scholarly journals Restructuring of the ‘Macaronesia’ biogeographic unit: A marine multi-taxon biogeographical approach

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Rui Freitas ◽  
Maria Romeiras ◽  
Luís Silva ◽  
Ricardo Cordeiro ◽  
Patrícia Madeira ◽  
...  

Abstract The Azores, Madeira, Selvagens, Canary Islands and Cabo Verde are commonly united under the term “Macaronesia”. This study investigates the coherency and validity of Macaronesia as a biogeographic unit using six marine groups with very different dispersal abilities: coastal fishes, echinoderms, gastropod molluscs, brachyuran decapod crustaceans, polychaete annelids, and macroalgae. We found no support for the current concept of Macaronesia as a coherent marine biogeographic unit. All marine groups studied suggest the exclusion of Cabo Verde from the remaining Macaronesian archipelagos and thus, Cabo Verde should be given the status of a biogeographic subprovince within the West African Transition province. We propose to redefine the Lusitanian biogeographical province, in which we include four ecoregions: the South European Atlantic Shelf, the Saharan Upwelling, the Azores, and a new ecoregion herein named Webbnesia, which comprises the archipelagos of Madeira, Selvagens and the Canary Islands.

2017 ◽  
Vol 145 (2) ◽  
pp. 599-616 ◽  
Author(s):  
Abdou L. Dieng ◽  
Saidou M. Sall ◽  
Laurence Eymard ◽  
Marion Leduc-Leballeur ◽  
Alban Lazar

In this study, the relationship between trains of African easterly waves (AEWs) and downstream tropical cyclogenesis is studied. Based on 19 summer seasons (July–September from 1990 to 2008) of ERA-Interim reanalysis fields and brightness temperature from the Cloud User Archive, the signature of AEW troughs and embedded convection are tracked from the West African coast to the central Atlantic. The tracked systems are separated into four groups: (i) systems originating from the north zone of the midtropospheric African easterly jet (AEJ), (ii) those coming from the south part of AEJ, (iii) systems that are associated with a downstream trough located around 2000 km westward (termed DUO systems), and (iv) those that are not associated with such a close downstream trough (termed SOLO systems). By monitoring the embedded 700-hPa-filtered relative vorticity and 850-hPa wind convergence anomaly associated with these families along their trajectories, it is shown that the DUO generally have stronger dynamical structure and statistically have a longer lifetime than the SOLO ones. It is suggested that the differences between them may be due to the presence of the previous intense downstream trough in DUO cases, enhancing the low-level convergence behind them. Moreover, a study of the relationship between system trajectories and tropical depressions occurring between the West African coast and 40°W showed that 90% of tropical depressions are identifiable from the West African coast in tracked systems, mostly in the DUO cases originating from the south zone of the AEJ.


2019 ◽  
Vol 59 ◽  
pp. e20195958
Author(s):  
Luciane Augusto De Azevedo Ferreira ◽  
Marcos Tavares

Porcellana paivacarvalhoi Rodrigues da Costa, 1968, described from southeastern Brazil (São Sebastião, São Paulo), is morphologically similar to the eastern Atlantic P. platycheles (Pennant, 1777), and also to the west African P. africana Chace, 1956. The synonymy between P. paivacarvalhoi and P. platycheles was proposed by previous authors without examination of any specimens of P. platycheles, nor did they considered the morphological similarities between P. paivacarvalhoi and P. africana. This synonymy has been implicitly accepted without further analysis. The recent discovery of one male and two females syntypes of P. paivacarvalhoi has prompted new investigations into the status of P. paivacarvalhoi as a junior synonym either of P. platycheles or P. africana. Porcellana paivacarvalhoi is redescribed and illustrated based upon its lectotype herein designated. It is confirmed to be a junior synonym of P. platycheles; all evidence suggests that P. africana is a distinct, separate species. All previous records of P. platycheles from the Brazilian coast are reviewed. Its presence in southeastern Brazil in the late 1960’s most probably represents an historical case of human-mediated introduction by shipping activities. Porcellana platycheles did not manage to establish itself in São Sebastião, nor has it been recorded subsequently elsewhere in Brazil.


1981 ◽  
Vol 4 ◽  
pp. 421-428
Author(s):  
W. L. Brinckman

Total sheep population in Nigeria is probably around 8 million (anonymous, 1975). The majority of these sheep live in the northern part of the country. The three most important breeds in the north are the Uda, the Balami and the Yankasa. The former two are examples of the typical longlegged, long-tailed, hairy sheep, living along the southern border of the Sahara. The Yankasa occupies the middle and most of the northern part of the country. It probably developed as a cross between the West African Dwarf (or Forest) Sheep from the south and the Uda from the north. It possesses the heavy neck ruff that is typical of the West African Dwarf but is taller and heavier.


Author(s):  
Kofi Yakpo

AbstractThis article explores the nexus between language policies and language ideologies in Equatorial Guinea and West Africa. By analyzing spoken and written discourses in Spanish and Pichi, I identify a set of ideas and beliefs about Pichi and the semiotic processes by which they have emerged. The comparison of Pichi with Krio, Nigerian Pidgin, Cameroon Pidgin and Ghanaian Pidgin English shows that Pichi is the most disadvantaged of the West African English-lexicon creoles with respect to a number of sociolinguistic characteristics. I argue that linguistic ideologies about Pichi have contributed significantly to disregarding language policy options for elevating the status and extending the uses of Pichi in Equatorial Guinea. Pichi is nevertheless expected to expand its social functions by gradually conquering additional domains of use as has been the case with the other English creoles of West Africa.


2009 ◽  
Vol 2 (1) ◽  
pp. 103-124
Author(s):  
Jan-Bart Gewald

Abstract In 1915 troops of the South African Union Defence Force invaded German South West Africa, present day Namibia. In the north of the territory the South African forces captured an African soldier serving in the German army named Mbadamassi. Upon his capture Mbadamassi demanded to be released and claimed that he was a British national from Nigeria. In addition, he stated that he had served in the West African Frontier Force, and that he had been shanghaied into German military service in Cameroon. Furthermore, whilst serving in the German army in Cameroon, Mbadamassi claimed that he had participated in a mutiny, and that, as a consequence, he had been deported to GSWA. The article covers the remarkable military career of the African soldier, Mbadamassi, who between 1903 and 1917 served both the King of the British Empire as well as the Kaiser of the German Empire. In so doing, the article sheds light on the career of an individual African soldier serving in three colonial armies; the West African Frontier Force, the Schutztruppe in Cameroon, and the Schutztruppe in GSWA. The article argues that beyond the fact that colonial armies were institutions of repression, they also provided opportunity for those willing or condemned to serve within their ranks. Furthermore the article provides some indication as to the extent of communication that existed between colonial subjects in the separate colonies of Africa at the time. En 1915, les troupes de l'Union de l'Afrique du Sud ont envahi l'Afrique du Sud-Ouest allemande, l'actuelle Namibie. Dans le Nord du territoire, les forces sud-africaines ont capturé un soldat africain servant dans l'armée allemande nommé Mbadamassi. Celui-ci exigea d'être libéré et revendiqua être un Britannique du Nigeria. De plus, il déclara avoir servi dans la West African Frontier Force et avoir été enrôlé de force dans l'armée allemande au Cameroun. En outre, pendant qu'il servait dans l'armée allemande au Cameroun, Mbadamassi a prétendu avoir pris part à une mutinerie, ce qui avait conduit à sa déportation vers l'Afrique du Sud-Ouest allemande. Cet article couvre la remarquable carrière militaire du soldat africain Mbadamassi, qui, entre 1903 et 1917, a servi à la fois le roi de l'empire britannique et le Kaiser de l'empire allemand. Ainsi, l'article éclaire sur la carrière individuelle d'un soldat africain servant dans trois armées coloniales; la West African Frontier Force, le Schutztruppe au Cameroun et le Schutztruppe en Afrique du Sud-Ouest allemande. L'article soutient qu'au-delà du fait que les armées coloniales étaient des institutions de répression, elles ont aussi offert la possibilité à ceux qui le voulaient ou ceux qui y étaient condamnés de servir dans leurs rangs. En outre, l'article fournit une indication sur l'étendue de la communication qui a existé entre les sujets coloniaux dans les colonies d'Afrique séparées de l'époque.


1998 ◽  
Vol 51 (1) ◽  
pp. 46-57 ◽  
Author(s):  
W. G. L. Randles

Of the great oceans of the world, the Atlantic, because of its violence, was the last to be mastered by man. The task in its entirety had to wait for the Portuguese sailors of the Renaissance. Isidore of Seville (c. 570–636), a Christian writer of the late Roman Empire, had written of the Atlantic that it was ‘incommensurable and uncrossable’. Although Pliny (a.d. 23–79) refers vaguely to the Canary Islands, all knowledge of them disappears in the Middle Ages until a Portuguese expedition under the command of the Italian Lanzarotto Malocello ‘re- discovered’ them in 1336. Italian charts of the XIVth century begin progressively to show the Canaries, Madeira, Porto Santo and the Azores, but all aligned along a N/S axis without any appreciation of the relative distances between them or how far they lay from the European shore. The first written evidence of the Portuguese ‘discovery’ of the islands of Madeira and Porto Santo appears in 1419–20 and of the Azores in 1427, about the same time as they began to be colonised under the aegis of Prince Henry of Portugal, called the ‘Navigator’. The difficulties of returning to them on regular voyages was to motivate the Portuguese to develop methods of measurement using the Pole Star as a navigational aid and this led, not only to a greater accuracy in placing the islands on the charts, but also to a greater precision in the charting of the west African coastline which they were progressively exploring during the second half of the XVth century.Claims that Portuguese nautical astronomy originated in Aragon and was transmitted from there to Portugal or was introduced into Portugal from Germany by Regiomontanus and Martin Behaim have long ago been shown to be baseless.


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