Interactions between hypoxia tolerance and food deprivation in Amazonian oscars, Astronotus ocellatus (Agassiz)
نویسندگان
چکیده
منابع مشابه
Interactions between hypoxia tolerance and food deprivation in Amazonian oscars, Astronotus ocellatus.
Oscars are often subjected to a combination of low levels of oxygen and fasting during nest-guarding on Amazonian floodplains. We questioned whether this anorexia would aggravate the osmo-respiratory compromise. We compared fed and fasted oscars (10-14 days) in both normoxia and hypoxia (10-20 Torr, 4 h). Routine oxygen consumption rates (O2) were increased by 75% in fasted fish, reflecting beh...
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We found that vitamin C is an essential nutrient for an Amazonian ornamental fish, the oscar (Astronotus ocellatus). This was demonstrated by the absence of L-gulonolactone oxidase activity, the enzyme responsible for the biosynthesis of vitamin C, in liver or kidney of oscars and by a feeding trial in which oscars without vitamin C dietary supplementation developed clinical deficiency signs. F...
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The Amazonian oscar is extremely resistant to hypoxia, and tolerance scales with size. Overall, ionoregulatory responses of small ( approximately 15 g) and large oscars ( approximately 200 g) to hypoxia were qualitatively similar, but the latter were more effective. Large oscars exhibited a rapid reduction in unidirectional Na(+) uptake rate at the gills during acute hypoxia (Po(2) approximatel...
متن کاملSocial isolation and aggressiveness in the Amazonian juvenile fish Astronotus ocellatus.
We tested the effect of social isolation on the aggressiveness of an Amazonian fish: Astronotus ocellatus. Ten juvenile fishes were transferred from a group aquarium (60 x 60 x 40 cm) containing 15 individuals (without distinguishing sex) to an isolation aquarium (50 x 40 x 40 cm). Aggressiveness was tested by means of attacks on and displays toward the mirror image. The behavior was video-reco...
متن کاملاثر سطوح مختلف پروتئین جیره بر شاخص های رشد ماهی اسکار (Astronotus ocellatus, Agassiz, 1831)
آزمایشی جهت تعیین میزان پروتئین بهینه جیره غذایی ماهی اسکار (Astronotus ocellatus) طراحی شد. ماهیان با چهار نوع جیره غذایی با میزان کالری یکسان و با میزان پروتئین 40، 45، 50 و 55 درصد به مدت 8 هفته تغذیه شدند. کم ترین و بیش ترین افزایش وزن به ترتیب در ماهیان تغذیه شده با جیره 40 و 50 درصد پروتئین مشاهده شد. تنها اختلاف معنی داری در افزایش وزن ماهیان تغذیه شده با جیره 40 ...
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ژورنال
عنوان ژورنال: Journal of Experimental Biology
سال: 2013
ISSN: 1477-9145,0022-0949
DOI: 10.1242/jeb.082891