Avtor/Urednik		Schlegel, Peter A; Briegleb, Wolfgang; Bulog, Boris; Steinfartz, Sebastian
Naslov		Revue et nouvelles donnees sur la sensitivite a la lumiere et orientation non-visuelle chez Proteus anguinus, Calotriton asper et Desmognathus ochrophaeus (Amphibiens urodeles hypoges)
Prevedeni naslov		Review and new data on light sensitivity and non-visual orientation in Proteus anguinus, Calotriton asper and Desmognathus ochrophaeus (Hypogean Amphibian; Urodela)
Tip		članek
Vir		Bull Soc Herp Fr
Vol. in št.		, št. 118
Leto izdaje		2006
Obseg		str. 1-31
Jezik		fre
Abstrakt		A review is given on several sensory systems that enable troglophile and troglobian urodele species to non-visually orient in their extreme hypogean habitat. In particular, recently a new sense was discovered allowing the animals to compass-orient according to the Earths magnetic field which could serve as a basic and, only in correlation with gravy-perception, would be an always available reference for orientation. Moreover, working with permanent magnetic field stimuli offers a very sensitive experimental method to discover the urodeles thresholds for light and acoustical stimuli and perhaps other sense in competition to the magnetic one. Olfaction as well as electrical and mechanical senses were not studied yet with this method, but underwater hearing was. In general, all non-visual sensory capabilities may facilitate certain behavioral strategies which compensate for missing visual orientation. Some genetically differentiating tests, comparing two populations of the endemic Pyrenean species, Calotriton asper from separated habitats, surface and cave, as well as ethological and ecological considerations led to the conclusion that cavernicoles (and eventually deep sea organisms) are more likely to own and regularly use the sensorial opportunities of a magnetic sense for spatial orientation: Compared to their epigean relatives, cave animals may have retained phylogenetically older sensorial properties, transformed or improved them, or finally acquired new ones which enable them to successfully survive in dark habitats. Sister species/populations living at the surface did not necessarily take advantage of these highly evolved sensory system and orientation strategies of the troglobian species and may have lost them. (Abstract truncated at 2000 characters)
Deskriptorji		URODELA SENSE ORGANS ORIENTATION PHOTIC STIMULATION ACOUSTIC STIMULATION ELECTROMAGNETIC FIELDS SENSORY THRESHOLDS AUDIOMETRY