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- ItemAcesso aberto (Open Access)Anurans of the sandy coastal plains of the Lagamar Paulista, state of São Paulo, Brazil(Instituto Virtual da Biodiversidade | BIOTA - FAPESP, 2012-03-01) Zina, Juliana; Prado, Cynthia Peralta de Almeida; Brasileiro, Cinthia Aguirre [UNIFESP]; Haddad, Célio Fernando Baptista; Universidade Estadual do Sudoeste da Bahia Departamento de Ciências Biológicas; Universidade Estadual Paulista (UNESP); Universidade Federal de São Paulo (UNIFESP)Insular habitats are considered ideal for biogeographic studies, as they represent almost closed habitats with known formation timelines. Although São Paulo state in Brazil has a large number of continental and oceanic islands, few studies have examined the composition of the fauna in each locality. These studies are crucial to determine the community structure and to make biogeographic and phylogenetic inferences. From February 2007 to January 2009, we surveyed the anuran community of sandy coastal plains in four municipalities of the Lagamar Paulista: Cananéia, Ilha Comprida, Iguape and Pariquera-Açu, in the state of São Paulo, Brazil. This region is located in the Cananéia-Iguape estuary complex, comprising three continental islands: Ilha de Cananéia, Ilha Comprida, and Ilha do Cardoso, and the continental portions adjacent to these islands in the municipalities of Iguape and Pariquera-Açu. Through the use of pitfall traps and active search, we registered a total of 32 anuran species: 17 in Ilha Comprida, 21 in Ilha de Cananéia, 26 in Ilha do Cardoso, 27 in Iguape, and 23 in Pariquera-Açu. The analysis of the richness indices of the study sites revealed higher values in continental areas. This result is very common in comparative studies between islands and continents. This may be caused by an island effect and may reveal the historical process of island formation in the Lagamar. Our findings provide important information for identifying patterns of amphibian distribution in insular areas of the São Paulo coast, and for examining how events of marine transgression and regression have affected the local amphibian communities.
- ItemSomente MetadadadosMelanomacrophage functions in the liver of the caecilian Siphonops annulatus(Wiley, 2018) Gutierre, Robson Campos [UNIFESP]; Jared, Carlos; Antoniazzi, Marta Maria; Coppi, Antonio Augusto; Egami, Mizue Imoto [UNIFESP]Melanomacrophages are phagocytes that synthesize melanin. They are found in the liver and spleen of ectothermic vertebrates, and in the kidney of fish. In agnathan and elasmobranch fish, melanomacrophages are seen as isolated cells, and forming clusters in all the other vertebrates. The natural phagocytic activity of melanomacrophages is poorly characterized, as most of the research works have focused on induced phagocytic activity only. Furthermore, little is known about amphibian melanomacrophages, mainly about those in caecilians - wormlike amphibians in the order of Gymnophiona, which is the least known group of terrestrial vertebrates. The present research work aimed at the structure and function of hepatic melanomacrophages of Siphonops annulatus, a species largely found in South America. We identified the role of these cells in the control of circulating basophils (pro-melanogenic cells), in the turnover of liver collagen stroma and in the hemocatheresis, interrelated physiological mechanisms.
- ItemSomente MetadadadosMineralized dermal layer of the Brazilian tree-frog Corythomantis greeningi(Wiley-Blackwell, 2001-04-01) Katchburian, E.; Antoniazzi, M. M.; Jared, C.; Faria, F. P.; Santos, H. S.; Freymuller, E.; Universidade Federal de São Paulo (UNIFESP); Inst Butantan; Universidade de São Paulo (USP)Some species of anuran amphibians possess a calcified dermal layer (the Eberth-Kastschenko layer) located between the stratum spongiosum and the stratum compactum. This layer consists of calcium phosphate deposits, proteoglycans, and glycosaminoglycans. Although regarded as a protective layer against desiccation, a calcium reservoir, or possibly a remnant of a dermal skeleton present in anuran ancestors, very little is known about its origin, structure, and function. Thus, we studied the structure and composition of the mineralized dermal layer of Corythomantis greeningi, a peculiar hylid from the Brazilian semiarid region (caatinga), using conventional and cryosubstitution methods combined with transmission, scanning, and analytical electron microscopy. Results show that the dermal layer consists of dense, closely juxtaposed, globular structures. Although the electron opacity of the globules was variable, depending on the type of preparation, crystal-like inclusions were present in all of them, as confirmed by dark field microscopy. Electron probe X-ray microanalysis showed calcium, phosphorus, and oxygen, and electron diffraction revealed a crystalline structure comparable to that of a hydroxyapatite. (C) 2001 Wiley-Liss, Inc.
- ItemSomente MetadadadosTestosterone-immunopositive primordial germ cells in the testis of the bullfrog, Rana catesbeiana(Blackwell Publishing, 2005-06-01) Sasso-Cerri, Estela [UNIFESP]; Freymüller-Haapalainen, Edna [UNIFESP]; Miraglia, Sandra Maria [UNIFESP]; Univ Estadual São Paulo UNESP; Universidade Federal de São Paulo (UNIFESP)In amphibia, steroidogenesis remains quiescent in distinct seasonal periods, but the mechanism by which spermatogenesis is maintained under low steroidogenic conditions is not clear. in the present study, testosterone location in the testes of Rana catesbeiana was investigated immunohistochemically during breeding (summer) and nonbreeding (winter) periods. in winter, the scarce interstitial tissue exhibited occasional testosterone immunopositivity in the interstitial cells but the cytoplasm of primordial germ cells (PG cells) was clearly immunopositive. By contrast, in summer, PG cells contained little or no immunoreactivity whereas strong immunolabelling was present in the well-developed interstitial tissue. These results suggest that PG cells could retain testosterone during winter. This androgen reservoir could be involved in the control of early spermatogenesis in winter and/or to guarantee spermiogenesis and spermiation in the next spring/summer. the weak or negative immunoreaction in the summer PG cells might reflect consumption of androgen reservoir by the intense spermatogenic activity from spring to summer. Thus, besides acting as stem cells, PG cells of R. catesbeiana could exert an androgen regulatory role during seasonal spermatogenesis.