11 resultados para Rhipicephalus sanguineus sensu lato

em Deakin Research Online - Australia


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Based on nearly complete (1125 bp) cytochrome-b sequence data and morphological characters, two new endemic species of Miniopterus are described from Madagascar that were previously identified as M. manavi. Using phylogenetic analysis, the basal nodes of major lineages in the Malagasy members of this genus are weakly supported, while, in most cases, the branches leading to each of the clades are well resolved. Miniopterus mahafaliensis, new species, occurs in the southwestern semidesert areas and M. brachytragos, new species, has a broad distribution across the northern half of the island, ranging across several different biomes. Phylogenetic inference indicates that these two new taxa are not closely related to M. manavi sensu stricto, with average genetic distances of 9.2% and 5.7% from this taxon, respectively. On the basis of this and previous revisions, the former M. manavi complex is now recognized to represent at least five taxa, which do not form a monophyletic group with respect to one another, and represent extraordinary examples of convergent evolution. Miniopterus brachytragos is closely related to the recently named M. aelleni, while M. mahafaliensis is not closely associated with any of these species. Molecular phylogenetic analysis was imperative to resolve the species limits of these taxa and morphology then provided the means to corroborate the recovered clades. There are localities on the island, specifically limestone karstic zones, where four species of the former M. manavi sensu lato complex occur in strict sympatry. These species often use the same day-roost caves and have similar external and craniodental measurements. This raises intriguing questions as to how these animals divide their worlds with regard to dietary regimes and foraging strategies, as well as their speciation history.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Complexity is increasingly the hallmark in environmental management practices of sandy shorelines. This arises primarily from meeting growing public demands (e.g., real estate, recreation) whilst reconciling economic demands with expectations of coastal users who have modern conservation ethics. Ideally, shoreline management is underpinned by empirical data, but selecting ecologically-meaningful metrics to accurately measure the condition of systems, and the ecological effects of human activities, is a complex task. Here we construct a framework for metric selection, considering six categories of issues that authorities commonly address: erosion; habitat loss; recreation; fishing; pollution (litter and chemical contaminants); and wildlife conservation. Possible metrics were scored in terms of their ability to reflect environmental change, and against criteria that are widely used for judging the performance of ecological indicators (i.e., sensitivity, practicability, costs, and public appeal). From this analysis, four types of broadly applicable metrics that also performed very well against the indicator criteria emerged: 1.) traits of bird populations and assemblages (e.g., abundance, diversity, distributions, habitat use); 2.) breeding/reproductive performance sensu lato (especially relevant for birds and turtles nesting on beaches and in dunes, but equally applicable to invertebrates and plants); 3.) population parameters and distributions of vertebrates associated primarily with dunes and the supralittoral beach zone (traditionally focused on birds and turtles, but expandable to mammals); 4.) compound measurements of the abundance/cover/biomass of biota (plants, invertebrates, vertebrates) at both the population and assemblage level. Local constraints (i.e., the absence of birds in highly degraded urban settings or lack of dunes on bluff-backed beaches) and particular issues may require alternatives. Metrics - if selected and applied correctly - provide empirical evidence of environmental condition and change, but often do not reflect deeper environmental values per se. Yet, values remain poorly articulated for many beach systems; this calls for a comprehensive identification of environmental values and the development of targeted programs to conserve these values on sandy shorelines globally.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The ostracod species originally described as Cythere tricristata Brady, 1880 from the Admiralty Islands, Papua New Guinea, appears to belong to the SW Pacific and Australasian genus Ponticocythereis McKenzie, 1967 (sensu Warne & Whatley 1996). This interpretation is based on the presence of some posterior pointing scale-like spines on the carapace surface of this species. SEM images of the type material for Ponticocythereis tricristara n. comb., which are presented here for the first time, enable the clear differentiation of this species from the very similar Ponticocythereis ichthyoderma (Brady, 1890), Ponticocythereis quadriserialis (Brady, 1890) and Ponticocythereis laingensis (Wouters, 1981). As a consequence of the subdued manifestation of scale-like or blade-like spines on adult specimens of P. tricristata, this species closely resembles juvenile rather than adult specimens of some other Ponticocythereis species. This ontogenetic/phylogenetic relationship suggests that paedomorphic processes were significant in the Quaternary evolutionary radiation of Ponticocythereis species within tropical SW Pacific and Australasian regions.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Until recently, species of the deep-water ascophoran genus Siphonicytara have been recorded from only two areas, nearly 10,000 km apart. Three species were known from the East Indies and one from the southwest Indian Ocean. A hitherto unrecognized species is now known from the southern-most Philippine region, and six new species have recently been described from New Caledonia. A further new species from relatively shallow water, S. occidentalis, is described here from Western Australia. Examination of fossil specimens from the Tertiary of Victoria and South Australia has shown that specimens attributed to Parina clypeata Waters have a close relationship with Siphonicytara, and the species is referred here to this genus, as is Mucronella airensis Maplestone. Another Tertiary species with a similar distribution, 'Eschara elevata' Waters not Tenison Woods, is assigned to Siphonicytara irregularis (Maplestone). The stratigraphic range for the family extends from the Late Eocene to Recent. Eschara elevata Tenison Woods sensu stricto is the type species of the genus Tubitrabecularia Bassler, and a discussion of the nature and status of this genus is included. A key to the species described is given.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Corbulipora MacGillivray is redefined to include only species which occur in successive growth phases. The fossil type species, Corbulipora ornata MacGillivray, occurs in an encrusting ancestrulate phase, an erect quadriserial, ovicellate phase, and a frontally-budded partially kenozooidal phase. The encrusting ancestrulate phase of the Recent species, C tubulifera (Hincks), is the type species of the genus Acanthocella Canu and Bassler, which is a junior synonym of Corbulipora. The succeeding, ovicellate, flustrine phase, known as Watersia militaris (Waters), is the type species of Watersia, another junior synonym of Corbulipora. It produces a third bilaminar phase known as C. oriparma, a synonym of C. tubulifera. This has rhizoids and develops further flustrine phases. Fossil specimens assigned to Acanthocella tubulifera in the past are here considered to be the primary encrusting phase of a bilaminar phase, known as Corbuhpora suggerens (Waters). from which it has become separated. A thinly calcified intervening erect phase similar to the flustrine phase of C. tubulifera IS inferred to have existed but not to have been preserved as a fossil. Some species previously referred to Watersia are assigned to Klugeflustra Moyano which, like Neoflustra Lopez Gappa, has flustrine colomes with large, hyperstomial ovicells, unlike those of the family Flustridae sensu stricto. A key to species of Corbulipora and their various phases is given.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Priest Pot is an example of the abundant ponds that, collectively, contribute crucially to species diversity. Despite extensive biological study, little has been reported about the physical framework that supports its ecological richness. This article elucidates the physical character of Priest Pot’s water column and thus that of similar water bodies. Vertical thermal microstructure profiles were recorded during summer 2003 and analyzed alongside concurrent meteorological data. During summer stratification, the thermal structure appeared to be dominated by surface heat fluxes. Surface wind stress, limited by sheltering vegetation, caused turbulent overturns once a surface mixed layer was present but appeared to contribute little to setting up the thermal structure. Variations in full-depth mean stratification occurred predominantly over seasonal and ∼5-day time scales, the passage of atmospheric pressure systems being posited as the cause of the latter. In the uppermost ∼0.5 m, where the stratification varied at subdaily time scales, turbulence was active (sensu Ivey and Imberger 1991) when this layer was mixed, with dissipation values ε ∼ 10−8 m2 s−3 and vertical diffusivity KZ = 10−4 — 10−6 m2 s−1. Where the water column was stratified, turbulence was strongly damped by both buoyancy and viscosity, and KZ was an order of magnitude smaller. Vertical transport in the mixed layer occurred via many small overturns (Thorpe scale r.m.s. and maximum values were typically 0.02 m and 0.10 m, respectively), and seston were fully mixed through the water column.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Drawing on studies of humans, rodents, birds and arthropods, I show that 'cognitive maps' have been used to describe a wide variety of spatial concepts. There are, however, two main definitions. One, sensu Tolman, O'Keefe and Nadel, is that a cognitive map is a powerful memory of landmarks which allows novel short-cutting to occur. The other, sensu Gallistel, is that a cognitive map is any representation of space held by an animal. Other definitions with quite different meanings are also summarised. I argue that no animal has been conclusively shown to have a cognitive map, sensu Tolman, O'Keefe and Nadel, because simpler explanations of the crucial novel short-cutting results are invariably possible. Owing to the repeated inability of experimenters to eliminate these simpler explanations over at least 15 years, and the confusion caused by the numerous contradictory definitions of a cognitive map. I argue that the cognitive map is no longer a useful hypothesis for elucidating the spatial behaviour of animals and that use of the term should be avoided.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Species originally assigned to the pterygocytherine genus Alataleberis by McKenzie & Warne, 1986 are placed here in two genera—Alataleberis sensu stricto and Alatapacifica gen. nov. Alataleberis species possess poorly defined dorsal ridges marked by a few spines in adult specimens and lack a subcentral tubercle. Alatapacifica species possess well-developed and buttressed dorsal ridges and a well-developed subcentral tubercle. Pterygocytherine genera/species groups recognized here from the southwest Pacific region are Alataleberis, Alatapacifica (septarca and robusta species groups), Alatahermanites Whatley & Titterton, 1981 and the velivola species group of Pterygocythereis Blake, 1933.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The evolutionary relationships of the eutherian order Insectivora (Lipotyphla sensu stricto) are the subject of considerable debate. The difficulties in establishing insectivore phylogeny stem from their lack of many shared derived characteristics. The grouping is therefore something of a ‘wastebasket ’ taxon. Most of the older estimates of phylogeny, based on morphological evidence, assumed insectivore monophyly. More recently, molecular phylogenies argue strongly against monophyly, although they differ in the extent of polyphyly inferred for the order. I review the history of insectivore phylogenetics and systematics, focussing on the relationships between the six extant families (Erinaceidae – hedgehogs and moonrats, Talpidae – moles and desmans, Soricidae – shrews, Solenodontidae – solenodons, Tenrecidae – tenrecs and otter-shrews and Chrysochloridae – golden moles). I then examine how these various phylogenetic hypotheses influence the results of comparative analyses and our interpretation of insectivore life-history evolution. I assess which particular controversies have the greatest effect on results, and discuss the implications for comparative analyses where the phylogeny is controversial. I also explore and suggest explanations for certain insectivore life-history trends : increased gestation length and litter size in tenrecs, increased encephalization in moles, and the mixed fast and slow life-history strategies in solenodons. Finally, I consider the implications for comparative analyses of the recent strongly supported phylogenetic hypothesis of an endemic African clade of mammals that includes the insectivore families of tenrecs and golden moles.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Based on recent molecular phylogenetic studies, the Old World bat family Miniopteridae, composed of species in the genus Miniopterus, has been shown to contain complex paraphyletic species, many of which are cryptic based on convergent morphological characters. Herein we resolve the phylogenetic relationships and taxonomy of the species complex M. manavi on Madagascar and in the Comoro Archipelago, where these animals occur in different bioclimatic zones. First using mitochondrial cytochrome-b sequence data to define clades and then morphology to corroborate the molecular data, including comparisons to type specimens, we demonstrate that animals identified as this taxon are a minimum of three species: M. manavi sensu stricto occurs in at least the central portion of the Central Highlands; M. griveaudi has a broad distribution in lowland northern and central western Madagascar and the Comoros (Anjouan and Grande Comore), and M. aelleni sp. n. has been found in northern and western Madagascar and the Comoros (Anjouan). In each case, these three clades were genetically divergent and monophyletic and the taxa are diagnosable based on different external and craniodental characters. One aspect that helped to define the systematics of this group was isolation of DNA from one of the paratypes of M. manavi collected in 1896 and new topotypic material. Miniopterus manavi is most closely allied to a recently described species, M. petersoni. At several localities, M. griveaudi and M. aelleni have been found in strict sympatry, and together with M. manavi sensu stricto show considerable convergence in morphological characters, but are not immediate sister taxa. In defining and resolving the systematics of cryptic species, such as miniopterid bats, the process of defining clades with molecular tools, segregating the specimens accordingly, and identifying corroborative morphological characters has been notably efficient.