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61.
Numerous phenological studies on spiders belonging to the families Oxyopidae, Thomisidae, Lycosidae, Selenopidae (e.g. Selenops cocheleti) and Salticidae (e.g. Psecas chapoda and Psecas viridipurpureus) have been conducted in the neotropical region. However, studies that simultaneously compare population dynamics and age structure in populations of sympatric species are limited, especially in Oxyopidae. The population dynamics and phenology of two congeneric lynx spider (Peucetia rubrolineata and Peucetia flava) were examined in southeastern Brazil. Several characteristics of the age structure were compared between the two spider species. The variation in the total abundance of individuals and age structure and their relationship with climatic variables were similar between the two spiders. Adults of these spiders were present mainly in spring, indicating an annual reproductive cycle and a ‘stenochronous spring’ phenological pattern. The recruitment of spiders occurred in summer for P. rubrolineata and P. flava, followed by successive phenological peaks at all stages of development. Rainfall and temperature had a positive correlation to population flux in the two spider species studied. Despite the significant climatic effects observed in the Serra do Japi, the phenological pattern of the population in this study was not always repeated in other species of spiders (e.g. Selenops cocheleti).  相似文献   
62.
利用来自欧洲中期天气预报中心(ECMWF——European Centre for Medium-Range Weather Forecasts)的长时间序列、高精度的ERA-40海表10 m风场资料,对北大西洋海域海表风场的季节特征、长期变化趋势进行深入研究,研究发现:(1)北大西洋海域的海表风速等值线在各季均大致呈东西带状分布,且由高纬度向赤道表现出高—低—高—低的分布特征。MAM和SON期间海表风速的分布特征较为相似,大值中心分布于北半球西风带海域;DJF期间的海表风速为全年最大;JJA期间的海表风速为全年最小。加勒比海海域常年存在一风速的相对大值中心。从多年平均来看,风速存在一明显的、范围较广的大值区:西风带海域,加勒比海也存在一范围较小的大风区。(2)1958年至2001年期间,北大西洋海域的海表风速以0.0049 m.s-1.a-1的速度显著性逐年线性递增。(3)北大西洋海表风速的变化趋势表现出较大的区域性差异:呈显著性逐年线性递增的区域主要分布于30°N以下的低纬度海域,变化趋势在0.01~0.025 m.s-1.a-1左右,西班牙东北部近海的递增趋势最为强劲,达到0.035 m.s-1.a-1以上,墨西哥湾和加勒比海则呈显著性逐年线性递减,趋势为-0.015 m.s-1.a-1左右,其余海域的海表风速无显著变化趋势。(4)近44年期间,北大西洋海域的海表风速存在明显的突变现象,突变期为1972年前后。  相似文献   
63.
The genera Cratera Carbayo et al., 2013 and Obama Carbayo et al., 2013, belonging to the subfamily Geoplaninae, were recently proposed to encompass some of the species that belonged to the genus Geoplana Stimpson, 1857. Herein we describe two new species of Geoplaninae, occurring in areas of ombrophilous forest which belong to the southern portion of the Brazilian Atlantic Rain Forest. The species are sympatric in their type-locality. In general, both new species herein described match the diagnostic characteristics of their genera. However, some of these features are noteworthy when characters of the new species are taken into consideration, especially the pattern of the sensory pits and the morphology of the prostatic vesicle. Both species are differentiated from their congeners by a combination of morphological characteristics, corroborated by phylogenetic analyses of the cytochrome c oxidase subunit I gene, using maximum likelihood and Bayesian inference, as well as the Automatic Barcode Gap tool.  相似文献   
64.
The purpose of this study was to determine the shell occupation pattern of Pagurus exilis using the percentage of shell types that were occupied and the morphometric relationship between hermits and occupied shells. Specimens were collected monthly from July 2001 to June 2003. A total of 1737 individuals were collected, occupying 19 gastropod shell species. Buccinanops gradatum (82%) was the most occupied shell, followed by Natica isabelleana (6.4%), Stramonita haemastoma (3.2%), and Cymatium parthenopeum (2.2%). There was a differential shell utilization pattern between sexes; males occupied larger and heavier shells while the non‐ovigerous females occupied the lightest ones. Pagurus exilis occupied more bare shells instead of incrusted ones. Buccinanops gradatum was the most occupied shell species as a function of its availability in the survey, and this occupation is strongly associated with the higher internal volume presented by these shells.  相似文献   
65.
Although the genus Halecium is easy to recognize, identifications at the species level are often difficult, this even for quite common and supposedly well‐known species of the north‐eastern Atlantic. This paper revises and re‐describes some Halecium species which resemble each other closely and which are not easy to distinguish. Additional information on a few rare species is also provided. The study is based on material collected from the North Atlantic, Mediterranean, South Africa, and New Zealand. Halecium scutum Clark, is recognized as a valid species and distinct from both H. beanii and H. halecinum; colony form and microscopic characters allow a distinction. The pinnate colony form of H. halecinum is a characteristic trait, but not all colonies show this growth form. Halecium beanii can occur in monosiphonic and polysiphonic colonies. Monosiphonic colonies of H. beanii have probably been misidentified by some authors as H. lankesterii. The differences of H. lankesteri to H. beanii and H. petrosum are discussed. The South African population of the reportedly cosmopolitan H. beanii has distinct gonothecae and could belong to a separate species. The Mediterranean Halecium mediterraneum is hardly distinguishable from the New Zealandic H. delicatulum, but it is kept separate mainly for biogeographic reasons. The rare Mediterranean Halecium banyulense is re‐described based on a second find from Naples. The male gonothecae of Halecium corrugatissimum are described for the first time.  相似文献   
66.
《Journal of Natural History》2012,46(18):1483-1489
A new species of the genus Atlantistylis Reyss, (Diastylidae) is described from the Atlantic Frontier Margin (North‐East Atlantic). This is the first record of the genus Atlantistylis from the North Atlantic. The new species Atlantistylis borealis can be recognized by the presence of spines on the frontal and lateral lobes of the carapace combined with their absence on the pereon and pleon; the first pereopods are very long. The small telson with two small apical acuminate setae and the absence of pleopods in the male are characteristic of the genus.  相似文献   
67.
68.
《Journal of Natural History》2012,46(19-20):1181-1198
The vocal repertoire is a tool that can be used to support systematics, conservation, ecology and behavioural studies. We characterize the acoustic parameters of the vocal repertoire of the white-bibbed antbird (Myrmeciza loricata) and describe the possible functions of each vocalization. The male’s song is related to territorial defence, and we found three calls in the repertoire. Call I is an alarm call, and call II is used for mutual recognition and remaining in contact with one another. Call III was emitted when the animals were foraging and when the individuals of the couple were very near to each other. Males and females sing as a duet, and their songs were individually distinct. The duet is possibly related to maintaining the pair bond, synchronizing breeding and warning potential intruders of the mated condition of the pair. This work is the first to describe the vocal repertoire of the white-bibbed antbird.  相似文献   
69.
《Journal of Natural History》2012,46(35-36):2245-2256
Itapotihyla langsdorffii is a large “casque-headed” treefrog (Hylidae: Lophiohylini) found along most of the Brazilian Atlantic Forest biome. We studied some aspects of the ecology of a population of I. langsdorffii from the Estação Biológica de Santa Lúcia, in Espírito Santo State, southeastern Brazil. Itapotihyla langsdorffii shows considerable sexual size dimorphism, with females (mean snout-vent length 103 mm) being significantly larger than males (mean snout-vent length 81 mm). This species is an explosive breeder with a generalized reproductive mode and has a mean brood size of over 6000 eggs. It feeds on few, large prey, with orthopterans being the dominant items in the diet, though even smaller frogs may occasionally be preyed upon. We discuss our data, making comparisons with other Neotropical hylids, with emphasis on other species in the Tribe Lophiohylini.  相似文献   
70.
《Journal of Natural History》2012,46(17-18):1021-1034
The reproductive phenology and guild of the floral visitors of Canistropsis microps in an Atlantic Forest area in Ilha Grande, RJ were studied for 4 years. The rates of flowering, fruiting and mortality were related to air temperature, rainfall and photoperiod. To register the flower visitors, observations were carried out for 5 days in each reproductive season. The flowering and fruiting occurred in the rainy season and were positively related to the studied climatic variables, whereas the highest mortality rates occurred in the dry season and were negatively related to the climatic variables. The guild of floral visitors of C. microps was composed of Hymenoptera, characterizing the species as a melittophilous plant. These results indicate that the rainy season presents more favourable conditions for investment in sexual reproduction, besides being the period in which potential pollinators have larger population densities and a longer period of activity.  相似文献   
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