Browsing by Author "Betts, Madison"

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    No Stone Unturned: Studying Bluehead Chubs at Virginia Tech
    Bustamante, Thomas; Betts, Madison; Brooks, Samantha; Frimpong, Emmanuel A. (New River Symposium, 2022-04)
    The bluehead chub (Nocomis leptocephalus) is a common, medium-sized freshwater minnow found in streams across the southeastern United States. Each summer, mature male chubs construct mound nests out of thousands of pebbles using only their mouths, a behavior only thirteen known species are capable of. These mound nests attract other “nest associates,” of which there can be as many as a few hundred fishes representing up to a dozen species on any one nest at a time. Thus, bluehead chubs play an active role in the persistence of the aquatic ecosystems they inhabit. The Frimpong Lab at Virginia Tech seeks to understand the complex relationships between bluehead chubs and their environment. To do this, members of the lab investigate concepts such as symbiotic interactions, behavior, and adaptive responses of bluehead chubs. Further, the Frimpong Lab strongly advocates for the use of an arts-science connection to engage the local community and emphasize the importance of this fascinating species.
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    Two Layers of Selfish-Herds in Spawning Aggregations of Chub (Nocomis Sp.) and its Nest Associates
    Betts, Madison (Virginia Tech, 2023-08-18)
    Many species have evolved to live in groups. Gregarious behavior was believed to be adaptive for whole-population survival and predator evasion until selfish-herd theory was introduced. It proposed that individuals congregate not as a method of protection for the entire population, but instead to better the individual's chance of survival, thereby using the group to benefit itself (i.e., "selfishness"). Selfish behavior is a common part of mutualisms, which are complex, dynamic interactions that often change with biotic or abiotic circumstance. Here, I investigate potential selfish behavior within the mixed-species spawning aggregations hosted by bluehead chub (Nocomis leptocephalus). I hypothesized that the host benefits more directly from the aggregation it supports than previous research suggests – specifically, by using nest associates to decrease its own risk of predation (creating a selfish-herd) and simultaneously forcing associate embryos into marginal nest locations while locating its own embryo in the safer locations within the nest (creating an "embryonic selfish-herd"). In Chapter 1, I investigated the adult spawning aggregation for possible selfishness by monitoring the chub's spatial location within the aggregation and vigilance behavior under varying associate abundances. I found that the host occupied the central location within the aggregation and was less vigilant when associate abundance was high. In Chapter 2, I examined the "embryonic herd" contained within Nocomis nests for possible embryonic selfishness orchestrated by the chub host, leading to increased embryonic survival for chub young and elevated fitness for chub parents. I found that deeper nest sections support higher embryonic survival than shallower sections, and that chub embryo make up a disproportionate percentage of embryos found in those deeper sections. I also conducted a preliminary study investigating embryo-predation by host on associate embryo which produced evidence for embryo-predation by both host and two associates on each other's offspring. Cohesively, my results support the identification of the host as a selfish participant and confirm the presence of both an adult and embryonic selfish-herd in this mutualism. This is the first study to demonstrate selfish behavior on the part of the host in this system and the first to prove the existence of an embryonic selfish-herd.