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Pollença, Spain

Gracia F.,Grup Nord de Mallorca GNM | Gracia F.,University of the Balearic Islands | Jaume D.,CSIC - Mediterranean Institute for Advanced Studies
Monografies de la Societat d'Historia Natural de les Balears | Year: 2011

This paper discusses the aquatic troglobiontic taxa discovered mostly since 1987 in the Balearic Islands, with some brief comments, if appropriate, on its general distribution pattern. At the same time, some mention is made about species from the interstitial environment. The last two decades have represented a qualitative leap in the knowledge of the aquatic fauna from the coastal caves of the Balearic Islands, thanks to advances in taxonomy conducted by two local renowned zoologists: Damià Jaume and Joan Lluís Pretus. The description of numerous endemic species, including thalasso-stygo-biontic organisms (marine aquatic troglobionts), has experienced a really remarkable growth. The task of speleo-divers, exploring the underwater caves of the archipelago, has allowed the discovery of completely drowned underground systems with huge and unexpected dimensions. In this manner, the faunistic researches have not been limited to the cave pools, but also to underwater passages whose depths exceed 30 m, developing even kilometres away from the cave entrances. The main contribution, besides the discovery of some new genus and species, has been exploring, surveying and studying these habitats. Groundwaters, either occupying the marine interstitial environment or located inland and accessible only by caves and wells, as well as those in river-beds and floodplains (hyporheic environment) tend, by their relative isolation, to host a large number of endemic species. A lot of them belong to primitive lineages, often unknown at the surface, and they should be considered as phylogenetic or biogeographic relics. It is, therefore, an extremely relevant fauna both from the scientific point of view as well as regarding conservation. Finally, the faunistic register from anchialine and freshwater cave-habitats of the Balearic Islands is presented, together with the inventory of strictly subterranean species of crustaceans. Source

Gracia F.,Grup Nord de Mallorca GNM | Gracia F.,Karst and Littoral Geomorphology Research | Clamor B.,Grup Nord de Mallorca GNM | Gamundi P.,Grup Nord de Mallorca GNM | Fornos J.J.,Karst and Littoral Geomorphology Research
Monografies de la Societat d'Historia Natural de les Balears | Year: 2011

In Mallorca Island, the genesis of caves and solutional morphologies that characterize the eogenetic endokarst of the littoral fringe attain particular intensity within the Upper Miocene carbonate rocks. Dissolution processes occur preferentially in the mixing zone between freshwater-of meteoric origin- and marine waters, all along the coastal areas. The submerged passages and chambers, existing in the caves of Migjorn and Llevant regions of the island, show a high diversity of solutional features that are categorized into four groups according to their dimensions, the forms they present and the genetic processes involved. The resulting morphologies are conditioned by the existence of significant lithological differences, of textural character, within the Upper Miocene calcarenites where caves develop, due to environmental variations between the reef front facies and those corresponding to lagoon facies. The difficul-ties encountered when cataloguing and systematizing the primary morphologies should be, so often, attributed to the difficulty in ascribing solutional features to a certain typology, as there are juxtapositions of different classes, with intermediate forms and different degrees of intensity in the process of dissolution. At the same time, variations in the size of solutional morphologies also increase their difficulty of classification. The inventory of forms has been structured into 4 different categories: megaforms (organization of the cave systems), macroforms (morphologies from hectometric to decametric order), mesoforms (morphologies from decametric to metric order) and microforms (morphologies from metric by centimetric order). Some of the morphologies can be found simultaneously in two different categories. Source

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