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The influence of environmental drivers and biological invasion on intraspecific variation in crayfish behavior

Scarasso, Marco
http://orcid.org/0000-0002-0534-5353
http://rave.ohiolink.edu/etdc/view?acc_num=osu1629219877129227

Abstract Details

2021, Master of Science, Ohio State University, Environment and Natural Resources.
Environmental heterogeneity in stream conditions and anthropogenic stressors, such as species introductions, can lead to intraspecific variation in traits of stream-dwelling crayfish. The rusty crayfish, Faxonius rusticus, and virile crayfish, Faxonius virilis, are distributed across a wide geographic range largely due to introductions outside of the native ranges. Previous research on these two species have demonstrated significant intraspecific variation in behavior traits across populations of both species. In this study I investigated: 1) whether behavioral differences across populations of the rusty crayfish are associated with their invasion status (e.g. native vs non-native), and 2) what environmental drivers (predation risk, resource availability, and climate) are associated with variation in behavior of both rusty and virile crayfish. I predicted that selection during the invasion process would result in non-native rusty crayfish being bolder, more active, and foraging more than native rusty crayfish, and that there would be less variance in behavior in non-native crayfish than native crayfish. I predicted that crayfish behavioral traits would be predictably associated with differences in predation risk, resource availability, and climate across populations. Furthermore, I predicted that crayfish from sites with lower predation pressure, sites with poor resource availability, and colder sites would be more bold, active and forage more than crayfish from sites with higher predation pressure, sites with abundant resource availability, and warmer sites respectively. To test whether behavior varied as a function of invasion status and environmental drivers, I quantified behavioral differences across multiple populations of rusty and virile crayfish from streams across the Midwest. Furthermore, at each stream, I measured predation pressure, macroinvertebrate resource availability, benthic algal resource availability, stream temperature, and crayfish density. I found significant, increased foraging behavior within non-native rusty crayfish compared to native rusty crayfish, but did not find significant difference in boldness or activity between the two groups. This suggests that foraging behavior may be important to the invasion process and experiences selection process throughout the process, likely due to its role in the growth-mortality tradeoff and in outcompeting competitors. I found that climate best explained variation in boldness in virile crayfish, with virile crayfish from warmer streams being bolder than those from cooler streams. Counter to expectations, I found that virile crayfish from streams with higher macroinvertebrate biomass had higher foraging rates (e.g. consumed more food in the lab) than streams with low biomass. The environmental drivers did not, however, explain variation in rusty crayfish behavioral traits or virile crayfish activity. These results suggest that the selected environmental variables may important drivers of different behavioral traits in virile crayfish, and that these behavioral traits may be predictable across environmental gradients. Overall, my study confirmed that there is intraspecific behavioral trait variation across crayfish populations, and that this variation may be the result of both environmental drivers selecting for specific behavioral traits, and in non-native populations, the selection pressures of the invasion process.
Lauren Pintor (Advisor)
Mažeika Sullivan (Committee Member)
Lindsey Reisinger (Committee Member)
Robert Gates (Committee Member)
101 p.
Aquatic Sciences; Behavioral Sciences; Ecology; Environmental Science
Faxonius rusticus; Faxonius virilis; Rusty Crayfish; Virile Crayfish, Animal Behavior; Biological Invasions; Behavioral Trait Variation

Recommended Citations

Citations

  • Scarasso, M. (2021). The influence of environmental drivers and biological invasion on intraspecific variation in crayfish behavior [Master's thesis, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1629219877129227

    APA Style (7th edition)

  • Scarasso, Marco. The influence of environmental drivers and biological invasion on intraspecific variation in crayfish behavior. 2021. Ohio State University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1629219877129227.

    MLA Style (8th edition)

  • Scarasso, Marco. "The influence of environmental drivers and biological invasion on intraspecific variation in crayfish behavior." Master's thesis, Ohio State University, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=osu1629219877129227

    Chicago Manual of Style (17th edition)

osu1629219877129227
48
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