scholarly journals Seasonal and spatial variation of phytoplankton assemblages, biomass and cell size from spring to summer across the north-eastern New Zealand continental shelf

2003 ◽  
Vol 25 (7) ◽  
pp. 737-758 ◽  
Author(s):  
F. H. Chang
The Festivus ◽  
2018 ◽  
Vol 50 (1) ◽  
pp. 36-54
Author(s):  
John Daughenbaugh

For researchers, isolated regions at the periphery of species’ distributions hold a peculiar fascination. The causes of their remoteness vary based on: distance (e.g. the Tropical Eastern Pacific), distance and countervailing currents (e.g. the Marquesas), location in a present day gyre (e.g. the Pitcairn Group) or the absence of present day means of veliger transport (e.g. the Vema Seamount). (Daughenbaugh & Beals 2013; Daughenbaugh 2015a & b, 2017). The northern New Zealand Region from the Kermadec Islands (Kermadecs) to the coastal and shelf areas in the northernmost part of New Zealand’s North Island (Northland), including the Poor Knights Islands (PKI), constitute the distributional boundaries for a number of Cypraeidae species. The boundaries are the result of the absence of coastal shelves along the east side of the Kermadec Ridge (Ridge) and precipitous drops to abyssal depths along Northland’s east coast continental shelf. Tropical waters, with their potential to transport Cypraeidae larvae, flow eastward from southern Queensland, Australia, entrained in the Tasman Front which terminates when reaching North Cape, the northernmost tip of Northland. There, the North Cape Eddy captures most of this flow while the remainder, the East Auckland Current (EAUC), flows intermittently southward along the eastern coastal, shelf and offshore areas of Northland into waters incapable of supporting Cypraeidae populations.


Author(s):  
Jean-Claude Dauvin ◽  
Denise Bellan-Santini

The genus Ampelisca comprises more than 150 species and is one of the more important benthic genus of marine amphipods. New species are regularly added (Barnard & Agard 1986; Bellan-Santini & Marques, 1986; Goeke, 1987). Ampelisca are found from the intertidal zone to abyssal depths but most of them live on the continental shelf. In spite of many studies, it is often difficult to distinguish some species which are morphologically similar. In the last ten years, twenty-two species have been described from the north-eastern Atlantic (BellanSantini & Kaïm-Malka, 1977; Bellan-Santini & Dauvin, 1981, 1986; Dauvin & Bellan-Santini, 1982, 1985; Bellan-Santini & Marques, 1986). Materials come from MNHN of Paris collection, collected by Chevreux (1894–1924) (Dauvin & Bellan-Santini, 1985, 1986) and specimens collected during the last 25 years. All these new species are described from the Atlantic coast from northern Brittany to the Sahara and from the Mediterranean Sea.


Polar Biology ◽  
2012 ◽  
Vol 36 (3) ◽  
pp. 391-408 ◽  
Author(s):  
F. Hoe Chang ◽  
Michael J. M. Williams ◽  
Jill N. Schwarz ◽  
Julie A. Hall ◽  
Elizabeth W. Maas ◽  
...  

2021 ◽  
Vol 8 ◽  
Author(s):  
Jean-Claude Dauvin ◽  
Leandro Sampaio ◽  
Ana Maria Rodrigues ◽  
Victor Quintino

The Ampeliscidae Kröyer, 1842 is amongst the most diverse amphipod families; it comprises four genera, Ampelisca being the richest with more than 200 species. The Ampelisca genus presents high morphological homogeneity and the identification of the species by ecologists remains difficult. Ampelisca are also characterized by a high degree of sympatry, a rare situation in amphipods, and in this study we report up to nine species coexisting at the same site. Recent benthic sampling and publications, namely on the Portuguese continental shelf and the English Channel, permit to revisit the available data on the taxonomy and propose an updated species identification key, as well as the distribution and ecology of the 40-recorded Ampelisca species along the North Eastern Atlantic coast, from the Strait of Gibraltar, in the South, to the Strait of Dover, in the North. The data allow discussing on the sympatry and syntopy of such diverse amphipod family with the co-occurrence of several species at various scales of observations, from the wider regional area, to the narrower local habitat. Two Ampelisca species were recorded exclusively on hard bottom, while the other tend to inhabit specific types of soft bottom, ranging from deep mud to shallow coarse sand and gravel, with a preference for continental shelf muddy and sandy habitats. A future sea water temperature increase scenario could modify the species geographical distribution and reproductive cycle, in this temperate North-eastern Atlantic province.


2014 ◽  
Vol 28 (4) ◽  
pp. 401 ◽  
Author(s):  
Rosa Fernández ◽  
Gonzalo Giribet

Aoraki denticulata, a widespread mite harvestman endemic to the NW South Island of New Zealand, was postulated to constitute an old lineage with deep genetic history. Expanding on previous studies, we explored its genetic diversity and population structure, phylogeography and diversification patterns. We also examined the systematic implications of such a complex scenario through species delimitation analyses under coalescent-based and barcoding gap discovery methodologies. Our results depict the deep evolutionary history of the A. denticulata lineage, which shows high geographic structure and low genetic connectivity among modern populations. Aoraki denticulata is further subdivided into three lineages: a lineage presently inhabiting the northern region of the Southern Alps (and including the subspecies A. d. major), a second lineage in the north-eastern part of the sampled land, and a third one occupying the south-eastern localities. When using species delimitation methods based on coalescence approaches, large numbers of cryptic species were estimated. Based on morphological and biological evidence, we thus argue that these methods may overestimate species in cases in which genetic divergence is unusually large and discuss the systematic implications of our findings.


1992 ◽  
Vol 6 (4) ◽  
pp. 843 ◽  
Author(s):  
GCB Poore ◽  
TM Bardsley

The family Austrarcturellidae is established for Austrarcturella, gen. nov., Abyssarcturella, gen. nov., Pseudarcturella Tattersall (1921) and Scyllarcturella, gen. nov. Males of this family share a uniquely modified first pleopod in which the exopod has a lateral secondary ramus. The pleotelson is usually of a unique inverted flat-bottomed boat-shape, and the dactyli of pereopods 2 and 3 have a minute proximal part and elongate unguis. The genus Pseudarcturella Tattersall (1921) is redefined; its type species, P. chiltoni Tattersall, is redescribed and P. crenulata, sp. nov. added. Thirteen species of Austrarcturella, gen. nov. are described from the Australian continental shelf and slope: A. oculata (Beddard) (type species), A. aphelura, sp. nov., A. brychia, sp. nov., A. callosa, sp. nov., A. cava (Hale), A. corona, sp. nov., A. hirsuta, sp. nov., A. inornata, sp. nov., A. macrokola, sp. nov., A. pictila, sp. nov., A. sexspinosa, sp. nov., A. spinipes, sp, nov. and A. thetidis, sp. nov. One further species, A. galathea, sp, nov., is described from New Zealand. Abyssarcturella, gen. nov. is diagnosed and two species from deep water in eastern Australia are described: A. panope, sp. nov. (type species) and A. cidaris, sp. nov. Scyllarcturella, gen, nov. is diagnosed for S. falcata, sp. nov. from deep water in north-eastern Australia. Keys to all taxa are presented and their distributions are briefly discussed.


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