Data from: Male lake char release taurocholic acid as part of a mating pheromone
Data files
Jan 26, 2024 version files 25.13 KB
Abstract
The evolutionary origins of sexual preferences for chemical signals remain poorly understood, due, in part, to scant information on the molecules involved. In the current study, we identified a male pheromone in lake char (Salvelinus namaycush) to evaluate the hypothesis that it exploits a nonsexual preference for juvenile odour. In anadromous char species, the odour of stream-resident juveniles guides migratory adults into spawning streams. Lake char are also attracted to juvenile odour but have lost the anadromous phenotype and spawn on nearshore reefs, where juvenile odour does not persist long enough to act as a cue for spawning site selection by adults. Previous behavioural data raised the possibility that males release a pheromone that includes components of juvenile odour. Using metabolomics, we found that the most abundant molecule released by males was also released by juveniles but not females. Tandem mass spectrometry and nuclear magnetic resonance were used to identify the molecule as taurocholic acid (TCA), which was previously implicated as a component of juvenile odour. Additional chemical analyses revealed that males release TCA at high rates via their urine during the spawning season. Finally, picomolar concentrations of TCA attracted prespawning and spawning females but not males. Taken together, our results indicate male lake char release TCA, a mating pheromone, and support the hypothesis that the pheromone is a partial match of juvenile odour.
README: Male lake char release taurocholic acid as part of a mimetic pheromone
Data include:
- metabolomics results comparing chemical features of male, female, juvenile, and control water samples,
- concentrations of taurocholic acid in male and female urine and conditioned water,
- concentrations of taurocholic acid in male-conditioned water during and outside of the spawning season, and
- behavioral responses of pre-spawning and spawning male and female lake char to taurocholic acid in two two-channel flumes.
Description of the data and file structure
Metabolomics file:
- Water samples were collected by holding one male or female lake char, or 3 juveniles in 150 L of Lake Huron water for four hours.
- Peak1 through Peak5 are the relative magnitudes of the top five peaks found in male-conditioned water using high-resolution mass spectrometry.
- TCA is the concentration (ng/mL) of taurocholic acid in these water samples
- Juv.2 and Juv.3 are the weights and lengths of the 2nd and 3rd juveniles sampled.
Release route file:
- Water samples were collected by holding one male or female lake char in 150 L of Lake Huron water for four hours.
- Urine was collected via catheter one day after initial water samples were collected
- water.TCA is the concentration of TCA (ng/mL) in water
- urine.TCA is the concentration of TCA (ng/mL) in urine
Release rate by season file:
- Water samples were collected by holding one male in approximatly 563.4 L of Lake Huron water for 4 hours. Sampling was done during the spawning season (October) and outside of the spawning season (April)
- Start.TCA is the concentration of TCA (ng/mL) in water at time-0 h
- End.TCA is the concentration of TCA (ng/mL) in water at time-4 h
Behavior
- Behavioral responses of prespawning and spawning male and female lake char were tested in two two-channel flumes. Time (sec) spent in each of the two channels was recorded before and after appplication of 1 x10-12M TCA
- im = prespawning male; if = prespawning female; mm = spawning male; mf = spawning female
- id is individual id of fish
- period is pre-odor application (pre) and post-odor application (post)
- con.s is the time (sec) spent in the control channel
- trt.s is the time (sec) spent in the treatment channel
- trt.p is the proportion of time spent in the treatment channel
Code/Software
statistical analysis of the data were ran in R using the script "trout_script"