Galaxias maculatus: An explanation of its biogeography

1996 ◽  
Vol 47 (6) ◽  
pp. 845 ◽  
Author(s):  
TM Berra ◽  
LELM Crowley ◽  
W Ivantsoff ◽  
PA Fuerst
Keyword(s):  
Gene Flow ◽  
New Zealand ◽  
Oceanic Islands ◽  
Western Pacific ◽  
Disjunct Distribution ◽  
South American ◽  
Salt Tolerant ◽  
Galaxias Maculatus ◽  
Break Up ◽  
The Western Pacific

Galaxias maculatus is a small diadromous fish found in Australia, New Zealand, South America and on some oceanic islands. Two hypotheses have been advanced to explain this widespread, disjunct distribution. McDowall promoted dispersal through the sea of salt-tolerant juveniles but Rosen and others claimed that the distribution reflected the break-up of Gondwana and subsequent drift of the southern continents. Allozyrne electrophoresis of muscle extracts of specimens of Galaxias maculatus from eastern and western Australia, New Zealand and Chile was used to test the hypothesis that populations of G. maculatus from the western Pacific and the eastern Pacific do not differ genetically. FST based on allele frequencies and genotypes was 0.14, suggesting only minor differentiation between eastern and western Pacific populations. Minor differentiation in allele frequency existed at some loci, but no fixation of alternative alleles has occurred. The populations examined appear to be part of the same gene pool, indicating that gene flow via dispersal through the sea occurs today. It is unlikely that South American and Australasian populations would be conspecific if they have exchanged no migrants since the break-up of Gondwana at the end of the Mesozoic.

Progress towards advanced practice roles in Australia, New Zealand and the Western Pacific

Radiography ◽  
2008 ◽  
Vol 14 ◽  
pp. e20-e23 ◽  
Author(s):  
Tony Smith ◽  
Jill Yielder ◽  
Olusegun Ajibulu ◽  
Edward Caruana
Keyword(s):  
New Zealand ◽  
Western Pacific ◽  
Advanced Practice ◽  
The Western Pacific

scholarly journals Towards American Dependence: New Zealand's Developing Politico-Military Relations with the United States of America, 1919-1942

2021 ◽  
Author(s):  
◽  
Richard Maximilian Luppi
Keyword(s):  
United States ◽  
New Zealand ◽  
The United States ◽  
Point Of View ◽  
Western Pacific ◽  
Grand Strategy ◽  
Command Area ◽  
Defence Policy ◽  
Military Relations ◽  
The Western Pacific

<p>The purpose of this study is to describe and explain a crucial transition in New Zealand's defence policy the outcome of which was that, instead of relying on the United Kingdom (and in particular the Royal Navy) for her Pacific security, New Zealand began to rely on the military and naval power of the United States in the Western Pacific. The study therefore focuses on New Zealand's developing politico-military relations with the United States in the context of the informal and then formal Anglo-American alliance between 1919 and 1942. There are three parts. The first investigates the events which led up to New Zealand's abrupt reorientation in 1940 from relying on Britain for her Pacific security to relying on the United States. In the course of this, British and American defence planning and co-operation for a possible war in the Pacific between 1919 and 1939 are examined in some detail. The second part deals with New Zealand's efforts to secure an American naval shield in the course of British and American negotiations to develop a combined British-Dutch-American defence against Japan between 1940 and 1942. The final part goes into the reasons for the change of defence policy and concludes that: 1. The fundamental cause was the British failure in 1919 and the immediately following years to challenge Japan for naval supremacy in the Western Pacific by establishing a Far Eastern Fleet. It was a consequence of this that in June 1940 Britain tried to get the United States to assume a major strategic responsibility in the Western Pacific by undertaking to dispatch an American fleet to Singapore if Japan joined in the war whch had already broken out with Germany and Italy. 2. Australia and New Zealand, accepting the British grand strategy, prepared their local defences between October 1940 and March 1941 on the assumption that America would keep in step and send a fleet to Singapore. 3. Despite the failure of Britain's grand strategy between June 1940 and March 1941, America did assume strategic responsibility, particularly for the naval defence of New Zealand, in March 1941. In turn New Zealand, unlike Britain and Australia, consistently tried to meet the American point of view regarding a combined British-Dutch-American Pacific defence plan. This was part of her continuing effort to secure an American naval shield in the event of war with Japan. 4. Britain and America were unable to agree on a combined British-Dutch-American defence plan before Japan entered the war in December 1941. This delayed the final realization of New Zealand's goal, pursued since October 1940, of gaining an American naval shield. The establishment of the ANZAC unified Pacific command area in February 1942 saw this goal at long last attained.</p>

scholarly journals New taxonomic and phylogeographic data on three nominal species of the genus Septaria Férussac, 1807 (Gastropoda: Cycloneritida: Neritidae)

Zootaxa ◽  
2021 ◽  
Vol 4915 (1) ◽  
pp. 28-40
Author(s):  
AHMED ABDOU
Keyword(s):  
Indian Ocean ◽  
Western Indian Ocean ◽  
Western Pacific ◽  
Disjunct Distribution ◽  
Coi Gene ◽  
Nominal Species ◽  
Combined Analysis ◽  
The Western Pacific

Due to superficial morphological similarities, there is often confusion in the identification of some species of the genus Septaria. A combined analysis of the genital anatomy, morphometric and DNA, based on a portion of the COI gene, applied to three nominal species of this genus, confirmed the validity of Septaria tahitiana Eichhorst, 2016, and suggested that Septaria borbonica (Bory de Saint Vincent, 1804) is a subspecies of Septaria porcellana (Linnaeus, 1758), both taxa with disjunct distribution areas: Septaria borbonica in the western Indian Ocean and Septaria porcellana the western Pacific and eastern Indian Oceans. The possible presence of Septaria tesselata (Lamarck, 1816) in Mayotte (Comoros Archipelago) needs to be confirmed. 

scholarly journals Phylogeny, Phylogeography and Population Connectivity of Lessonia (Phaeophyceae)

2021 ◽  
Author(s):  
◽  
Peter Martin
Keyword(s):  
New Zealand ◽  
South America ◽  
Cryptic Species ◽  
Population Connectivity ◽  
Disjunct Distribution ◽  
South American ◽  
Rocky Shores ◽  
South American Species ◽  
Cook Strait ◽  
Algal Genus

<p>The brown algal genus Lessonia is distributed in the Southern Hemisphere where it can form dominant kelp beds on the exposed rocky shores of New Zealand, South America and Tasmania. Its disjunct distribution within the West Wind Drift contrasts with the view that it is a poor disperser. Apart from studies in Chile, where it is an economically important genus, little is known about Lessonia and in some areas even the number of species is unknown. Using different genetic markers I examined the phylogeny, phylogeography, and the connectivity of populations in Lessonia. Using the literature, species affiliations and nomenclatural problems have been investigated. Combining the sequences of three mitochondrial, one chloroplast and two nuclear markers, a supermatrix approach was used to investigate the phylogenetic relationship and the timing of speciation for all known Lessonia species. The Australasian Lessonia species form a clade within a paraphyletic grouping of South American species. Radiation in Lessonia occurred about 5 Mya at the beginning of the Pliocene and rapid radiation took place in Australasia 3.5 Mya. The data also revealed cryptic species within a L. variegata species complex. Further analysis within the Australasian clade, using mitochondrial (atp8-sp) and chloroplast (rbc-sp) markers and wider sampling (469 individuals from 57 sample sites) supported four cryptic species and revealed localized distribution for all Australasian lineages. Genetic breaks between Lessonia lineages corresponded well to known biogeographic regions and could be correlated to the geographic structure of New Zealand at the end of the Pliocene. The Cook Strait region was analysed more closely with newly developed microsatellite markers to test the influence of geographic breaks (Cook Strait and Palliser Bay) on the connectivity of populations. The results suggested that connectivity depends on the width of unsuitable habitat, and within inner Cook Strait it is facilitated by sometimes strong tidal flows that create turbulences and unique current patterns. The results implied that rafting is an important mean of dispersal. The study of the early literature on Lessonia supported the new lectotypification of L. flavicans but revealed that L. frutescens and possibly L. ovata (supported by images of rediscovered herbarium material) are synonymous to L. searlesiana and as the older epithets they should have priority. Suggestions have been made for the lectotypification of L. fuscescens and L. ovata. In general Lessonia shows non-overlapping distribution in Australasia but overlapping distribution in South America. Despite being a poor disperser, indicated by fine scale genetic structure, Lessonia is also able to connect populations over wide areas of unsuitable habitats.</p>

scholarly journals Quantifying dispersal from hydrothermal vent fields in the western Pacific Ocean

2016 ◽  
Vol 113 (11) ◽  
pp. 2976-2981 ◽  
Author(s):  
Satoshi Mitarai ◽  
Hiromi Watanabe ◽  
Yuichi Nakajima ◽  
Alexander F. Shchepetkin ◽  
James C. McWilliams
Keyword(s):  
Gene Flow ◽  
Pacific Ocean ◽  
Hydrothermal Vent ◽  
Larval Dispersal ◽  
Marine Conservation ◽  
Western Pacific ◽  
Biophysical Model ◽  
Plate Boundaries ◽  
Western Pacific Ocean ◽  
The Western Pacific

Hydrothermal vent fields in the western Pacific Ocean are mostly distributed along spreading centers in submarine basins behind convergent plate boundaries. Larval dispersal resulting from deep-ocean circulations is one of the major factors influencing gene flow, diversity, and distributions of vent animals. By combining a biophysical model and deep-profiling float experiments, we quantify potential larval dispersal of vent species via ocean circulation in the western Pacific Ocean. We demonstrate that vent fields within back-arc basins could be well connected without particular directionality, whereas basin-to-basin dispersal is expected to occur infrequently, once in tens to hundreds of thousands of years, with clear dispersal barriers and directionality associated with ocean currents. The southwest Pacific vent complex, spanning more than 4,000 km, may be connected by the South Equatorial Current for species with a longer-than-average larval development time. Depending on larval dispersal depth, a strong western boundary current, the Kuroshio Current, could bridge vent fields from the Okinawa Trough to the Izu-Bonin Arc, which are 1,200 km apart. Outcomes of this study should help marine ecologists estimate gene flow among vent populations and design optimal marine conservation plans to protect one of the most unusual ecosystems on Earth.

Australian Sympycninae II: Syntormon Loew and Nothorhaphium, gen. nov., with a treatment of the Western Pacific fauna, and notes on the subfamily Rhaphiinae and Dactylonotus Parent (Diptera : Dolichopodidae)

1999 ◽  
Vol 13 (1) ◽  
pp. 179 ◽  
Author(s):  
Daniel J. Bickel
Keyword(s):  
New Zealand ◽  
Southern Africa ◽  
New Guinea ◽  
Western Pacific ◽  
New Combination ◽  
Australian Species ◽  
Late Tertiary ◽  
Close Relationship ◽  
The Western Pacific

The Australian species of two genera, Nothorhaphium, gen. nov. andSyntormon Loew (Diptera : Dolichopodidae), are described, illustrated and keyed, and discussed in context of the Western Pacific fauna. The two genera are phylogenetically close. The Australian Nothorhaphium comprises four species: N. aemulans Becker, comb. nov. (= Xiphandrium pudicum Parent, syn. nov.), N. nudicorne, sp. nov., N. callosum, sp. nov., and N. curalo, sp. nov. The montane New Guinean N. oro, sp. nov. is also described, and its close relationship with the predominantly southern temperate Australian fauna is discussed, suggesting it was part of a common Australian fauna which became isolated with the uplift of New Guinea in the mid–late Tertiary. The Australian Syntormon comprises six species: S. xiphandroides Parent, S. flexibile Becker, S. singularis, sp. nov., S. tasmanense, sp. nov., S. janelithae, sp. nov., and S. lucare, sp. nov. As well, S. aotearoa is described from New Zealand. Genera once thought to be close to Syntormon are discussed. The subfamily Rhaphiinae is briefly discussed, noting the problem of subfamily definition. The New Zealand Syntormon formosus Parent is placed in new combination [= Dactylonotus formosus (Parent)] in a genus previously known only from southern Africa.

Conspicuous genetic similarity within a widely distributed and newly described species of Parasesarma De Man, 1895 from Western Pacific oceanic islands, with notes on the allied P. calypso group (Crustacea : Brachyura : Sesarmidae)

2021 ◽  
Author(s):  
Adnan Shahdadi ◽  
Christoph D. Schubart ◽  
Jose Christopher E. Mendoza
Keyword(s):  
New Species ◽  
Pacific Islands ◽  
New Caledonia ◽  
Oceanic Islands ◽  
Western Pacific ◽  
Cox1 Gene ◽  
Similar Species ◽  
Brachyuran Crab ◽  
De Man ◽  
The Western Pacific

Some brachyuran crab species of the Western Pacific appear to be widespread throughout the region and distributed across a large geographic area, without obvious phylogeographic structuring. In the present study, we describe a new species of Parasesarma that appears to be restricted to Western Pacific islands (so far Guam, Palau, Vanuatu, Fiji, Wallis and New Caledonia). Comparisons of partial sequences of the COX1 gene show that individuals of this species, though from relatively isolated and widely separated islands, are monophyletic and, surprisingly, genetically uniform. These results give credence to the hypothesis that these oceanic islands serve as ‘stepping stones’ for the current-mediated dispersal and genetic homogenisation of coastal–littoral marine species. Morphologically, the new species differs most significantly from similar congeners in the tuberculation pattern of the chelar dactyli, whereas genetically it is markedly divergent from other morphologically similar species of Parasesarma, with a minimum COX1 p-distance of 6.9%. With such evidence, the new species is here formally described as Parasesarma daviei sp. nov. It is the fifth species of Parasesarma reported from oceanic islands of the Western Pacific. Compared to other congeners, P. daviei sp. nov. shows a close relationship with a clade including P. calypso. Therefore, P. calypso (De Man, 1895), and three of its former subspecies or varieties were subjected to a closer examination and are here rediagnosed and illustrated. In consequence, we suggest full species status for P. kuekenthali (De Man, 1902), P. lanchesteri (Tweedie, 1936), and P. ellenae (Pretzmann, 1968).

Biogeography of Caladenia (Orchidaceae), with special reference to the South-west Australian Floristic Region

2009 ◽  
Vol 57 (4) ◽  
pp. 259 ◽  
Author(s):  
Ryan D. Phillips ◽  
Gary Backhouse ◽  
Andrew P. Brown ◽  
Stephen D. Hopper
Keyword(s):  
New Zealand ◽  
Western Pacific ◽  
The South ◽  
South West ◽  
Eastern Australia ◽  
Key Drivers ◽  
Almost All ◽  
Acting In Concert ◽  
The Western Pacific ◽  
Eleven Species

Caladenia contains 376 species and subspecies, of which almost all are endemic to temperate and southern semiarid Australia. Eleven species occur in New Zealand, 10 of which are endemic, and one species is widely distributed in eastern Australia and the western Pacific. Only three species occur in both south-western and south-eastern Australia. At subgeneric level, Drakonorchis is endemic to the South-west Australian Floristic Region (SWAFR), Stegostyla to eastern Australia and New Zealand, whereas three subgenera, Calonema, Phlebochilus and Elevatae occur on both sides of the Nullarbor Plain. Subgenus Caladenia is primarily eastern Australian but also extends to the western Pacific. The largest subgenera (Calonema and Phlebochilus) have radiated extensively, with Calonema exhibiting a greater concentration of species in more mesic parts of the SWAFR than Phlebochilus. Within the SWAFR, the major biogeographic division within Caladenia follows the 600-mm isohyet. Within rainfall zones, biogeographic districts for Caladenia correlate with a combination of underlying geology and surface soils. Areas of high endemism contain diverse edaphic environments. Climatic and edaphic requirements are likely to be key drivers of rarity in Caladenia, although these parameters may be acting in concert with mycorrhizal and pollinator specificity.

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