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University of Michigan Biological Station

The University of Michigan Biological Station (UMBS) was founded in 1909.

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Impact of Degree of Aggression on Cohabitation of Faxonius rusticus and Faxonius virilis

Aquatic
Organismal
Spatial Data
crayfish
Personality
Behavioral analysis
competition
Project Abstract: 
Invasive species are a continuous problem for conservation biologists. Success or failure of a non-native species invasion into novel environments can have cascading impacts on ecosystem functioning. Crayfish are in a unique position, being the second most imperiled aquatic group and most invasive aquatic organism. In crayfish, abiotic factors play a role in the potential success of Faxonius rusticus invasions and a single biotic factor, aggressiveness, is thought to give invasive crayfish advantages over native crayfish. Interactions between abiotic and biotic factors are missing within the literature. In a more individualistic approach, crayfish personalities (behavioral syndromes) are likely to interact with abiotic factors to determine successful invasion. Two such syndromes (aggression and bold-shy spectrum) are potentially critical behavioral factors involved in native species replacement. In northern Michigan, F. rusticus is a common invasive species, that has been recorded to extirpate F. virilis from waterbodies to varying degrees. Douglas and Burt Lake are waterbodies that have cohabitating populations of both species. Determining the personalities of both populations in varying systems and environmental factors will allow for a better understanding of what forces are in play during species invasion. Further understanding the complexities of crayfish invasion can help create better prevention plans.
Investigators: 
pmoore
storern
Status of Research Project: 
Active
Years Active: 
2024
Methods: 
Fifteen waterbodies in northern Michigan will be sampled. These sites include lakes, streams, and rivers in the surrounding area, including Douglas and Burt Lake. Twenty-five F. rusticus and 25 F. virilis will be collected from each site. Individuals will be captured using three minnow traps baited with sardines, and left for 24 hours. Traps will be placed at various habitat subtypes within the water body. All individuals captured will be transported back to the Experimental Stream Research Facility at the University of Michigan Biological Station (UMBS). Intraorbital length and propodus length (claw length) will be measured for each individual as well as sex and reproductive form. Crayfish will be housed by site in large tubs with flow through of untreated water from the East Branch of the Maple River, which runs adjacent to the facility. All sites and individuals will be physically and chemically isolated from each other. Individuals will be housed between June and August of 2024, in ambient temperatures and light and dark cycles for that time period. All individuals will be marked with white out to as a marker that will not impact behavior but allow for proper identification (Bergman & Moore, 2003, 2005) Crayfish will be fed natural detritus that flows in from the stream along with the water. Environmental data collection will be conducted before traps are set at each site including, temperature, flow, turbidity, pH, and conductivity will be collected using a Hydrolab multimeter. Substrate composition will be determined by the dry mass percentage of substrate sizes. A kg of substrate will be removed from the site and allowed to dry for 24. Substrate will then separate by using multiple substrate sieve to get finally ratios of substrate types. In addition, macrophyte composition will be established using three 1-meter quadrats placed randomly around the collection sites. MacKay & Moore determined that the crayfish parasite Microphallus spp. could alter the behavior of infected hosts (MacKay & Moore, 2021). Due to this, post-experiment parasite analysis will be done by the dissection of the crayfish to remove the hepatopancreas for analysis. Boldness/shyness scale and aggression level assays will be run on all individuals. Crayfish will be run through two different behavioral assays, each day for three consecutive days. The order that crayfish will be run through the tests will be randomized.