Behavioral metrics of swimming Hydromedusae in a turbulence generator near Friday Harbor dock and laboratory in 2012 (Jellyfish predation in turbulence project)

Website: https://www.bco-dmo.org/dataset/650006
Data Type: experimental
Version:
Version Date: 2016-07-06

Project
» Influence of organism-scale turbulence on the predatory impacts of a suite of cnidarian medusae (jellyfish predation in turbulence)
ContributorsAffiliationRole
Sutherland, Kelly RakowUniversity of Oregon (OIMB)Principal Investigator
Copley, NancyWoods Hole Oceanographic Institution (WHOI BCO-DMO)Guest, BCO-DMO Data Manager


Dataset Description

Swimming behaviors of four species of cnidarian hydromedusae (Aequorea victoria, Mitrocoma cellularia, Stomotoca atra, Aglantha digitale) exposed to two flow conditions in a laboratory turbulence generator - still water and turbulent (ε ~10-7 m2 s-3).

Related Datasets:
HydroSwimParams_N
ANOVA means


Methods & Sampling

The x and z position of the most aboral point on the bell were digitized in ImageJ (NIH, Bethesda, Maryland, USA) at 1-s intervals to produce trajectories from a total of 82 individual hydromedusae from 34 tank trials.  Resultant data don’t agree well with in situ measurements suggesting that there may have been tank artifacts.

Measured swimming parameters from each individual hydromedusa included depth in the tank, observed speed, acceleration, the net-to-gross displacement ratio (NGDR), time spent swimming and swimming direction.


Data Processing Description

BCO-DMO Processing:

- added conventional header with dataset name, PI name, version date
- renamed parameters to BCO-DMO and BODC standards


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Data Files

File
HydroSwimParams_indstats.csv
(Comma Separated Values (.csv), 1.00 KB)
MD5:daf52706869af4a0ea8afd45cfac1dda
Primary data file for dataset ID 650006

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Parameters

ParameterDescriptionUnits
species

hydromedusa genus

unitless
treatment

treatment: still or turbulent water

unitless
num_indiv

number of individuals

each
speed

speed of specimen

cm/sec
speed_sd

speed of specimen standard deviation

cm/sec
speed_mean_max

maximum swimming speed

cm/sec
speed_max_sd

maximum swimming speed standard deviation

cm/sec
accel

acceleration rate

cm/sec^2
accel_sd

acceleration rate

cm/sec^2
depth_mean

depth in turbulence generator (maximum depth of turbulence generator =  30 cm)

cm
depth_sd

standard deviation

cm
NGDR_mean

mean net-to-gross displacement ratio

unitless
NGDR_mean_sd

mean net-to-gross displacement ratio standard deviation

unitless
pcent_timeswim

percent time spent swimming faster than 0.2 cm/sec

unitless
pcent_timeswim_sd

percent time spent swimming

unitless
dir_mean_degr

mean swimming direction

degrees
dir_mean_degr_sd

mean swimming direction

degrees
Ua

average speed of plankton based on all instantaneous speeds

cm/sec
Ua_mean

Motility number: the ensemble average swim speed Ua divided by 2 component turbulence velocity q (Gallager 2004). q = 0.27

cm/sec


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Instruments

Dataset-specific Instrument Name
Generic Instrument Name
Camera
Dataset-specific Description
Sony HDR-HC9 camcorder (1920 x 1080 pixels, 30 frames s-1; Sony Electronics Inc., Fort Myers, FL, USA) with a 16 x 9 cm field-of view.
Generic Instrument Description
All types of photographic equipment including stills, video, film and digital systems.


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Deployments

FHL_Sutherland

Website
Platform
Friday_Harbor
Start Date
2012-06-01
End Date
2016-06-30


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Project Information

Influence of organism-scale turbulence on the predatory impacts of a suite of cnidarian medusae (jellyfish predation in turbulence)

Coverage: Friday Harbor Labs, WA


Bloom-forming jellyfish are increasing in number, frequency and magnitude, in part due to anthropogenic impacts, underscoring a need for enhanced understanding of trophic exchanges in jellyfish-dominated ecosystems. Interactions between jellyfish and their prey are driven by morphology, behavior, and unique fluid signatures that result in species-specific prey selection patterns. Fluid signatures generated by predators entrain prey, and motile prey organisms have evolved to sense and respond to these stereotyped fluid signatures. The shape and coherence of these unique fluid signatures are strongly mediated by turbulence, which is ubiquitous in the ocean. Yet, the effects of turbulence are almost always neglected in feeding studies. This three-year project will investigate the influence of turbulence on predator-prey interactions using a suite of cnidarian hydromedusae with unique morphologies, fluid signatures and prey selection patterns collected in the region of Friday Harbor Laboratory, WA.

This project seeks to establish a detailed, mechanistic understanding of the effects of turbulence on organism-scale predator-prey interactions using gelatinous zooplankton predators with contrasting predation modes. The PI will investigate prey selection under varying levels of turbulence by studying swimming behavior, wake structure, and predator-prey interactions in a laboratory turbulence generator designed for fragile plankton. The PI will also make in situ measurements of turbulence and observations of organism behavior using a Self-contained Underwater Velocimetry Apparatus (SCUVA). This is a fully submersible instrument for flow visualization, and its use will provide a cross-calibration of field and laboratory rates and behaviors. The influence of turbulence on trophic position among the different species of hydromedusae will be quantified through field studies of prey selection patterns. The proposed comparative approach using species with distinct predation modes will provide insights applicable to other planktonic predators that can be similarly grouped.

 



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Funding

Funding SourceAward
NSF Division of Ocean Sciences (NSF OCE)

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