Book Description

"Chemosensory capabilities of the Colorado squawfish (Ptychochelius lucius) and the razorback sucker (Xyrauchen texanus) to the synthetic chemicals morpholine and phenethly alcohol were investigated in order to determine their feasibility as an artificial imprinting tool. Chemoreception may be involved in the life history strategy of the Colorado squawfish and razorback sucker for such events as spawning site selection and homing to natal imprinting sites. The objectives of this study were to determine if these species were chemosensitive to the synthetic chemicals; determine threshold limitations; determine if these synthetic chemicals could be used to substitute for natural odors; determine the steady state concentrations of the chemicals for artificial impriniting experiments; and to compare the chemosensitivity of the Colorado squawfish and the razorback sucker to other known chemosensitive species. Flow-through behavioral chambers were utilized to test individual squawfish and razorback suckers as distinct concentrations of morpholine and phenethyl alcohol were injected into the tanks. A positive response to the chemical was determined by a subsequent decrease in opercular rate. No change in opercular rate indicated a negative response. A total of 39 razorback suckers were tested with two trials per each odor for a total sample size of 74 - 76 trials for each synthetic chemical or control odor. The razorback sucker is clearly chemosensitive to morpholine and phenethyl alcohol, but did not respond to the controls used. Threshold concentrations were determined to be about 5 x 10−6 mg/l for morpholine and 5 x 10−4 mg/1 for phenethly alcohol. A total of 26 Colorado squawfish were tested with two trials for each odor for a total sample size of 52 - 53 trials for each synthetic chemical or control odor. The Colorado squawfish is clearly chemosensitive to morpholine and phenethly alcohol but did not respond to the controls used. Threshold concentrations were