Stomach evacuation rate in the planktivorous Antarctic fish Pagothenia borchgrevinki

Polar Biology ◽  
1989 ◽  
Vol 9 (6) ◽  
pp. 405-408 ◽  
Author(s):  
John C. Montgomery ◽  
Brian A. Foster ◽  
John M. Cargill
Keyword(s):  
Antarctic Fish ◽  
Evacuation Rate ◽  
Pagothenia Borchgrevinki

scholarly journals In SituGene Mapping of Two Genes Supports Independent Evolution of Sex Chromosomes in Cold-Adapted Antarctic Fish

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Laura Ghigliotti ◽  
C.-H. Christina Cheng ◽  
Céline Bonillo ◽  
Jean-Pierre Coutanceau ◽  
Eva Pisano
Keyword(s):  
Sex Chromosome ◽  
Antarctic Fish ◽  
5S Rdna ◽  
Cold Adapted ◽  
Antifreeze Glycoprotein ◽  
Y Chromosomes ◽  
Pagothenia Borchgrevinki ◽  
History Of ◽  
Sex Chromosome System

Two genes, that is, 5S ribosomal sequences and antifreeze glycoprotein (AFGP) genes, were mapped onto chromosomes of eight Antarctic notothenioid fish possessing a X1X1X2X2/X1X2Y sex chromosome system, namely,Chionodraco hamatusandPagetopsis macropterus(family Channichthyidae),Trematomus hansoni,T. newnesi,T. nicolai,T. lepidorhinus, andPagothenia borchgrevinki(family Nototheniidae), andArtedidraco skottsbergi(family Artedidraconidae). Through fluorescencein situhybridization (FISH), we uncovered distinct differences in the gene content of the Y chromosomes in the eight species, withC. hamatusandP. macropterusstanding out among others in bearing 5S rDNA and AFGP sequences on their Y chromosomes, respectively. Both genes were absent from the Y chromosomes of any analyzed species. The distinct patterns of Y and non-Y chromosome association of the 5S rDNA and AFGP genes in species representing different Antarctic fish families support an independent origin of the sex heterochromosomes in notothenioids with interesting implications for the evolutionary/adaptational history of these fishes living in a cold-stable environment.

A role of 5-HT2 receptors in the gill vasculature of the antarctic fish Pagothenia borchgrevinki.

1998 ◽  
Vol 201 (14) ◽  
pp. 2129-2138 ◽  
Author(s):  
L Sundin ◽  
W Davison ◽  
M Forster ◽  
M Axelsson
Keyword(s):  
Receptor Antagonist ◽  
Vascular Resistance ◽  
Receptor Agonist ◽  
Antarctic Fish ◽  
Cardiovascular Responses ◽  
Arterial Oxygen ◽  
Nerve Fibres ◽  
Aortic Blood ◽  
Pagothenia Borchgrevinki ◽  
The Antarctic

This study was conducted to describe the cardiovascular responses to intra-arterial injections of serotonin in the Antarctic fish Pagothenia borchgrevinki and to elucidate the underlying mechanisms. Immunohistochemistry was used to localise serotonin-containing cells within the gills. Simultaneous and continuous recordings of ventral and dorsal aortic blood pressure, heart rate and ventral aortic blood flow (cardiac output) were made using standard cannulation procedures in combination with Doppler flow measurement. An extracorporeal loop with an in-line oxygen electrode allowed continuous measurements of arterial oxygen pressure PaO2. Pre-branchial injection of serotonin (5-hydroxytryptamine, 5-HT) or the 5-HT2 receptor agonist alpha-methylserotonin increased the branchial vascular resistance and ventral aortic pressure, while the 5-HT1 receptor agonist piperazine was without effect. The branchial vasoconstriction produced by serotonin injection was completely blocked by the 5-HT1/5-HT2 receptor antagonist methysergide and the branchial vasoconstriction produced by WIDTH="9" HEIGHT="12" ALIGN="BOTTOM" NATURALSIZEFLAG= alpha-methylserotonin injection was completely blocked by the specific 5-HT2 receptor antagonist LY53857. The results suggest that the 5-HT2 receptor alone mediates the branchial vasoconstriction. Serotonin also mediated a methysergide-sensitive reduction in PaO2, the reduction being greatest when the pre-injection PaO2 value was high. 5-HT-immunoreactive cells and nerve fibres were present within the gill tissues. All the 5-HT-immunoreactive cells were located on the efferent side of the filaments, but 5-HT-immunoreactive nerve fibres were found lining both of the branchial arteries. Our findings demonstrate a potential serotonergic control system for the gills in Pagothenia borchgrevinki. In contrast to its effects on the branchial vasculature, serotonin produced a methysergide-insensitive decrease in the systemic vascular resistance. However, neither the specific 5-HT1 nor 5-HT2 receptor agonists produced a decrease in the resistance of the systemic vasculature. The nature of the serotonergic receptor(s) inducing vasodilation in teleost fish is uncertain.

Nervous control of the spleen in the red-blooded Antarctic fish, Pagothenia borchgrevinki

1996 ◽  
Vol 270 (3) ◽  
pp. R599-R604 ◽  
Author(s):  
S. Nilsson ◽  
M. E. Forster ◽  
W. Davison ◽  
M. Axelsson
Keyword(s):  
Antarctic Fish ◽  
Cholinergic Innervation ◽  
Maximal Contraction ◽  
Nervous Control ◽  
Major Function ◽  
Pagothenia Borchgrevinki ◽  
The Antarctic ◽  
Stimulation Of

The mechanisms of splenic control in the Antarctic fish, Pagothenia borchgrevinki, were investigated using isolated spleen and mesenteric artery strips in vitro and perfused spleen preparations in situ. Splenosomatic index (SSI) [100 x (spleen wt/body wt)] and hematocrit were determined in animals treated with atropine and phentolamine. Atropine injection increased the SSI from 0.60 +/- 0.06 to 0.89 +/- 0.04, whereas phentolamine decreased SSI to 0.45 +/- 0.03. In atropine-injected fish, hematocrit was 18.6 +/- 1.4 before and 6.6 +/- 0.8% 3 h after injection. Electrical stimulation of the splenic nerves produced biphasic flow responses. In 11 of 12 tested preparations, atropine (3 x 10(-7) to 10(-6) M) abolished the response, suggesting a major cholinergic component in the splenic innervation. Isolated spleen strip preparations contracted in response to carbachol, a response that was antagonized by atropine. The response to acetylcholine was markedly enhanced by the specific cholinesterase inhibitor BW-284c51. Catecholamine effects were somewhat irregular, and maximal contraction force with epinephrine and norepinephrine was 41 and 56%, respectively, of the carbachol response. The results suggest a mainly, if not solely, cholinergic autonomic control of the borch spleen, and a major function of the cholinergic innervation in the control of hematocrit in this species.

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