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Biologia populacional e reprodutiva e padrão de ocupação de conchas de gastrópodos por Clibanarius antillensis Stimpson, 1859 (Crustacea: Decapoda: Diogenidae) na praia de Baixa Grande (Areia Branca/RN)Moura, Nayara Gurgel de 11 March 2016 (has links)
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Previous issue date: 2016-03-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The purpose of this study was providing population biology and reproduction data
and to determine the shell utilization pattern of Clibanarius antillensis at Baixa
Grande Beach, State of Rio Grande do Norte, Brazil (4°57’22”S / 37°08’13”W), using
the percentage of the different shell type that were occupied and the morphometric
relationship between hermit crabs and occupied shells. Specimens were collected at
two-months intervals from October 2012 to August 2013, using sampling effort of two
collectors for 1 hour during spring low tides. The hermit crabs collected were
identified and had their carapace shield length measured (mm). All occupied
gastropod shells were identified and had their shell biometric parameters (aperture
width, aperture length and internal volume) measured (mm). A total of 576 individuals
ofClibanarius antillensis was obtained of which 191 were males (33.16%), 140 nonovigerous
females (24.31%), 125 intersex (21.70%) and 120 ovigerous females
(20.83%), using seven species of gastropods. Cerithium atratum and Stramonita
haemastoma were the most occupied shells, with 69.97%, and 24.31%, respectively.
The average size of male ranged from 1.43 to 9.64 mm of CEC (4.29 ± 1.56 mm); 1.6
to 6.88 mm for non ovigerous females (3.79 ± 1.18 mm); 1.42 to 8.38 mm for intersex
(3.69 ± 1.36 mm) and 2.1 to 7.27 mm for ovigerous females (3.76 ± 1.09 mm).
Sexual dimorphism was recorded by the larger average size attained by males in
relation to females (ovigerous and non-ovigerous) and intersexes. The shells of C.
atratum had higher frequency of occupation by smaller organisms, especially in the
size class 3.00 -] 4.00mm, while Stramonita haemastoma housed larger organisms,
predominantly in the size class 4,00--] 5.00mm. There were differences in the pattern
of occupation by males, not ovigerous females, intersex and ovigerous females.
Males were significantly higher than the other categories. The size difference strongly
influenced the shell utilization pattern, principaly in S. haemastoma, which has the
largest Shell volume, being preffered by males. The other categories have occupied
most significantly shells of C. atratum due to small size and lower width of the
apperture width and length of the shells. Annual size-frequency distirbutions were
unimodal, with non-normal distribution. The overall sex ratio was 1: 1.36 (M: F) and
did not differ significantly from the expected sex ratio of 1: 1. Ovigerous females were
present in all year-round. The fecundity of the studied population was of 178.14, with
an average number of eggs of 178.14 ± 85.61 ranging from 51 eggs (CEC = 3.21
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mm) to 325 eggs (CEC = 6.77 mm), being much smaller than that of subtropical
popultions of this species. The regression analysis shows that the number of eggs
increase linearly with the increase of crabs shield lenght and internal volume of
shells. Regression analysis showed a positive correlation between the dimensions of
hermit crabs and the utilized shells. In this study, occupation by C. antillensis varied
as a function of shell morphometric charactistic, with intraspecific differences in
occupation partterns also occuring at Baixa Grande Beach / O objetivo desse estudo foi fornecer dados populacionais e reprodutivos da espécie
de caranguejo-eremita Clibanarius antillensis Stimpson, 1859, e definir sua
preferência na ocupação de conchas de gastrópodos nos recifes de arenito, da praia
de Baixa Grande, Areia Branca, Rio Grande do Norte (4°57’22”S / 37°08’13”W). As
coletas foram realizadas a cada dois meses, de outubro de 2012 a agosto de 2013,
utilizando esforço amostral de dois coletores por hora durante as marés baixas de
sizígia. Os caranguejos-eremitas foram coletados manualmente e, em laboratório, as
conchas dos moluscos e os exemplares de anomuros foram identificados e medidos.
Um total de 576 indivíduos foram coletados, sendo 191 machos (33,16%), 140
fêmeas não ovígeras (24,31%), 125 intersexos (21,70%) e 120 fêmeas ovígeras
(20,83%), ocupando 7 espécies de gastrópodos, sendo Cerithium atratum a mais
ocupada (69,97%), seguida de Stramonita haemastoma (24,31%), Pisania pusio
(1,22 %), Leucozonia nassa (3,47%), Tegula viridula (0,52%), Anachis obesa
(0,35%) e Olivella minuta (0,17%). O tamanho médio dos indivíduos machos variou
de 1,43 a 9,64 mm de CEC (média de 4,29 1,56 mm); de 1,6 a 6,88 mm de CEC
para as fêmeas não ovígeras (3,79 1,18 mm); de 1,42 a 8,38 mm de CEC para os
intersexos (3,69 1,36 mm) e de 2,1 a 7,27 mm de CEC para as fêmeas ovígeras
(3,76 1,09 mm). A população apresentou dimorfismo sexual quanto ao tamanho,
sendo os machos significativamente maiores do que demais categorias. Os machos
ocorreram em 10 classes de tamanho, os intersexos em nove enquanto as fêmeas
(ovígeras e não-ovígeras) ocorrem em apenas seis classes. Houve diferença
também no padrão de ocupação de conchas. As conchas de S. haemastoma foram
preferidas por machos, devido às maiores dimensões de comprimento e largura da
abertura da concha, e espaço internodessas conchas. As demais categorias
ocuparam mais significativamente conchas de C. atratum, devido ao seu tamanho
reduzido e medidas da abertura de concha menores, promovendo maior proteção
contra estresses ambientais e bióticos. As conchas de C. atratum tiveram maior
frequência de ocupação por organismos menores, principalmente na classe de
tamanho 3,00--]4,00 mm, enquanto S. haemastoma abrigou organismos maiores,
com predominância na classe de tamanho 4,00--]5,00 mm. A distribuição da
população nas classes de tamanho foi unimodal, com distribuição não normal (KS =
0,15; p <0,001), o que reflete um recrutamento contínuo ao longo do ano. A razão
xiv
sexual total foi de 1: 1,36 (M:F) e não diferiu significativamente da razão sexual
esperada de 1:1. As fêmeas ovígeras estiveram presentes em todos os meses
amostrados. O índice de fecundidade média foi de 178,14, com número médio de
ovos de 178,14 85,61 variando de 51 ovos (CEC = 3,21 mm) a 325 ovos (CEC =
6,77 mm). Existe uma correlação positiva entre o tamanho do escudo cefalotorácico
e do volume interno da concha com o número de ovos, sendo que a primeira é a que
mais explica a variação na quantidade de ovos.Ao analisar as medidas do
comprimento da abertura, largura da abertura e volume interno das conchas elas
mostraram uma correlação positiva com o tamanho dos caranguejos-eremitas / 2017-03-23
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Kompatibilita vozidel při čelním střetu / Compatibility of Vehicles in a Frontal CollisionVašíček, Jiří January 2013 (has links)
Thesis deals with the compatibility of vehicles in a frontal collision. The first section discusses about compatibility from different views. There are the physical processes used in the mechanics of impact. The second part is focused on solving the compatibility of vehicles in a frontal collision by crash analysis using the finite element method. Firstly there are described collisions of vehicles from different vehicle classes (small cars, lower middle class, Pick up / SUV) into the fixed barrier by the US NCAP. Furthermore there are simulated head-on collisions of vehicles from different vehicle classes. In the end there is shown the possibility of using data from crash tests to determine the EES.
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