Behavior and Ethology Commons^™

Acute Effects Of The Psychoactive Pollutant Fluoxetine On The Antipredator Behavior Of The Gulf Killifish (Fundulus Grandis), Semyra Reus

Honors Theses

Pharmaceutical contaminants are increasingly prevalent in aquatic environments, yet their sublethal effects on ecologically relevant behaviors remain poorly understood, particularly in estuarine systems. Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine, are of particular concern due to the conserved role of serotonin in regulating behavior across vertebrates. Here, we investigated how acute exposure to environmentally relevant concentrations of fluoxetine influences anti-predator behavior in Gulf killifish (Fundulus grandis), a key estuarine fish commonly found in saltmarsh habitats. Killifish were exposed to control (0 ng/L), low (17.8 ng/L), and high (596 ng/L) fluoxetine concentrations and subsequently tested in the presence …

Feeding Ecology In Coastal Systems, Randi L. Cannon

Graduate Theses and Dissertations (2019 - present)

Oysters (Crassostrea virginica) are critical foundation species in estuaries, providing numerous ecological and economic benefits. However, oyster populations have diminished worldwide. Effective oyster restoration and aquaculture require a mechanistic understanding of the physiological and environmental factors that govern oyster feeding, growth, and resilience under changing coastal conditions. We investigated how oyster ploidy and environmental conditions influenced oyster feeding and investigated how changes in abiotic conditions affected behavioral performance of oyster drills (Stramonita spp.), a key oyster predator. To better understand feeding responses and behaviors of both predator and prey we 1) used in-situ filter feeding assays to determine if feeding …

Emerald Bowfin Amia Ocellicauda Ecology In Three Minnesota Lakes: Abundance, Age Analysis, Diet Composition, And Stable Isotope Food Web, Griffin Blegen

Biology Graduate Theses

The Emerald Bowfin Amia ocellicauda is a predatory fish species native to Minnesota that has often been discriminated against. This research expands ecological knowledge of Bowfin in Minnesota and provides population data to guide future management. Bowfin were sampled in the spring of 2024 and 2025 and a multi-census mark–recapture model was used to estimate abundance in three lakes. Estimated populations were 196 individuals in Little Toad Lake (95% CI: 116, 242) or 4.4 fish/littoral ha (95% CI: 2.7,5.7), 657 in Lake Sarah (95% CI: 436, 1014) or 4.2 fish/littoral ha (95% CI: 3.0, 6.7), and 612 in Gun Lake …

Largemouth Bass Diet Changes Through The Summer In Central Minnesota, Ethan Kunz

Journal of Earth and Life Science

Largemouth Bass Micropterus nigricans is one of the most widespread fish species in the world, due in part to human introduction for angling. Largemouth Bass are opportunistic predators that will consume the largest prey they can often find; however, it has been shown that their diet mainly consists of invertebrates such as crayfish, with less focus on other fish species. This research aimed to determine what the Largemouth Bass diets in Central Minnesota consist of, and how they may change from the beginning of summer through the beginning of fall. A total of 174 Largemouth Bass were sampled from late …

Statewide Northern Pike Response To Minnesota’S 2018 Regulation Change, Elijah Wozniak

Journal of Earth and Life Science

Management of northern pike (Esox lucius) is challenging because it attempts to balance ecological sustainability with angler interests. Northern pike often stunt their own growth by diminishing the size and abundance of prey fish, their food source. Anglers are often displeased when small pike occur in high population densities. In response to populations of small northern pike, the DNR implemented a new, statewide northern pike regulation in 2018. The objective of this study was to determine whether the regulation successfully changed the mean weight, length, and CPUE of northern pike in Minnesota. The secondary objective was to test …

Comparison Of Calcified Structures To Estimate Ages Of Northern Pike Esox Lucius In Various Lakes, Kaed Rauk

Journal of Earth and Life Science

Northern pike Esox lucius are a dominant predatory fish in many aquatic systems. They can have significant impacts on the ecosystems they inhabit and are also a popular game fish among anglers. However, northern pike are a difficult species to age accurately. This study aimed to compare calcified aging structures to identify trends and determine which structure provides the most accurate age estimates. A total of 119 northern pike were sampled, and multiple structures from each fish were independently aged by two readers. The coefficient of variation (CV) was calculated for each structure to assess precision. Sectioned sagittal otoliths exhibited …

Transcriptional Profiles Reveal Physiological Mechanisms For Compensation During A Simulated Marine Heatwave In Yellowtail Kingfish (Seriola Lalandi), Sharon E. Hook, Ryan J. Farr, Jenny Su, Alistair J. Hobday, Catherine Wingate, Lindsey Woolley, Luke Pilmer

Fisheries Research Articles

Background

Changing ocean temperatures are already causing declines in populations of marine organisms. Predicting the capacity of organisms to adjust to the pressures posed by climate change is a topic of much current research effort, particularly for species we farm or harvest. To explore one measure of phenotypic plasticity, the physiological compensations in response to heat stress as might be experienced in a marine heatwave, we exposed Yellowtail Kingfish (Seriola lalandi) to sublethal heat stress, and used the transcriptome in gill and muscle, benchmarked against heat shock proteins and oxidative stress indicators, to characterise the acute heat stress …

Evaluating The Condition Of Age-0 Burbot In Relation To Diet, Cian Verbridge

Journal of Earth and Life Science

Burbot are becoming more and more popular for angling and aquaculture. However, populations have been declining across the world. Very little information is available about their early life and their interactions in the ecosystem due to challenges in sampling. Condition estimates and diet metrics were used to better understand the status of burbot in Lake Bemidji. Using backpack electrofishing, 45 young of the year burbot were collected. The lengths ranged from 86 to 146 mm and the wet weights ranged from 4.29 to 24.36 g. The stomach contents were removed and stored in ethanol for later analysis. The burbot were …

Size Of Age-0 Sander Vitreus Pre And Post Dreissena Polymorpha Infestation On Brainerd And Bemidji Area Lakes, Quady Bernu

Journal of Earth and Life Science

Walleye Sander vitreus is the Minnesota state fish and a vital predator fish in lake ecology. Zebra mussels, Dreissena polymorpha were first found in Minnesota inland lakes in the 1980’s. These mussels have had huge impacts on water clarity as well as phytoplankton and zooplankton population levels which affect how age-0 fish feed, especially a low light feeding predator fish like walleye. A study took place on age-0 walleye size and it supported the conclusion that age-0 walleye were negatively impacted by zebra mussels in Minnesota’s large lakes. The goals of this study were to determine how the size of …

‘Who’S Your Daddy?’: Ddradseq Parentage In Broodstock-Offspring Pairs Of Diadema Antillarum In A Population Restoration Initiative, Bianca R. Rosendahl

Undergraduate Scholarship and Creative Works

In the early 1980s Diadema antillarum, or the long-spined urchin, was hit by a catastrophic mass mortality event across the western Atlantic and Gulf of Mexico, inclusive of the Florida Keys. The cause of this die-off event was likely triggered by a pathogen or environmental stressor that decimated native populations by up to 98%. The species has not yet fully recovered and is struggling with recruitment success which is why it may benefit from an ex-situ recovery program. In this study, I used single nucleotide polymorphisms (SNPs) to identify genetic variation and analyze parentage in a captive population of …

Does Depth Affect Zebra Mussel Length In Scalp Lake?, Zanden Mellen

Journal of Earth and Life Science

Since its first sighting in 1996, zebra mussels Dreissena polymorpha have been confirmed in hundreds of Minnesota lakes. Not only were they found in lakes, but they are also found in rivers too. With lack of effective treatments to impede their spread, zebra mussels continue to colonize new areas causing ecological as well as economic harm. The objective of this study was to see if there was a relationship between a zebra mussel length and the depth, they are found using shell length (mm) and depth (cm). The comparison of zebra mussel length and depth was done by performing a …

Psychological And Social Well-Being Of Bony Fishes In Zoos And Aquariums, Ronald G. Oldfield, Patrick Bonano

Animal Sentience

Research on the behaviour of animals in zoos has been conducted for decades, and observations have provided information that has improved the psychological and social well-being of animals. However, research on fishes in zoos and aquariums seems to be lacking. Here, we assess the current state of research on fishes in zoos and aquariums by surveying the peer-reviewed literature. Our assessment differs from previous surveys in that we examine the taxonomic classes Chondrichthyes (sharks and rays) and Osteichthyes (bony fishes) separately. Our survey finds that bony fishes have been drastically underrepresented in zoo journals, more drastically than chondrichthyans, revealing an …

Trophic Ecology Of Black Swallowers (Scombriformes: Chiasmodontidae: Chiasmodon) In The Deep-Pelagic Gulf Of Mexico, Travis J. Kirk

All HCAS Student Capstones, Theses, and Dissertations

The ecology of deep-pelagic predatory fishes remains poorly understood despite their importance as ecosystem regulators and energy transfer vectors. This study investigated the trophic ecology of three species of the predatory fish genus Chiasmodon (“black swallowers”) in the Gulf of Mexico, a region that serves as an analog for the global low-latitude deep pelagial, the world’s largest cumulative ecosystem. Foraging habits (e.g., selectivity, chronology, daily ration) of an “advanced” evolutionary fish in a system that is otherwise dominated by basal fish taxa, were quantitatively estimated via high-resolution stomach content analysis. A quantitative dataset of both predator and prey abundance, the …

Genomic Population Structure Of Great Hammerhead Sharks (Sphyrna Mokarran) Across The Indo-Pacific, Naomi L. Brunjes, Samuel M. Williams, Alexis L. Levengood, Matt K. Broadhurst, Vincent Raoult, Alastair V. Harry, Matias Braccini, Madeline E. Green, Julia L. Y. Spaet, Michael J. Travers, Bonnie J. Holmes

Fisheries Research Articles

Context

Currently, little information exists describing the population structure of great hammerhead sharks (Sphyrna mokarran) in Australian waters. Aims

This study used single nucleotide polymorphisms to investigate fine-scale population structure in S. mokarran across the Indo-Pacific. Methods

DNA was extracted from 235 individuals across six Australian locations and a Red Sea outgroup. Population parameters were calculated and visualised to test structuring across locations. Key results

No fine-scale population structuring was observed for S. mokarran across the Indo-Pacific. However, population structuring occurred for all Australian locations when compared to the Red Sea outgroup. Conclusions

Findings suggest a single stock …

Striped Blenny (Chasmodes Bosquianus) Presence And Behavior Between Sunrise And Sunset At Oyster Landing, South Carolina, Madeline Schuetze

Honors Theses

Lunar and diel cycles of fishes can help to interpret their behaviors during their reproductive season. Temperate estuaries are used by many benthic fishes for shelter and reproduction. This study examined the behavior and presence of striped blennies (Chasmodes bosquianus) during diel and lunar cycles. PVC pipe shelters were placed to mimic oyster shell nests, a natural habitat for blennies, and cameras were placed to monitor these shelters in April, May, and June 2022, during the striped blenny reproductive period. Video footage was reviewed and analyzed for the presence and behavior of both male and female blennies. Male presence …

Do Channel Catfish Consume Zebra Mussels?, Casey M. Myers

Journal of Earth and Life Science

Channel catfish Ictalurus punctatus are a generalized opportunistic feeder with a wide range of diet compositions. In the Midwest, zebra mussels Dreissena polymorpha have quickly spread, causing large effects on aquatic ecosystems structures and functions. Channel catfish are known to consume native mollusks, however, little research has been done on the potential predation of zebra mussels by channel catfish. Therefore, the objective of this study was to analyze channel catfish diets to determine if zebra mussels are consumed. The channel catfish were obtained from the Sauk River chain of lakes between the dates of 14 June and 28 July 2023. …

Effects Of Oyster Aquaculture On Elasmobranch Abundance And Habitat Use In Humboldt Bay, Ca, Rose Harman

Cal Poly Humboldt theses and projects

Habitat modification from aquaculture can have large effects on natural communities, with the habitat complexity provided by aquaculture structure positively influencing benthic invertebrates and small fish abundance. However, the effects of aquaculture on larger predatory fish like elasmobranchs (i.e., sharks and rays), which use nearshore habitat to forage and provide top-down control of these ecosystems, is largely unknown. Over two years, I deployed baited remote underwater video systems (BRUVS) to examine the effects of oyster aquaculture and environmental variables such as habitat (mudflat or eelgrass), salinity (ppt), turbidity (m), temperature (°C), pH (mV), dissolved oxygen (mg · L^-1), …

An Assessment Of Burbot Life History In Minnesota With A Focus On Movement Dynamics And Spawning Vulnerability, Tyler Robinson

Biology Graduate Theses

Burbot have a circumpolar range spanning from rivers of Alaska to lentic systems in Minnesota. Although Burbot population dynamics have been studied, their movement dynamics have been rarely investigated. Our objectives were to assess seasonal home range changes of Burbot in a closed-lentic system and quantify the scale of spawning aggregations. Sixty-six Burbot were implanted with acoustic transmitters in Bad Medicine Lake, Minnesota, with 32 surviving the length of the study period between 10 April 2019 to 11 June 2020. The peak spawning date for Burbot in Bad Medicine Lake was estimated to be mid-March, when home range estimates were …

Translocation Of Timber Rattlesnakes At Two West Virginia State Forests, Elizabeth Morgan Johnson

Theses, Dissertations and Capstones

In wildlife management, translocation is defined as the purposeful movement of an individual(s) from one place to another with a wildlife management goal. Translocation has become a common tool for mitigating negative human-wildlife interactions. We conducted a translocation study on timber rattlesnakes (Crotalus horridus) in response to numerous human-rattlesnake encounters with the goal of developing a translocation protocol that would allow natural resources personnel to mitigate negative encounters between the public and rattlesnakes and reduce impacts to local timber rattlesnake populations. In this study, we scaled translocation distance to site-specific home range characteristics to assess whether translocation outcomes …

Spatio-Temporal Movement Patterns Of Sub-Adult Adfluvial Bull Trout, Aimee Taylor

All Master's Theses

Bull Trout in the Yakima River basin of Washington are primarily adfluvial, often using managed lakes as habitat. Kachess Lake, composed of Big and Little Kachess Lakes, is managed by the Bureau of Reclamation (BOR) for water storage. BOR plans to build a structure that can withdraw an additional 200,000 acre-feet of water in drought years, which would disconnect the two basins for multiple years. This study examined the spatio-temporal movement of sub-adult Bull Trout in Kachess Lake to understand distribution patterns and the effects of environmental variables. We sought to answer 1) does time (week of the year), diel …

Fish And Invertebrate Use Of Restored Vs. Natural Oyster Reefs In A Shallow Temperate Latitude Estuary, Jonathan H. Grabowski, Christopher J. Baillie, Adam Baukus, Rachael Carlyle, F. Joel Fodrie, Rachel K. Gittman, A. Randall Hughes, David L. Kimbro, Juhyung Lee, Hunter S. Lenihan, Sean P. Powers, Kevin Sullivan

University Faculty and Staff Publications

Coastal marine habitats continue to be degraded, thereby compelling largescale restoration in many parts of the world. Whether restored habitats function similarly to natural habitats and fully recover lost ecosystem services is unclear. In estuaries, oyster reefs have been degraded by multiple anthropogenic activities including destructive fishing practices and reduced water quality, motivating restoration to maintain oyster fisheries and other ecosystem services, often at relatively high cost. We compared fish and invertebrate communities on recently restored (0–1 year post-restoration), older restored (3–4 years post-restoration), and natural oyster reefs to determine if and when restored reefs support functionally similar faunal communities. …

Design And Validation Of Artificial Feeders To Study Feeding Preferences And Growth Of Hematophagous Juvenile Sea Lamprey (Petromyzon Marinus), Gracie Li-Ting-Wai

Theses and Dissertations (Comprehensive)

The parasitic and invasive land-locked sea lamprey Petromyzon marinus populations contributed to the collapse of the Great Lakes fisheries in the mid-1900s, while native anadromous populations are currently under threat and require conservation efforts for protection. Despite the increasing concern for both populations of this species, the juvenile stage of the sea lamprey’s life cycle has not been well studied. This is due, in part, to ethical concerns raised around holding live host fish with juveniles and the lack of an alternative feeding method to maintain these juveniles in the laboratory. The feeder should be designed to minimize fouling of …

Feeding Patterns And Diet Overlap Of Muskellunge And Co-Occurring Piscivores In Minnesota Lakes, Kamden Glade

Biology Graduate Theses

Muskellunge Esox masquinongy are the largest member of the family Esocidae found in Minnesota and are managed for trophy angling opportunities with large minimum size requirements, limited harvest, and stocking to support existing populations or expand angling opportunities. While Muskellunge impacts at the community level appear minimal based on available literature, relatively little is known about Muskellunge diets, eat the le particularly in Minnesota. In this study, we used gastric lavage to examine gut contents of Muskellunge, Northern Pike Esox lucius, Walleye Sander vitreus, and Largemouth Bass Micropterus salmoides. Diets were quantified using an index of relative importance (IRI) and …

Abiotic Factors Effect On Summertime Fish Sampling, Kyle Oxley

Journal of Earth and Life Science

Fish surveys are vital in understanding various information about a fishery. Surveys lay the groundwork to how an agency views the status of the fishery, are used to set appropriate regulations, and manage stocking. Understanding which areas of a fishery holds the greatest density of fish is key to achieving the most accurate sample that reflects the fishery. The objective of this study was to track fish densities throughout the summer of 2021 and establish if there is a relationship between high fish density locations and specific water column characteristics. Fish density, temperature, and dissolved oxygen were measured bimonthly at …

Documentation Of Atlantic Tarpon (Megalops Atlanticus) Space Use And Move Persistence In The Northern Gulf Of Mexico Facilitated By Angler Advocates, J. Marcus Drymon, Matthew B. Jargowsky, Michael A. Dance, Mitchell Lovell, Crystal L. Hightower, Amanda E. Jefferson, Andrea M. Kroetz, Sean P. Powers

University Faculty and Staff Publications

Atlantic tarpon (Megalops atlanticus, hereafter tarpon) are facing a multitude of stressors and are considered Vulnerable by the IUCN; however, significant gaps remain in our understanding of tarpon space use and movement. From 2018 to 2019, citizen scientists facilitated tagging of 23 tarpon with SPOT tags to examine space use and movement across the northern Gulf of Mexico. Movement-based kernel densities were used to estimate simplified biased random bridge-based utilization distributions and a joint move persistence model was used to estimate a behavioral index for each fish. Tarpon showed consistent east–west movement from the Alabama/Florida border to Louisiana, and utilization …

Do Beaver Dam Analogues Act As Passage Barriers To Juvenile Coho Salmon And Juvenile Steelhead Trout?, Christopher G. O'Keefe

Cal Poly Humboldt theses and projects

In the Pacific Northwest, the human-caused reduction of quality and quantity of freshwater rearing habitat is a limiting factor for Pacific Salmon populations. Beaver dam analogues (BDAs) increase suitable rearing habitat for juvenile salmonids and promote the restoration of critical stream processes. Installing BDAs is an increasingly popular alternative to more intensive restoration techniques, due to the relatively low cost and effort required to install BDA structures. However, widespread installation of BDAs has been slowed by regulatory agencies’ concerns that BDAs may impede fish passage. Few studies have empirically assessed the extent to which BDAs impede fish passage, and no …

Blenny Territoriality At Oyster Landing, North Inlet Estuary, South Carolina: Seasonal Patterns And Ecological Factors, Sydney Davis, Juliana Harding

Honors Theses

Temperate oyster reef blennies use oyster shells that are still articulated as habitat year round. During the breeding season when water temperatures are > 18-20°C, many species of blenny males use the oyster valves as nesting sites. Male blennies exhibit territorial behavior when guarding their nesting sites and can interact differently with conspecific and transient species. Striped blenny (Chasmodes bosquianus) and freckled blenny (Hypsoblennius ionthas) behavior was described from April 2020 to August 2020 at Oyster Landing, North Inlet estuary, South Carolina to quantify typical blenny behavior, general presence or absence of residents, and potential environmental parameters …

Characteristics Of A River Otter (Lontra Canadensis) Maternal Den In The Central Platte River Valley, Ne, Jenna M. Malzahn, Andrew J. Caven, Joshua D. Wiese

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

River otters (Lontra canadensis) encompass a broad geographic range including coastal, riverine, and lacustrine systems. However, knowledge of reproductive behavior and structural den characteristics remain relatively few in the literature, particularly in the Great Plains. Distinctions between the terms “den”, “den site”, “natal den”, and “maternal den” are often ambiguous, obscuring our understanding of river otter’s young-rearing behavior. We used observations and descriptions regarding a single maternal den site and a broad reading of the mustelid literature to propose a more standardized maternal den definition for river otters and specify hypotheses for future research. From 25 April to …

Size Selective Parasitism Of Rainbow Trout (Oncorhynchus Mykiss) By Chestnut Lampreys (Ichthyomyzon Castaneus) In An Artificial Setting, Jeremiah M. Salinger, Ronald L. Johnson

Southeastern Fishes Council Proceedings

Paradigms of optimal resource utilization by animals, both classical and more recent, were not originally developed in the context of parasitism. Though this oversight has slowly been reversed, little attention has been paid to optimal resource utilization by parasitic fishes, such as lampreys. Multiple explanations for host size selection by parasitic lampreys may be plausible, but results from previous studies have been inconsistent. We studied host size selection by Chestnut Lampreys (Ichthyomyzon castaneus) parasitizing Rainbow Trout (Oncorhynchus mykiss) in fish hatchery raceways in north central Arkansas during the late winter and early spring of 2013. Parasitized …

Is Anyone Home? Year Round Site Fidelity Vs. Temporal Territories In Estuarine Blennies, Nicholas Govostes

Honors Theses

Temperate oyster reef blennies use articulated oyster shells as nest sites in warmer months during breeding season but little is known about their site fidelity during non-breeding season. Unlike coral reef blennies that occupy territories year-round, rocky intertidal temperate blenny species display temporal territories and seasonally migrate into breeding shelters. Striped blenny (Chasmodes bosquianus) shelter use was described from November 2019 through March 2020 at Oyster Landing, North Inlet estuary, SC to quantify the proportion of daylight hours when fish were in residence and describe potential relationships between shelter occupancy and neighboring fishes. Replicate PVC shelters were monitored …