982 resultados para 1828-1863
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The aerial activities, leaps and slaps with parts of the body in the surface of water, are part of the behavioral repertoire of several species of cetaceans. Among them, the spinner dolphin, Stenella longirostris, shows greater diversity in such behavior. For the spinner dolphins of Fernando de Noronha, the aerial activities are classified as vertical and horizontal, with eight patterns to be noted (tail slap, head slap, motor boating, partial leap, leap, spin, tail over head and tail over head with spin) discriminated between these categories. Such behaviors can be used as a parameter to identify behavioral changes, as well as patterns of daily and seasonal activity. In this manner, this study aimed to characterize the frequency in performance of such activity while the dolphins were within the Dolphin Bay of Fernando de Noronha, and verify possible daily and seasonal hourly fluctuations on such behaviors. The data analyzed in this study was acquired during the period of January 2006 through December 2010, totaling 1431 days of observation from land set point, with 113027 aerial activities registered, daily average of 72,27 (SD=96,10). During 5478h and 54 min of observation the horizontal aerial activity was the most observed and rotation was the most executed pattern. Greater frequency of execution of aerial activity was observed in adults, but for both adults and calves, was observed a predominance of horizontal activities, with spin being the pattern most executed. Positive correlation was observed between the amount of aerial activity performed and the number of animals inside the Bay. Hourly daily fluctuation was observed in the expression of aerial activities by spinner dolphins, and was observed a peak of activity between 8h and 8h59min for the overall frequency relative of aerial activities, as well as for the categories and patterns. Seasonal differences were observed between the rainy and dry season with the greater amount of activity being observed during the rainy season. Nevertheless, the same profile of frequency relative of aerial activity was observed in both seasons with the peak amount being during the same period. When discriminated the aerial activities in categories and patterns, for both seasons, there was a similar pattern of hourly fluctuation; for most of parameters, higher frequency relative of execution of aerial activity remain between 8h and 8h59min
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Taeniophallus brevirostris is a dipsadid snake widely distributed in Amazon. Here we report a new Brazilian state record for the species, improving our knowledge of its geographic distribution. 0n 15 May of 2008, one female specimen was collected do Serra do Santo Expediot, Aripuana municipality, state of Mato Grosso, Brazil. This is the first record of this species for the state of Mato Grosso and extends its distribution ca. 300 kilometers from the nearest localities presented in literature.
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The juvenile development of Callinectes ornatus was studied from megalopae collected in the neuston off Ubatuba, São Paulo State, Brazil. The animals were raised in the laboratory under constant temperature (25 +/- 1 degrees C), filtered sea water (35 parts per thousand) from the sampling location, and the natural photoperiod. Eleven stages of the juvenile phase were obtained. The main features of the first juvenile stage diagnostic of the species are: the number of segments in the antenna; number of setae on the exopod, endopod, basal endite and coxal endite of the maxilla, on the exopod, endopod, basal endite, coxal endite and epipod of the 1(st) maxilliped, and on the exopod, endopod and epipod of the 2(nd) maxilliped. Sexual dimorphism becomes apparent from the fourth juvenile stage onwards.
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The male genitalia of Pseudopolybia vespiceps are described and compared to congeners. Characters of the male genitalia are combined with morphological characters of the females and nests and used in a phylogenetic analysis. The single cladogram resulting supports monophyly of the genus Pseudopolybia and interrelationships among the species as: P. langi + (P. difficilis + (P. compressa + P. vespiceps)). A new, illustrated identification key is presented.
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The objective of the present study was to characterize the fecundity of Callinectes ornatus from the northern coast of São Paulo, Brazil. To study the fecundity and its relationships to size, brood weight, and egg size, the ovigerous females were collected at 2-month intervals for two consecutive years (January, 1991 to November, 1992) in the Ubatuba region using a fishing boat equipped with an otter-trawl type of net. After collecting, the animals were screened, bagged, labeled, and stored frozen. Only data from 38 females carrying early stage eggs were considered. In the laboratory, the specimens were thawed at room temperature, the pleopod structure with the egg mass was removed and the eggs were carefully removed from the pleopods. The samples were then fixed in 10% formalin and stored in 70% ethanol, until the time for processing. Processing followed the method of Hines (1982, 1988). Following the frequency determination of carapace width and fecundity, mean egg number, mean volume and mean dry weight of brooded egg mass were determined for each class obtained. Data were analyzed by regressions of log-log transformations for allometric plots (Y = aX(b)) of reproductive variables versus carapace width. Carapace width was one of the main factors for the determination of fecundity, which ranged 171 570 +/- 94 634 eggs, with females of the same size class presenting a wide amplitude of variation. This supports the hypothesis that portunid females present staggered spawning, possibly presenting more than one period of reproduction within one year. The present species showed lower fecundity than the remaining portunids studied, but they did show a rapid and efficient embryonic development, presumably capable of assuring reproductive success.
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The locomotory and feeding activity rhythms of Callinectes ornatus Ordway, 1863 and Callinectes danae Smith, 1869 were examined under laboratory conditions. Light significantly influenced the activity of these organisms. However, activity in both species was affected by the presence of food, independently of photoperiod regime.
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Population structure and reproductive season of the portunid crab Callinectes ornatus were studied in animals collected from the Ubatuba bays, Sao Paulo, Brazil (23°20' to 23°35' S and 44°50' to 45°14' W). The samples were taken in three trawls performed every other month from January 1991 to May 1993. A total of 3,829 specimens of C. ornatus were obtained. Their size ranged from 9.3 to 84.6 mm (carapace width). Their median size based on their cephalothoracic width and their size frequency were determined as well. Their reproduction was continuous, with variable proportions of ovigerous females. The highest incidence of ovigerous females occurred in January 1991, 1992 and 1993 and March and November 1992. The oscillations of the environmental factors between the seasons are not so intense in subtropical regions, therefore allowing the continuity of the physiological process of growth and reproduction throughout the year.
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The feeding activity along the day cycle and the time consumed for extracellular digestion were evaluated in the portunids C. ornatus and C. danae. Swimming crabs were obtained from trawling in Ubatuba bay, São Paulo, Brazil, during both the rainy and dry seasons. In each season, daily scheduled samples were taken at dawn (±6 h), noon (±12 h), dusk (±18 h) and midnight (±24 h). All individuals were dissected and the degree of stomach replenishment was recorded. In order to estimate the time elapsed for extracellular digestion, crabs were fed, and groups were dissected at 30 min intervals to check the conditions of their stomachs. In general, both species show a higher feeding activity during periods of lower light intensity, as evidenced by an increased percentage of full stomachs in dusk and midnight samples. The obtained results support higher feeding activity at night in these species and indicate short time for extracellular digestion, not exceeding 8 h. Nevertheless, full stomachs were recorded in all sampling schedules. In this case, it should be considered that elimination of certain food items such as fish bones, mollusk shells and carapace fragments of crustaceans could take more time than other items. Additionally, some crab species could require a cycle of cell replacement in the midgut gland epithelium until they can take their next meal.
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Distribution patterns of most of the 20 Neotropical freshwater turtles belonging to the family Chelidae are usually based on few locality records. We here report on vouchered records of three species of the chelid genus Mesoclemmys in the Brazilian state of Mato Grosso. Presence of M. vanderhaegei is confirmed for the Amazon River Basin, and M. gibba and M. raniceps are recorded in Mato Grosso for the first time. © 2012 Check List and Authors.
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The ultrastructure of the sperm of the gecarcinid land crab Cardisoma guanhumi is described by scanning and transmission electron microscopy. Ultrastructural sperm morphology lends support for the monophyletic origin of the Thoracotremata, and for the placement of C. guanhumi in that clade. Additionally, it further attests the low level of variability within the thoracotreme clade. With regard to ultrastructural morphology, small differences concerning the apical button, the hyaline periopercular rim, the inner acrosome zone, and the outer two lamellations in the outer acrosome zone have been found between the spermatozoa of C. guanhumi and Cardisoma carnifex, the only other species in this genus studied for spermatozoal morphology. Copyright © 2013 Taylor & Francis.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em História - FCHS