Dataset: Copepod escape direction

Name: Experimental results on the direction of escape for five species of calanoid copepod and multiple developmental stages in response to artificial hydrodynamic stimuli (PreyEscape project)
Published: 2017-04-04
Keywords: Calanoida, Escape direction, Myelin, biota, oceans

Cite This Dataset

Spatial Extent: N:21.3 E:-157.8197 S:21.3 W:-157.8197

Project:

The Drive to Survive: Copepods vs Ichthyoplankton (PreyEscape)

Principal Investigator:

Petra H. Lenz (University of Hawaiʻi at Mānoa, PBRC)

Co-Principal Investigator:

Daniel K. Hartline (University of Hawaiʻi at Mānoa, PBRC)

BCO-DMO Data Manager:

Nancy Copley (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version Date:

2017-04-04

Restricted:

Validated:

Yes

Current State:

Final no updates expected

Experimental results on the direction of escape for five species of calanoid copepod and multiple developmental stages in response to artificial hydrodynamic stimuli (PreyEscape project)

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Description

This dataset includes the direction of escape for five species of calanoid copepod nauplii and copepodites in response to an abrupt hydromechanical stimulus (moving sphere, suction).

These data were published in:
Buskey, E.J., Strickler, J.R., Bradley, C.J., Hartline, D.K. and Lenz, P.H., 2017. Escapes in copepods: comparison between myelinate and amyelinate species. Journal of Experimental Biology, 220(5), pp.754-758. doi:10.1242/jeb.14830

Related Reference:
Takagi, D. & Hartline, D.K. (2017). Directional hydrodynamic sensing by free-swimming organisms. Bulletin of Mathematical Biology, in press doi: 1 0.1007/s11538-017-0368-0

Methods & Sampling

Copepods' approaches to and escapes from the source of a fluid disturbance were recorded on high-speed digital video (500 fps) in 3D. The optical set-up used is a scaled down version of a system described in Strickler (1998). The system, which uses beam splitters and prisms, generates in a single recorded image of two views, the front (x, z) and the side (y, z). These 3-D views were recorded high-speed digital video cameras (in Texas by a Photron FastCam Super 10K series, in Hawaii by a Kodak Motioncorder SR-3000) at 500 frames per second.

For the behavioral experiments, sets of individuals were transferred into the experimental chamber (1.25 x 1.25 x 4.5 cm) at densities of 7 to 15 ind mL-1 for nauplii, and 1.5 to 3 ind mL-1 for copepodites. When one or more individuals were within the camera view the hydromechanical stimulus was triggered and a video sequence that included footage from before and after the trigger was recorded.

The hydromechanical stimulus: a 3-mm diameter inert plastic sphere was attached to a stiff rod mounted to a piezoelectric pusher (DSM LPA 100 Dynamic Structures) and positioned in the upper quarter of the optical vessel. A pulse trigger controlled the pusher, which displaced the sphere downward by 35 microns in 0.5 ms, returning it to its initial position 60 ms later.

Reference:
Strickler JR. 1998. Observing free-swimming copepods mating. Phil. Trans. R. Soc. Lond. B 353: 671-680.

Data Processing Description

For the data analysis, more than 800 escape sequences in response to the stimulus were reviewed and the copepods’ body-axis orientation just prior to the stimulus trigger was recorded, as was the direction of its subsequent escape jump. Initial orientation and escape direction were categorized using a simple classification system: towards the sphere or away from it, according to the angle relative to the horizontal plane. In a few cases, the copepod’s swim/escape direction was perpendicular to the stimulus (± 5º from horizontal), and these were excluded from the analysis (fewer than 5 % of observations). Results for each group (myelinate vs. amyelinate) were combined and tested using the Fisher Exact test (two-tailed) to compare swimming behavior of the two groups. Nauplii and copepodites were tested separately. Specific comparisons included: 1) swim direction prior to stimulus; 2) whether the escape direction was in the direction of the original swim (“original swim direction” vs. “reverse direction”) and 3) whether escapes were directed towards or away from the stimulus (“towards sphere” vs. “away from sphere”).

BCO-DMO Processing Notes:
- added conventional header with dataset name, PI name, version date
- modified parameter names to conform with BCO-DMO naming conventions

Data Files

File
copepod_escape_direction.csv (Comma Separated Values (.csv), 1.37 KB) MD5:5a9805f1af94e84a579c70c8b28a880b Primary data file for dataset ID 686922

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-1235549
NSF Division of Ocean Sciences	OCE-0451376
NSF Division of Ocean Sciences	OCE-0452159

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
CopepodEscape_2017		2017-01-01	Lenz_lab	Petra H. Lenz (Principal Investigator)	data info

Instruments

Camera

Supplied Name: Photron FastCam 10K series or Kodak Motioncorder SR-3000

Supplied Description:

Used to record swimming behavior of copepods

Instrument Type

Generic Name: Camera

Acronym: camera

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/311/

Generic Description:

All types of photographic equipment including stills, video, film and digital systems.

Parameters

Date and time formats are described in python strftime() syntax.

Supplied Name	Supplied description	Supplied Units	Standard Name
escape_toward_count	number of observations of escapes directed towards stimulus	escapes	numb_obs
escape_away_count	number of observations of escapes directed away from stimulus	escapes	numb_obs
num_observ	total number of escapes observed	escapes	numb_obs
stage	copepod developmental stage	unitless	stage
myelin_flag	whether species possess (yes) or lack (no) myelin sheath on nerve cells	unitless	flag
species	copepod species	unitless	species
orig_swim_dir	original swim direction which is either towards or away from stimulus; total is the sum of "towards" and "away"	unitless	no_bcodmo_term

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Database

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Dataset: Copepod escape direction