Use of Geothermal Water in the Production of Channel Catfish

Lang, R. P., R. P. Romaire, G. S. Roppolo, and T. R. Tiersch, Aquaculture Research Station, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge, LA 70820

The purpose of this project was to use geothermal well water to raise pond temperatures to induce early spawning in channel catfish Ictulurus punctatus. From February 23 to March 5, groups of 15 female and 8 male channel catfish were stocked into six 0.04-ha ponds with an average depth of 1.3 m. Temperature was controlled by addition of water (~ 29 °C) from a 700-m well, and was raised from ambient at ~2 °C per d until reaching the target of 26 °C. One week prior to the addition of heated water, spawning cans (80-L) were placed at the corners of all ponds. Data loggers were suspended 1 m above the pond bottom and temperature was recorded at 24-min intervals. Cans were checked every 3 d until four egg masses (per pond) were collected and the cans were removed. The ponds were seined and artificial spawning was induced in recirculating systems by pairing of males with females injected with synthetic leuteininzing hormone-releasing hormone (100 mg/kg). Eggs were stripped into greased bowls and fertilized with sperm collected from males from the same pond. Percent fertilization was estimated for egg masses when collected from the pond and at 24 h after fertilization for artificially spawned masses. Ponds 1 and 2 were heated from March 14 to April 22. Egg masses were collected from March 26 to April 10. In total, 47% (7 of 15) of the females spawned from Pond 1; fertilization was 91 ± 2% for pond spawns and 88 ± 2% for artificial spawns (n = 3). For Pond 2, 67% (10 of 15) of the females spawned; fertilization was 90 ± 4% for pond spawns and 91 ± 2% for artificial spawns (n = 6). Pond 3 was heated March 23 to April 22, and egg masses were collected from April 7 to April 16. Artificial spawn data was not collected, and fertilization for was 90 ± 4% for pond spawns. Pond 4 was heated from March 23 to Mar 30, and then allowed to return to ambient temperature. Egg masses were collected from April 10 to April 28. In total, 60% (9 of 15) of the females spawned; fertilization was 80 ± 9% for pond spawns and 73 ± 12% for artificial spawns (n = 5). Masses were collected from unheated ponds (5 and 6) from April 28 to May 7. For Pond 5, 30% (5 of 15) of the females spawned; fertilization was 83 ± 6% for pond spawns and 90% for artificial spawns (n = 1). For Pond 6, 40% (6 of 15) of the females spawned; fertilization was 89 ± 2% for pond spawns and 90% for artificial spawns (n = 2). Heated Ponds 1 through 4 each produced four egg masses each before the onset of natural spawning. Thus, channel catfish in ponds can spawn when ambient water temperature would otherwise be below the minimum temperature threshold for natural spawning (~ 24 °C) if the ponds are provided with supplemental heat. In addition, temporarily raising pond temperature accelerated the onset of natural spawning. Future studies could address polyculture in heated ponds and explore alternative sources of energy to heat ponds.

Copyright © 1999
Texas Chapter of the American Fisheries Society
Last modified: 01/07/09 06:45:17 AM