INIBIOMA   20415
INSTITUTO DE INVESTIGACIONES EN BIODIVERSIDAD Y MEDIOAMBIENTE
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Distribution and ecology of freshwater ostracods in northern Patagonia: an approach
Autor/es:
COVIAGA, CORINA; CUSMINSKY GABRIELA; PEREZ, A. PATRICIA; DIAZ, ANALIA; ALPERIN, MARTA
Reunión:
Simposio; 17th ISO; 2013
Resumen:
There are only a few studies about the ostracod faunal assemblages and
their environmental
requirements from Patagonia (e.g. Cusminsky et al. 2011; Ramón
Mercau et al. 2012).
Here we present the results of a survey of thirteen water bodies
(streams, springs,
temporary habitats) in Northern Patagonia (39° 52? ? 41°50? S; 70°36? ?
71°27? W) and
their comparison with those of previous studies in the earstern
Patagonia. The goal of this
research is to enhance our understanding of the regional Patagonian
ostracoda fauna and
evaluate the relationship between ostracod species and physical and
chemical (depth,
temperature, pH, conductivity, dissolved oxygen concentration, seston
and main ions)
parameters of host waters along a W-E precipitation gradient (ranging
from 1200 to
160mm/annually). To date, seven species were identified: Amphicypris
nobilis Sars 1901,
Bradleystrandesia
fuscata (Jurine,
1820), Cypridopsis vidua (O. F. Müller, 1776), Cypris
pubera O. F. Müller 1776, Eucypris
virens (Jurine, 1820), Heterocypris incongruens
(Ramdohr, 1808) and Tonnacypris lutaria (Koch, 1838). The more
frequent species were T.
lutaria and E. virens, while A.
nobilis and C. vidua were only found in one site. Males of A.
nobilis were found while the other
species were represented only by females. The
environment of this fauna is related to low conductivity and salinity in
the water.
Conversely, previous studies in the easternmost area of Patagonia have
shown different
fauna such us Penthesinelula
incae (Delachaux, 1928), Potamocypris smaradigma (Vávra,
1891), Ilyocypris ramirezi Cusminsky and Whatley, 1996, Limnocythere
patagonica
Cusminsky and Whatley, 1996, Eucypris fontana (Graf, 1931), Kapcypridopsis
megapodus
Cusminsky et al. 2005 and Limnocythere rionegroensis, Cusminsky
and Whatley, 1996
living in comparatively higher conductivity (Cusminsky et al.
2011). The latter suggest that
the decreasing precipitation trend towards eastern Patagonia is reflected
in the distribution
of different ostracod fauna association. On the other hand, new
distributions of
cosmopolitan species are present, spreading out their geographical
distribution to the
Neotropical region (Martens et
al. 2008). Some of the species such us C.
pubera, E. virens
and B. fuscata have been also
described in the Neartic region, suggesting that birds could
be responsible to their dispersion. However, the mode of dispersion of T.
lutaria in this
region is still
an open question.