1. NITROGEN OXIDES ELICIT ANTIPREDATOR RESPONSES IN JUVENILE CHANNEL CATFISH, BUT NOT IN CONVICT CICHLIDS OR RAINBOW TROUT: CONSERVATION OF THE OSTARIOPHYSAN ALARM PHEROMONE GRANT E. BROWN,1;¤ JAMES C. ADRIAN JR.,2 NABIL T. NADERI,1 MARK C. HARVEY,1 and JOCELYN M. KELLY1 1Department of Biology Concordia University 1455 de Maisonneuve Boul. O. Montr´eal Queb´ec H1G 3M8, Canada 2Department of Chemistry Science and Engineering Center Union College Schenectady New York 12308, USA

2. FIG. 1. Hypoxathine-3-N-oxide, with standard purine numbering system.

3. FIG. 2. General phylogeny of Euteleost fishes, showing relationship within the superorder Ostariophysi (heavy lines). Asterisks denote orders previously tested for responses to purine-N-oxides. Names in bold type denote groups tested in the current study. Phylogeny based on Moyle and Cech (1996).

4. TABLE 1. CHEMICAL STRUCTURES OF THE SYNTHETIC STIMULI USED IN EXPERIMENT 1

5. FIG. 3. Mean (§SE) change in slow movement (A) and fast movement (B) time (sec) by juvenile channel catfish. Different letters denote significant differences based on Fisher’s Probability of Least Squared Differences (P < 0:05). CSE D conspecific skin extract, H3NO D hypoxanthine-3-N-oxide, PNO D pyridine-N-oxide, PNC D pyridine, PYR D 4(3H) pyrimidone, GUAN D guanine, HXAN D hypoxanthine, XAN D xanthine, SWT D swordtail skin extract, DW D distilled water.

6. FIG. 4. Mean (§SE) change in time (sec) spent motionless (A) and resting (B) by juvenile channel catfish. Different letters denote significant differences based on Fisher’s Probability of Least-Squared Differences (P < 0:05). CSE D conspecific skin extract, H3NO D hypoxanthine-3-N-oxide, PNO D pyridine-N-oxide, PNC D pyridine, PYR D 4(3H)- pyrimidone, GUAN D guanine, HXAN D hypoxanthine, XAN D xanthine, SWT D swordtail skin extract, DW D distilled water

7. FIG. 5. Mean (§SE) change in area use (A), distance to neighbor (cm, B) and number of aggressive interactions (C) for juvenile convict cichlids exposed to conspecific skin extract (CSE), hypoxanthine-3-N- oxide (H3NO) or distilled water (DW). Different letters denote significant differences based on Fisher’s Probability of Least-Squared Differences (P < 0:05).

8. FIG. 6. Mean (§SE) change in time spent moving (sec, A), time under shelter (sec, B) and time in front area (sec, C) for juvenile rainbow trout exposed to conspecific skin extract (CSE), hypoxanthine-3-N-oxide (H3NO) or distilled water (DW). Different letters denote significant differences based on Fisher’s Probability of Least-Squared Differences (P < 0:05).

9. Antipredator responses to skin extract of redbelly dace, Phoxinus eos, by free-ranging populations of redbelly dace and fathead minnows, Pimephales promelas Brian D. Wisendena & Kamil Barbourb Department of Biology, Minnesota State University Moorhead, Moorhead, MN 56563, U.S.A. (e-mail: wisenden@mnstate.edu) College of Biological Science, University of Minnesota, Saint Paul, Minnesota 55113, U.S.A.

10. Figure 1. The number of minnows (redbelly dace + fathead minnows) in view of the camera per 10 min before and after the addition of chemical alarm cues from the skin of redbelly dace (solid circles, solid line) or the addition of lake water (open triangles, dashed line). The faint dotted line represents the line of equality (slope ¼ 1).

11. Figure 2. The number of fish in view per 10 min before and after the addition of test stimuli (alarm cues from redbelly dace, or water) as a function of the depth at which the cues were released. Open symbols and dashed lines, pre-stimulus fish counts; solid symbols and solid lines, post-stimulus fish counts; circles and bold lines, alarm cue trials; triangles and light lines, water trials.

12. Figure 3. The number of fish in view per 10 min before and after the addition of test stimuli (alarm cues from redbelly dace, or water) as a function of the distance from shore at which the cues were released. Open symbols and dashed lines, pre-stimulus fish counts; solid symbols and solid lines, post-stimulus fish counts; circles and bold lines, alarm cue trials; triangles and light lines, water trials.

13. Figure 4. The number of fish in view per 10 min before and after the addition of test stimuli (alarm cues from redbelly dace, or water) as a function of the distance to a depth of 1 m from the point at which the cues were released. Open symbols and dashed lines, prestimulus fish counts; solid symbols and solid lines, post-stimulus fish counts; circles and bold lines, alarm cue trials; triangles and light lines, water trials.