995 resultados para Fish taxonomy
Resumo:
Outbreaks of the coral-killing seastar Acanthaster planci are intense disturbances that can decimate coral reefs. These events consist of the emergence of large swarms of the predatory seastar that feed on reef-building corals, often leading to widespread devastation of coral populations. While cyclic occurrences of such outbreaks are reported from many tropical reefs throughout the Indo-Pacific, their causes are hotly debated, and the spatio-temporal dynamics of the outbreaks and impacts to reef communities remain unclear. Based on observations of a recent event around the island of Moorea, French Polynesia, we show that Acanthaster outbreaks are methodic, slow-paced, and diffusive biological disturbances. Acanthaster outbreaks on insular reef systems like Moorea's appear to originate from restricted areas confined to the ocean-exposed base of reefs. Elevated Acanthaster densities then progressively spread to adjacent and shallower locations by migrations of seastars in aggregative waves that eventually affect the entire reef system. The directional migration across reefs appears to be a search for prey as reef portions affected by dense seastar aggregations are rapidly depleted of living corals and subsequently left behind. Coral decline on impacted reefs occurs by the sequential consumption of species in the order of Acanthaster feeding preferences. Acanthaster outbreaks thus result in predictable alteration of the coral community structure. The outbreak we report here is among the most intense and devastating ever reported. Using a hierarchical, multi-scale approach, we also show how sessile benthic communities and resident coral-feeding fish assemblages were subsequently affected by the decline of corals. By elucidating the processes involved in an Acanthaster outbreak, our study contributes to comprehending this widespread disturbance and should thus benefit targeted management actions for coral reef ecosystems.
Resumo:
In the latter half of the nineteenth century the railway became an emblem of technological advancement, stood for the improvement and progression of European life, and became a recognizable symbol for the achievements of governments and citizens. The implementation and use of the railway became closely linked with notions of national identity and character. The railway became an identifiable artefact in official history but at the same time it became a part of everyday life. Richard Flanagan’s Gould’s Book of Fish retells the life-story of a fictionalized convict sent to Sarah Island and who paints fish, eventually he metamorphoses into one. It could be thought that a novel set in convict times would have little to do with notions of national identity, technological advancement, and railway travel. However, Richard Flanagan, in this very complex, almost surreal, novel, has used the construction of a fictional national railway as one of the ways to explore Australia's complex relationship with history and space. The novel tells of the plans of a history-loving Commandant and his desire to build a national railway on Sarah Island. This paper explores how Sarah Island becomes a metonym for Australia as a whole and Flanagan's novel takes on a metaphysical dimension as he reveals the struggles that emerge when official history collides with non-official versions. The fabulations of the novel contribute to an historical reconstruction of the spatial/architectural history of the Tasmanian colonial project.
Resumo:
We provide a taxonomic redescription of the Fawn Antechinus, Antechinus bellus (Thomas). A. bellus is the only member of its genus to occur in Australia’s Northern Territory, where it can be found in savannah woodlands of the Top End. It is perhaps the most distinctive antechinus, and clearly distinguishable from the other 10 extant species of antechinus found in Australia: externally, A. bellus has pale body fur, white feet and large ears; A. bellus skulls have large auditory bullae and narrow interorbital width, while broadening abruptly at the molar row; mitochondrial and nuclear genes clearly dis-tinguish A. bellus from all congeners, phylogenetically positioning the Fawn Antechinus as sister to Queensland’s A. leo Van Dyck, 1980, with which it shares a curled supratragus of the external ear and a similar tropical latitudinal range.
Resumo:
We provide a taxonomic redescription of the ubiquitous and variable dasyurid marsupial Yellow-footed Antechinus, Antechinus flavipes (Waterhouse), which comprises three currently recognized subspecies whose combined geographic distribution spans almost the length and breadth of Australia. A. flavipes leucogaster Gray is confined to south-west Western Australia; A. flavipes flavipes is distributed in south-eastern Australia across four states—South Australia, Victoria, New South Wales and Queensland; A. flavipes rubeculus Van Dyck is confined to the wet tropics of Queensland. A. flavipes is readily distinguished from all extant congeners based on external morphology by the following combination of features: a grey head; orange-yellow toned flanks/rump, feet and tail base; pale eye-rings and a darkened tail tip. A. flavipes skulls are stout, being broad at the level of the rear upper molars, have small palatal vacuities and small entoconid cusps on the lower molars. However, notable differences among subspecies of A. flavipesprevent any obvious collection of skull characters being diagnostic for species-level discrimination among congeners. A. flavipes rubeculus is the largest of the three subspecies of Yellow-footed Antechinus and most similar in skull morphology to A. leo, A. bellus and A. godmani—all four species are geographically limited to tropical Australia. A. f. rubeculus is notably larger in many characters than its conspecifics: A. f. flavipes, the next largest, and A. f. leucogaster, the smallest of the group. A. f. flavipes and A. f. leucogaster diverge significantly at only a few skull characters, and both subspecies have cranial morphological affinities with the recently discovered A. mysticus, most notably A. f. leucogaster. Phylogenies generated from mt- and nDNA data strongly support Antechinus flavipes as monophyletic with respect to other members of the genus; within A. flavipes, each of the three recognized subspecies form distinctive monophyletic clades.
Resumo:
We provide a taxonomic redescription of the dasyurid marsupial Atherton Antechinus, Antechinus godmani (Thomas). A. godmani is only rarely encountered and limited to wet tropical rainforests of north-east Queensland, Australia, between the towns of Cardwell and Cairns (a distribution spanning 135 kilometres from north to south). The distinctive species occurs at altitudes of over 600 meters asl, in all major rainforest types, and can be found with both the northern subspecies of the Yellow-footed Antechinus, A. flavipes rubeculus Van Dyck and the Rusty Antechinus, A. adustus (Thomas). A. god-mani is clearly separated from all congeners on the basis of both morphometrics and genetics. A. godmani can be distin-guished from all extant congeners based on external morphology by a combination of large size, naked-looking tail and reddish fur on the face and head. A. godmani skulls are characteristically large, with a suite of long features: basicranium, palate, upper premolar tooth row, inter-palatal vacuity distance and dentary. Phylogenies generated from mt- and nDNA data position Antechinus godmani as monophyletic with respect to other members of the genus; A. godmani is strongly supported as the sister-group to a clade containing all other antechinus, but excluding the south-east Australian Dusky An-techinus, A. swainsonii (Waterhouse) and Swamp Antechinus, A. minimus (Geoffroy). Antechinus godmani are genetically very divergent compared to all congeners (mtDNA: range 12.9–16.3%).
Resumo:
"The ongoing review of the NFS highlighted that engagement with recreational fishers and the Indigenous community, in particular, could be enhanced. This was the impetus for the Talking Fish project which acknowledged the important relationship people have with their local rivers and fish within the Murray-Darling Basin. Within these relationships a wealth of historical information about rivers and fish was held and it was recognised that this needed to be captured..."--publisher website.
Resumo:
The Namoi River winds its way through 42 000 square kilometres of blacksoil plain in the north east of New South Wales. Fed by the rivers of the western slopes of the Great Dividing Range, it contributes about one quarter of the Darling River’s flow. The river, its floodplain, wetlands, swamps and waterholes, are the traditional lands of the Gamilaraay* people. The Namoi is a very different river to the one the Gamilaraay people once knew and fished...
Resumo:
In recent years, the Web 2.0 has provided considerable facilities for people to create, share and exchange information and ideas. Upon this, the user generated content, such as reviews, has exploded. Such data provide a rich source to exploit in order to identify the information associated with specific reviewed items. Opinion mining has been widely used to identify the significant features of items (e.g., cameras) based upon user reviews. Feature extraction is the most critical step to identify useful information from texts. Most existing approaches only find individual features about a product without revealing the structural relationships between the features which usually exist. In this paper, we propose an approach to extract features and feature relationships, represented as a tree structure called feature taxonomy, based on frequent patterns and associations between patterns derived from user reviews. The generated feature taxonomy profiles the product at multiple levels and provides more detailed information about the product. Our experiment results based on some popularly used review datasets show that our proposed approach is able to capture the product features and relations effectively.
Resumo:
Once known as Crabb’s Creek, Katarapko Creek is a small anabranch of the Murray River, located between the towns of Berri and Loxton in the Riverland region of South Australia. Its 9 000 hectare grey clay floodplain is covered with blackbox, saltbush and lignum. The creek’s horseshoe lagoons, marshes and islands are the traditional lands of the Meru peoples. They fished the creek and surrounding waterways and hunted the wetlands. The ebb and flow of water guided their travels and featured in their stories. The Meru have seen their land and the river change...
Resumo:
The Goulburn River’s cold, clear waters rush westward down from the steep hills and mountains of the Great Dividing Range toward Seymour. The river then turns northward and meanders through hills and plains until the river meets the Murray upstream of Echuca. These are the traditional lands of the Taungurung, Bangerang and Yorta Yorta peoples. However, the Goulburn River today is not the river the Taungurung, Bangerang and Yorta Yorta once knew and fished...
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The Upper Murrumbidgee cuts its way through the Snowy Mountains in south‐eastern New South Wales, snaking its way south, then turning north before dropping into the lowland and heading west to join the Murray downstream of Swan Hill. The Upper ‘Bidgee floodplain is only a couple of hundred metres wide, a stark contrast to the kilometres‐wide floodplains in other parts of the Murray‐ Darling Basin. When the floods come, they come up quickly and roar through the narrow valleys. These are the traditional lands of the Ngunnawal and Ngarigo peoples. They fished the river and surrounding waterways and hunted the wetlands. The seasonal rise and fall of the water guided their travels and featured in their stories. The Ngunnawal and Ngarigo people have seen their land and the river change...
Resumo:
The Murray River is the boundary between NSW and Victoria. The river both defines boundaries and unites them with the waters that sustain townships, irrigation and the floodplain forests, including the 70 000ha of the iconic Barmah and Millewa Forest. The river and its floodplain are the traditional lands of the Yorta Yorta and Bangerang people. The Murray is a very different river to the one the Yorta Yorta and Bangerang peoples once knew and fished...
Resumo:
The Lower Darling River and Great Darling Anabranch are located in south west New South Wales. Muddy waters meander over the grey soil floodplains past red dunes, spiky saltbush and gnarled red gums. These are the traditional lands of the Paakintji people. But the land and the river are no longer what the Paakintji once knew and fished...
Resumo:
To say ‘Back o’ Bourke’ means ‘miles from anywhere’ to most Australians, however the Barwon and Darling Rivers that pass by the townships of Brewarrina and Bourke, respectively, are at the heart of the Murray‐Darling Basin. These are the traditional lands of the Ngiyampaa, Murawari and Yuwalaraay peoples (refer Aboriginal language groups in the Bringing back the fish section at the back of this booklet). They fished the river and surrounding waterways and hunted the wetlands. The Ngiyampaa, Murawari and Yuwalaraay people have seen their land and the rivers change...
Resumo:
The Ovens River rises in the Victorian Alps where it is linked to significant freshwater meadows and marshes. It flows past Harrietville, Bright, Myrtleford and Wangaratta where it is joined by the King River on its way to meet the Murray near the top of Lake Mulwala. These the traditional lands of the Bangerang people and their neighbours the Taungurung and Yorta Yorta peoples. They have fished the river and surrounding waterways and hunted the wetlands. The ebb and flow of water guided their travels and featured in their stories. The Bangerang, Taungurung and Yorta Yorta have seen their land and the river change...