scholarly journals Unique features of the hemoglobin system of the Antarctic notothenioid fish Gobionotothen gibberifrons

2003 ◽  
Vol 270 (19) ◽  
pp. 3981-3987 ◽  
Author(s):  
Panagiotis Marinakis ◽  
Maurizio Tamburrini ◽  
Vito Carratore ◽  
Guido Di Prisco
Author(s):  
Chiara Papetti ◽  
Massimiliano Babbucci ◽  
Agnes Dettai ◽  
Andrea Basso ◽  
Magnus Lucassen ◽  
...  

Abstract The vertebrate mitochondrial genomes generally present a typical gene order. Exceptions are uncommon and important to study the genetic mechanisms of gene order rearrangements and their consequences on phylogenetic output and mitochondrial function. Antarctic notothenioid fish carry some peculiar rearrangements of the mitochondrial gene order. In this first systematic study of 28 species, we analysed known and undescribed mitochondrial genome rearrangements for a total of eight different gene orders within the notothenioid fish. Our reconstructions suggest that transpositions, duplications and inversion of multiple genes are the most likely mechanisms of rearrangement in notothenioid mitochondrial genomes. In Trematominae, we documented an extremely rare inversion of a large genomic segment of 5300 bp that partially affected the gene compositional bias but not the phylogenetic output. The genomic region delimited by nad5 and trnF, close to the area of the Control Region, was identified as the hot spot of variation in Antarctic fish mitochondrial genomes. Analysing the sequence of several intergenic spacers and mapping the arrangements on a newly generated phylogeny showed that the entire history of the Antarctic notothenioids is characterized by multiple, relatively rapid, events of disruption of the gene order. We hypothesised that a pre-existing genomic flexibility of the ancestor of the Antarctic notothenioids may have generated a precondition for gene order rearrangement, and the pressure of purifying selection could have worked for a rapid restoration of the mitochondrial functionality and compactness after each event of rearrangement.


1997 ◽  
Vol 9 (4) ◽  
pp. 407-413 ◽  
Author(s):  
Masanori Takahashi ◽  
Tetsuo Iwami

The stomach contents of demersal fish in late January 1982 were analysed. Samples were taken at 100, 300 and 500 m depth south of Elephant Island, Bransfield Strait and north of Livingston Island, and at 800 m to the east of Smith Island. Fifty four taxa of fish belonging to 11 families were collected. The diets of 2101 fish representing 38 taxa were examined. These were classified into three categories, fish feeders, krill feeders and benthos feeders. Fish prey species fed on krill and/or benthos. Krill was a major dietary component for 32 (84.2%) out of 38 taxa. Gobionotothen gibberifrons was distributed at all 10 stations (100–800 m in depth) and its diet comprised krill and benthos. The present findings verify the importance of krill in the Antarctic marine ecosystem and indicate that krill is consumed by benthic fish at greater depths than previously reported.


2006 ◽  
Vol 6 (1) ◽  
pp. 157-159 ◽  
Author(s):  
J. K. J. VAN HOUDT ◽  
B. HELLEMANS ◽  
A. VAN DE PUTTE ◽  
P. KOUBBI ◽  
F. A. M. VOLCKAERT

1996 ◽  
Vol 8 (2) ◽  
pp. 155-160 ◽  
Author(s):  
A.W. North

The occurrence of fish in the diet of the Antarctic fur seal (Arctocephalus gazella) at Bird Island, South Georgia was investigated by analysis of fish otoliths in scats (faeces) collected during late May to early November 1983. Of the 55 scats examined, 49 contained fish remains, and 45 contained fish otoliths. Ten fish species were represented by 415 otoliths, and 33 otoliths were too digested to be identified unequivocally. Fish size was estimated from otolith size based on published allometric equations. Four coastal notothenioid fishes dominated the fish component of the diet: Champsocephalus gunnari and Gobionotothen gibberifrons each comprised about 40% of the total fish mass; Chaenocephalus aceratus was ranked third by mass and the smaller Lepidonotothen larseni occurred in one quarter of the scats but was of lower importance in terms of mass. The length-frequency distribution of C. gunnari landed by the commercial fishery in October 1982 to June 1983 is similar to that which comprised the bulk of the diet in the present study. Compared with recent studies on the fish component of the diet in the literature, the dominance of C. gunnari is generally similar, however, there was a greater proportion of G. gibberifrons during the 1983 winter and spring than reported for recent winters.


2008 ◽  
Vol 25 (2) ◽  
pp. 254-262 ◽  
Author(s):  
Lucélia Donatti ◽  
Tânia Zaleski ◽  
Patrícia Calil ◽  
Edith Fanta

The influence of photoperiod on the ability of Notothenia rossii Richardson, 1844 to detect prey was studied experimentally. In 12L/12D there was the highest number of individuals stimulated visually and chemically while in 24D chemical perception was the same as that observed in 12L/12D, the latter being lower than in 24L. The ultrastructure of chemo- and photo-sensory structures, involved in the detection of food, was studied. The photoreceptor cells of the retina are single and double cones, and rods. Taste buds were concentrated in the central part of upper and lower lips. Their shape is even, but the size is variable. The olfactory rosette has a sensory and a non-sensory epithelium, being rich in different mucosubstances. The conclusion was that in different photoperiods there is a difference in the response to visual and chemical stimulation for prey detection and that all sensory systems are more stimulated in periods of more luminosity, mainly when there is an alternation between light and dark periods. Sensory organs are complex when compared to some other Antarctic fish such as Gobionotothen gibberifrons Lönnberg, 1905 and Ophthalmolycus amberensis Tomo, Marshoff & Torno, 1977 but similar to those of N. coriiceps Rchardson, 1844.


Polar Biology ◽  
2002 ◽  
Vol 25 (7) ◽  
pp. 506-511
Author(s):  
Simona Candiani ◽  
Diana Oliveri ◽  
Sara Carbonetti ◽  
Andrea Augello ◽  
Mario Pestarino

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