Location: Warmwater Aquaculture Research UnitTitle: Oxygen requirements of separated hybrid catfish female Ictalurus punctatus male I. furcatus eggs
Submitted to: Aquaculture America Conference
Publication Type: Abstract Only
Publication Acceptance Date: 10/26/2017
Publication Date: 2/19/2018
Citation: Torrans, E.L., Ott, B.D. 2018. Oxygen requirements of separated hybrid catfish female Ictalurus punctatus male I. furcatus eggs. Aquaculture America Conference. P. 359.
Interpretive Summary: It has previously been determined that channel catfish egg masses require water near air-saturation with oxygen to avoid any negative effect of oxygen stress. The necessary oxygen concentration for hybrid catfish eggs, which are incubated as loose eggs in large tube incubators, has not yet been determined. This study determined that loose hybrid catfish eggs require water only 80% saturated with oxygen during the last day of incubation.
Technical Abstract: Channel catfish Ictalurus punctatus egg masses require ambient water with over 95% air saturation to maintain maximum oxygen consumption as they near hatch. Since hybrid catfish eggs (channel catfish ' X blue catfish I. furcatus ') are often kept separated after fertilization by the addition of fuller’s earth and incubated in large tube incubators, it is assumed that the critical oxygen requirement is lower. This study was conducted to determine the recommended dissolved oxygen concentration for incubation of hybrid catfish eggs. A 300 ml Wharton BOD bottle with a Hach LED oxygen sensor was used as the respirometer. A 2” magnetic spin bar was placed in the bottle and used to mix water throughout the chamber and suspend the loose egg/sac fry sample. The bottle was placed in a water bath at 24.8°C on a stir plate and the rotational speed adjusted to the minimum required to suspend the eggs in the bottle (60-90 RPM). The exact time of fertilization was noted for each spawn as the eggs were fertilized and placed in separate McDonald jars to incubate. The age (hours post-fertilization) was noted when each egg or fry sample was tested. A 15-45 gram egg or fry sample was siphoned from each of several McDonald jars daily through the incubation period and three days post-hatch.