1000 resultados para Zoologia
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The first record of Argyrodiaptomus bergi (Richard, 1897) from a small roadside pool at high altitude in the southern region of Brazil is presented. This is the ninth record of this species in South America (previously known from Argentina and Uruguay) since its original description, and a new occurrence after 36 years, extending its known distribution to the northeast. The environments where this species was found differ sharply, and possible explanations include the loss of habitat, high species selectivity or deficient sampling efforts. An additional description is provided, with scanning electron microscopy (SEM) photomicrographs and line drawings. Similarly to other species of Argyrodiaptomus, such as Argyrodiaptomus falcifer (Daday, 1905), Argyrodiaptomus denticulatus (Pesta, 1927) and Argyrodiaptomus granulosus (Brehm, 1933), this species shows a restricted distribution in the lower stretches of the Paraná and Uruguay rivers, particularly in small pools. The importance of better understanding the dynamics and diversity of small water bodies is discussed.
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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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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Thoropa megatympanum, sp. n., is described from the Serra do Cipó, Minas Gerais, Southeastern Brasil. The new species is related to T. miliaris (Spix), from which it is readily distinguished by its smaller size, broader head, larger tympanum, shorter legs, and dorsal pattern mottled. The eggs and the tadpole are also described.
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The data suggest that Polybia (Myrapetra) paulista colonies are established by means of swarm formation having the existence of an initial polygyny and a pleometrose being proved. The reproductive forms are produced once a year (at the start of the year); however, the colonies can last for two or three years. The observations evidenced that the duration of a development period is about 100 days.
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Crossodactylus bokermanni, sp. n., is described from Serra do Cipó, Minas Gerais, Southeastern Brasil. The new species is characterized by the small size (20-27 mm), slender build, long legs, narrow head, long and acuminate snout, rounded but fairly defined canthus rostralis, and small tympanum. Also, notes on its habits are made and its tadpole is described.
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The present study reveals that the excretory system of Glossoscolex paulistus is formed by open holonephridia (exonephridia). It is noticed that different zones are recognized in the nephridial canal, with defined histological and histochemical characteristics: 1) primary canal; 2) lobed canal; 3) first rounded segment; 4) afferent thin segment; 5) efferent thin segment; 6) second rounded segment; 7) ciliary tube; 8) clear canal; 9) pigmented canal; 10) intermediate canal; 11) bladder; 12) terminal canal; 13) nephridiopore. All these regions are intercellular and cilia are found in regions 1, 2, 3, 6, 7 and 13. The connections between afferent and efferent capillary of the vascular supply of the nephridium are made of capillary loops and dilatations which we call glomeruli in this paper. Filtering functions are suggested for the glomerulus. The response of the lobed canal and the first and second rounded segments to Gomori's reaction is strongly positive and this is found to coincide with the largest concentration of glomeruli in the main loops 1 and II, that suggests a higher filtration capacity for the canal and segments.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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All the larval stages of the hermit crab Pagurus brevidactylus were studied in the laboratory, with special emphasis on external morphology and on the duration of each stage. The larvae were kept in individual containers, with water of 35 salinity and fed on nauplii of Artemia salina; room temperature was maintained at 24±1ºC. The post-embryonic development includes four stages of zoea and one of megalopa. All the larval stages are drawn and described in detail.
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Twetve external morphological traits and seven traits of food-gathering behavior were studied in africanized and caucasian (A. m. caucasica), bees. Discriminant analysis showed that neither the length of the fourth segment of the abdomen, nor bee weight can be considered as the traits with the highest discriminatory power between africanized and caucasian bees, with any in-bred bees. In the case of in-bred bees the discriminam traits had a lower interorbital width and time to reach the feeder. Multivariate comparisons between the data of in-bred colonies and twenty hibrid colonies, suggest dominance of the genes group of the africanized subspecies.
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Six zoeal stages and the megalopa of the comestible crab Ucides cordatus cordatus (Linnaeus, 1763) are described and illustrated. The larvae were reared in the laboratory at temperature 25 ± 1ºC and water salinity of 24 ; duration of stages and survival rates were measured. Comparisons with the descriptions of the zoeal morphologic characters of Ocypodidae and Gecarcinidae permited to include definitively U. c. cordatus in the family Ocypodidae, subfamily Ocypodinae.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Morphology of the testicles of some brazilian species of Diplopoda and their phyllogenetic relations
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The morphology of the testicles of some Brazilian species of Diplopoda is described. One type is scalariform, with two deferent ducts and the other consists of some single deferent duct. Phyllogenetic considerations on the structure are made.