Buoyancy of Sub-Antarctic Notothenioids including the sister lineage of all other notothenioids (Bovichtidae)

FERNÁNDEZ, D.A.; CEBALLOS, S.G.; MALANGA, G.F.; BOY, C.C.; VANELLA, F.A.

POLAR BIOLOGY

SPRINGER

Lugar: Heidelberg; Año: 2012 vol. 35 p. 99 - 106

0722-4060

Static buoyancy was measured on 225 adult fish specimens from the Beagle Channel, representing seven species of the sub-Antarctic sub-order Notothenioidei (belonging to the families Bovichthydae, Eleginopidae, Nototheniidae and Harpagiferidae) and one Zoarcoidei . Measurements were expressed as percentage of buoyancy (%B = Wwater / Wair x 100). All the species analysed showed negative buoyancy with values varying from 3.61% to 6,96%, and therefore, according to previous studies, they could be all considered benthic species. These results are in accordance with previous studies indicating neutral buouyancy in notothenioids is rare. Between the notothenioids there were significant difference among the less buoyant Harpagifer bispinis, Patagonotothen cornucola and Cottoperca gobio and the more buoyant Paranotothenia magellanica. The zoarcid showed very low buoyancy values averaging 4.51%. The static buoyancy values of all the species analyzed correlate well with the habitat previously observed in the field and at the laboratory.