000			02876nab a2200349 a 4500
003			AR-ReUNN
005			20260702003101.0
008			260630s2007 ag |||||||||||||||||eng
041	0		_aeng
100	1		_aMenni, Roberto Carlos _9117941
700	1		_aGómez, Sergio e. _9144725
700	1		_aLópez Armengol, María Fernanda _9110822
245	1	0	_aSubtle relationships : freshwater fishes and water chemistry in southern South America
264		1	_c2007
300			_a25 páginas
520			_aAbstract : We investigated the relationships between water chemistry and the occurrence, distribution, physiology, and morphology of fish faunas. We examined 34 species (ca. 10% of the Argentinean freshwater fish fauna) from 120 localities (5 areas) situated between 26°15 S (Trancas, Tucumán) and 38°30 S (Sierra de la Ventana, Buenos Aires). Fourteen chemical features are described by: conductivity, total dissolved solids, temperature, pH, CO 3 2 - , CO3H-, Cl -, SO 4 2- Ca2+, K+, Mg2+, Na+, Mg/Ca, Mg+Ca/Na+K. Three Basic Data Matrices considering the mean, maximum and minimum values of each variable for each fish species were used in a Cluster and Principal Component Analysis. Groups of species clustered in similar ways to particular water chemistries. Similarity was the common occurrence of species in a defined area and preference for a common range of the factors considered. Groups of species so defined showed patterns of distribution related to climate, environment, trophic state and hydrographic complexity. Each cluster included some eurytopic species which appeared together at extreme chemical and geographic characteristics. Twenty four species had ranges of tolerance for the 14 variables and evidence of a grouping according to these ranges. Eighteen species which occurred at maximum or minimum absolute values for more than one factor were ordered along an eurytopy - stenotopy axis. We support the statement that species with a larger tolerance range for most factors have a higher probability of being widely distributed. Astyanax fasciatus and A. bimaculatus tolerated the highest number of maximum and minimum values, followed by Jenynsia l. lineata, A. eigenmanniorum and Trichomycterus corduvensis. Groups of species based on chemical factors showed differences in the relative number of basic morphological types.
650		4	_aIchthyology _9119207
650		4	_aIctiología _99239
650		4	_aPeces de Agua Dulce _96471
650		4	_aFreshwater Fish _9117439
650		4	_aInland Waters _9117440
650		4	_aArgentina _94258
650		4	_aEcology _9117438
650		4	_aFish _9130097
650		4	_aGeography _9129729
650		4	_aPhysiology _9125964
650		4	_aWater Chemistry _9147723
773	0		_tHydrobiología _x0018-8158 _gv. 328 n. 3 (1996) _w234475
942			_cART
035			_a(INICN)40451
001			234865
999			_c234865 _d234865
040			_aAR-ReUNN _bspa _cAR-ReUNN _eaacr2