Identifier

etd-11112004-174523

Degree

Master of Science (MS)

Department

Renewable Natural Resources

Document Type

Thesis

Abstract

The goal of this study was to develop several techniques that utilize the use of geothermal water that can contribute to increased profitability for commercial catfish producers. The primary objectives of this study were to: 1) determine the heating requirement using degree-days of channel catfish spawning 2) improve the efficiency of artificial spawning and, 3) evaluate the effectiveness of stocking outdoor ponds and pools with channel catfish fry. The heating requirement for channel catfish spawning was determined to be between 99 and 129 degree days at the peak of spawning. There was no difference in degree-day values between spawns collected from heated ponds, and those collected from ambient ponds. There was also no difference in the weight and fertilization percentages between the egg masses collected before and after the start of natural spawning. In artificial spawning, female-female and male-female pairs showed no differences in the volume of unfertilized eggs collected, spawning latency, and neurulation in trials conducted before and after the start of natural spawning. Spawning behavior and egg release proved to be the most accurate way to determine the optimum time to manually strip female broodstock. Survival of fry before the start of regular spawning was greater in pools then in 0.04-ha ponds but that there was no difference in the stocking of sacfry or swim-up fry before or after the start of regular spawning in ponds or pools. The size, growth rate and number of fingerlings harvested are all affected by the survival percentage of fry stocked. Lower survival results in fewer fingerlings that grow faster and larger. Survival was mostly affected by the date of stocking and the number of growing days the fingerlings remained in the ponds or pools. These results support the use of geothermally heated ponds to increase the productivity of commercial catfish producers by providing better control over spawning, increased opportunities for artificial spawning, production of improved seedstock (including hybrids), and lengthened growing period for channel catfish fry. Future research needs to focus on improving these techniques and develop methods for efficient use of geothermal water in commercial catfish production.

Date

2004

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Terrence R. Tiersch

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