INVESTIGADORES
CUSSAC Victor Enrique
artículos
Título:
Lethal temperatures of a Neotropical fish relic in Patagonia, the scale-less characinid Gymnocharacinus bergi Steindachner 1903
Autor/es:
ORTUBAY, S.G.; S.E. GÓMEZ; V.E. CUSSAC
Revista:
ENVIRONMENTAL BIOLOGY OF FISHES
Editorial:
Springer
Referencias:
Año: 1997 vol. 49 p. 341 - 350
ISSN:
0378-1909
Resumen:
Southern South America has a rather low fish species diversity. Gymnocharacinus bergi, the southernmost
characid fish of the world, is the only member of Characoidei in the Argentine Patagonia. The isolation of this
species in an endorheic stream has been linked to the thermal conditions of its habitat, the head-waters of the
Valcheta Stream, which is the only site where this species occurs. We provide information on the distribution
and thermal habitat of this species and other fishes in the Valcheta Stream. The responses of G. bergi to high
and low temperatures were assessed in the laboratory under different temperatures and heating and cooling
rates. Our results suggest that G. bergi is unable to extend its distribution to the colder waters nearby, as well as
to waters with greater temperature fluctuations. We discuss the implications of our experimental data, the
habitat of G. bergi, and the known responses of a few other paranensean fishes to temperature, within the
framework of the thermal ecology of freshwater fishes.Gymnocharacinus bergi, the southernmost
characid fish of the world, is the only member of Characoidei in the Argentine Patagonia. The isolation of this
species in an endorheic stream has been linked to the thermal conditions of its habitat, the head-waters of the
Valcheta Stream, which is the only site where this species occurs. We provide information on the distribution
and thermal habitat of this species and other fishes in the Valcheta Stream. The responses of G. bergi to high
and low temperatures were assessed in the laboratory under different temperatures and heating and cooling
rates. Our results suggest that G. bergi is unable to extend its distribution to the colder waters nearby, as well as
to waters with greater temperature fluctuations. We discuss the implications of our experimental data, the
habitat of G. bergi, and the known responses of a few other paranensean fishes to temperature, within the
framework of the thermal ecology of freshwater fishes.G. bergi to high
and low temperatures were assessed in the laboratory under different temperatures and heating and cooling
rates. Our results suggest that G. bergi is unable to extend its distribution to the colder waters nearby, as well as
to waters with greater temperature fluctuations. We discuss the implications of our experimental data, the
habitat of G. bergi, and the known responses of a few other paranensean fishes to temperature, within the
framework of the thermal ecology of freshwater fishes.G. bergi is unable to extend its distribution to the colder waters nearby, as well as
to waters with greater temperature fluctuations. We discuss the implications of our experimental data, the
habitat of G. bergi, and the known responses of a few other paranensean fishes to temperature, within the
framework of the thermal ecology of freshwater fishes.G. bergi, and the known responses of a few other paranensean fishes to temperature, within the
framework of the thermal ecology of freshwater fishes.