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141.
SANDRA KUPFERNAGEL HANS‐PETER RUSTERHOLZ BRUNO BAUR 《Biological journal of the Linnean Society. Linnean Society of London》2010,99(2):350-361
Mating frequency has important implications for patterns of sexual selection and sexual conflict, and hence for issues such as the maintenance of genetic diversity and speciation. We assessed the level of multiple paternity and sperm utilization patterns in four natural populations of the simultaneous hermaphrodite land snail Arianta arbustorum using four polymorphic microsatellite loci. A total of 1088 offspring from 26 wild‐caught snails were genotyped to determine the number of fathers siring each brood and paternity skew in succeeding clutches. Multiple paternity was detected in the offspring of all 26 mother snails examined with the contribution of two to six fathers. The four populations examined differed in the level of multiple paternity. Snails in the population with the highest density of adults showed the highest level of multiple paternity, whereas snails in the population with the lowest density exhibited the lowest value of multiple paternity. Highly skewed paternity patterns were found in the progeny of 15 (57.7%) of the 26 mother snails. The number and identity of fathers siring the offspring of single mothers also varied among successive clutches. Furthermore, genetic analyses indicate a low level of self‐fertilization in one of the four populations. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 350–361. 相似文献
142.
STEFANO GRIGNOLIO IVA ROSSI ELISA BERTOLOTTO BRUNO BASSANO MARCO APOLLONIO 《The Journal of wildlife management》2007,71(3):713-719
Abstract: Mammalian females change their behavior during the last stages of pregnancy and during the weaning as a response to new energetic requirements and antipredator behavior. From March 2001 to December 2004, we studied the effects of parturition and weaning on home-range sizes and habitat selection in 28 female Alpine ibex (Capra ibex) in a 1,700-ha free area in the Gran Paradiso National Park (Western Italian Alps). We calculated Kernel home range enclosing 95% of each female's locations according to seasonal and bimonthly timescales. Pregnancy did not seem to modify spatial behavior. Lactating females showed smaller home ranges than nonlactating ones after the birth period in June-July. Hot summers slowed kids' growth and prolonged maternal care, modifying mothers' behavior. In summer 2003, which was hotter and drier than usual, weaning females showed even smaller home ranges. Because of their use of antipredator tactics during the weaning season, lactating females showed a higher use of safer habitats, such as rocky slopes. Our results are consistent with the findings of previous cervid and bovid studies, and they suggest that ungulate mothers may move to suboptimal, but safer, habitats during weaning to reduce the predation risk for their offspring. 相似文献
143.
Abstract. To evaluate the vector competence of some Lutzomyia spp. (Diptera: Psychodidae) for Leishmania (Viannia) spp. (Kinetoplastida: Trypanosoma-tidae), experimental infections of anthropophilic sandflies from the Colombian Pacific coast were performed, through membrane feeding and xenodiagnosis on hamsters infected with Le.(V.)braziliensis or Le.(V.)panamensis. Wild-caught or F, generation females of Lutzomyia gomezi, Lu.hartmanni, Lu.panamensis and Lu. trapidoi were allowed to feed on hamster lesions and then maintained at 26o C and >80% r.h. on a sugar-water diet until dissection on the fifth day post-infection (p.i.).
Despite similar infection rates (range 37–44%) in both Lu.gomezi and Lu.trapidoi , infections were heavier (>100 parasites) in the latter species. Infections of Lu.trapidoi with Le.braziliensis ( n = 21) and Le.panamensis (n = 27) showed parasite migration toward the foregut, with promastigote colonization of the stomodeal valve and appearance of infective forms. In contrast, infections of Lu.gomezi with Le. braziliensis (n = 10) and Le.panamensis (n = 5) were light (<50 parasites) and usually restricted to the pylorus. In Lu.hartmanni , only a few promastigotes were found in the pylorus and midgut of 3/8 specimens infected with Le.braziliensis , and no Le.panamensis developed (n = 19). By day 5 p.i., promastigote colonization of the hind- and midgut by Le.panamensis was observed in 2/4 Lu.panamensis but not Le.braziliensis (n = 3).
It was concluded that Lu.trapidoi is a more efficient vector than Lu.gomezi for both Le.braziliensis and Le.panamensis , and that Lu.hartmanni and Lu.panamensis are of minor importance for Leishmania transmission in this endemic area. 相似文献
Despite similar infection rates (range 37–44%) in both Lu.gomezi and Lu.trapidoi , infections were heavier (>100 parasites) in the latter species. Infections of Lu.trapidoi with Le.braziliensis ( n = 21) and Le.panamensis (n = 27) showed parasite migration toward the foregut, with promastigote colonization of the stomodeal valve and appearance of infective forms. In contrast, infections of Lu.gomezi with Le. braziliensis (n = 10) and Le.panamensis (n = 5) were light (<50 parasites) and usually restricted to the pylorus. In Lu.hartmanni , only a few promastigotes were found in the pylorus and midgut of 3/8 specimens infected with Le.braziliensis , and no Le.panamensis developed (n = 19). By day 5 p.i., promastigote colonization of the hind- and midgut by Le.panamensis was observed in 2/4 Lu.panamensis but not Le.braziliensis (n = 3).
It was concluded that Lu.trapidoi is a more efficient vector than Lu.gomezi for both Le.braziliensis and Le.panamensis , and that Lu.hartmanni and Lu.panamensis are of minor importance for Leishmania transmission in this endemic area. 相似文献
144.
BATTELLI MARIA GIULIA; LORENZONI ENZO; STIRPE FIORENZO; CELLA RINO; PARISI BRUNO 《Journal of experimental botany》1984,35(6):882-889
The effect of ribosome-inactivating proteins (RIPs), eithersingle-chain or toxins, was studied on plant ribosomes. RIPsdid not affect ribosomes from their own plants, while inhibitingto a variable extent protein synthesis by heterologous plantribosomes. Ricin stimulated and PAPS inhibited the growthof carrot cells in culture. Key words: Plant ribosomes, Ribosome-inactivating proteins, Protein synthesis, Ribosome specificity, Plant cell cultures 相似文献
145.
LEDERGERBER STEPHAN; BAMINGER HELMUT; BISENBERGER AGNES; KLEEWEIN DORIS; SATTMAN HELMUT; BAUR BRUNO 《Journal of Molluscan Studies》1997,63(1):1-8
Resting-site preference and patterns of spatial distributionwere examined in the sympatric land snails Arianta arbustorumand A. chamaeleon on two opposite slopes in the south-easternAlps, Austria. The two slopes did not differ in proportion ofA. arbustorum and A. chamaeleon (74.4% vs. 25.6% on the NNE-exposedslope and 68.3% vs. 31.7% on the SSW-exposed slope). Individualsof both species showed aggregated dispersion patterns. The nearest-neighbourmethod indicated that in both species snail aggregations predominantlyconsisted either of A. arbustorum or A. chamaeleon on the NNE-exposedslope with a mosaic of rocks and distinct patches of differentplants. On the SSW-exposed slope, which was less variable invegetation cover, snail aggregations consisted of conspecificand hetero-specific individuals. Juvenile and adult A. arbustorumpreferred to rest attached to leaves of Adenostyles alliariae,but avoided rock surfaces and patches of grass on the NNE-exposedslope. In contrast, juvenile and adult A. chamaeleon preferentiallyrested on rock surfaces, and also avoided grass patches. Juvenileand adult A. chamaeleon did not differ in resting-site preference,whereas small differences in resting sites were observed betweenjuvenile and adult A. arbustorum. Differences in resting-sitepreference is one way of niche differentiation which may allowindividuals of the two Arianta species to coexist. (Received 14 March 1996; accepted 8 July 1996) 相似文献
146.
ROSALÍA AGUILAR‐MEDRANO BRUNO FRÉDÉRICH EFRAÍN DE LUNA EDUARDO F. BALART 《Biological journal of the Linnean Society. Linnean Society of London》2011,102(3):593-613
Pomacentridae are one of the most abundant fish families inhabiting reefs of tropical and temperate regions. This family, comprising 29 genera, shows a remarkable diversity of habitat preferences, feeding, and behaviours. Twenty‐four species belonging to seven genera have been reported in the Eastern Pacific region. The present study focuses on the relationship between the diet and the cephalic profile in the 24 endemic damselfishes of this region. Feeding habits were determined by means of underwater observations and the gathering of bibliographic data. Variations in cephalic profile were analyzed by means of geometric morphometrics and phylogenetic methods. The present study shows that the 24 species can be grouped into three main trophic guilds: zooplanktivores, algivores, and an intermediate group feeding on small pelagic and benthic preys. Shape variations were low within each genus except for Abudefduf. Phylogenetically adjusted regression reveals that head shape can be explained by differences in feeding habits. The morphometric phylogeny recovered the subfamily Stegastinae and the relationship between Abudefduf troschelii and Chromis species. The cephalic profile of damselfishes contains a clear and strong phylogenetic signal. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 593–613. 相似文献
147.
Capuchin monkeys (Cebus sp.) are notable among New World monkeys for their widespread use of tools. Like chimpanzees, they use both hammer tools and insertion tools in the wild to acquire food that would be unobtainable otherwise. Recent evidence indicates that capuchins transport stones to anvil sites and use the most functionally efficient stones to crack nuts. We further investigated capuchins’ assessment of functionality by testing their ability to select a tool that was appropriate for two different tool‐use tasks: A stone for a hammer task and a stick for an insertion task. To select the appropriate tools, the monkeys investigated a baited tool‐use apparatus (insertion or hammer), traveled to a location in their enclosure where they could no longer see the apparatus, made a selection between two tools (stick or stone), and then could transport the tool back to the apparatus to obtain a walnut. We incorporated tool transport and the lack of a visual cue into the design to assess willingness to transport the tools and the monkeys’ memory for the proper tool. Six brown capuchins (Cebus apella) were first trained to select and use the appropriate tool for each apparatus. Four animals completed training and were then tested by allowing them to view a baited apparatus and then travel to a location 8 m distant where they could select a tool while out of view of the apparatus. All four monkeys chose the correct tool significantly more than expected and transported the tools back to the apparatus. Results confirm capuchins’ propensity for transporting tools, demonstrate their capacity to select the functionally appropriate tool for two different tool‐use tasks, and indicate that they can retain the memory of the correct choice during a travel time of several seconds. 相似文献
148.