Electrolyte and trace metal levels in Commerson’s dolphin (Cephalorhynchus c. commersonii) from Tierra del Fuego, Argentina

CÁCERES SAEZ, I.; RIBEIRO GUEVARA, S.; GOODALL, R.N.P.; CAPPOZZO, L.

Jalisco, México

Congreso; XXXIII Reunión Internacional para el Estudio de los Mamíferos Marinos; 2012

SOMEMMA

The concentration of essential trace elements and electrolytes must range within adequate values to assure health conditions; this concentration range depends on the species physiology. The Commerson's dolphin (Cephalorhynchus c. commersonii) is an endemic small dolphin inhabits South America (40ºS - 56ºS), affected by incidental catch in Tierra del Fuego, Argentina (TdF-Arg). Our purpose is to report concentrations of electrolyte (Br, Rb, Cs) and trace (Fe, Zn, Co) essential elements in liver, kidney and muscle of seven specimens of Commerson’s dolphin recovered from incidental catch during 2009 to 2011 by the Museo Acatushún de Aves y Mamíferos Marinos Australes (AMMA), Estancia Harberton, TdF-Arg. The elemental determinations were carried out by instrumental neutron activation analysis. Liver was the organ with the highest mean concentration of Fe (897±79) ugg-1 dry weight (DW), and kidney had the highest levels of Br (73±12) ugg-1 DW (the uncertainty reported is the standard deviation). Zinc was similar in hepatic and renal tissue, ranging from 117 to 122 ugg-1 DW. The concentration of electrolyte elements ranged from 6.3 to 6.7 ugg-1 DW for Rb, and from 0.200 to 0.252 ugg-1 DW for Cs, whereas for the other trace element reported, Co, the concentration (from 0.030 to 0.100 ugg-1 DW) was similar among the three tissues studied. Likewise, as in other marine mammals, the concentrations of the electrolytes and essential trace elements studied showed little variation between the specimens studied, since they are regulated biochemically. This study is part of the first description of the elemental composition of Commerson's dolphin tissues from subantarctic waters, and this information could have relevance in nutritional and environmental researches.