282 resultados para Apiomithrax violaceus


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Apiomithrax violaceus (A. Milne Edwards, 1868 ) is a pisid majoid crab occurring in tropical and subtropical coastal waters of the eastern and western South Atlantic. Larval development consists of two zoeal stages and a megalopa. Beginning with the first zoea, the duration of each larval stage at 24degreesC was 3-8 (5+/-1), 3-5 (4+/-0.5) and 9-15 (11+/-2) days, the megalopa and first crab instar appearing 9-11 (10+/-1) and 20-27 (23+/-2) days after hatching, respectively. Larval characters agree with those proposed for the Majoidea, in having nine or more setae on the scaphognathite in the first zoea and well-developed pleopods in the second zoea. However, larvae of A . violaceus do not fit larval pisid features. Zoeal stages differ from most other Pisidae in having lateral spines, a long rostral spine extending beyond the antenna, two spines per telson fork and a dorsolateral process on the third abdominal somite. The megalopa differs in having a spine dorsally on the carapace and on the basial segment of the second pereiopod. Two characters that are potentially unique to Apiomithrax include a zoeal antenna with an exopod that is much longer than the protopod, and a rostral spine that is longer than the dorsal spine. These characters should facilitate the identification of this taxon and could also be useful for phylogenetic studies. A review of larvae of 28 species among 14 genera indicated that there is no apparent single larval character that differentiates the Pisidae, with more limited phylogenetic analyses suggesting that this is a paraphyletic group. Apiomithrax , Eurynolambrus , Pisoides , Rochinia and Scyra have the most divergent morphological characters within the family. The analysis and inclusion of additional taxa is likely to shed more light on the sister-group relationships of the Pisidae. However, based on the extent of morphological interspecific variability of known larvae it is likely that the group, as presently defined by adult morphology, is not monophyletic.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

无类囊体蓝藻Gloeobacter violaceus的细胞有厚胶质鞘包裹并形成群体,难以进行遗传操作.用注射器反复吸打的方法将胶质鞘剥落,得到大量单个细胞,通过接合转移将外源广宿主质粒pKT210转入G.violaceus.用斑点杂交方法以及对质粒进行酶切图谱分析,均证实外源质粒pKT210确已导入G.violaceus并稳定复制,未发生结构上的变化.从G.violaceus提取的pKT210可转化mcr和mrr基因缺陷的大肠杆菌DH10B却不能转化mcr+mrr+菌株DH5α,表明G.vio-lace

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Gloeobacter violaceus, a cyanobacterium lack of thylakoids, is refractory to genetic manipulations because its cells are enveloped by a thick gelatinous sheath and in colonial form. In this study, a large number of single cells were obtained by repeated pumping with a syringe with the gelatinous sheath removed. And an exogenous broad host range plasmid pKT210 was conjugatively transferred into G. violaceus. Analyses with dot-blot hybridization and restriction mapping showed that the exogenous plasmid pKT210 had been introduced into G. violaceus and stably maintained with no alteration in its structure. pKT210 extracted from G. violaceus exconjugants could be transformed into the mcr - mrr - E. coli strain DH10B but not the mcr(+) mrr(+) strain DH5alpha, which suggests that a methylase system may be present in G. violaceus.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Neste trabalho, os frutos e sementes de P. violaceus foram descritos morfoanatômica e ontogeneticamente, visando a verificar a origem da ala pericárpica e checar a ocorrência de poliembrionia, previamente descrita para outros gêneros da tribo Dalbergieae. Observouse que o fruto é uma sâmara circular, de aspecto glabro e que a semente possui alguns caracteres típicos de Faboideae, especialmente os relacionados ao hilo. Foram caracterizados atomicamente seis estádios de desenvolvimento. A ala pericárpica origina-se da parede ovariana, por extensões dorso-ventral, apical e basal, produzindo uma estrutura achatada. Não foi possível encontrar poliembrionia, mesmo analisando-se grande número de sementes. Pôde-se também concluir que, no que se refere à estrutura do fruto, P. violaceus é filogeneticamente derivada com relação às outras espécies de Dalbergieae já registradas na literatura, devido à presença de fusão dos feixes ventrais do carpelo.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Adult male Satin Bowerbirds build and decorate stick bowers to which they attract females for matings; females choose among males based on these complex bowers, decorations placed at these bowers, and displays consisting of vocalisations and posturing. Male Satin Bowerbirds undergo an extended period of delayed morphological maturation during which they retain female-like plumage and are assumed to learn adult male behavioural traits. Little is known, however, of how immature males acquire the ability to display and build and decorate bowers, except that they observe the displays of adult males at adults' bowers, and practise their own displays at both adults' and 'practice' bowers. We present data on the home ranges and movement patterns of six immature males, acquired through radio-tracking at the Bunya Mountains in south-east Queensland. Home-range size averaged 13.67 +/- 3.38 ha and immature males visited only some of the bowers located in their home ranges. On average, they visited 2.33 +/- 0.52 adults' bowers and 4.00 +/- 2.00 practice bowers.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Geographic variation in the advertisement call of the male Satin Bowerbird, Ptilonorhynchus violaceus, was investigated in three populations in south-eastern Queensland. The call was found to differ significantly among the three geographically distinct populations. A discriminant function analysis using five measurements of call frequency and duration provided 100% classification success of the 25 individuals. The observed geographic variation in this call may result from adaptation to the local acoustic environment in these populations, or from genetic or cultural divergence among populations. Further research involving the acoustic properties of the habitats, population genetics and a larger number of populations is required to fully understand this pattern of call variation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We isolated 13 polymorphic microsatellite markers from the satin bowerbird, Ptilonorhynchus violaceus from a genomic library enriched in (AAGG)(n) repetitive elements and characterized them in 20 individuals. The number of alleles ranged from two to 18 per locus with the observed heterozygosity ranging from 0.15 to 1.00. These markers will be useful for analysing questions concerning parentage, population genetic structure and models of speciation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Australian wet forests have undergone a contraction in range since the mid-Tertiary, resulting in a fragmented distribution along the east Australian coast incorporating several biogeographical barriers. Variation in mitochondrial DNA and morphology within the satin bowerbird was used to examine biogeographical structure throughout almost the entire geographical extent of these wet forest fragments. We used several genetic analysis techniques, nested clade and barrier analyses, that use patterns inherent in the data to describe the spatial structuring. We also examined the validity of the two previously described satin bowerbird subspecies that are separated by well-defined biogeographical barriers and tested existing hypotheses that propose divergence occurs within each subspecies across two other barriers, the Black Mountain corridor and the Hunter Valley. Our data showed that the two subspecies were genetically and morphologically divergent. The northern subspecies, found in the Wet Tropics region of Queensland, showed little divergence across the Black Mountain corridor, a barrier found to be significant in other Wet Tropics species. Biogeographical structure was found through southeastern Australia; three geographically isolated populations showed genetic differentiation, although minimal divergence was found across the proposed Hunter Valley barrier. A novel barrier was found separating inland and coastal populations in southern New South Wales. Little morphological divergence was observed within subspecies, bar a trend for birds to be larger in the more southerly parts of the species' range. The results from both novel and well-established genetic analyses were similar, providing greater confidence in the conclusions about spatial divergence and supporting the validity of these new techniques.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Geographic variation in vocalizations is widespread in passerine birds, but its origins and maintenance remain unclear. One hypothesis to explain this variation is that it is associated with geographic isolation among populations and therefore should follow a vicariant pattern similar to that typically found in neutral genetic markers. Alternatively, if environmental selection strongly influences vocalizations, then genetic divergence and vocal divergence may be disassociated. This study compared genetic divergence derived from 11 microsatellite markers with a metric of phenotypic divergence derived from male bower advertisement calls. Data were obtained from 16 populations throughout the entire distribution of the satin bowerbird, an Australian wet-forest-restricted passerine. There was no relationship between call divergence and genetic divergence, similar to most other studies on birds with learned vocalizations. Genetic divergence followed a vicariant model of evolution, with the differentiation of isolated populations and isolation-by-distance among continuous populations. Previous work on Ptilonorhynchus violaceus has shown that advertisement call structure is strongly influenced by the acoustic environment of different habitats. Divergence in vocalizations among genetically related populations in different habitats indicates that satin bowerbirds match their vocalizations to the environment in which they live, despite the homogenizing influence of gene flow. In combination with convergence of vocalizations among genetically divergent populations occurring in the same habitat, this shows the overriding importance that habitat-related selection can have on the establishment and maintenance of variation in vocalizations.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Satin bowerbirds Ptilonorhynchus violaceus have an elaborate multi-component sexual display, some components of which have been extensively studied. We describe a relatively unstudied component of this display, bower painting, and birds' responses to manipulations of their paint. Males of this species focus their display around a stick bower constructed on the forest floor which they decorate with a variety of objects and paint. Painting involves a male masticating plant material and wiping the plant-saliva mixture onto the inside walls of the bower; during courtship visits to bowers, females nibble at this paint. We found that 93% of 53 males painted their bowers at our study site and the time males spent painting their bowers accounted for 24% of their time at the bower. We experimentally removed and added paint to bowers to test whether males respond to these changes in their paint. Males gave more advertisement calls and spent less time manipulating sticks at the bower when we added fresh wet paint to their bowers compared to older dried paint or a control treatment. They did not respond to the removal of paint from their bowers, perhaps because it was primarily older dried paint that was removed. We also found that males painted more frequently when there was measurable wind in their bowers, which could have degraded the quality of the signal. Our findings indicate that fresh wet paint is more important to males than older dried paint and, together with previous work at this site, suggest that paint may act as a signal to females. Given that females nibble bower sticks during courtship, we suggest that bower paint may function as a chemical sexual signal rather than a visual signal.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Male Satin Bowerbirds (Ptilonorhynchus violaceus) build stick structures known as bowers that serve as the focus for courtships and matings. Males decorate their bowers with numerous coloured decorations and are known to steal these decorations from one another. We investigated the stealing of bower decorations among males at the Bunya Mountains in Queensland, Australia. We aimed to (1) determine which classes of decorations were targets for theft in the studied population, and (2) examine whether the frequency at which individual decorations were stolen related to their intrinsic properties. To address our first aim, all decorations on the bowers of 21 adult males were labelled and their movements tracked throughout one mating season. To address our second aim, decorations stolen at least three times during the season were collected and their morphological and reflectance properties compared to those of decorations that were not stolen. In terms of the classes of decorations, tail feathers of Crimson Rosella (Platycercus elegans) were stolen more than any other class of decoration, but blue plastic bottletops were the most popular decorations relative to their availability on bowers. Frequently stolen individual decorations were similar to non-stolen items in their weights and surface areas, but were darker blue in colour than the decorations never stolen. Both bottletops and feathers reflected higher levels of ultraviolet (UV) light than did all other classes of bower decorations tested, thus suggesting that males may be using UV reflectance in sexual signalling. The darker blue, stolen decorations may increase contrast between the decoration collection and the platform, while the UV-reflecting subset of most frequently stolen decorations (bottletops and feathers) may increase contrast within the decoration collection. This in turn may increase the attractiveness of the display to females.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A survey of the marine gastropod genus Conus Linnaeus was conducted along the TamilNadu Coast of India to explore the regional geographic distribution and diversity. The 60 species observed increased the number of Indian Conidae from 77 to 81. Conus imperialis Linne, C. mitratus Hwass in Bruguiere, C. striolatus Kiener and C. violaceus Gmelin are newly recorded from the study area. Conus amadis Gmelin was the most widely distributed species. The highest diversity (48 species) occurred in the Gulf of Mannar, followed by 22 species from northern, six from southern, and five from the Palk Bay regions. We suggest that the rich diversity recorded in the Gulf of Mannar reflects the physical conditions, microhabitats and required resources such as food and shelter that favour the occurrence of the large number of Conus species.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

木材腐朽菌是生物多样性的重要组成部分,在森林生态系统中起着关键的降解还原作用;同时,木材腐朽菌还是重要的生物资源,与人类的生产与生活密切相关,具有重要的经济价值。因此,木腐菌一直是真菌研究的重点领域之一,然而过去对华东地区木腐菌的研究还非常薄弱,对华东地区木腐菌的种类和资源还缺乏清晰的认识。本文对华东地区不同森林生态类型中的木腐菌进行了广泛的调查采样,通过形态学、分子系统学和单孢融合交配实验,对华东地区的木腐菌多样性与资源进行了系统的研究,同时对具有重要经济意义和潜在应用价值的种类进行了菌种的分离保藏,并初步分析了华东地区木腐菌的区系特点。通过本论文的研究,提高了对华东地区木腐菌资源与多样性的认识,丰富了我国木材腐朽菌的种类,为控制林木病原菌、开发利用有益真菌资源提供了基本信息和科学依据。本论文的主要研究结论如下: 1.华东地区的木腐菌有3目13科92属270种,其中真菌新种6个,分别是:铁杉集毛孔菌Coltricia tsugicola Y.C. Dai & B.K. Cui,香榧嗜蓝孢孔菌Fomitiporia torreyae Y.C. Dai & B.K. Cui,拟囊状体大孔菌Megasporoporia cystidiolophora B.K. Cui & Y.C. Dai,菌索多年卧孔菌Perenniporia rhizomorpha B.K. Cui, Y.C. Dai & Decock,微小硬孔菌Rigidoporus minutus B.K. Cui & Y.C. Dai,浅黄芮氏孔菌Wrightoporia luteola B.K. Cui & Y.C. Dai;中国新记录种9个,分别是:紫多孢孔菌Abundisporus violaceus (Wakef.) Ryvarden,卡玛蜡孔菌Ceriporia camaresiana (Bourdot & Galzin) Bondartsev & Singer,撕裂蜡孔菌Ceriporia lacerata N. Maek., Suhara & R. Kondo,塔斯马尼亚集毛孔菌Coltriciella tasmanica (Cleland & Rodway) D.A. Reid,瑞克纤孔菌Inonotus rickii (Pat.) D.A. Reid,骨质多年卧孔菌Perenniporia minutissima (Yasuda) T. Hatt. & Ryvarden,灰硬孔菌Rigidoporus cinereus Núñez & Ryvarden,凹形栓孔菌Trametes ectypus (Berk. & M.A. Curtis) Gilb. & Ryvarden,变形干酪菌Tyromyces transformatus Núñez & Ryvarden。 2.利用分子系统学方法,确定了一些通过形态学研究难以鉴定或容易混淆的种类的分类地位,并对嗜蓝孢孔菌属、彩孔菌属和多年卧孔菌属进行了系统发育分析,发现木腐菌新种3个:Fomitiporia sp.、Hapalopilus sp. 和Perenniporia sp.。 3.华东地区的异担子菌为岛生异担子菌,并且存在两个生物种:T生物种和Y生物种。T生物种为腐生菌,Y生物种为兼性腐生菌,华东地区不存在多年异担子菌这一严重的森林病原菌。 4.华东地区的木腐菌种类丰富,组成复杂多样。优势科为多孔菌科,其次为锈革孔菌科,这两科的种类构成了华东地区木腐菌类区系的主体;优势属主要有多年卧孔菌属、多孔菌属、针层孔菌属和泊氏孔菌属。 4.华东地区木腐菌科的地理成分分为3类:热带亚热带成分,北温带成分和世界广布成分,以世界广布成分为主。属的地理成分分为5类:世界广布属,北温带分布属,热带–亚热带分布属,东亚–北美分布属,大洋洲–北温带分布属,以世界广布属和北温带分布属为主。种的地理成分分为8类:世界广布种,北温带分布成分,泛热带分布成分,亚–欧共有成分,东亚–北美共有成分,东亚–澳大利亚共有成分,东亚成分,中国特有种,以北温带分布种和世界广布种为主。 5.华东地区木腐菌的各主要区系成分均有分布,以世界广布成分和北温带成分为主,表现出明显的北温带性质,可能起源于北半球,华东地区木腐菌类的区系地理成分与其所处的地理位置、气候特点与植物区系的组成密切相关。此外,华东地区的中国特有种类也较为丰富,说明了华东地区木腐菌类的区系具有一定的独特性,也在一定程度上反映了华东地区生态环境条件的特殊性,而木腐菌的生长与环境条件和寄主树木种类有很大的关系。 6.华东地区的木腐菌资源非常丰富,林木病原菌有36种,其中新发现的病原菌有3种;野生的食用木腐菌有11种,野生的药用木腐菌64种,工业用木腐菌有28种。对其中的一种重要经济真菌——黄白多年卧孔菌进行了分离培养,找出了最佳生长条件:最适生长温度为25℃左右,相对最适pH值为5.5,相对最好的碳源为可溶性淀粉和葡萄糖,相对最好的氮源为酵母汁。