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Abstract: The recent invasion of the Prussian carp (Carassius gibelio) in freshwater environments in central Canada threatens native aquatic species and ecosystems. The fish’s hardiness, fecundity, and monozygotic reproduction pose challenges to their eradication, making population suppression and preventing spread priorities when it comes to addressing the invasion. Accurate distribution information is essential for targeting such efforts but is challenging to obtain given the logistics of continually sampling all locations within Prussian carp’s potential range. Could resource users be used in a citizen science program to generate species distribution data? Here we investigate whether reports of Prussian carp by recreational anglers in Alberta, Canada could have application as a cost-effective alternative to or complimentary tool for traditional population distribution sampling and early warning systems for aquatic invasive species (AIS). Specifically, we ask 1) What factors affect an angler’s willingness to report Prussian carp? (Chapter 2) and 2) To what extent does the distribution of Prussian carp generated by angler reports predict the distribution of the species determined by traditional biological sampling methods? (Chapter 3) To address these questions, we surveyed Albertan anglers in the summer of 2019, and in addition to having them report sightings of Prussian carp, asked a variety questions regarding characteristics that may influence their likeliness to report Prussian carp. Our survey revealed that anglers’ personal attachment to freshwater fisheries in Alberta and their perceived need for action to protect the fishery are important characteristics for predicting anglers’ willingness to report Prussian carp, as well the angler’s location (i.e., within or outside the province’s largest urban center - Calgary; Chapter 2). These results suggests that in addition to detailing the ecological impact of the Aquatic Invasive Species (AIS), fisheries managers could encourage behaviours and programs that develop anglers’ personal attachments to the fishery and frame the threat of AIS in ways that highlight the effects of the invasion on their angling experience or the aspects of the aquatic environment they are attached to. Clarifying how action by anglers addresses the threat posed by AIS such as Prussian carp, so the efficacy of any proposed behaviour is understood, may also increase reporting. Gathering reports of Prussian carp by recreational anglers in Alberta revealed that anglers can be a powerful resource for tracking an invasive species’ distribution when compared with biological sampling; 88% of the Prussian carp reports aligned with regions known to be invaded based on biological sampling, and for every report of Prussian carp received in a HUC-8 area (hydrological unit code 8; the second finest Albertan watershed unit), the probability that area was invaded (as indicated by biological sampling) increased by more than 10 times (Chapter 3). We also found a positive relationship between anglers’ fish identification abilities and likelihood of reporting Prussian carp. Anglers that fished more frequently were also more likely to have correctly identified Prussian carp, although the mechanism behind this relationship, be it sampling effort or angling specialization, is still unclear. This greater understanding of the factors that affect angler engagement in pro-conservation behaviours such as AIS reporting could aid in campaigns that aim to use such reports to determine AIS distributions. Beyond reporting, information on angler motivations could aid managers in investigating opportunities for anglers to aid in AIS removal efforts.

I have used HRP to examine the organization of the motoneurons innervating the axial musculature of the goldfish, the mudpuppy, and the Florida water snake. In goldfish, different populations of motoneurons innervate the functionally different red and white musculature. The red is innervated by relatively small, secondary, motoneurons which occupy the ventral part of the motor column. The white is innervated by a population of large, primary motoneurons in the dorsal part of the column which do not innervate red muscle; it is also probably innervated by some small motoneurons similar to those innervating red muscle. The position of a motoneuron in the motor column is not related to the dorso-ventral position of the muscle it innervates in the myomeres. The motor column in the mudpuppy is similar in some important respects to the column in goldfish. There are large, primary motoneurons, and their axons are grouped together in the cord. The majority of motoneurons are smaller, secondary ones. As in goldfish, both primary and secondary motoneurons project axons into both the dorsal and ventral rami; there are some differences in the spatial distributions of the motoneurons innervating epaxial and hypaxial muscle, but their distributions overlap extensively. The motor column in snakes is very different from the motor columns in goldfish and mudpuppies. The musculature is formed by many discrete muscles, and the motor pools of the muscles occupy separate, characteristic locations in the transverse and longitudinal extent of the ventral horn. Unlike goldfish and mudpuppies, epaxial motoneurons are spatially segregated from hypaxial ones. The motor pools in the Florida water snake are very similar to those in rats. The very different arrangement of motoneurons in snakes versus goldfish and mudpuppies requires that a major reorganization of the motor column occurred during the evolution of vertebrates.