CADIC   02618
CENTRO AUSTRAL DE INVESTIGACIONES CIENTIFICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Differences in the metabolism of two morphospecies Munida gregaria and M. subrugosa (Anomura: Galatheidae) from Beagle Channel
Autor/es:
AVALOS, CECILIA; HEILMAYER, OLAF; GUSTAVO ALEJANDRO LOVRICH
Lugar:
Coquimbo, Chile
Reunión:
Congreso; Mid-Year Meeting The Crustacean Society; 2007
Institución organizadora:
Universidad de Coquimbo / The Crustacean Society
Resumen:
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Munida gregaria and M.
subrugosa are closely related galatheid crabs of 5-7
cm total length that play a key role in the coastal sub-Antarctic
ecosystem of South America. Both morphospecies
are sympatric in the Beagle Channel. Although as adults both morphospecies are
benthic, M. gregaria is known to
perform migrations in the water column, whereas M. subrugosa is always on the sea-bottom. Due to the different
activity patterns, we expect to find differences in the aerobic metabolism of
both morphoespecies. Here we study differences in the metabolism of these two
morphospecies at the austral summer temperature. Animals were caught in Beagle
Channel (54º 50´S; 68º 17´W) by means of an epibenthic trawl. Twelve
individuals per morphopecies were acclimated to 8ºC in individual flasks during
four to eight weeks. Oxygen consumption of crabs was measured using an intermittent flow-through system. After obtaining values for standard metabolism (defined as oxygen consumption of
unfed, unstressed animals) Specific Dynamic Action (SDA) was evaluated. A different set of crabs (n=4 per
morphospecies and sex) was dissected after acclimation, and gills and muscles
were frozen to determine activity of Citrate synthase (CS) and pyruvate kinase
(PK) as well as Arrhenius breakpoint temperatures. The mean standard metabolic rate for both
morphospecies at 8°C
was 61,65 ± 11,05 µl O2· l-1·h-1·gWM-1.
No significant differences
of standard
metabolic rates were found in M. gregaria and M. subrugosa or between sexes (F=3.1; p=0.13 and F=1.4;
p=0.67, respectively). Peaks of O2 consumption after feeding were
different between both morphospecies, being significantly higher in M. subrugosa. Moreover, the pospandrial
increase (SDA) was also higher in M.
subrugosa than in M. gregaria. Our
results show no differences in the standard metabolism between both
morphospecies, however significant differences were found in SDA showing possible
differences on phisiological answers. This study was funded by the CENSOR project European
Union Contract 511071
ORAL