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Marcon L.,Programa de Pos graduacao em Zoologia de Vertebrados da PUC Minas | Lopes D.S.,Federal University of Vicosa | Mounteer A.H.,Federal University of Vicosa | Goulart A.M.A.,Federal University of Vicosa | And 2 more authors.
Ecotoxicology and Environmental Safety | Year: 2016

Female individuals of Hyphessobrycon eques were exposed to Diflubenzuron (Dimilin®) in order to determine whether exposure to sublethal levels of this insecticide causes changes in gill morphology. Fish were exposed to 0.01, 0.1 and 1.0 mg L-1 for 96 h and 17 days and then submitted to pathological and histometric evaluation. Pathological lesions, such as hyperplasia, lamellar fusion, vascular congestion, secondary lamellar disarray, vasodilatation, hemorrhage and increased lamellar epithelium, were significantly more common in the gills of fish exposed to Dimilin® than the control. Histometric analysis documented significant changes in blood vessel diameter, primary lamellae width and secondary lamellae length, and the appearance of hemorrhage foci in all concentrations tested. Even at low Dimilin® concentrations, the histopathological alteration index was mild to moderate, thereby indicating that the function of this tissue was compromised. These findings indicate that indiscriminate use of Dimilin® can adversely affect the structural integrity of the gills of H. eques, which can cause numerous problems for fish farming systems. © 2016 Elsevier Inc. Source

Dos Santos M.L.,Programa de Pos graduacao em Zoologia de Vertebrados da PUC Minas | Arantes F.P.,Programa de Pos graduacao em Zoologia de Vertebrados da PUC Minas | Santiago K.B.,Companhia de Desenvolvimento dos Vales do Sao Francisco e do Parnaiba | Dos Santos J.E.,Programa de Pos graduacao em Zoologia de Vertebrados da PUC Minas
Anais da Academia Brasileira de Ciencias | Year: 2015

The digestive tracts of 44 specimens of Schizodon knerii were studied using anatomical, histological and histochemical techniques. The mouth has terminal position, the lip epithelium is squamous stratified with mucous, claviform cells and taste buds, teeth have an incisive form and the tongue has a stratified squamous epithelium with mucous cells and taste buds. The oropharynx cavity is formed by gill apparatus and pharyngeal teeth. The oesophagus presented pleated mucosa, a stratified squamous epithelium with mucous cells, oesophageal glands and taste buds. The stomach presented cardiac, fundic and pyloric regions, simple prismatic epithelium with tubular glands, with none in the pyloric region. The intestine contains 11-15 pyloric caeca, a simple prismatic epithelium with brush border, goblet cells and lymphocytes. Mucosal cells, oesophageal glands and goblet cells reacted positively to PAS, amylase + PAS, Ab pH 2.5 and Ab pH 0.5. Gastric prismatic cells reacted positively to PAS, amylase + PAS, but only those in the pyloric region reacted positively to Ab pH 2.5 and Ab pH 0.5. The results improve the understanding of the anatomy of S. knerii feeding habits and the presence of mucosubstances in the epithelium, highlights the importance of glycoproteins for passing food through the digestive tract. © 2015, Academia Brasileira de Ciencias. All rights reserved. Source

Marcon L.,Programa de Pos graduacao em Zoologia de Vertebrados da PUC Minas | Bazzoli N.,Programa de Pos graduacao em Zoologia de Vertebrados da PUC Minas | Honor Mounteer A.,Federal University of Vicosa | Anjos Benjamin L.D.,Federal University of Vicosa
Anatomical Record | Year: 2015

To investigate possible morphological changes to the liver tissue of lambaris, Astyanax bimaculatus (Linnaeus, 1758), females were exposed to treatments of sublethal concentrations of the insecticide Thiodan® for 96 hr. Treatments included three sublethal concentrations of 1.15, 2.3, and 5.6 μg L-1 of Thiodan® and a control group without insecticide. The action of Thiodan® at sublethal concentrations did not affect the morphological structure of the liver as a whole, but changes in isolated locations of the hepatic parenchyma were observed. Glycogen depletion, nuclear and cytoplasmic deformation, nuclear and cytoplasmic hypertrophy, hyperemia, and cellular degeneration in liver cells at the different concentrations studied were recorded. These observed changes in the livers were greater in groups exposed to Thiodan® in comparison to the control group. Furthermore, there was a change in the diameter of the nuclei and cytoplasm of hepatocytes in the different treatments. The groups exposed to Thiodan® also exhibited a larger number of hepatocyte nuclei and a reduction in the amount of cytoplasm. We conclude that for the exposure period and concentrations of Thiodan® analyzed, the morphology of hepatic tissue had a cellular adaptive response. © 2015 Wiley Periodicals, Inc. Source

Specht G.V.A.,Programa de Pos graduacao em Zoologia de Vertebrados da PUC Minas | Goncalves G.L.,Programa de Pos graduacao em Zoologia de Vertebrados da PUC Minas | Young R.J.,Programa de Pos graduacao em Zoologia de Vertebrados da PUC Minas
Lundiana | Year: 2013

The burrowing-owl, Athene cunicularia (Molina, 1782) has a wide distribution, which extends from western North America to southern South America. They are an opportunistic plunderer species preying on insects and small mammals. Data on hunting tactics of this specie are scarce in the literature. Here, the general and hunting behaviors of the species are described in an urban environment, a university campus, in the city of Belo Horizonte, Minas Gerais state, Brazil. An adult male of A. cunicularia had its behavior studied during 14 days, in July 2005, totaling 20 hours of systematic observations using the instantaneous focal-animal method. The observations were done using 10x50 binoculars, between 06:00 and 09:00 and after 16:00, from a minimal distance of 25 m. We identified and described five behavioral categories: self-maintenance, locomotion, hunting, non-agonistic social and alert. No difference was found between behaviors displayed during morning and afternoon periods. Four hunting strategies displayed by A. cunicularia were identified (hunting in soil, air hunting, perch to soil hunting and hover flight hunting) but no difference between their frequencies was found. These behaviors were observed only after 1 8:00. Thesenon-significant patterns suggest that the oportunistic hunting behavior of the birds of prey ("sit-and-wait") and the active search hunting patterns are alternated according to opportunity, identification and capture of the prey and the place of capture. © 2013 Instituto de Cîncias Biológicas - UFMG. Source

Santos M.L.,Programa de Pos graduacao em Zoologia de Vertebrados da PUC Minas | Sales N.G.,Programa de Pos graduacao em Zoologia de Vertebrados da PUC Minas | Arantes F.P.,Programa de Pos graduacao em Zoologia de Vertebrados da PUC Minas | Pessali T.C.,Programa de Pos graduacao em Zoologia de Vertebrados da PUC Minas | And 2 more authors.
Journal of Veterinary Medicine Series C: Anatomia Histologia Embryologia | Year: 2014

The testicular morphology, spermatogenesis and occurrence of sperm in the ovarian lumen of Trachelyopterus striatulus were studied using anatomical, histological and biometric techniques. A total of 50 catfish (T. striatulus) were captured, measuring 14.9 ± 2.5 cm of standard length, body weight was 81.2 ± 34.5 g and their testes weighed 16.9 ± 6.1 g. The testes of T. striatulus are paired organs, showing two distinct regions: cranial, which shows a compact medial part and with fringes ventrally, and caudal region, which is formed of the seminal vesicle with fringes laterally and two saculiform expansions. The testes presented a length of 35.2 ± 6.9 mm, and the fringes showed a cranial length of 12.1 ± 3.8 mm and caudal length of 6.4 ± 2.6 mm. Histologically, the cranial fringes are spermatogenic and showed cells with significantly different nuclear diameters, ranging from 8.2 ± 1.5 μm (primary spermatogonia) to 1.88 ± 0.3 μm (spermatid). The seminal vesicles and saculiform expansions showed tubules with a simple prismatic secretory epithelium containing spermatozoa and secretion into the lumen. The caudal fringes are exclusively for secretory flow, consisting of tubules with a simple cuboidal epithelium. The common spermatic duct showed a simple cuboidal epithelium and contained spermatozoa with secretion into the lumen. The secretion of the caudal region is acidophilic, with neutral glycoproteins and sialomucin. T. striatulus ovaries showed free spermatozoa or were organized in spermatozeugmata into the ovarian lumen and between the ovuligers lamellae. © 2013 Blackwell Verlag GmbH. Source

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