Tag: Kelly Sutherland

Biomechanics of Jellyfish in Turbulence

Presenter : Susan Brush

Mentor : Kelly Sutherland

Major : Marine Biology

Poster 25

Hydromedusan jellyfish are planktonic organisms and, as such, are exposed to ocean water motion that directly impacts how they eat, disperse and eventually spawn. To understand the effect that realistic levels of water motion has on individual organisms, our research examines the role that turbulence plays in the swimming behavior of hydromedusae. Using a laboratory turbulence tank, we observed the behavior of two species of hydromedusae with distinct body shapes at two levels of turbulence. We were able to establish that these two species occupy different depths within the water. While statistical comparison resulted in no significant dif- ference in swimming speed and acceleration between turbulence treatments, qualitative comparisons between swimming patterns of the two species suggests that turbulence does influence the swimming trajectories of prolate individuals (bullet-shaped) com- pared oblate individuals (plate-shape). Swimming behavior is closely tied with feeding behavior in hydromedusae. Therefore these findings indicate that turbulent conditions, which are ubiquitous in the ocean, may disproportionately influence feeding in certain species and could impact the overall success of these organisms.

Prey detection and feeding success of the comb jelly Mnemiopsis leidyi on the copepod Acartia tonsa in still and turbulent waters

Presenter: Clare Chisholm (Environmental Science)

Mentor: Kelly Sutherland

Oral Presentation

Panel B: “Vertebrate Expression” Walnut Room

Concurrent Session 3: 1:45-3:00pm

Facilitator: Chris Moe

The comb jelly or ctenophore, Mnemiopsis leidyi, is a voracious predator in both its native and non-native habitats. Though M. leidyi inhabits coastal waters that are frequently turbulent, previous feeding studies have been conducted in still water tanks. This study aimed to research their feeding behaviors in turbulent waters, which is more representative of their natural environment. Interactions between the free-swimming ctenophores and copepod prey (Acartia tonsa) were observed and recorded (n = 73) in a laboratory turbulence tank. Turbulence was created using submersible speakers, and the interactions were recorded using a video camera. Capture efficiency denoted interactions containing direct contact between copepods and M. leidyi that led to eventual capture, frequently after multiple interspecies contacts. Overall copepod capture efficiency was similar in still (48%) and turbulent (43%) water, as were the overall prey retention rates for each (still = 26%; turbulent = 20%). However, M. leidyi exhibited anticipatory responses, defined as altering the position of feeding structures, nearly twice as often in still (41%) waters than in turbulent (20%) waters. The hydromechanical “noise” produced by background turbulence may inhibit the capacity of the ctenophore to detect and respond to fluid motions produced by its prey.

A Reflection in the Mirror: How Noir Championed the Voice of a Generation

Presenter: Brennan Heller

Mentors: Ulrick Casimir, English; Kelly Sutherland, Biology

Oral Presentation

Majors: Business and Psychology 

Dark lighting. Risqué women. Hard liquor paid in cold cash within the corrupt cities of noir. During its apotheosis, noir fully critiqued the social, cultural, and political changes in American ideology through powerful aesthetics. Analyzing how the economic restrictions of World War II on the United States influenced noir’s developed use of novel lighting, characterization, and fatalistic narrative, I will demonstrate how the aesthetics of this genre captured the anxious zeitgeist of American society distraught by the war and its aftermath. By examining noir’s stylized cinematography,

I show how noir was the aesthetic response from an apprehensive America faced with ideological upheaval in the wake of World War II.

Radiole Regeneration of the Feather Duster Worm, Schizobranchia insignis

Presenter: Shannon Brown

Faculty Mentor: Richard Emlet, Kelly Sutherland

Presentation Type: Poster 49

Primary Research Area: Science

Major: Marine Biology

The annelid feather duster worm, Schizobranchia insignis, is a prevalent marine invertebrate found along the coastlines of the Northeastern Pacific Ocean. The regenerative ability of feather duster worms is frequently studied as a model for regeneration because the annelid phylum demonstrates a pronounced array of regeneration processes. The main purpose of my study is to examine the regeneration of a single radiole in S. insignis. Previous studies have examined the regeneration of the entire posterior and anterior region of the worm; however, limited information is available on radioles, the anterior appendages used for feeding and respiration. By cutting S. insignis radioles and observing resulting regeneration, I was able to categorize the regeneration into 12 distinctive stages with detailed descriptions of the external and internal structures that developed during each stage. In addition, to support potential regenerative conclusions, I performed an overall survey of the feather duster worm’s branchial crown and found that there is a non-significant positive linear relationship between the number of radioles and the weight of the S. insignis. Although a full analysis of the data has not been completed, I expect that the information collected for this study will provide additional knowledge to the currently limited regeneration field.

Sea Star Plasticity: Morphological Variation of Pisaster ochraceus in Response to Wave Exposure

Presenter: Alyssa Bjorkquist

Faculty Mentor: Richard Emlet, Kelly Sutherland

Presentation Type: Poster 47

Primary Research Area: Science

Major: Marine Biology, Psychology

Funding Source: Undergraduate Research Opportunity Mini-Grant, UROP, $1000

Pisaster ochraceus (the Ochre Sea Star) is a keystone species in the NE Pacific whose role as an ecological engineer influences intertidal diversity by predating on space-competing organisms. Individuals inhabit a broad range of habitats ranging from sheltered coves to exposed cliffs and experience large temporal and spatial variability in water flow throughout their lifetime. However, it is largely unknown how sea star body shape changes between wave- exposed and wave-sheltered environments throughout an organism’s lifetime. Wave exposure was measured at each study site near Charleston, OR using dissimilar metal dissolution and intertidal zonation of sessile organisms. Furthermore, I analyzed how aspects of juvenile and adult P. ochraceus morphology differed between sites as functions of wave exposure.

Sites with more wave exposure were associated with greater anode mass loss over time (F1,30 = 256.21, p < 0.001) and broader vertical zone boundaries relative to mean water level than sheltered sites (F2,8 = 3.03, p < 0.01). Adult sea star populations from wave-exposed sites had longer, narrower arms and smaller central discs relative to individuals from sheltered habitats for a given weight (F2,152 = 70.0, p < 0.001). Juveniles appeared to exhibit similar morphological trends but results were inconclusive. The relationship between wave exposure and sea star morphology indicate that hydrodynamic conditions play a large role in shaping sea star development and environmental adaptability post-larval metamorphosis.

The effect of seasonal changes on reproductive status of Clytia gregaria along the Pacific Northwest

Presenter(s): Ya Li—Environmental Science

Faculty Mentor(s): Marco Corrales-Ugalde, Kelly Sutherland

Session: Prerecorded Poster Presentation

Cnidarian jellyfish are ubiquitous predators of pelagic communities, however, very little is known about their phenology and how food availability affects their reproductive cycles . However, research shows that starved jellyfish tend to decrease somatic growth and allocate more resources to gonad development . Thus, a ratio of body size to gonad size might work as a proxy to the nutritional state of jellyfish . We hypothesize that when food is scarce, C . gregaria will have larger gonads relative to their body size . The jellyfish observed were collected both in a period of low primary productivity where food was scarce (winter) and a period of high primary productivity (summer) along two longitudinal transects in the North California Current System . ImageJ was used to analyze photos taken of the preserved specimens to obtain bell diameter and gonad area to then create a gonadal index (gonad area/bell area) . The data shows a slightly higher gonad area to bell area ratio in the winter C . gregaria than those from summer indicating an increased effort towards reproduction when resources are depleted . Due to the preservation method causing a loss in biomass of the collected specimens, it makes it difficult to relate morphological measurements on preserved specimens to the morphology of live organisms . In the future, we will make a correction factor to convert between the measurements of live and preserved organisms . Understanding the links between oceanographic conditions and population dynamics of gelatinous predators will allow us to better predict their effects on zooplankton community dynamics .