Abstract | Introduction | Presentation | Diversity | Main marine currents | The different oceanic zones : Summary of the species - Marine currents and other maps | Cosmopolitanism and endemism |
Species indicative of continental drift | Species whose localization is difficult to explain | Anthropic mechanisms | Conclusion
Presentation :
Map 1 shows the spatial resolution and defines the localisation of each form in this arbitrarily chosen framework. The definition of the various geographical zones in the distribution matrix is perhaps debatable as no correlation with the various types of water body is assumed a priori, but it synthesises current knowledge on the localisation of the species. The means of geographical distribution for the various species, and further information for some of them, may be correlated after cross check of a group of species with no apparent phyletic link.
The matrix showing species by geographical zone has a list of the recorded forms on the y-axis and the following 25 columns on the x-axis:
3 : | Sub-Antarctic | 4 : | Antarctic | 5 : | South Africa (E & W), Namibia | 6 : | Gulf of Guinea (sensu lato): Angola-Liberia | 7 : | Venezuela, Caribbean Sea, Gulf of Mexico, Caribbean, Florida, Sargasso Sea | 8 : | Cape Verde Is., Canary Is., Madeira Is., Azores, Bay of Biscay, Ibero-Moroccan Bay | 9 : | Ireland, English Channel, Faroe, Norway, North Sea, Baltic Sea | 10 : | Southern Iceland, southern Greenland (E & W), Strait of Davis, Labrador Sea | 11 : | Cape Cod, Nova Scotia, Island of Newfoundland | 12 : | Central South-Atlantic (Tristan da Cunha-Trinidad-St Helena-N Ascension) | 13 : | Brazil-Argentina | 14 : | Mediterranean Sea, Black Sea | 15 : | Red Sea | 16 : | Indian Ocean | 17 : | Gulf of Thailand, Malaysia-Indonesia-Philippines | 18 : | Australia (E), Great Barrier Reef, Tasman Sea, New Zealand, New Caledonia | 19 : | Central Tropical Pacific | 20 : | Eastern Tropical Pacific (Central America, Galapagos, Northern Peru) | 21 : | China Seas, Vietnam | 22 : | Japan Sea, Japan | 23 : | North West Pacific (Sea of Okhotsk-Kuril Islands-Kamtchatka-Sea of Bering) | 24 : | North East Pacific (Gulf of Alaska, "P" station, British Columbia) | 25 : | California-Gulf of California | 26 : | Chile (sensu lato) | 27 : | Arctic Ocean |
These subsets reveal dispersal mechanisms corresponding to models linked :
1 - |
surface or deep currents as initially shown by Sewell
(1948); |
2 - |
latitude zones related to the surface and sub-surface temperatures of the different water masses
(Van der Spoel & Heyman, 1983); |
3 - |
anthropogenic transport
(Carlton & Geller, 1993); |
4 - |
the process of continental drift
(a problem addressed by
Sewell, 1956); |
5 - |
species whose locality records are surprising, perhaps due to debatable identifications (generally impossible to confirm) or to not yet established synonymies; |
6 - |
quantitative changes in the specific composition in a geographical area
(Kouwenberg & Razouls, 1990). |
|