|Distribution of the Tanaidacea: synopsis of the known data and suggestions on possible distribution patterns|
Sieg, J. (1986). Distribution of the Tanaidacea: synopsis of the known data and suggestions on possible distribution patterns, in: Gore, R.H. et al. (1986). Crustacean biogeography. Crustacean Issues, 4: pp. 165-194
In: Gore, R.H.; Heck, K.L. (1986). Crustacean biogeography. Crustacean Issues, 4. A.A. Balkema: Rotterdam, The Netherlands [etc.]. ISBN 90-6191-593-7. 292 pp., more
In: Schram, F.R. (Ed.) Crustacean Issues. Balkema/CRC Press/Taylor & Francis: Rotterdam. ISSN 0168-6356, more
As in other biological disciplines zoogeography can be divided into a descriptive and an analytic section. A synopsis of the known, but scattered, data allows remarks on faunistics as well as on systematic, ecological, and phylogenetic zoogeography. Within faunistics, an overview of the established zoogeographic regions is given. The tanaidacean fauna of the main regions (cold water areas of the Antarctic and Arctic, northern and southern temperate waters, tropical warm water) are discussed. The Antarctic cold water area is characterized by having a much higher percentage of endemic elements (approximately 63%) than the Arctic (about 10%). There are only two or three species in these regions that show a bipolar distribution. Only a limited comparison of the tanaidacean faunas of the northern temperate and tropical warm water areas can be made, and relies mainly on data from the Atlantic Ocean, an area much better explored than any other region of the world. It can be shown that there exists a much closer relationship between the northern temperate waters and the tropical warm water than with the southern temperate area in either the Pacific and the Atlantic. On the other hand the main areas of the tropical warm water regions are each characterized by an independent tanaidacean species-composition. Only the Indo-West Pacific may be called (with some reservation) an interceding area. In total the Atlantic tanaidacean fauna shows a closer relationship to the Pacific than to the Indian Ocean. The shallow-water family Tanaidae probably has a southern 'evolution center'. It is then shown that the phylogenetic method also allows an analysis of the geographic origin of the members of a special fauna. This is exemplified by the tanaid fauna of the Gulf of Mexico. Finally, the relationship between body size and depth is discussed. An analysis shows that the order Tanaidacea is characterized by a constant size reduction during evolution. Therefore, there is a much stronger correlation between size and the phylogenetic age of a taxon than with depth. Probably all known large deep-sea or cold water species of a particular taxon are plesiomorphic compared to the small members occurring in the same region.