower caudal-fin lobe, an oblique blotch on dorsal-fin, 9-11 scale rows above lateral line, 58-66 perforated lateral line scales, and 17-20 circumpeduncular scales. Comments on the conservation status of the new species, as well as its relationships among Hemiodus species, are made.


Assuntos
Caraciformes , Animais , Brasil , Registros , Rios
8.
Ecotoxicology ; 29(4): 375-388, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32166694

RESUMO

Hypoxia and mercury contamination often co-occur in tropical freshwater ecosystems, but the interactive effects of these two stressors on fish populations are poorly known. The effects of mercury (Hg) on recorded changes in the detailed form of the electrocardiogram (ECG) during exposure to progressive hypoxia were investigated in two Neotropical freshwater fish species, matrinxã, Brycon amazonicus and traíra, Hoplias malabaricus. Matrinxã were exposed to a sublethal concentration of 0.1 mg L-1 of HgCl2 in water for 96 h. Traíra were exposed to dietary doses of Hg by being fed over a period of 30 days with juvenile matrinxãs previously exposed to HgCl2, resulting in a dose of 0.45 mg of total Hg per fish, each 96 h. Both species showed a bradycardia in progressive hypoxia. Hg exposure impaired cardiac electrical excitability, leading to first-degree atrioventricular block, plus profound extension of the ventricular action potential (AP) plateau. Moreover, there was the development of cardiac arrhythmias and anomalies such as occasional absence of QRS complexes, extra systoles, negative Q-, R- and S-waves (QRS complex), and T wave inversion, especially in hypoxia below O2 partial pressures (PO2) of 5.3 kPa. Sub-chronic dietary Hg exposure induced intense bradycardia in normoxia in traira, plus lengthening of ventricular AP duration coupled with prolonged QRS intervals. This indicates slower ventricular AP conduction during ventricular depolarization. Overall, the data indicate that both acute waterborne and sub-chronic dietary exposure (trophic level transfer), at sublethal concentrations of mercury, cause damage in electrical stability and rhythm of the heartbeat, leading to myocardial dysfunction, which is further intensified during hypoxia. These changes could lead to impaired cardiac output, with consequences for swimming ability, foraging capacity, and hence growth and/or reproductive performance.


Assuntos
Peixes/fisiologia , Mercúrio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Caraciformes , Ecossistema , Eletrocardiografia , Eutrofização , Água Doce , Hipóxia
9.
Ecotoxicol Environ Saf ; 195: 110477, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32200148

RESUMO

Bioindicator organisms are important tools in environmental monitoring studies. Understanding this, the overall goal of the present study was to evaluate the sensitivity and viability of the native fish species Banded tetra, (Astyanax aeneus; Günther, 1860), widely spread in the aquatic ecosystems of the Yucatan Peninsula in Mexico, as a bioindicator organism. In order to do this, we performed a bioassay at sublethal concentrations using copper (CuSO4) to experimentally evaluate and validate the relationship between the trace metals and oxidative stress biomarkers response [(catalase (CAT), lipoperoxidation content (LPO)], detoxification [(glutathione S-transferase (GST), metallothionein content (MT)] and neurotoxicity (AChE) in muscle of A. aeneus. Results showed changes in biomarkers after 96 h: Catalase activity (CAT) was significantly higher above 1.5 and 2 mg/L (154.35 and 172.50% increase, respectively); lipid peroxidation contents (TBARS), GST activity, and MT content were very similar to CAT activity at 1.5 and 2 mg/L of Cu. In terms of neurotoxicity, AChE activity was significantly inhibited at 0.1 mg/L (64%; p < 0.001) and 0.5 mg/L (44%; p < 0.001) of Cu. Based on the bioassay results, we performed a trace metal monitoring campaign in muscle of A. aeneus caught in 15 sites with different anthropogenic activities, during the summer of 2017, to establish a baseline of trace metals pollution in the state of Campeche. A. aeneus showed the highest trace metal accumulation in the following order: Al > Fe > Mn > Zn > Cu > Hg > Cr > Pb > Cd > V > As, while sites were arrange as follows: Xnoha lagoon > Palizada River > Candelaria River > Ululmal > Maravillas > López Mateos. PCA showed a cluster between biomarkers (GST, CAT, TBARS, and MT) and concentration of metals (Cd, Cu, Fe, Zn, Hg and Cr). Conversely, AChE inhibition was not related to a specific metal, but highest inhibitions (>50%) were present in those sites with intensive agricultural practices. These results determined that, based on its physiological response and trace metal bioaccumulation, Astyanax aeneus can be considered a good bioindicator for evaluating the presence of trace metals in tropical aquatic systems of the Yucatan Peninsula.


Assuntos
Caraciformes , Biomarcadores Ambientais , Metais/toxicidade , Poluentes Químicos da Água/toxicidade , Acetilcolinesterase/metabolismo , Animais , Monitoramento Biológico , Biomarcadores , Catalase/metabolismo , Caraciformes/metabolismo , Cobre/toxicidade , Ecossistema , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Metalotioneína/metabolismo , Metais/análise , México , Músculos/efeitos dos fármacos , Músculos/enzimologia , Músculos/metabolismo , Estresse Oxidativo , Poluentes Químicos da Água/análise
10.
Chemosphere ; 248: 125989, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32007773

RESUMO

Fish has great socioeconomic, cultural, and nutritional importance for Amazonian populations. Despite all health benefits, fish can accumulate great amounts of mercury (Hg). The entry of Hg in aquatic trophic chains is an issue of concern to animal and human health. Higher risks of human exposure are strongly related to fish consumption. Upper Solimões population has one of the highest fish consumption rates of the Amazon. This study aimed to access the concentration of total Hg (THg) in muscle, liver, and gills of 17 species of fishes marketed in the Upper Solimões Region and Health Risk Assessment. Higher concentrations were observed in Carnivores/Piscivores. The highest THg concentration was found in liver of Cichla ocellaris (4.549 µg/g) and the lowest in gills of Hoplosternum littorale (0.002 µg/g). Most species had higher THg concentrations in muscle>liver>gills, in the Ebb period, and liver>muscle>gills, in the Flood period. Hoplias malabaricus, Pseudoplatystoma fasciatum, Plagioscion squamosissimus, Ageneiosus inermis, and C. ocellaris presented average THg concentrations above the safe limit stablished by WHO. THg levels in C. ocellaris, H. malabaricus, P. squamosissimus, P. fasciatum, and Semaprochilodus insignis were higher than those found in fish of heavily impacted areas. Signs of bioaccumulation and biomagnifications of Hg can already be observed in this region. The Western Amazon Region urgently needs government actions to inhibit Hg release in aquatic ecosystems and to advise this population on the safe amount of fish to be eaten according to species and period of the year.


Assuntos
Monitoramento Ambiental , Peixes/metabolismo , Mercúrio/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Caraciformes , Ciclídeos , Exposição Dietética/estatística & dados numéricos , Ecossistema , Cadeia Alimentar , Contaminação de Alimentos/estatística & dados numéricos , Brânquias/química , Humanos , Mercúrio/análise , Músculos/química , Medição de Risco , Rios , Alimentos Marinhos , Poluentes Químicos da Água/análise
11.
Cytogenet Genome Res ; 160(1): 38-46, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32092756

RESUMO

The repetitive DNA content of fish sex chromosomes provides valuable insights into specificities and patterns of their genetic sex determination systems. In this study, we revealed the genomic satellite DNA (satDNA) content of Megaleporinuselongatus, a Neotropical fish species with Z1Z1Z2Z2/Z1W1Z2W2 multiple sex chromosomes, through high-throughput analysis and graph-based clustering, isolating 68 satDNA families. By physically mapping these sequences in female metaphases, we discovered 15 of the most abundant satDNAs clustered in its chromosomes, 9 of which were found exclusively in the highly heterochromatic W1. This heteromorphic sex chromosome showed the highest amount of satDNA accumulations in this species. The second most abundant family, MelSat02-26, shared FISH signals with the NOR-bearing pair in similar patterns and is linked to the multiple sex chromosome system. Our results demonstrate the diverse satDNA content in M. elongatus, especially in its heteromorphic sex chromosome. Additionally, we highlighted the different accumulation patterns and distribution of these sequences across species by physically mapping these satDNAs in other Anostomidae, Megaleporinusmacrocephalus and Leporinusfriderici (a species without differentiated sex chromosomes).


Assuntos
Caraciformes/genética , DNA Satélite/genética , DNA/genética , Cromossomos Sexuais/genética , Animais , Linhagem da Célula , Mapeamento Cromossômico , Evolução Molecular , Feminino , Genoma , Genômica , Heterocromatina/metabolismo , Hibridização in Situ Fluorescente , Masculino , Metáfase , Análise de Sequência de DNA
12.
Cytogenet Genome Res ; 160(1): 29-37, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32092757

RESUMO

The fish family Cynodontidae belongs to the superfamily Curimatoidea, together with the Hemiodontidae, Serrasalmidae, Parodontidae, Prochilodontidae, Chilodontidae, Curimatidae, and Anostomidae. The majority of the species of this superfamily that have been analyzed to date have a diploid chromosome number of 2n = 54. Differentiated sex chromosomes (with female heterogamety) have been observed only in the Prochilodontidae, Parodontidae, and Anostomidae. The present study provides the first description of differentiated sex chromosomes in the cynodontid species Cynodon gibbus, which has a ZZ/ZW system, and shows that repetitive DNA has played a fundamental role in the differentiation of these sex chromosomes.


Assuntos
Caraciformes/genética , Cromossomos Sexuais , Animais , Bandeamento Cromossômico , DNA , Evolução Molecular , Feminino , Heterocromatina/química , Hibridização in Situ Fluorescente , Cariotipagem , Masculino , Hibridização de Ácido Nucleico , Sequências Repetitivas de Ácido Nucleico
13.
J Fish Biol ; 96(6): 1349-1359, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32096231

RESUMO

A new species of Megaleporinus is described from the Rio de Contas, a coastal drainage of eastern Brazil, and its phylogenetic relationships are studied using molecular data. The new species is unique among Anostomidae by possessing two exclusive features: an irregular dark longitudinal stripe from supracleithrum to second midlateral blotch and anterior cranial fontanel partially closed. In addition, the new species is diagnosed by having three premaxillary teeth, three dentary teeth, 37 or 38 scales in lateral line, 16 scale rows around caudal peduncle, three dark midlateral blotches on body, and red fins in life. The new species is closely related to M. obtusidens from the São Francisco basin, corroborating previous studies that indicated that the latter represents a species complex as currently defined. The new species exhibits the first rib enlarged in mature males, a feature described for some congeners. The new species is herein considered to be Endangered under the IUCN criteria.


Assuntos
Caraciformes/anatomia & histologia , Caraciformes/classificação , Espécies em Perigo de Extinção , Nadadeiras de Animais/anatomia & histologia , Animais , Brasil , Masculino , Filogenia , Costelas/anatomia & histologia , Rios , Crânio/anatomia & histologia , Especificidade da Espécie , Dente/anatomia & histologia
14.
Ecotoxicol Environ Saf ; 190: 110165, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31918258

RESUMO

Environmental disasters such as the rupturing of mine tailings dams are a major concern worldwide. In the present study, we assess the effects of the release of mine waste due to the rupture of the Fundão dam on two native fish species (Hoplias intermedius and Hypostomus affinis) from the Doce River basin. Two sampling sites were chosen: S1, a reference site, and S2, contaminated by mining waste. Water and sediment were collected to evaluate metals concentration. Adult fish were caught to analyse biological parameters, hepatic histopathology, and biomarkers of metal contamination. Compared to site S1, the concentration of manganese was statistically higher in water while lead, nickel, and arsenic were statistically higher in the sediment from site S2, and iron had no significant difference between sites. At site S1, fish of both species presented hepatic tissue with normal architecture. At site S2, hepatic alterations, such as cytoplasmic vacuolization and necrosis were frequently found in both species. Regarding the histopathological index, higher values were found in both species from site S2. The positive antibody reactions for cytochrome P450 1A (CYP1A) and metallothionein (MT) were statistically greater in site S2 for both species. The oxidative stress biomarkers, superoxide dismutase (SOD) and catalase (CAT) were statistically higher in H. intermedius from site S2, but only CAT was statistically greater in H. affinis at site S2. These results demonstrate that the release of mineral residues from the rupture of the Samarco mine dam is provoking hepatic damage in the fish from the Doce River besides inducing the expression of proteins and enzymes related to metal contamination.


Assuntos
Arsênico/toxicidade , Peixes-Gato/metabolismo , Caraciformes/metabolismo , Fígado/efeitos dos fármacos , Metais Pesados/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Arsênico/análise , Brasil , Catalase/metabolismo , Monitoramento Ambiental , Resíduos Industriais , Fígado/metabolismo , Fígado/patologia , Metais Pesados/análise , Mineração , Rios/química , Superóxido Dismutase/metabolismo , Poluentes Químicos da Água/análise
15.
Parasitol Res ; 119(3): 871-878, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31897794

RESUMO

Myxozoans of the family Ceratomyxidae are common coelozoic parasites of marine, anadromous, and freshwater fish, and may also be found, less frequently, parasitizing the tissue of these hosts. The diversity and ecology of the freshwater species of the genus Ceratomyxa have been poorly investigated, leading to a knowledge gap that restricts the understanding of the distribution and prevalence of this group of parasites. In the present study, parasites were found inside vermiform plasmodia, characterised by oscillatory movements in the characiform species Hemiodus unimaculatus. The crescent-shaped and elongated spores, perpendicular to the suture line, have a mean length of 28.9 ± 2.7 µm and width of 2.6 ± 0.1 µm, with two symmetrical oval polar capsules, 1.9 ± 0.3 µm in length and 1.7 ± 0.2 µm in width, containing polar filaments with three or four coils, located near the central suture, with symmetrical lateral elongations 14.3 ± 1.1 µm in length and binucleate amoeboid sporoplasm. The integrated comparative analysis of the morphological characteristics and partial SSU rRNA sequences supported the identification of a new species of coelozoic Ceratomyxa, found in the gallbladder of H. unimaculatus, from the Tocantins basin, in the municipalities of Estreito and Imperatriz in eastern Brazilian Amazonia.The new species was denominated Ceratomyxa fonsecai n. sp.


Assuntos
Caraciformes/parasitologia , Doenças dos Peixes/parasitologia , Myxozoa/fisiologia , Doenças Parasitárias em Animais/parasitologia , Plasmodium/parasitologia , Animais , Brasil , Água Doce/parasitologia , Vesícula Biliar/parasitologia , Myxozoa/classificação , Myxozoa/citologia , Myxozoa/genética , Filogenia , Plasmodium/fisiologia
16.
Sci Total Environ ; 704: 135332, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-31806348

RESUMO

Copper nanoparticles can contaminate the aquatic environment, but their effects on fish and how they may differ from copper salts is not understood. Thus, in this work we compare the sublethal effects of copper nanoparticles (nCu) and copper chloride (Cu) on the freshwater teleost Prochilodus lineatus, known for its sensitivity to copper. Juveniles (n = 8/group) were exposed to 20 µg L-1 of copper as CuCl2 (Cu), 40 µg L-1 of copper nanoparticles (nCu), or only water (control), for 96 h. These concentrations were chosen to achieve similar dissolved copper concentration in both treatments (Cu: 10.29 ± 0.94 µg L-1; nCu: 12.16 ± 1.77 µg L-1). After the exposure, the following biological parameters were evaluated: copper accumulation in the gills, liver, gastrointestinal tract, kidney, and muscle; hematocrit (Ht) and hemoglobin content (Hb); branchial activity of Na+-K+-ATPase (NaKATP), H+-ATPase (HATP), Ca2+-ATPase (CaATP), and carbonic anhydrase (CA); glutathione content (GSH) and lipid peroxidation (LPO) in the liver; acetylcholinesterase activity (AChE) in the brain and muscle; and histopathology of the gills and liver. The gills of Cu-exposed fish were adversely affected, with increased copper content, inhibition of H+-ATPase and Ca2+-ATPase, and histological damage, including proliferation of mitochondria rich cells and/or mucous cells. In addition, LPO levels increased in the liver of Cu-exposed fish, indicating the occurrence of oxidative stress. Exposure to nCu promoted a decrease in Ht and Hb, indicating anemia, and an increase in branchial Na+-K+-ATPase and H+-ATPase activities, which can be an adaptive response to metabolic acidosis. Within the chosen biomarkers and the conditions tested, copper nanoparticles were less toxic than copper. However, the effects promoted by the nanoparticles were different from those promoted by copper. These results emphasize the need for a better understanding of copper nanoparticles toxicity in order to establish safe concentrations and avoid environment impacts.


Assuntos
Caraciformes/fisiologia , Cobre/toxicidade , Nanopartículas Metálicas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Água Doce , Glutationa/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , ATPase Trocadora de Sódio-Potássio/metabolismo
17.
Mol Genet Genomics ; 295(1): 195-207, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31624915

RESUMO

The origin of supernumerary (B) chromosomes is clearly conditioned by their ancestry from the standard (A) chromosomes. Sequence similarity between A and B chromosomes is thus crucial to determine B chromosome origin. For this purpose, we compare here the DNA sequences from A and B chromosomes in the characid fish Characidium gomesi using two main approaches. First, we found 59 satellite DNA (satDNA) families constituting the satellitome of this species and performed FISH analysis for 18 of them. This showed the presence of six satDNAs on the B chromosome: one shared with sex chromosomes and autosomes, two shared with sex chromosomes, one shared with autosomes and two being B-specific. This indicated that B chromosomes most likely arose from the sex chromosomes. Our second approach consisted of the analysis of five repetitive DNA families: 18S and 5S ribosomal DNA (rDNA), the H3 histone gene, U2 snDNA and the most abundant satDNA (CgoSat01-184) on DNA obtained from microdissected B chromosomes and from B-lacking genomes. PCR and sequence analysis of these repetitive sequences was successful for three of them (5S rDNA, H3 histone gene and CgoSat01-184), and sequence comparison revealed that DNA sequences obtained from the B chromosomes displayed higher identity with C. gomesi genomic DNA than with those obtained from other Characidium species. Taken together, our results support the intraspecific origin of B chromosomes in C. gomesi and point to sex chromosomes as B chromosome ancestors, which raises interesting prospects for future joint research on the genetic content of sex and B chromosomes in this species.


Assuntos
Characidae/genética , Caraciformes/genética , DNA Satélite/genética , Cromossomos Sexuais/genética , Animais , Mapeamento Cromossômico/métodos , DNA Ribossômico/genética , Evolução Molecular , Histonas/genética , Cariótipo , Sequências Repetitivas de Ácido Nucleico/genética
18.
J Fish Biol ; 96(1): 251-260, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31762020

RESUMO

This study describes anatomical, histological and histochemical features of the digestive tract mucosal layer of the matrinxã Brycon amazonicus, an omnivorous freshwater fish endemic from the Amazon basin. This species presents short thick oesophagus with longitudinal folds, that allow the passage of large food items. The mucosa is lined with a stratified secretory epithelium rich in goblet cells that secrete neutral and acid mucins. The two mucin types provide different viscosity in anterior and posterior oesophagus related to the protective and lubricant functions, respectively. The stomach is a highly distensible Y-shaped saccular organ. Here, it is proposed that this anatomical shape plays an essential role in food storage when food availability is abundant. The stomach mucosa is composed of epithelial cells with intense neutral mucin secretion to protects against gastric juice. The intestine is slightly coiled and presents internally a complex pattern of transversal folds that increases the absorption surface and the retention time of food. Goblet cells in the intestine secrete acid and neutral mucins that lubricate the epithelium and aid in the digestive processes. In the rectum, an increase in goblet cells population occurs that may be related to better lubrication.


Assuntos
Caraciformes/anatomia & histologia , Mucosa Gástrica/citologia , Trato Gastrointestinal/anatomia & histologia , Trato Gastrointestinal/citologia , Animais , Comportamento Alimentar , Mucosa Gástrica/metabolismo , Mucinas/metabolismo
19.
Artigo em Inglês | MEDLINE | ID: mdl-31683014

RESUMO

Sublethal exposures to environmental pollutants may cause changes in physiological parameters. Thus, knowledge of basal physiological rates of the species and the development of methods to quantify these rates are extremely important. Considering the scarcity of cardiac and muscle physiological studies in native Amazonian fish species and that no evaluation of electrophysiological responses by exposure to a stressor has been reported in Bryconops caudomaculatus, the aim of this study was to develop techniques of electromyographic and electrocardiographic recordings of normal responses, during toxicity induction and short-term recovery. A total of 9 animals were used, divided into two groups: control group (n = 4) and treated group (n = 5), with records lasting 5 min. The results showed that the basal electromyographic records indicate that the studied species has a very intense swimming activity, whereas the basal cardiac parameters clearly showed the patterns in P wave tracing, QRS complex, T wave and Q-T and R-R intervals. During exposure to the stressor, muscle activity ceased presenting intense decrease and myorelaxant effect expected. Electrocardiographic responses confirmed cardiotoxicity with intense bradycardia, ventricular bigeminism, prolongation of QRS complex duration and cardiac arrhythmias, indicating cardiac dysfunction. It was concluded that the electrophysiological responses are excellent biomarkers and showed the susceptibility of the species to the tested substance. In addition, the electrocardiogram and the electromyogram are excellent techniques to reflect the degree of environmental stress when organisms are exposed to toxic substances in the environment.


Assuntos
Caraciformes/fisiologia , Eletrocardiografia/veterinária , Eletromiografia/veterinária , Poluentes Químicos da Água/toxicidade , Xenobióticos/toxicidade , Animais , Eletrocardiografia/métodos , Eletromiografia/métodos , Natação
20.
J Fish Biol ; 96(1): 49-58, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31648365

RESUMO

The aim of the present study was to perform comparative histological analyses of the ontogenetic development of two fish species endemic to the São Francisco River in Brazil: Prochilodus argenteus and Lophiosilurus alexandri. Histological analyses were performed every 24 h from the moment of hatching until 14 days post-hatching (dph) for the observation of larval development and until 39 dph for the observation of gonadal development. Whole larvae were fixed in Bouin's solution and the histological slides were stained with haematoxylin-eosin. Lophiosilurus alexandri larvae had a larger body size compared with P. argenteus larvae since hatching. Lophiosilurus alexandri larvae had mouth opening and pigmentation of the eyes upon hatching, whereas these events were observed at 1 dph in P. argenteus larvae. The visualisation and the inflation of the swim bladder occurred at 1 and 3 dph, respectively, in the P. argenteus, whereas these events occurred at 2 and 8 dph, respectively, in L. alexandri. Yolk granules were absorbed at 4 dph in P. argenteus and the 10 dph in L. alexandri. At 7 dph, the digestive tube was more differentiated in L. alexandri than P. argenteus and at 14 dph, the digestive system of both species had features of their eating habits: broad stomach and short intestine in L. alexandri, typical of carnivorous habits; stomach with a mechanical function and long intestine in P. argenteus, typical of detritivorous habits. The epithelial lining tissue, formed by a single layer of cells in the newly hatched larvae (0 dph), differentiated throughout the study, exhibiting scales in P. argenteus and numerous club cells in the middle epithelial region of L. alexandri at 39 dph. Undifferentiated gonads with somatic cells and primordial germ cells were observed at 39 dph, with caudal-cranial migration since 1 dph in both species. The anatomic changes during the ontogeny of P. argenteus and L. alexandri larvae are directly associated with the evolutionary history of each species, which explains their feeding habits, behaviour and distribution in the environment: Prochilodus argenteus is detritivorous and actively swims in the water column, whereas L. alexandri is carnivorous and inhabits bottom regions. At 39 dph neither species exhibited sexual differentiation.


Assuntos
Peixes-Gato/crescimento & desenvolvimento , Caraciformes/crescimento & desenvolvimento , Animais , Evolução Biológica , Brasil , Peixes-Gato/genética , Caraciformes/genética , Larva/genética , Larva/crescimento & desenvolvimento , Rios
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