232 resultados para skull ontogeny


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Pós-graduação em Biologia Geral e Aplicada - IBB

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This paper analyzes the Psychology of Play developed by D. Elkonin and his followers through examining the central theses of the cultural-historical theory. The goal is to identify elements that can support the organization of early childhood education practices. The cultural-historical theses represent a solid theory about children's play, featuring an original contribution to understand the historical emergence of play and its social nature in ontogeny. Based on Cultural-historical theory of play, we conclude that early childhood education which considers play as the leading activity must relate to the experience of various spheres of social life and the content of human activities. It is understood that the goal of educational intervention in children play is the development of the social role represented in the game. It is argued that play should neither oppose nor prevail over other activities.

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Muitas espécies de peixes de água doce são consideradas miniaturas, entretanto, sua identificação é frequentemente baseada apenas no critério arbitrário que é seu reduzido tamanho corporal. Apesar de algumas espécies de Otothyris terem sido propostas como miniaturas, informações acerca do processo de miniaturização no gênero e suas consequências são escassas. Aqui detalhamos eventos de perda, fusão, modificações em muitos ossos, sistema laterossensorial e no cérebro, que juntos evidenciam a miniaturização em todas as espécies do gênero. Nossos resultados podem ser úteis na identificação de outras espécies miniaturas dentro de Loricariidae.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The juvenile development of the freshwater crab Dilocarcinus pagei Stimpson, 1861 was studied under laboratory conditions, focusing on setae morphology. The ovigerous females were collected manually associated with water hyacinth at the Municipal Dam of Sao Jose do Rio Preto (Sao Paulo, Brazil). The specimens were raised in the laboratory under constant aeration, photoperiod (12: 12 h) and temperature (27 +/- 1 degrees C). Twelve juvenile stages were obtained with descriptions of the main morphological characters that allow their identification are presented. Fourteen types of setae were discovered: dentate, denticulate, serrulate, papposerrate, cuspidate, plumose, plumodenticulate, plumoserrulate, simple, pappose, brush, curved, nail and setules. The greatest diversity of setae was found on the mouth appendages, especially the maxillule. The gill ontogeny and sexual dimorphism becomes apparent from the second juvenile stage onwards. At the third juvenile stage, the carapace begins to exhibit a wider shape, becoming similar to that of the adults.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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In recent years, a number of South American freshwater fish have gained increasing attention for their potential in aquaculture, not only because of their excellent performance in farming systems but also to meet the high consumer demand for these species due to declining fishery resources. Many South American freshwater species are migratory and produce altricial larvae, with a small amount of yolk reserves. Unlike precocial freshwater species and altricial coldwater marine fish, these freshwater fish investigated have rapid yolk depletion and metamorphosis. Specific studies on the initial development of South American fish are scarce and fragmented. One of the most widely studied species is the pacu (Piaractus mesopotamicus), farmed in warm continental waters. In the present review we compile new and published data on the initial development of pacu, including morphogenesis of the skeletal, muscle, digestive and sensory systems; compare it to other Neotropical species; and discuss the importance of this information to develop larviculture protocols. When pacu larvae exhaust yolk reserves, they initiate a new form of interaction with the environment, becoming exclusively exotrophic. This type of interaction is made possible by the rapid development of sensory, skeletal, locomotor and digestive structures. In addition to understanding fish ontogeny, studies on larval development are necessary to improve farming systems and larviculture techniques aimed at producing high-quality juveniles in aquaculture. (C) 2014 Elsevier B.V. All rights reserved.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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While viviparity confers protection to the embryos during gestation, it increases energetic costs for the mother, which acquires new relations to its offspring. Maternal-fetal transfer of nutrients can occur in different patterns: as lecithotrophy (nourished by yolk) or matrotrophy (nourished by the mother). The development of Poecilia vivipara embryos was described macroscopically and microscopically, and the form of nutritional provisioning was identified. Embryonic development was divided into three prefertilization and seven postfertilization stages. The first organ to appear is the notochord, followed by the nervous, digestive and cardiovascular systems, and then by muscles and eyes. Embryonic nutritional provisioning was lecithotrophic, with yolk persisting until the last developmental stages and rich in proteins and polysaccharides. This kind of embryonic nutrition confirms the pattern found in the family Poeciliidae.

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In this study the occurrence of sensory structures on the antennules and antennae of the giant river prawn Macrobrachium rosenbergii (De Man) during postembryonic ontogenetic development were examined. Larvae and postlarvae were obtained from hatchery recirculating tanks, juveniles from indoor nursery tanks, and adults from earthen grow-out ponds. The animals were fixed with Karnovsky fixative and dissected. Antennules and antennae were removed, metal-coated, and photodocumented using a scanning electron microscope. The antennules have aesthetascs and simple plumose and pappose setae; the antennae have simple, plumose and pappose setae. These structures increase in density, covered surface, and distribution during ontogeny and should be related to chemoreception and mechanoreception. The antennular statocyst that appears during larval stage VII of the giant river prawn has an array of sensory structures that enable the perception of chemical and tactile stimuli beginning with its early life stages. The ontogenetic changes observed allow an inference that initial-stage larvae, advance-stage larvae, juveniles, and adults have different capacities to exploit the environment.