visual motion with pink noise induces predation behaviour - styrene sheets
Visual Motor cues are one of the most important factors that trigger animal behavior, including predators-
Prey Interactions in aquatic environments.
In order to understand the elements of motion that cause this selective predator behavior, we used a virtual plankton system in which the predator behavior response computer-
The prey produced was analyzed.
First of all, we conducted a movement analysis of plankton (Daphnia magna)
Extract mathematical functions for the biological related motion of prey.
Next, program the virtual prey model on the computer and present it to medaka (Single chain length plus latipes)
It's a meat-eating fish.
Medaka showed predatory behavior for several typical virtual plankton movements, especially for swimming patterns that can be described as pink noise movements. Analysing prey-
Predator interaction through pink noise motion will be an interesting research area in the future. Medaka (, Black variety)
Purchased from a local pet store (
Encho, Japan's Big Mac).
Before moving to the experimental system, they were placed in a 60-liter glass aquarium system for at least 7 days.
Stock population (
50 fish per aquarium)
In the light/dark cycle of 12/12 µh, remain in the inflatable and filtered water at 26 ± 1 °c (
Light from 08: 00 to 20: 00)
Eat artificial dry food (
Japan, Tokyo, Japan).
The fish is fed at 08: 30.
Water is filled by mixing de-
Ionization HO and artificial sea salt (18u2005g/60u2005L;
Tokyo, Japan, Tetra Japan, Tetra marine salt Pro). Adult fish (
Weight 250 ± 50 mg)
For all experiments.
After the study, the fish were transferred to a retired aquarium and are being maintained for another research project.
It was donated by the professor. Taisen Iguchi.
Donated plankton was raised immediately after hatching at the 30-liter aquarium (
Water for 20 µL House)
Four days before the experiment.
The population number remained under the same conditions as medaka, but was not ventilated and filtered. A suspension (0.
3 ml/10 µL, C. L. , Tokyo, Japan)
Add to the housing tank once a day at 08: 30 as a food source.
The study was approved by the animal experimental Committee of the National Institute of Natural Sciences of Japan (
Approval numbers: 10A044 and 11A019).
[Aloes words】 box glass
Inner Length: 9. 5u2005cm (
Horizontal width)× 1. 0u2005cm (
Horizontal depth)× 9. 5u2005cm (vertical depth)]
Used as a test tank for motion analysis.
The aquarium is full of water (
The vertical depth is 8. 0u2005cm).
Through the air conditioning of the laboratory, the temperature of the water tank is kept at 26 °c ± 1 °c.
There are 1% qiongjiao applied to each tank bottom (
Nacalai Tesque in Kyoto, Japan)
To prevent reflection of lighting.
The side of the tank (excluding the side where the camera is located) is covered with black rubber to prevent excessive lighting.
The test tank was placed in a dark room.
Using 3 white fluorescent lamps placed on the outside of each vertical water tank surface, adjust the lighting on the water surface to 3000 Lux, excluding the side where the camera is placed.
10 to 20 were transferred to the tank to record the movement of plankton with a digital camera (EXILIM EX-
Tokyo, Japan, Casio Computer, F1).
Video images (
30 fps, 1280 pixels x 720 pixels)
2D motion software (
Automatically track the prime coordinates of plankton in each video frame.
The data points of plankton collision or tank wall collision were excluded.
In order to adapt to the size limit of the virtual plankton reconstructed on the computer display, there are only two-
Dimension coordinates (horizontal-vertical axes)were analysed.
The moving distance of each frame is calculated from a series of coordinates and converted to swimming speed (mm/sec)
, Which is calculated separately for the horizontal axis (
And vertical axis (
Positive in the upward direction).
Calculate the swimming speed in the absolute value of the swimming speed.
Power spectral density (PSD)
Extracted from 256 swim speed sequences and using a fast Fourier transform (FFT).
The results showed an average PSD of 48 plankton.
Slope of average PSD (log-log plot)
It's calculated by a power supply.
Virtual plankton in 15-
In a CRT display with a refresh rate of 70 hz and a resolution of 1024 × 768 pixels.
All stimuli are controlled by the software of psythesps (
Develop the C library of psychological and physical visual stimulation;
Please refer to our previous paper)
, Running on a Windows PC.
Presenting visual stimuli in an area of 500 × 230 pixels (130 × 60u2005mm;
Distance between pixels: 0. 26u2005mm)
Located in the center of the display.
Coordinates at the bottom-
The upper left corner of the area is defined (0, 0).
Draw Virtual plankton with 6 white dots (
80cd cd · m, psythesps ellipse function with a diameter of 3 pixels)
The background is black.
The starting coordinate of the center of the point is (65, 100), (145, 100), (225, 100), (275, 100), (355, 100), and (435, 100).
The position of the moving point is updated every 2 video frames according to the digital sequence in the data file, which describes the timeline data of the moving distance of each video frame (see below).
If the virtual Plankton leaves the area, they will re-
Enter the demo area from the diagonal to the exit position.
The position of the moving point is reset to the starting position every 10 seconds.
In order to reconstruct the virtual plankton on the CRT display, 9 types of numerical sequences were prepared using the following program.
The next value in progress adds a value smaller than the inter-pixel interval.
A new numerical sequence is generated for each test.
As mentioned earlier, the movement analysis of virtual plankton also examined the validity of the numerical sequence.
The experimental settings are shown.
The cubic glass is fragrant (
Inner side length 15 cm)
Used as a test tank in the meaka behavior experiment.
To limit the external visual stimulation of the fish, 2 sides are covered with white polystyrene sheets.
Test Tank 1. 46u2005L of medium;
The composition of the water is the same as the enclosure tank.
The vertical depth of water is 6. 5u2005cm.
Through the air-conditioned laboratory, the water tank is kept at a temperature of ± 1 °c at 26 °c.
A total of 142 innocent fish were used for 10 visual stimuli (
The number of fish in each case is shown in).
First, the test tank is placed at the front of the recording room.
Three innocent fish were randomly selected from the population and carefully transferred to the test pool (
From 09: 00 to 15: 00). Twenty-
After 4 hours, the test tank was moved to the recording room and connected to the CRT display, and the animal was allowed to adapt for 1 hour.
The lighting at the bottom of the test tank is adjusted to 1500 lux and 2 white fluorescent lamps are placed outside the surface of the vertical tank.
After the adaptation period, the behavior of the animal is recorded from the above using a network camera (Qcam-130E;
Tokyo, Japan)for 2u2005min.
At the last minute, visual stimuli were displayed on the CRT display.
The generated video images are stored in AVI file format (
15 fps, 960x720 pixels)
, And use DIPP-Analysis
2D software for motion.
A brief overview of the quantitative criteria for fish behavior is presented.
Automatically track the coordinates of the head and mass center of the fish in each video frame.
The center of the head is defined as the center position of the two quality centers of the eye.
From the coordinates of the head and mass center, calculate the angle of the body axis with respect to the line perpendicular to the CRT display side to the inside surface of the tank. An area 7.
Starting from the inside surface of the tank on the side of the CRT display, with a width of 5mm, is defined as the prey area.
The width of the area is approximately equivalent to the length from the front edge of the fish to the root of the thoracic fin (
Average length of fish: 25. 5 ± 3. 4u2005mm, n = 134).
The dwell time of the head center in the prey area is calculated as a measure of attraction behavior.
When the center of the head is located in the prey area and the angle of the body axis is within ± 30 °, the dwell time is calculated as a measure of the predatory behavior.
The results of each test were calculated as the average of 3 Fish.
The results of the determination of statistical significance (2-tailed)or unpaired (2-
Tail band Bonferroni correction)-tests.
The cut-off value of