... in white-blooded icefishes from the family Channichthyidae. Loss of key elements of the cellular stress response, notably the heat shock response, has also been observed. Along with their attainment of cold tolerance, notothenioids have developed an extreme stenothermy and many species perish...

...Kimberly A. Borley; Jody M. Beers; Bruce D. Sidell SUMMARY Antarctic icefishes possess several cardiovascular characteristics that enable them to deliver oxygen adequately in the absence of hemoglobin (Hb). To gain insight into mechanisms driving development of these cardiovascular characteristics...

... differences in vessel morphometries among notothenioid species. Hemoglobinless (–Hb) icefishes display mean vessel length densities that are greater ( Chaenocephalus aceratus , 5.51±0.32 mm mm –2 ; Champsocephalus gunnari , 5.15±0.50 mm mm –2 ) than those observed in red-blooded (+Hb) species( Gymnodraco...

..., 100 μm. * Author for correspondence (e-mail: [email protected] ) 18 4 2005 © The Company of Biologists Limited 2005 2005 icefish visual pigment retina photoreceptor The Notothenioidei is a suborder of teleosts largely endemic to the Antarctic region...

...D. Pellegrino; C. A. Palmerini; B. Tota SUMMARY The role of nitric oxide (NO) in cardio-vascular homeostasis is now known to include allosteric redox modulation of cell respiration. An interesting animal for the study of this wide-ranging influence of NO is the cold-adapted Antarctic icefish...

...Deena J. Small; Thomas Moylan; Michael E. Vayda; Bruce D. Sidell SUMMARY Six of the 16 known species of Antarctic icefish (family Channichthyidae) have lost the ability to express cardiac myoglobin (Mb) via at least four independent events during radiation of these species. We report here...

... found in the pectoral muscle fibres of the icefish Chaenocephalus aceratus , which lacks the respiratory pigments haemoglobin and myoglobin. Red-blooded notothenioids found in the sub-Antarctic had a similar muscle fine structure to those caught south of the Antarctic Convergence, with an MFD of 20–41...

... to mitochondrial volume densities. Cristae are more densely packed within the mitochondria of hearts of G. gibberifrons than in those of Chionodraco rastrospinosus and Chaenocephalus aceratus . The lower cristae surface densities within mitochondria suggest that icefish might have a lower oxidative capacity...