Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


POCOCK_MS_Thesis_FINAL.pdf (1.11 MB)

ETD Abstract Container

Abstract Header

Trait differences in a non-native and native Ohio crayfish and the effect on rates of leaf decomposition

Pocock, Krystal
http://orcid.org/0000-0001-8534-8046
http://rave.ohiolink.edu/etdc/view?acc_num=osu1618839590167714

Abstract Details

2021, Master of Science, Ohio State University, Environment and Natural Resources.
As the dominant consumers of leaf litter in streams, crayfish play a critical role in the transformation of energy by breaking down leaf material. Yet the replacement of native crayfish by non-natives can result in the alteration of ecosystem processes. In particular, the non-native Rusty crayfish, Faxonius rusticus, has been shown to reduce standing leaf litter stocks in streams outside of their native range. Additionally, leaf breakdown rates by crayfish may be species-specific, driven by differences in behavioral traits. Non-native Rusty crayfish have begun to competitively displace native Sanborn crayfish, Faxonius sanbornii, in Ohio. The impact of this species replacement on leaf breakdown is poorly understood. Here, my two main objectives were to 1) determine species-level differences in behavioral and physiological traits in Rusty and Sanborn crayfish related to foraging, and 2) determine species-level differences in leaf consumption and decomposition rates in a stream dominated by Rusty crayfish and a stream dominated by Sanborn crayfish. I predicted that if Rusty crayfish are bolder than Sanborn crayfish, they would consume more prey items and excrete more than Sanborn crayfish. Additionally, I predicted that if Rusty crayfish consumed more prey items than Sanborn crayfish, they would consume more leaf material and accelerate leaf decomposition at sites where they were present. To test these predictions, I completed a series of laboratory experiments to quantify differences in boldness, foraging behavior, and excretion in Rusty and Sanborn crayfish. I also quantified leaf consumption between species. Finally, I completed a field leaf pack experiment to quantify leaf decomposition in one stream dominated by Rusty crayfish and one stream dominated by Sanborn. Results of my experiments suggest that there are species level differences in boldness and foraging behavior, but that excretion rates are more associated with the amount of prey consumed and differences in crayfish sex and size, regardless of species. The field and lab experiments together suggest that Rusty and Sanborn crayfish do not have a direct consumptive effect on leaf litter biomass, but rather the reduction in ash-free dry mass (AFDM) of leaf litter in these two stream systems is due to consumption by macroinvertebrates. However, leaf litter loss due to macroinvertebrates, as well as the total loss of AFDM from the leaf pack experiment were greater in the Sanborn stream. This suggests that leaf decomposition by macroinvertebrates is different in streams where Rusty crayfish are present. Overall, these results suggest that there are trait differences between the two species and that leaf decomposition due to macroinvertebrates is lower in streams containing Rusty crayfish.
Lauren Pintor (Advisor)
Mazeika Sullivan (Committee Member)
Suzanne Gray (Committee Member)
74 p.
Aquatic Sciences; Behaviorial Sciences; Biology; Conservation; Environmental Science; Environmental Studies; Freshwater Ecology; Natural Resource Management
ecosystem process; leaf decomposition; non-native crayfish; Rusty crayfish; trait differences; behavior; species displacement; Sanborn crayfish

Recommended Citations

Citations

  • Pocock, K. (2021). Trait differences in a non-native and native Ohio crayfish and the effect on rates of leaf decomposition [Master's thesis, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1618839590167714

    APA Style (7th edition)

  • Pocock, Krystal. Trait differences in a non-native and native Ohio crayfish and the effect on rates of leaf decomposition. 2021. Ohio State University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1618839590167714.

    MLA Style (8th edition)

  • Pocock, Krystal. "Trait differences in a non-native and native Ohio crayfish and the effect on rates of leaf decomposition." Master's thesis, Ohio State University, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=osu1618839590167714

    Chicago Manual of Style (17th edition)

osu1618839590167714
36
© 2021, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.