Surfacing activity and food utilization in a tropical air-breathing fish exposed to different temperatures

Vivekanandan, E. ; Pandian, T. J. (1977) Surfacing activity and food utilization in a tropical air-breathing fish exposed to different temperatures Hydrobiologia, 54 (2). pp. 145-160. ISSN 0018-8158

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Official URL: http://www.springerlink.com/content/382w076r852068...

Related URL: http://dx.doi.org/10.1007/BF00034989

Abstract

Reared in tubular aquaria containing different depths of water (2.5, 5.0, 15.5, 31.0 and 40.0 cm), the obligatory air-breathing fish Ophiocephalus striatus (760 mg; 4.5 cm L) was forced to swim vertically a longer or shorter distance per surfacing. Interaction of temperature (17, 22, 27, 32 and 37°C) and aquarium depth reveals that surfacing frequency of the fish, fed ad libitum on Tilapia muscle, increased with increasing aquarium depth, but the increase was significant only at 27 and 32°C; in the starving series, the frequency was not depth-dependent at any temperature. Owing to the sustained surfacing activity and the consequent fatigue, the test individuals 'hung' to the surface for a definite period. Hanging frequency was temperature-dependent, but not a depth-dependent activity either in the starving or feeding series. At any temperature and aquarium depth, the feeding series hung more frequently than the starving series. Hanging duration increased from about 1 hr/day in either series at 17°C to 6 and 18 hr/day in the feeding and starving series at 37°C. At any tested temperature, distance swum by the feeding and starving series was a depth-dependent activity. The feeding series at 32°C exhibited the maximum swimming speed of 2 L/sec for 4.8 hr/day in the 40 cm depth. With increasing temperature and depth, feeding rate increased (from 24 to 225 g cal/g live fish/day); between 17 and 27°C, it was more a temperature-dependent activity. The highest rate (47 g cal / g/day) and efficiency (27%) of conversion were observed at 32°C; whereas the efficiency was depth-dependent, the rate was not. Oxygen uptake was a temperature-dependent activity; aquarium depth played a secondary role. Briefly, O. striatus in deeper aquaria consumed significantly more food and converted lesser, as it surfaced more frequently and swam longer distance, dissipating more energy on metabolism and swimming activity. Hence, culturing O. striatus in shallow waters at the optimum temperature of 32°C will be advantageous.

Item Type:Article
Source:Copyright of this article belongs to Springer.
Keywords:Temperature Effects-Surfacing; Hanging Frequencies-Swimming Speed; Distance-Food Intake; Absorption; Conversion-O2 Uptake
ID Code:39834
Deposited On:17 May 2011 16:48
Last Modified:17 May 2011 16:48

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