Wallice Paxiúba Duncan

Implications for osmorespiratory compromise by anatomical remodeling in the gills of Arapaima gigas.

The gill structure of the Amazonian fish Arapaima gigas, an obligatory air breather, was investigated during its transition from water breathing to the obligatory air breathing modes of respiration. The gill structure of A. gigas larvae is similar to that of most teleost fish; however, the morphology of the gills changes as the fish grow. The main morphological changes in the gill structure of a growing fish include the following: (1) intense cell proliferation in the filaments and lamellae, resulting in increasing epithelial thickness and decreasing interlamellar distance; (2) pillar cell system atrophy, which reduces the blood circulation through the lamellae; (3) the generation of long cytoplasmic processes from the epithelial cells into the intercellular space, resulting in continuous and sinuous paracellular channels between the epithelial cells of the filament and lamella that may be involved in gas, ion, and nutrient transport to epithelial cells; and (4) intense mitochondria‐rich cell (MRC) proliferation in the lamellar epithelium. All of these morphological changes in the gills contribute to a low increase of the respiratory surface area for gas exchange and an increase in the water–blood diffusion distance increasing their dependence on air‐breathing as fish developed. The increased proliferation of MRCs may contribute to increased ion uptake, which favors the regulation of ion content and pH equilibrium. Anat Rec, 296:1664–1675, 2013.

Effect of fatty Amazon fish consumption on lipid metabolism

The groups treated with enriched diets showed a significant reduction in body mass and lipogenesis in theepididymal and retroperitoneal adipose tissues and carcass when compared with the control group. However,lipogenesis in the liver showed an increase in Matrinxa group compared with the others groups. The levels ofserum triglycerides in the treated groups with Amazonian fish were significantly lower than those of the controlgroup. Moreover, total cholesterol concentration only decreased in the group1 Instituto Nacional de Pesquisas da Amazônia, Coordenação Sociedade Ambiente e Saúde, Laboratório de Alimentos e Nutrição. Av. André Araújo, 2936, Aleixo, 69060-001, Manaus, AM, Brasil. Correspondência para/Correspondence to: FCA SOUZA. E-mail: . 2 Universidade Federal do Amazonas, Instituto de Ciências Biológicas, Departamento de Fisiologia. Manaus, AM, Brasil. 3 Universidade Federal do Amazonas, Instituto de Ciências Biológicas, Departamento de Morfologia. Manaus, AM, Brasil. Effect of fatty Amazon fish consumption on lipid metabolism

Morphology and Morphometry of the Ovaries and Uteri of the Amazonian Freshwater Stingrays (Potamotrygonidae: Elasmobranchii).

The reproductive biology of South American freshwater stingrays (family Potamotrygonidae) is still poorly studied compared to other marine species. In the present study, we examined the gross anatomy and histology of six species of potamotrygonids from the Amazon basin and described the structural asymmetry of the ovaries and their relationship between ovarian and uterine fecundities. Stereological techniques were used to quantify the volume of ovarian and epigonal organ tissue associated with the left and right sides of the Potamotrygon wallacei, a recently described species, locally known as the cururu ray. This species presented ovarian asymmetry; the left epigonal organ‐ovary complex was 55 times larger than the right side. The right side was composed of, volumetrically, 7.3% ovarian tissue and 92.7% epigonal organ tissue whereas the left side was 51.2% of ovarian tissue and 48.8% epigonal organ tissue. In all species, six types of follicles were identified in both right and left ovaries. Uteri were symmetrical and the fecundity ratio between the right and left sides was 0.9:1.1, respectively. Despite the volumetric difference of ovarian tissue between the two sides, the uterine fecundity shows that both ovaries are functional and that ovarian fecundity alone is not an accurate measure to determine the reproductive potential of freshwater stingrays. Anat Rec, 300:265–276, 2017.

Efeito do congelamento na composição química e perfil de aminoácidos da carne mecanicamente separada de peixes amazônicos

The objective of this article was to assess the influence of refrigerated storage on the chemical characteristics and amino acid composition of fillets automatically processed from the following species of Amazonian fish: aracu (Schizodon fasciatum), jaraqui (Semaprochilodus spp.) and mapará (Hypophthalmus edentatus). The fillets were industrially processed and stored at -30o C for 120 days. The chemical and nutritional composition of the samples was analyzed based on their contents of: humidity, protein, fat, ash, nifext fraction and amino acid profile. After characterizing the chemical and nutritional aspects of the species, jaraqui and aracu were classified as semi-fat; they also showed the contents of protein and callories observed in other studies on freshwater fish. Mapará was considered a fat species and showed lower protein contents. It was observed that the contents of essential amino acids are responsible for an average of aproximately 42.51% of all the amino acids in the fillets of the species analyzed. Storage time did not influence their quality or composition of amino acids. This study suggests that the species analyzed are promising and likely to show a high added value. Furthermore, their technological and nutritional characteristics tend to remain stable, even under prolonged freezing.

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

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

Gill dimensions in near-term embryos of Amazonian freshwater stingrays (Elasmobranchii: Potamotrygonidae) and their relationship to the lifestyle and habitat of neonatal pups

This comparative study of gill morphometrics in near-term embryos of freshwater stingray potamotrygonids examines gill dimensions in relation to neonatal lifestyle and habitat. In embryos of the potamotrygonids Paratrygon aiereba, Plesiotrygon iwamae, Potamotrygon motoro, Potamotrygon orbignyi, and cururu ray Potamotrygon sp. the number and length of filaments, total gill surface area, mass-specific surface area, water-blood diffusion distance, and anatomical diffusion factor were analysed. In all potamotrygonids, the 3rd branchial arch possessed a larger respiratory surface than the other gill arches. Larger embryos had more gill surface area and large spiracles, which are necessary to maintain the high oxygen uptake needed due to their larger body size. However, the higher mass-specific gill surface area observed in near-term embryos may be advantageous because neonates can use hypoxic environments as refuges against predators, as well as catch small prey that inhabit the same environment. As expected from their benthic mode of life, freshwater stingrays are sluggish animals compared to pelagic fishes. However, based on gill respiratory morphometry (such as gill area, mass-specific gill area, the water-blood diffusion barrier, anatomical diffusion factor, and relative opening of the spiracle), subtypes of lifestyles can be observed corresponding to: active, intermediate, and sluggish species according to Grays scale.

Hematology and plasma biochemistry in rats fed with diets enriched with fatty fishes from Amazon region

grupo-controle (dieta-padrao); grupomapara (dietas enriquecidas com Hypophthtalmus edentatus); grupo matrinxa (dietas enriquecidas com Bryconspp.); grupo tambaqui (dietas enriquecidas com Colossoma macropomum). Os parâmetros hematologicos e asvariaveis bioquimicas plasmaticas foram analisadas nos animais apos 30 dias de experimentacao.

Effects of freezing on the chemical characteristics and on the amino acid composition of fillets automatically processed from Amazonian fish

The objective of this article was to assess the influence of refrigerated storage on the chemical characteristics and amino acid composition of fillets automatically processed from the following species of Amazonian fish: aracu (Schizodon fasciatum), jaraqui (Semaprochilodus spp.) and mapará (Hypophthalmus edentatus). The fillets were industrially processed and stored at -30o C for 120 days. The chemical and nutritional composition of the samples was analyzed based on their contents of: humidity, protein, fat, ash, nifext fraction and amino acid profile. After characterizing the chemical and nutritional aspects of the species, jaraqui and aracu were classified as semi-fat; they also showed the contents of protein and callories observed in other studies on freshwater fish. Mapará was considered a fat species and showed lower protein contents. It was observed that the contents of essential amino acids are responsible for an average of aproximately 42.51% of all the amino acids in the fillets of the species analyzed. Storage time did not influence their quality or composition of amino acids. This study suggests that the species analyzed are promising and likely to show a high added value. Furthermore, their technological and nutritional characteristics tend to remain stable, even under prolonged freezing.

Efecto del congelamiento en la composición química y el perfil de aminoácidos de la carne mecánicamente separada de peces amazónicos

The objective of this article was to assess the influence of refrigerated storage on the chemical characteristics and amino acid composition of fillets automatically processed from the following species of Amazonian fish: aracu (Schizodon fasciatum), jaraqui (Semaprochilodus spp.) and mapará (Hypophthalmus edentatus). The fillets were industrially processed and stored at -30o C for 120 days. The chemical and nutritional composition of the samples was analyzed based on their contents of: humidity, protein, fat, ash, nifext fraction and amino acid profile. After characterizing the chemical and nutritional aspects of the species, jaraqui and aracu were classified as semi-fat; they also showed the contents of protein and callories observed in other studies on freshwater fish. Mapará was considered a fat species and showed lower protein contents. It was observed that the contents of essential amino acids are responsible for an average of aproximately 42.51% of all the amino acids in the fillets of the species analyzed. Storage time did not influence their quality or composition of amino acids. This study suggests that the species analyzed are promising and likely to show a high added value. Furthermore, their technological and nutritional characteristics tend to remain stable, even under prolonged freezing.