Artículo
Adaptive radiation at a low taxonomic level: Divergence in buoyancy of the ecologically similar Antarctic fish Notothenia coriiceps and N. rossii
Fecha de publicación:
10/2011
Editorial:
Inter-Research
Revista:
Marine Ecology Progress Series
ISSN:
0171-8630
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
We studied the buoyancy of 263 specimens of the sympatric sister species Notothenia coriiceps and N. rossii captured at King George Island. In these species without a swim bladder, we expressed measurements of buoyancy as percentage buoyancy (%B = weight in water/weight in air × 100), with smaller numbers reflecting more buoyant (i.e. less dense) species. Mean %B of N. coriiceps (4.34%) was significantly greater than that of N. rossii (3.82%), reflecting the lower density and more active swimming, migratory, and feeding behavior of N. rossii compared to N. coriiceps. Skeletal weight as a percentage of body weight was also significantly greater in N. coriiceps (2.46%) than N. rossii (1.65%). Paradoxically, the weight of the vertebral column as a percentage of skeletal weight was significantly greater in N. rossii (28.01%) than in N. coriiceps (24.29%); however, this is intelligible in light of the bone anatomy and histology. Our sample encompassed a wide size and age range, and trend lines for scatter plots of %B against standard length were curvilinear for both species, peaking at 140 to 160 mm, a phenomenon not previously seen in studies of notothenioid buoyancy. We conclude that the ontogenetic increase in %B (reduced buoyancy) in fingerlings/young juveniles and the ontogenetic decrease in %B (increased buoyancy) in older juveniles/immature adults reflects disproportionate growth of skeletal and visceral tissues, respectively, and is not causally related to concurrent pelagic-demersal habitat shifts.
Archivos asociados
Licencia
Identificadores
Colecciones
Articulos(MACNBR)
Articulos de MUSEO ARG.DE CS.NAT "BERNARDINO RIVADAVIA"
Articulos de MUSEO ARG.DE CS.NAT "BERNARDINO RIVADAVIA"
Articulos(SEDE CENTRAL)
Articulos de SEDE CENTRAL
Articulos de SEDE CENTRAL
Citación
Eastman, Joseph T.; Barrera Oro, Esteban; Moreira, María Eugenia; Adaptive radiation at a low taxonomic level: Divergence in buoyancy of the ecologically similar Antarctic fish Notothenia coriiceps and N. rossii; Inter-Research; Marine Ecology Progress Series; 438; 10-2011; 195-206
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