WO2022188059A1 - Plankton phototaxis detection device and analysis method - Google Patents

Abstract

The present invention provides a plankton phototaxis detection device, comprising: a detection box and a light induction unit disposed on one side of the detection box, the light induction unit comprising a wavelength-switchable induction light source; an illumination unit, distributed around the detection box, and used for illumination of the detection box; and an imaging unit, disposed above the detection box, and used for acquiring an image of the interior of the detection box. The plankton phototaxis detection device can be used for studying the phototaxis characteristics of plankton for light having different wavelengths. Further, the illumination unit can switch between bright-field illumination and dark-field illumination, so that different types of plankton can be well observed. The present invention further provides a plankton phototaxis analysis method, comprising: analyzing the motion state of plankton on the basis of an acquired plankton phototaxis video, and generating data used for scientific research. In addition, according to the detection device in the present invention, plankton can be directly observed, position detection of the plankton is accurate, and it is beneficial to obtaining more accurate analysis results.

Description

A kind of plankton phototaxis detection device and analysis method technical field

The invention relates to the technical field of scientific instruments and devices, in particular to a plankton phototaxis detection device and an analysis method.

Background technique

Plankton is the foundation of the marine ecosystem, and most plankton have obvious phototaxis. It is of great significance to study the phototaxis of plankton. For example, the larvae of the lichen lichen have obvious phototaxis, and the larvae attached to various marine devices will grow into the adult population of the lichen lichen, causing serious fouling problems. Studying the phototaxis of the larvae of the multicellular bryophyte will help to improve the increasingly serious problem of bryophyte fouling. Since it is very difficult to study plankton phototaxis in the actual environment, it is necessary to provide a plankton phototaxis detection device for research.

Existing plankton phototaxis detection devices are generally equipped with a single light source. After turning on the light source, the detection device is left to stand still. By observing the number distribution of plankton in different positions in the device after a certain period of time, or by observing the projected grayscale situation reflected within a certain period of time. For the analysis, there are many shortcomings in the setting of the detection device, so that the detection results are difficult to be used for scientific research, and the analysis carried out has strong limitations. Specifically, the arrangement of a single light source makes the detection device only used to measure the phototactic response of plankton to a certain type of light source. Moreover, there is also a limitation that when using brightfield illumination, the contrast of samples for observing transparent plankton is weak, so it is only suitable for observing the phototaxis of non-transparent plankton. Further, the projected position observed by the projection of the observed plankton is different from its actual position, and the detection result may be erroneous. In addition, existing plankton phototaxis detection devices cannot quantify the characterization of plankton phototaxis, and it is difficult to generate data for scientific research.

SUMMARY OF THE INVENTION

In view of this, in order to overcome the above-mentioned defects of the prior art, the present invention proposes a method with strong universality, which can be used to analyze the phototaxis characteristics of different plankton for different wavelengths of light, and can generate the observation results for scientific research. The data of the plankton phototaxis assay device.

Specifically, the plankton phototaxis detection device of the present invention includes a detection box and a light induction unit arranged on one side of the detection box, the light induction unit includes an induction light source, an optical fiber and a beam coupler, and the wavelength of the induction light source is switchable, the optical fiber is connected to the beam coupler and the inducing light source, and the beam coupler is used for emitting light; further comprising: an illumination unit, distributed around the detection box, for illuminating the detection box; an imaging unit, It is arranged above the detection box and is used for acquiring the image in the detection box. The light-inducing unit can emit light of different wavelengths for analyzing the phototaxis characteristics of plankton to light of different wavelengths. Further, it also includes a blocking member, the blocking member is detachably placed in the detection box, the blocking member can move in the detection box, and can divide the inner space of the detection box into two parts for Limit the initial position of the test sample in the test box. When the light intensity is constant, when it is necessary to measure the phototaxis of plankton at a specific distance from the induced light source, the distance between the blocking member and the induced light source can be adjusted by moving the blocking member.

Preferably, the lighting unit includes a plurality of illuminators disposed below the detection box, and the plurality of illuminators are respectively disposed in the bright field lighting area and the dark field lighting area;

The bright field illumination area is located below the detection box, and the dark field illumination area is located beside the detection box. The lighting environment can be switched between bright field and dark field lighting, which can observe both non-transparent plankton and transparent plankton, and has strong universality. The bottom of the detection box and the side close to the inducing light source are transparent walls, and the other walls are non-transparent walls. Optionally, the non-transparent wall surface can be black frosted glass to prevent the light emitted by the induced light source from being reflected by the wall surface of the detection box to affect the behavior and movement direction of plankton, resulting in inaccurate observation results.

In some embodiments, in order to form a good illumination angle of the induced light source, the optical axis of the beam coupler is located in the center of the cross section of the water body in the detection box. Preferably, a collimator is also included, the collimator is connected to the beam coupler, and is used to limit the beam divergence range of the light inducing unit to achieve better lighting effect.

Further, it also includes a fixed support unit, the fixed support unit includes a support structure, a connecting sheet metal and a fixed sheet metal, the detection box is detachably connected to the support structure, and the connecting sheet metal connects the support structure and the imaging unit, and the fixed sheet metal connects the support structure and the light-inducing unit. The fixed support unit can limit the positional relationship between the various parts of the detection device, so as to facilitate continuous research under the same or similar detection conditions.

A method for analyzing the phototaxis of plankton, which is used for analyzing the motion state of plankton, and the method for analyzing the phototaxis of plankton includes:

S1: use the plankton phototaxis detection device according to any one of claims 1-6 to record a plankton phototaxis video;

S2: convert the video into an image sequence;

S3: performing grayscale processing on the images in the image sequence;

S4: Correct the image obtained after grayscale;

S5: Select a tracking target to track according to the corrected image obtained in step S4;

S6: obtain the motion trajectory of the tracking target;

S7: Analyze the motion trajectory.

A method for analyzing the phototaxis of plankton, which is used for analyzing the number distribution of plankton, and the method for analyzing the phototaxis of plankton includes:

A1: Use the plankton phototaxis detection device according to any one of claims 1-6 to record plankton phototaxis video;

A2: Convert the video into a sequence of images;

A3: Perform grayscale processing on the images in the image sequence;

A4: Correct the image obtained after grayscale;

A5: extract the background image of the video;

A6: Grayscale and correct the background image;

A7: Binarize the background image to obtain the region of interest of the detection box;

A8: Crop the background image and the background image of the sequence image, and extract the background-corrected image according to the above image;

A9: Perform a Gaussian filter-binarization operation on the background-corrected image;

A10: Perform spot detection on the binarized image and mark it;

A11: Draw plankton number distribution map based on spot location information.

Further, the "recording plankton phototaxis video" includes:

a: add the water sample to the detection box;

b: turn on the lighting unit;

c: adjusting the distance between the blocking member and the inducing light source;

d: Add the test sample to the test box;

e: The blocking member and the inducing light source are opened, and the imaging unit performs recording.

Preferably, the "correcting the image obtained after grayscale" includes performing distortion correction and rotation correction. Distortion correction can correct the distortion caused by the difference in magnification of the lens lens system, and rotation correction can correct the angle error caused by the misalignment of the detection box and the camera, which is conducive to obtaining more accurate results in subsequent analysis.

To sum up, the plankton phototaxis detection device of the present invention adopts a wavelength-switchable inducing light source, and can analyze the phototaxis characteristics of plankton to light of different wavelengths. Further, the lighting unit includes a bright-field illuminator and a dark-field illuminator, so that the lighting environment can be switched between bright-field and dark-field lighting, and both non-transparent plankton and transparent plankton can be observed, with strong universality. The phototaxis analysis method of plankton using the plankton phototaxis detection device of the present invention is based on video data, and can analyze the motion state of plankton, including motion trajectory, motion angle, motion rate and its quantity distribution. In addition, the detection device directly observes the plankton body, and the position detection of the plankton is accurate and accurate.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present application more clearly, the following briefly introduces the drawings that are used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

1 is a schematic diagram of the overall structure of the plankton phototaxis detection device of the present invention;

2 is a cross-sectional view of the plankton phototaxis detection device shown in FIG. 1;

3 is a schematic diagram of the support structure of the plankton phototaxis detection device of Example 2;

4 is a schematic structural diagram of a connecting sheet metal of the plankton phototaxis detection device of Example 2;

5 is a schematic structural diagram of a fixture of the plankton phototaxis detection device of Example 2;

6 is a schematic structural diagram of a fixed sheet metal of the plankton phototaxis detection device of Example 2;

7 is a top view of the plankton phototaxis detection device shown in FIG. 1;

8 is a schematic structural diagram of an adapter of the plankton phototaxis detection device of Example 2;

9 is a cross-sectional view of the adapter shown in FIG. 8;

10 is a schematic structural diagram of the illuminator of the plankton phototaxis detection device of Example 2;

Figure 11 is a cross-sectional view of the illuminator shown in Figure 10;

Fig. 12 is the result diagram after grayscale of the phototaxis video sequence image of the larvae of the multi-chamber grass lichen;

FIG. 13 is a result diagram of FIG. 12 after performing distortion correction;

Fig. 14 is the result graph after performing rotation correction in Fig. 13;

15 is a schematic diagram of selecting a tracking target according to Embodiment 3;

Fig. 16 is the tracking result diagram of embodiment 3;

Fig. 17a is the movement angle curve of the larvae of the multi-chamber grass lichen obtained by the analysis of Example 3;

Fig. 17b is the movement rate curve of the larvae of the multi-chamber grasshopper obtained by the analysis of Example 3;

Fig. 18 is the result graph of the background extraction of embodiment 4;

FIG. 19 is a result diagram after image correction is performed in FIG. 18;

Fig. 20 is the result picture after the background image binarization;

Figure 21 is a schematic diagram of automatic selection of ROI;

22 is a schematic diagram of background correction obtained according to a background image and ROI;

Figure 23 is a schematic diagram of the distribution of plankton numbers at the beginning;

Figure 24 is a schematic diagram of the distribution of plankton numbers at the end;

Figure 25 is a histogram of plankton population distribution at the beginning;

Figure 26 is a histogram of plankton population distribution at the end.

Reference number:

101-infrared camera; 102-copper column; 201-inducing light source; 202-fiber; 203-beam coupler; 204-collimator; 301-first illuminator; 302-first adapter; 303-second Adapter; 304-third adapter; 305-fourth adapter; 306-second illuminator; 307-third illuminator; 308-elastic protrusion; 309-first through hole; 310-th 2 through holes; 401-detection box; 402-blocker; 501-support structure; 5011-first plate; 5012-second plate; 5013-side plate; 502-connecting sheet metal; 5021-installation plate; 503 - Fixed parts; 504 - Fixed sheet metal.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The invention provides a plankton phototaxis detection device, comprising a sample detection unit, a light induction unit, an illumination unit and an imaging unit. The light induction unit is used to emit light to detect the phototaxis of plankton, and the illumination unit will not affect the plankton. The light source illuminates the sample detection unit, and the imaging unit is set to obtain the movement of plankton. Using the plankton phototaxis detection device of the present invention for research can analyze the motion state of plankton, including motion trajectory, motion angle, motion rate and its quantity distribution, based on the image acquired by the imaging unit. Quantifying the acquired phototaxis images of plankton and generating corresponding data for scientific research is conducive to obtaining more accurate analysis results.

Example 1

Referring to FIG. 1 and FIG. 2, it is a schematic structural diagram of the plankton phototaxis detection device of the present invention. The fixed support unit includes a support structure 501, a connecting sheet metal 502, a fixed sheet metal 504 and a fixing member 503, and the sample detection unit, the light induction unit, the illumination unit and the imaging unit are connected through the fixed support unit. Specifically, the support structure 501 includes a side plate 5013 and a first plate member 5011 and a second plate member 5012 arranged in parallel. The side plate 5013 connects the first plate member 5011 and the second plate member 5012 . The sample detection unit includes a detection box 401, and the detection box 401 is detachably connected to the first plate member 5011 and the second plate member 5012 of the support structure 501. Preferably, the sample detection unit further includes a detachable blocking member 402, such as a baffle plate, a filter screen, and the like. The blocking member 402 has the same cross-sectional shape and size as the detection box 401 , and is placed inside the box body of the detection box 401 . Location. When the light intensity is constant, when the phototaxis of plankton needs to be measured at a specific distance from the inducing light source 201 , the distance between the blocking member 402 and the inducing light source 201 can be adjusted by moving the blocking member 402 horizontally.

The distance between the detection box 401 and the induction light source 201 can be adjusted to affect the divergence range of the induction light source 201 in the detection box 401 . The connecting sheet metal 502 is installed on the side plate 5013, and the imaging unit is arranged above the detection box 401 through the connecting sheet metal 502 to obtain the image in the detection box 401. The connecting sheet metal 502 can be adjusted up and down to determine the appropriate imaging position .

The light inducing unit includes an inducing light source 201, an optical fiber 202, and a beam coupler 203. The inducing light source 201 is connected to the beam coupler 203 through the optical fiber 202. The beam coupler 203 is installed on the fixing member 503, and the fixing member 503 is installed through the fixing sheet metal 504. On the first plate 5011 of the support structure 501 , specifically, the optical axis of the induced light source 201 is located on the vertical center axis of the detection box 401 , and the fixed sheet metal 504 can be adjusted up and down to determine a suitable light emitting height. When using the plankton phototaxis detection device of the present invention, the optical axis of the induced light source 201 is adjusted so that the optical axis of the induced light source 201 is located at the center of the cross section of the water body in the detection box 401 . Preferably, the inducing light source 201 is set as a light source with switchable wavelengths, for example, a multi-wavelength laser, a supercontinuum white light laser, a broad-spectrum light source plus a filter, a multi-wavelength LED array, etc., which can detect plankton by emitting light of different wavelengths response to different wavelengths of light. Preferably, the light inducing unit further includes a collimator 204, the collimator 204 is connected to the beam coupler 203, and the collimator 204 can limit the beam divergence range of the light inducing unit to achieve better lighting effect. The lighting unit includes a plurality of illuminators connected to the support structure 501, the illuminators are arranged at a position lower than the detection box 401, and the illuminators can be adjusted up and down to determine a suitable lighting position.

Example 2

Referring to FIG. 3 of the specification, it is a schematic diagram of a specific structure of the support structure 501 used in this embodiment. The side plate 5013 includes a first part and a second part that are perpendicular to each other, the first part is vertically arranged, and two ends of the second part are respectively connected to the first plate part 5011 and the second plate part 5012. The first plate 5011 , the second plate 5012 and the first part are provided with a plurality of rounded rectangular through holes, wherein the through holes on the first plate 5011 and the second plate 5012 are symmetrically arranged. The first illuminator 301, the second illuminator 306, the third illuminator 307 and the connecting sheet metal 502 are connected to the support structure 501 by a bolt structure. When adjusting the above structure, first unscrew the nut, and then move it in the through hole , after moving to the target position, tighten the nut to fix it.

Referring to FIG. 4 in the description, the connecting sheet metal 502 is L-shaped, and the top is a mounting plate 5021 for mounting the imaging unit. Specifically, the imaging unit includes an infrared camera 101 and a plurality of copper pillars 102 . The infrared camera 101 passes through the through holes on the mounting plate 5021 and is connected to the mounting plate 5021 through the plurality of copper pillars 102 for fixing. In this embodiment, the viewing angle of the camera used is 76.6°, the size of the detection box 401 is 100mmⅹ20mmⅹ20mm, and the camera is 100mm away from the bottom of the detection box 401 to ensure that the field of view of the camera covers the entire detection box 401 . Referring to FIG. 5 and FIG. 6 , it is a schematic structural diagram of the fixing member 503 and the fixing sheet metal 504 . The beam coupler 203 is connected with the disc-shaped fixing member 503 by screws, and the disc-shaped fixing member 503 and the fixing sheet metal 504 are connected by bolts.

Referring to FIGS. 7-11 , in this embodiment, the lighting unit includes three illuminators which are respectively arranged in the bright field illumination area and the dark field illumination area. Specifically, the first illuminator 301 is arranged under the detection box 401, The illuminators 306 and the third illuminators 307 are symmetrically distributed on both sides of the detection box 401 and below the bottom of the detection box 401 . The first illuminators 301 , the second illuminators 306 and the third illuminators 307 are infrared illuminators. Specifically, the second illuminator 306 is connected to the support structure 501 through the first adapter 302 and the second adapter 303 , and the third illuminator 307 is connected to the support structure through the third adapter 304 and the fourth adapter 305 501 Connect. Preferably, the adapter is provided with a first through hole 309 for connecting the support structure 501 and a second through hole 310 for fixing the illuminator. The second through hole 310 includes two or more connected circular through holes with different diameters. The connecting part on one side of the illuminator is provided with an elastic protrusion 308. The elastic protrusion 308 cooperates with the second through hole 310 to form a fixed position for the illuminator. The central axis of the hole 310 is rotated to adjust the illumination angle. Specifically, when the first illuminator 301 is used, the distance between the first illuminator 301 and the bottom of the detection box 401 can be adjusted according to the height of the water surface in the detection box 401. For example, in this embodiment, the water added in the detection box 401 accounts for the detection of 1/3 of the volume of the box 401, the first illuminator 301 is 20mm away from the bottom of the detection box. When using the second illuminator 306 and the third illuminator 307 for illumination, the bottom of the detection box 401 is required to be within the divergence angle of the light source, the lens of the imaging unit is outside the divergence angle of the light source, and the light emitted by the light source cannot directly enter the lens.

Further, the bottom of the rectangular detection box 401 and the side close to the inducing light source 201 are transparent walls, and the other walls are non-transparent walls. In this embodiment, the non-transparent wall surface is black frosted glass, which prevents the light emitted by the induced light source 201 from being reflected by the wall surface of the detection box 401 to affect the behavior and movement direction of plankton, resulting in inaccurate observation results. When conducting research, turn on different illuminators to form different lighting environments according to the needs of observation, for example: when it is necessary to observe or record black plankton, turn on the first illuminator 301 at the bottom of the detection box 401 to form a bright field lighting environment, Highlight the non-transparent plankton; when it is necessary to observe or record the transparent plankton, turn on the second illuminator 306 and the third illuminator 307 to perform dark field illumination to highlight the transparent plankton.

Example 3

This embodiment is a method for acquiring the motion track, motion angle and motion speed of plankton by applying the plankton phototaxis detection device of the present invention.

In the process of using the plankton phototaxis detection device of the present invention, the judgment of using bright field illumination or dark field illumination can be judged by the following methods:

The image of plankton in the detection box 401 is taken under the bright field lighting environment, and the sample contrast is obtained

Compare the obtained sample contrast with the required sample contrast standard to determine whether the sample contrast standard is met;

If the result is yes, brightfield illumination is used, and if the result is no, darkfield illumination is used.

Optionally, the determination can also be made by calculating the sample contrast by taking an image in a dark field lighting environment.

After determining the required lighting environment, carry out the phototaxis detection of plankton:

S1: Record plankton phototaxis video in a dark room, taking the multi-chamber lichen larvae as an example, the recording process is as follows:

S101, adding the water sample to the detection box 401;

S102, turn on the first illuminator 301 in the lighting unit;

S103, adjusting the distance between the blocking member 402 and the inducing light source 201 according to the distance between the multi-chambered lichen larvae and the inducing light source 201 to be observed;

S104, adding the multi-chamber lichen larvae to the side of the detection box 401 away from the inducing light source 201;

S105, start the induction light source 201, remove the blocking member 402, and the infrared camera 101 starts recording;

S106. After waiting for a period of time, the infrared camera 101 ends the recording, and obtains a phototaxis video of the larvae of the multi-chamber lichen.

S2: Convert the recorded video into an image sequence.

S3: Perform grayscale processing on the images in the sequence to obtain a grayscale image, as shown in Figure 12. Grayscale processing of an image can convert a three-channel color image into a single-channel grayscale image, simplifying subsequent image processing operations.

S4: Perform image correction, and perform lens distortion correction on the grayscale image to obtain Figure 13. Lens distortion correction corrects distortion due to differences in magnification of the lens system of the lens. Rotation correction is performed on the corrected image to obtain Figure 14. Rotation correction can correct angular errors due to misalignment of the detection box 401 with the camera.

S5: After the corrected image is obtained, track the trajectory of the larvae of the grass lichen, and first select the tracking target, as shown in Figure 15. After selecting the tracking target, start tracking. Optionally, one or more targets can be selected for tracking according to research needs.

S6: After the tracking is completed, the movement trajectory of the multi-chamber lichen larvae is obtained, as shown in FIG. 16 .

S7: Analyzing the movement trajectory of the bryophyte larvae to obtain a curve diagram of its movement angle and speed changing with time, as shown in Figure 17a and Figure 7b.

The phototaxis was analyzed according to the movement angle and velocity information of the larvae.

Example 4

This embodiment is a method for obtaining the number distribution of plankton by applying the plankton phototaxis detection device of the present invention, wherein, in this embodiment, when recording the plankton phototaxis video in step 1, a blocking member is not used to adjust the multi-chamber bryophyte larvae The distance from the light source, optionally, step 1 can be the same as that of embodiment 3 when obtaining the number distribution of plankton; the processing method of sequence images in steps 2-4 is the same as that of embodiment 3.

A1: Record a video of plankton phototaxis in a dark room, taking the multi-chamber lichen larvae as an example:

A101. Add the water sample and the larvae of the multi-chamber lichen to the detection box 401, and let stand so that the larvae of the multi-chamber lichen are distributed in the entire detection box 401;

A102. Turn on the first illuminator 301, start the induction light source 201, and the infrared camera starts recording;

A103. After waiting for a period of time, the infrared camera 101 ends the recording, and obtains a phototaxis video of the multi-chamber lichen larvae.

A2: Convert the recorded video to an image sequence.

A3: Grayscale the images in the sequence to obtain a grayscale image, as shown in Figure 12.

A4: Perform image correction, and perform lens distortion correction on the grayscale image to obtain Figure 13.

A5: Extract the background image of the recorded video with the MOG2 (Gaussian Mixture) algorithm to obtain Figure 18.

A6: Perform grayscale-distortion correction-rotation correction on the background image to obtain Figure 19.

A7: Binarize the background image, analyze the binarized image, and obtain the ROI (region of interest) of the detection box 401, as shown in Figures 20 and 21. Among them, Figure 20 is the structure diagram of the background image after binarization. Perform the maximum contour detection on Figure 20 to find the coordinates of the upper left corner of the contour, and then according to the pixel length of the region of interest = the number of pixels corresponding to the length of the container, the interested The pixel width of the region = the number of pixels corresponding to the width of the container to obtain the region of interest. The region of interest obtained in this embodiment is shown in FIG. 21 .

A8: Crop the ROI (region of interest) of the background image and the sequence image, and obtain the background-corrected image accordingly. Specifically, in this embodiment, the two are subtracted to obtain a background-corrected image after background subtraction, as shown in FIG. 22 . Optionally, the background-corrected image can also be obtained by dividing the two.

A9: Perform a Gaussian filter-binarization operation on the background-corrected image.

A10: As shown in Fig. 23 and Fig. 24, spot detection is performed on the binarized image, and the detected spots are the larvae of the multicellular lichen. The detected blobs are marked in the cropped raw image sequence. Among them, Figure 23 is a schematic diagram of the distribution of plankton number at the beginning, and Figure 24 is a schematic diagram of the distribution of plankton number at the end. In this embodiment, the recording time of the plankton phototaxis video is 30 seconds. FIG. 23 is a schematic diagram of the plankton number distribution when the recording is performed for 1 second, and FIG. 24 is a schematic diagram of the plankton number distribution when the recording is performed for 30 seconds. Figure 23 and Figure 24 both include the upper, middle and lower parts, which are the original image, the image after the background subtraction and binarization of the original image, and the spot detection on the binarized image to draw the spot, which can be intuitively It can be seen whether the binarization effect and the algorithm of blob detection are accurate.

A11: Draw a histogram of the number distribution of the larvae of the multi-chamber grasshopper based on the spot position information after spot detection, as shown in Figure 25 and Figure 26. Among them, FIG. 25 shows the distribution of the number of the larvae of the lichen in FIG. 23 , and FIG. 26 shows the distribution of the number of the larvae of the lichen in FIG. 24 .

According to the quantitative distribution information of planktonic multicellular lichen larvae at the beginning and the end, the phototaxis index was obtained.

The above number distribution histogram is drawn as follows: divide the ROI area into ten areas in the horizontal direction, calculate the percentage of larvae in each area to the total number of larvae, and finally draw the percentage of larvae in the ten areas as a sheet. Quantity distribution histogram.

In some embodiments, a plurality of plankton phototaxis detection devices are set at the same time, the same lighting position of the lighting unit, the distance between the induced light source and the detection box, the imaging distance of the imaging unit, etc. are set, and the same amount of water and the same number of plankton are respectively placed , respectively, using induced light sources of different wavelengths to record plankton phototaxis video, which can quickly and accurately obtain the phototaxis characteristic information of plankton to different wavelength light sources.

To sum up, the plankton phototaxis detection device provided by the present invention applies a wavelength-switchable induction light source, which can be used for the phototaxis characteristics of plankton to light of different wavelengths. Further, the lighting unit can switch between bright and dark field illumination, which can observe both non-transparent plankton and transparent plankton, which is highly universal, and the detector directly observes the plankton body, and the position detection of plankton is accurate and error-free. The plankton phototaxis characteristic analysis using the plankton phototaxis detection device of the present invention is based on video data, and can analyze the plankton's motion state, including motion trajectory, motion angle, motion rate and its quantity distribution. Quantifying the recorded video of plankton phototaxis and generating corresponding data for scientific research is conducive to more accurate analysis results.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. In addition to the above embodiments, different modifications are also possible. The technical features of the above embodiments can be combined with each other. Within the scope of the present invention, any modifications, equivalent replacements, improvements, etc. made should be included within the protection scope of the present invention.

Claims (10)

A plankton phototaxis detection device, comprising a detection box and a light-inducing unit arranged on one side of the detection box, characterized in that: The light inducing unit includes an inducing light source, an optical fiber and a beam coupler, the wavelength of the inducing light source can be switched, the optical fiber is connected with the beam coupler and the inducing light source, and the beam coupler is used for light output; further comprising: an illumination unit, distributed around the detection box, for illuminating the detection box; An imaging unit, disposed above the detection box, is used for acquiring an image in the detection box. The plankton phototaxis detection device according to claim 1, wherein the bottom surface of the detection box and the side close to the induced light source are light-transmitting wall surfaces. The plankton phototaxis detection device according to claim 2, wherein the illumination unit comprises a plurality of illuminators arranged below the detection box, and the plurality of illuminators are respectively arranged in the bright field illumination area and the dark area. Field lighting area; The bright field illumination area is located below the detection box, and the dark field illumination area is located beside the detection box. The plankton phototaxis detection device according to claim 1, further comprising a blocking member, wherein the blocking member is detachably placed in the detection box, and the blocking member is movable in the detection box. The plankton phototaxis detection device according to claim 1, further comprising a water body in the detection box, and the optical axis of the beam coupler is located at the center of the cross section of the water body in the detection box. The plankton phototaxis detection device according to any one of claims 1 to 5, further comprising a fixed support unit, the fixed support unit includes a support structure, a connecting sheet metal and a fixed sheet metal, and the detection box can be The support structure is detachably connected, the connecting sheet metal connects the support structure and the imaging unit, and the fixed sheet metal connects the support structure and the light inducing unit. The plankton phototaxis detection device according to claim 6, further comprising a collimator, wherein the collimator is connected to the beam coupler, and is used to limit the beam divergence range of the light inducing unit. A method for analyzing the phototaxis of plankton for analyzing the motion state of plankton, wherein the method for analyzing the phototaxis of plankton comprises: S1: use the plankton phototaxis detection device according to any one of claims 1-7 to record plankton phototaxis video; S2: convert the video into an image sequence; S3: performing grayscale processing on the images in the image sequence; S4: Correct the image obtained after grayscale; S5: Select a tracking target to track according to the corrected image obtained in step S4; S6: obtain the motion trajectory of the tracking target; S7: Analyze the motion trajectory. A method for analyzing the phototaxis of plankton, which is used for analyzing the quantity distribution of plankton, characterized in that the method for analyzing the phototaxis of plankton comprises: A1: Use the plankton phototaxis detection device according to any one of claims 1-7 to record plankton phototaxis video; A2: Convert the video into a sequence of images; A3: Perform grayscale processing on the images in the image sequence; A4: Correct the image obtained after grayscale; A5: extract the background image of the video; A6: Grayscale and correct the background image; A7: Binarize the background image to obtain the region of interest of the detection box; A8: Crop the background image and the background image of the sequence image, and extract the background-corrected image according to the above image; A9: Perform a Gaussian filtering-binarization operation on the background-corrected image; A10: Perform spot detection on the binarized image and mark it; A11: Draw plankton number distribution map based on spot location information. The plankton phototaxis analysis method according to any one of claims 8 or 9, wherein the "recording plankton phototaxis video" comprises: a: add the water sample to the detection box; b: turn on the lighting unit; c: adjusting the distance between the blocking member and the inducing light source; d: Add the test sample to the test box; e: The blocking member and the inducing light source are opened, and the imaging unit performs recording.

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