INVESTIGADORES
CUSSAC Victor Enrique
artículos
Título:
Aggressive behaviour between Gymnocharacinus bergi (Pisces, Characidae) and other Neotropical fishes from a thermal stream in Patagonia
Autor/es:
ORTUBAY, S.; M. LOZADA; V. CUSSAC
Revista:
ENVIRONMENTAL BIOLOGY OF FISHES
Editorial:
Springer
Referencias:
Año: 2002 vol. 63 p. 341 - 346
ISSN:
0378-1909
Resumen:
Gymnocharacinus bergi is a stenothermal endangered fish only found in the headwaters of a thermal stream within
the temperate Somuncur´a Plateau (Patagonia, Argentina). In spite of the presence of other fish species in the
Valcheta Stream basin, none of these has been found at the headwaters. Temperature and salinity cannot account
for the absence of extremely eurytopic Cnesterodon and Jenynsia. In addition, there is no evidence of diet overlapping
or territory defence between these species and G. bergi. Therefore, we hypothesise that agonistic behaviour
might be related to G. bergis isolation. Experiments were performed in order to analyse interspecific interaction
between G. bergi and individuals of the other two species. Cnesterodon decemmaculatus showed a submissive
behaviour while Jenynsia multidentata was clearly aggressive. G. bergi decreased its aggressive behaviour towardsis a stenothermal endangered fish only found in the headwaters of a thermal stream within
the temperate Somuncur´a Plateau (Patagonia, Argentina). In spite of the presence of other fish species in the
Valcheta Stream basin, none of these has been found at the headwaters. Temperature and salinity cannot account
for the absence of extremely eurytopic Cnesterodon and Jenynsia. In addition, there is no evidence of diet overlapping
or territory defence between these species and G. bergi. Therefore, we hypothesise that agonistic behaviour
might be related to G. bergis isolation. Experiments were performed in order to analyse interspecific interaction
between G. bergi and individuals of the other two species. Cnesterodon decemmaculatus showed a submissive
behaviour while Jenynsia multidentata was clearly aggressive. G. bergi decreased its aggressive behaviour towardsCnesterodon and Jenynsia. In addition, there is no evidence of diet overlapping
or territory defence between these species and G. bergi. Therefore, we hypothesise that agonistic behaviour
might be related to G. bergis isolation. Experiments were performed in order to analyse interspecific interaction
between G. bergi and individuals of the other two species. Cnesterodon decemmaculatus showed a submissive
behaviour while Jenynsia multidentata was clearly aggressive. G. bergi decreased its aggressive behaviour towardsG. bergi. Therefore, we hypothesise that agonistic behaviour
might be related to G. bergis isolation. Experiments were performed in order to analyse interspecific interaction
between G. bergi and individuals of the other two species. Cnesterodon decemmaculatus showed a submissive
behaviour while Jenynsia multidentata was clearly aggressive. G. bergi decreased its aggressive behaviour towardsG. bergis isolation. Experiments were performed in order to analyse interspecific interaction
between G. bergi and individuals of the other two species. Cnesterodon decemmaculatus showed a submissive
behaviour while Jenynsia multidentata was clearly aggressive. G. bergi decreased its aggressive behaviour towardsG. bergi and individuals of the other two species. Cnesterodon decemmaculatus showed a submissive
behaviour while Jenynsia multidentata was clearly aggressive. G. bergi decreased its aggressive behaviour towardsJenynsia multidentata was clearly aggressive. G. bergi decreased its aggressive behaviour towards
C. decemmaculatus throughout the experiment. However, when placed with J. multidentata, its aggressive behaviour
did not diminish.We suggest that the characteristics of the agonistic behaviour displayed by J. multidentata, opposite
from those displayed by C. decemmaculatus, might account for the absence of J. multidentata in G. bergis present
habitat. With respect to C. decemmaculatus, other factors such as its low counter current swimming ability might
play a major role in this phenomenon.throughout the experiment. However, when placed with J. multidentata, its aggressive behaviour
did not diminish.We suggest that the characteristics of the agonistic behaviour displayed by J. multidentata, opposite
from those displayed by C. decemmaculatus, might account for the absence of J. multidentata in G. bergis present
habitat. With respect to C. decemmaculatus, other factors such as its low counter current swimming ability might
play a major role in this phenomenon.J. multidentata, opposite
from those displayed by C. decemmaculatus, might account for the absence of J. multidentata in G. bergis present
habitat. With respect to C. decemmaculatus, other factors such as its low counter current swimming ability might
play a major role in this phenomenon.C. decemmaculatus, might account for the absence of J. multidentata in G. bergis present
habitat. With respect to C. decemmaculatus, other factors such as its low counter current swimming ability might
play a major role in this phenomenon.C. decemmaculatus, other factors such as its low counter current swimming ability might
play a major role in this phenomenon.