Ariani, Camassa & Wittmann 2000
Ariani, Camassa & Wittmann 2000
ARIANI, A. P., M. M. CAMASSA & K. J. WITTMANN, 2000: The dolinas of Torre Castiglione (Gulf of Tarent, Italy): environmental and faunistic aspects of a semi-hypogean water system. Mémoires de Biospéologie, 27: 1-14.
A brackish water dolinas system is described from the lonian coast of Apulia (SE-ltaly). These collapse cavities are locally termed ‘Spunnulate‘ and are of late Pleistocene or Recent origin. Six dolinas, scattered over about 0.1 km2 were studied upon 5-11 inspections from May 1998 to April 1999. The area occupied by the dark zone ranged between 1% and 100% of the accessible water surface. Salinity showed temporal fluctuations of up to ± 2 ‰ within each dolina, where average values decreased with increasing sea distance, from about 8 ‰ at 120 m to about 6 ‰ at 450 m. Temperature was generaily in the range of 16-19°C (max. 21°C) at 0.2 m depth; pH was mostly in the range of 7-8 (max. 9.5). The available data, especially ionic composition (Cl = Na Mg = Ca K) clearly indicate that all the studied dolinas belong to the same water body in the underground, pertaining to deep groundwaters contaminated by sea water and chemically influenced by the corrosion of carbonatic rock. The aquatic fauna was found to include representatives of several phyla from Protozoa to Chordata (four fish species), passing through Platyhelminthes Turbellaria, Rotatoria, Nematoda, Mollusca Gastropoda, Annelida Polychaeta and Oligochaeta, and Arthropoda, whereby Crustacea appeared as dominant elements, with the presence of four orders of Peracarida: Mysidacea, Tanaidacea, Isopoda and Amphipoda. In line with the environmental characteristics, where dark and light zones are close or in immediate contact, the aquatic fauna appeared as a strongly heterogeneous complex in which several ecological and/or chorological components could be recognized: from essentially Iagoon-dwelling, typically epigean and mainly cosmopolitan species to stygophilic or stygobiontic, endemic taxa. These last are represented by two mysidacean species: the Apulian endemic lepidomysid Spelaeomysis bottazzii and an undescribed species of the mysid genus Diamysis, showing a significant degree of eye reduction, i.e. smaller cornea and smaller eyestalks with respect to congeneric, epigean populations living in brackish or marine waters of the same region. Eye reduction may be regarded as the result of an adaptive process where colonization of a semi-hypogean environment was a crucial, intermediate step.
dolinas; faunistics; lonian coast of Apulia; aquatic fauna; stygophilic animals; physical and chemical characteristics
Anguilla anguilla; Blennius; Bryocamptus pygmaeus; Diacyclops bisetosus; Diamysis mesohalobia; Diamysis sp.; Eucyclops serrulatus; Gambusia affinis; Gammarus aequicauda; Halicyclops rotundipes; Hediste diversicolor; Hydrobia acuta; Hydrobia ventrosa; Islamia pusilla; Jaera italica; Lekanesphaera hookeri; Mugil cephalus; Notonecta glauca; Orchestia stephenseni; Paracyclops fimbriatus; Procerodes plebejus; Procladius choreus; Pseudamnicola conovula; Pyrrhosoma nymphulalata; Spelaeomysis bottazzii; Stenothoe monoculoides; Tanais dulongii; Theodoxus fluviatilis; Troglomysis