Morphological analysis of the digestive tract of Hypophthalmus marginatus (Valenciennes, 1840).

The mapará, Hypophthalmus marginatus, is a rheophilic and planktophagous catfish and it is one of the main fishing resources in the Amazon region. To understand its nutritional characteristics, this work described the morphology and histochemistry of the digestive tract of H. marginatus.

Morphological and histochemical features of the digestive tract of Leiarius marmoratus (Gill, 1870).

Leiarius marmoratus, a freshwater catfish from Pimelodidae family, shows great biological and commercial relevance because of its geographic distribution and adaptation to fish-farm. The knowledge of the morphological characteristics of the digestive tract is fundamental to the understanding of fish physiology and nutrition, which helps in the planning of diets to provide better management and success in fish farming. Thus, this work described the morphology and histochemistry of the digestive tract of L.

Differential effects of dexamethasone on arterial stiffness, myocardial remodeling and blood pressure between normotensive and spontaneously hypertensive rats.

Dexamethasone (DEX)-induced hypertension is observed in normotensive rats, but little is known about the effects of DEX on spontaneously hypertensive animals (SHR). This study aimed to evaluate the effects of DEX on hemodynamics, cardiac hypertrophy and arterial stiffness in normotensive and hypertensive rats. Wistar rats and SHR were treated with DEX (50 μg/kg s.

Myology of juvenile freshwater prawn Macrobrachium amazonicum (Decapoda, Caridea): Morphology and swimming implication.

Little is known about the functional morphology of locomotion in prawns, and even fewer studies have succeeded in relating a specific muscular group to the movement of the body. The present study aimed to describe the morphology of the thoracoabdominal muscle system and its implications for swimming in juveniles of Macrobrachium amazonicum. Ten muscles were observed in the abdominal muscular system in juveniles of M.

Heart structure in the Amazonian teleost Arapaima gigas (Osteoglossiformes, Arapaimidae).

The fish heart ventricle has varied morphology and may have a specific morpho-functional design in species adapted to extreme environmental conditions. In general, the Amazonian ichthyofauna undergoes constant variations in water temperature, pH and oxygen saturation, which makes these species useful for investigations of cardiac morphology. Arapaima gigas, a member of the ancient teleost group Osteoglossomorpha, is one of the largest freshwater fish in the world.

Myocardium Arrangement and Coronary Vessel Distribution in the Ventricle of Three Neotropical Freshwater Teleosts.

The ventricle of the fish heart is a chamber that exhibits great morphological and vascular variability among species. However, although the Neotropical region has the greatest taxonomic and functional diversity in freshwater fish, many considerations have been formed without previous knowledge of the ventricular morphology of these fishes. Thus, the purpose of the present study was to describe the anatomy, myoarchitecture, and distribution of coronary vessels in the ventricle of three species belonging to two representative groups from this geographical area, Leporinus elongatus, Hoplias malabaricus (Characiformes) and Pterodoras granulosus (Siluriformes), using gross anatomy and light microscopy.

Acid and alkaline phosphatase localization in the digestive tract mucosa of the Hemisorubim platyrhynchos.

This cytochemical study investigated the acid and alkaline phosphatase of the digestive tract of Hemisorubim platyrhynchos. Acid phosphatase was detected in the lining epithelium throughout the digestive tract, whereas alkaline phosphatase was only observed in the intestine. In the esophagus, an acid phosphatase reaction occurred in the apical cytoplasm of the epithelial cells and was related to epithelial protection and freeing of superficial cells for sloughing.

Ultrastructure of the digestive tract in neotropical carnivorous catfish Hemisorubim platyrhynchos (Valenciennes, 1840) (Siluriformes, Pimelodidae).

The surface of the digestive tract of Hemisorubim platyrhynchos was analyzed by scanning electron microscopy. Morphometric studies by transmission electron microscopy were performed to analysis the intestinal microvilli. H.

Morphology and histochemistry of the digestive tract in carnivorous freshwater Hemisorubim platyrhynchos (Siluriformes: Pimelodidae).

The aim of this study was to characterize the morphology and histochemistry of the digestive tract of Hemisorubim platyrhynchos, a freshwater carnivorous catfish found in Neotropical region, using gross anatomy, light microscopy and transmission electron microscopy. This species presented a short and tubular esophagus with thick longitudinal folds. The esophageal mucosa was lined by stratified squamous epithelium containing epithelial cells, club cells and also numerous goblet cells, which secreted acidic and neutral mucins to protect and lubricate the epithelium.

Liver anatomy, histochemistry, and ultrastructure of Eupemphix nattereri (Anura: Leiuperidae) during the breeding season.

The arrangement of the hepatic tissue is directly related to physiological characteristics of animals, such as ectothermy, diet, and reproductive status. Here, we describe the anatomy, histology, and ultrastructure of the liver in adult males of Eupemphix nattereri during the breeding season. The liver is an organ with an irregular shape, red in color, and occupies a large portion of the body cavity.

Testicular structure and description of the seminal pathway in Leporinus macrocephalus (Anostomidae, Teleostei).

The present study examined the testicular structure and the seminal pathway in freshwater fish Leporinus macrocephalus (Garavello and Britski, 1988). Twenty-five specimens of this species were studied. Testicular structure was analyzed using light and transmission electron microscopy.