Browsing by Author "Claus, Aaron"
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Item Chemosensory Control of Filter Feeding Behavior in Bigheaded Carps(2015-05) Claus, AaronBigheaded carps (silver carp, Hypophthalmichthys molitrix and bighead carp, H. nobilis) were used to investigate the physiological basis of filter feeding behavior in fish. I developed a new method for assaying chemically based food preferences by tracking the frequency of buccal-pharyngeal pumping behavior before and after a food and food chemical stimuli were presented. Spirulina algae (Arthrospira spp.), a cyanobacterium, was the most potent food type in releasing BPP behavior. Quality and quantity of chemical cues were important to the BPP response. Moderate responses to a mixture of L-Amino acids (common fish feeding cues) confirm their function in this genus but also suggest that there are other highly potent odorants and/or tastants present in the food mix filtrate. BPP behavior was markedly reduced without a functional olfactory sense. These results cumulatively suggest that chemical senses are integral to filter feeding behavior of Bigheaded carp.Item Contrasting Response to Predator and Brood Parasite Signals in the Song Sparrow (melospiza melodia)(2010-11-29) Campillo, Luke; Claus, AaronThe Song Sparrow is a widespread north American songbird that is preyed upon by the Cooper’s Hawk and is subject to nest parasitism by the Brown-Headed Cowbird. This study uses the response of twelve Song Sparrows, located around Itasca State Park, in terms of the frequencies of alarm call and song to investigate which threat is greater to this species in late June. The results show that the Song Sparrows do not consider the cowbird as a threat, but they certainly do consider the Cooper’s Hawk a threat with greatly suppressed song frequency.Item Near-field Behaviors of Carp at Bubble Barriers(2011-04-13) Claus, AaronCommon carp are arguably the most invasive and damaging fish worldwide. Increasingly, invasive fish species are targeted for population control by limiting their dispersal. Because of the species’ dependence on migration through streams and rivers for reproduction, the fish might be targeted using barriers that impede migration. Fish barriers usually consist of some sort of device laid across a stream or river channel that emits an aversive stimulus (electrical, acoustic, physical, etc.). Ongoing research at the Sorensen Lab is looking into the development of bubble-based acoustical barriers to limit the migration of carps. These acoustical barriers are designed to take advantage of the fact that cyprinid fishes (the family that includes invasive carps) possess a very acute auditory sense which is analogous to human hearing. In this way, aversive acoustical stimuli released by barriers should be especially effective at controlling movement of cyprinids. This study serves to quantify and qualify the behaviour of common carp in daylight and darkness through video capture of crossing events occurring near an acoustical bubble barrier. The role of vision in the fish’s response is examined in this way. The existing barrier apparatus was designed and used by Dan Zielinski in his thesis research. In general it is concluded that the fish displayed significant avoidance behaviour but also will occasionally enter and/or cross the barrier (as suggested by previous work). At the same time, the video proves that conditioning to the aversion can happen quickly. The fish schooled the majority of the time during trials, and most crossings were done in a parallel orientation to water flow. The distance from barrier and other associated behaviours are highly variable between groups and over time, suggesting a heavy role of fish personality (shy-bold axis) and learning in the efficacy of the barrier.