1 - Instituto de Biologia da UFRJ

higher than ECO and PP, where as total proteins levels in R2
N. rossii were lower than PP. The plasmatic levels of glucose,
TG and cholesterol in N. coriiceps of the three sampling
sites were not significantly different, but were observed
lower plasma total proteins and higher albumin levels in
N. coriiceps of R2.
Discussion
ECO inlet is close to a large penguin colony under
ornithogenic influence; R2 is located in the Mackellar inlet
and close to a glacier; whereas the PP is far from Penguin
rookeries, glaciers and scientific station. The differences
in these three environments were not able to modulate
the plasmatic levels of glucose, TG and cholesterol in
N.coriiceps, but the same was not observed in N. rossii.
The difference in the results for the two fish species could
be due to functional capacities, which differ according
to their lifestyle, and in turn defines their tolerance to
environmental changes (Bilyk & DeVries, 2011; Mark et al.,
2012). Glycaemia has been used to indicate stress in fish
(Pankhurst, 2011). The glucose metabolism has been
considered of secondary energy importance, even though
tissues such as brain, kidneys and gills have high glucose
consumption (Enes et al., 2009). The branchial tissue of
Antarctic fish has elevated oxidative potential for glucose,
compared to monounsaturated fatty acid (Crockett et al.,
1999). This way, the glicemia rise in vertebrates has been
associated with energy demands “fight to flight” reaction
(Pottinger et al., 2000). The hyperglycaemia of N. rossii
in R2 is not clear, but must be related to specific energy
demands, inherent to the local marine environment, and
must be the aim of future studies.
The lipid transport in fish is similar to that of mammals.
The very low density lipoprotein (VLDL) is the main
carrier of TG (Nanton et al., 2006). The high levels of TG
and cholesterol in N. rossii at R2 can be an indication of
high levels of the VLDL. Hepatic, muscular and cardiac
tissues of Antarctic fish have elevated oxidative potential
for monounsaturated fatty acids and supports an energy
metabolism based on lipid (Sidell et al., 1995). The cause of
the higher plasmatic TG at R2 is not clear, but may have a
relation with N. rossii feeding behavior. The Antarctic krill is
part of N. rossii diet, which is capable of migrating vertically
in the water column and feeding on this crustacean during
the summer. The presence of elevated levels of fluoride in
the krill carapace may have a relation with higher glucose
and TG levels observed in R2. Fluoride studies with non-
Antarctic organisms showed that this halogen is capable of
increasing the blood levels of glucose and lipid.
The albumin concentration in the fish blood is low
and absent in some cases (Metcalf et al., 2007). The main
physiological function of this protein includes the transport
of fatty acids, ions and coloidosmotic pressure control. These
differences can be related to the different physiological and
environmental characteristics. Taking into account and
comparing the base line data between the two species may
be N. corriceps shows advantages in being used for bioassays
for selection of biomarkers and monitoring programs.
Conclusion
The results presented showed that the marine environments
of Admiralty Bay may have particularities capable of
distinctly modulating glucose, TG, cholesterol, total proteins
and albumin levels in the blood of Antarctic fish N. rossii
and N. coriiceps. Therefore the levels of these plasmatic
constituents cannot be taken as homogenous in Admiralty
Bay for these fish species. This baseline study of plasmatic
constituents is important to environmental monitoring in
the context of climate changes.
Acknowledgements
Donatti, L. , and Rodrigues, E. thank the Brazilian Federal
Agency for the Support and Evaluation of Graduate
Education (CAPES) for the PhD Fellow of Rodrigues Jr 3 .
E. (Molecular and Cellular Biology Graduate Program,
Federal University of Paraná). This work integrates the
National Institute of Science and Technology Antarctic
Environmental Research (INCT-APA) that receives
scientific and financial support from the National
Council for Research and Development (CNPq process:
n° 574018/2008-5) and Carlos Chagas Research Support
Foundation of the State of Rio de Janeiro (FAPERJ n°
E-16/170.023/2008). The authors also acknowledge the
support of the Brazilian Ministries of Science, Technology
and Innovation (MCTI), of Environment (MMA) and Inter-
Ministry Commission for Sea Resources (CIRM).
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