INVESTIGADORES
CUSSAC Victor Enrique
artículos
Título:
The distribution of South American galaxiid fishes: the role of biological traits and post glacial history
Autor/es:
CUSSAC, V.; S. ORTUBAY; G. IGLESIAS; D. MILANO; M. LATTUCA; J. BARRIGA; M. BATTINI; M. GROSS
Revista:
JOURNAL OF BIOGEOGRAPHY
Editorial:
Blackwell
Referencias:
Año: 2004 vol. 31 p. 103 - 122
ISSN:
0305-0270
Resumen:
ABSTRACT
Aim The aim of this work is to update the distribution data of Galaxiidae in
South America, relating extant distribution to physiological and reproductive
characteristics of the species, latitude, temperature, and post-glacial opportunities
for colonization.
Location Lakes and rivers of Patagonia.
Methods We compared, and eventually reconsidered, general data about
distribution based on the original literature about capture sites, incorporating
several published and unpublished data to the analysis of the biological traits and
distribution of Galaxiidae.
Results The more consistent issue in the comprehension of galaxiid
biogeography in South America is the ability to establish landlocked
populations. Different founding events in landlocked populations of Galaxias
maculatus suggest the possible existence of older and younger landlocked
populations. This difference in the time since the establishment of lacustrine
populations could have been expressed in their ability for colonization of postglacial
areas. Galaxias maculatus, Aplochiton and Brachygalaxias are more clearly
excluded from the post-glacial area than G. platei. For all the species we could
note a more abundant record of lake populations at the area of glacial refuges. It
could be noted that the most successful species, Galaxias platei, is a specialized
deep bottom dweller. Deep bottom dwelling helps to endure winter constraints
and it appears to be an alternative to the colonization of the littoral and limnetic
zones of post-glacial lakes, the prefered habitat of the other Patagonian fish
species.
Main conclusions At the end of this process of post-glacial colonization, in the
beginning of twentieth century, man introduced several salmonid species in
Patagonia. In addition, antropogenic actions had its more recent consequences in
global warming. Nowadays we were able to observe new localities for Brazilian
fishes into the Austral Subregion and expect some changes in the distribution of
Galaxiidae. Northern limits for all species and southern limits for landlocked
G. maculatus, Brachigalaxias bullocki and Aplochiton zebra, could be displaced
southward. Probably, the species less affected by the changes will be G. platei.
These predictions could be accurately formulated using the model of B.J. Shuter
& J.R. Post (1990) Transactions of the American Fisheries Society 119, 314336,
when biological database on these species are completed.