Record Details
Field | Value |
---|---|
Title | Influence of dissolved oxygen concentration and swimming velocity on food consumption and growth of juvenile Coho salmon |
Names |
Hutchins, Floyd E.
(creator) Shumway, Dean L. (advisor) |
Date Issued | 1973-05-25 (iso8601) |
Note | Graduation date: 1974 |
Abstract | Laboratory studies were conducted on the food consumption, growth, and bioenergetics of juvenile coho salmon (Oncoynchus kisutch) held at various swimming velocities and dissolved oxygen concentrations at 15 C. Food consumption and growth of salmon fed to repletion on housefly larvae (Mus domesticus) were reduced by increasing activity at and above 3 lengths per second (L/sec) and 2 L/sec, respectively. Food conversion efficiencies for growth decreased with increasing activity; efficiencies of converting food to growth and activity combined, however, increased with increasing activity. The logarithm of the rate of energy loss of unfed swimming salmon increased exponentially with increasing velocity. The growth rates of salmon fed to repletion and held at 1.3 and 3.0 L/sec at an oxygen level of 3 mg/liter were reduced by 20 and 65 percent from that of control salmon held at respective velocities in air-saturated water. At the intermediate oxygen concentration of 5 mg/liter, growth rates of salmon were reduced by 0 and 15 percent over controls held at 1.3 and 3.0 L/sec, respectively. The total respiration rate (TRR) of salmon fed to repletion and held at air saturation remained nearly constant over the range of activity levels tested (0 to 3.8 L/sec). At 1.3 L/sec the TRR of salmon increased with increasing food consumption, while at 3.7 L/sec increased food consumption did not alter the TRR. Reduction in oxygen concentration lowered the TRR of salmon, although growth was not reduced in every case. The specific dynamic action of food (SDA), i.e., cost of food digestion and processing, ranged from 10 to 30 percent of the assimilated energy. The larger percentages were observed at high oxygen concentrations, generally at low food consumption rates, and at low velocities; and the lower percentages at low oxygen levels, high food consumption rates, and high velocities. The absolute value of SDA increased with increasing food consumption at 1.3 L/sec, but declined at 3.7 L/sec. In salmon fed to repletion, the SDA decreased with increased activity levels and reduced oxygen concentration. |
Genre | Thesis/Dissertation |
Topic | Coho salmon |
Identifier | http://hdl.handle.net/1957/22346 |