The elemental composition of swimbladders in some deepwater fishes of the North Atlantic

Resumo

The first data on the elemental contents of the swimbladder wall of three deepwater fish species from the North Atlantic (the snubnosed spiny eel Notacanthus chemnitzii, the Kaup’s arrowtooth eel Synaphobranchus kaupii, and the roughhead grenadier Macrourus berglax) are presented. It is supposed that survival of specimens of the first two species upon their ascent from great depths that subject them to sharp changes of pressure is connected with the properties of the durable and flexible swimbladder walls with increased contents of some metals (aluminum, copper, iron, mercury, potassium, manganese, chromium, and cadmium). Adaptation to sharp changes of pressure in N. chemnitzii and S. kaupii probably develops during ontogeny, during the transition from habitation in the epipelagic zone during the larval stage to the deepwater habitat of the adult fish.