A device and method for detecting phototaxis of plankton

Abstract

The present invention proposes a device for detecting the phototaxis of plankton, comprising a detection box and a light induction unit arranged on one side of the detection box, wherein the light induction unit comprises an induction light source with switchable wavelengths; further comprising: an illumination unit, which is distributed around the detection box and is used for illuminating the detection box; and an imaging unit, which is arranged above the detection box and is used for acquiring images in the detection box. The device for detecting the phototaxis of plankton can be used to study the phototaxis characteristics of plankton to light of different wavelengths. Furthermore, the illumination unit can switch between bright field illumination and dark field illumination, and can well observe different types of plankton. The present invention also proposes a method for analyzing the phototaxis of plankton, which analyzes the movement state of plankton based on the acquired plankton phototaxis video and generates data for scientific research. In addition, the detection device of the present invention directly observes the plankton body, accurately detects the position of the plankton, and is conducive to obtaining more accurate analysis results.

Description

Technical Field

[0001] The invention relates to the technical field of scientific instrument devices, and in particular to a device and an analysis method for detecting the phototaxis of plankton. Background Art

[0002] Plankton is the basis of the marine ecosystem. Most plankton has obvious phototaxis. It is of great significance to study the phototaxis of plankton. For example, the larvae of multilocular bryozoans have obvious phototaxis. When attached to various marine devices, the larvae will grow into adult multilocular bryozoans, causing serious fouling problems. Studying the phototaxis of multilocular bryozoans will help improve the increasingly serious problem of bryozoan fouling. Since it is very difficult to study the phototaxis of plankton in the actual environment, it is necessary to provide a device for detecting the phototaxis of plankton for research.

[0003] Existing devices for detecting the phototaxis of plankton generally have a single light source. After the light source is turned on, the detection device is left to stand still. The distribution of the number of plankton at different positions in the device after a certain period of time is observed, or the grayscale of the projection projected within a certain period of time is observed for analysis. The setting of the detection device has many disadvantages, which makes it difficult to use the detection results for scientific research, and the analysis conducted is highly limited. Specifically, the setting of a single light source makes the detection device only be used to measure the phototaxis reaction of plankton to a certain type of light source. Moreover, there is also a limitation that when using bright field illumination, the contrast of the sample for observing transparent plankton is weak, so it is only suitable for observing the phototaxis of non-transparent plankton. Furthermore, the projection position observed when observing the projection of plankton is different from its actual position, and the detection result will have errors. In addition, the existing device for detecting the phototaxis of plankton cannot quantify the characterization of the phototaxis of plankton, and it is difficult to generate data for scientific research. Summary of the invention

[0004] In view of this, in order to overcome the defects of the above-mentioned prior art, the present invention proposes a plankton phototaxis detection device with strong universality, which can be used to analyze the phototaxis characteristics of different plankton to light of different wavelengths and can generate data for scientific research based on the observation results.

[0005] Specifically, the device for detecting the phototropism of plankton of the present invention comprises a detection box and a light induction unit arranged on one side of the detection box, wherein the light induction unit comprises an induction light source, an optical fiber and a beam coupler, wherein the wavelength of the induction light source is switchable, the optical fiber connects the beam coupler and the induction light source, and the beam coupler is used to emit light; further comprising: an illumination unit, which is distributed around the detection box and is used to illuminate the detection box; and an imaging unit, which is arranged above the detection box and is used to obtain an image in the detection box. The light induction unit can emit light of different wavelengths for analyzing the phototropism characteristics of plankton to light of different wavelengths. Further, a blocking member is also included, which can be detachably placed in the detection box, and the blocking member can be moved in the detection box, and can divide the internal space of the detection box into two parts, so as to limit the initial position of the detection sample in the detection box. When the light intensity is constant, when it is necessary to measure the phototropism of plankton at a specific distance from the induction light source, the distance between the blocking member and the induction light source can be adjusted by moving the blocking member.

[0006] Preferably, the lighting unit comprises a plurality of illuminators arranged below the detection box, and the plurality of illuminators are respectively arranged in a bright field lighting area and a dark field lighting area;

[0007] The bright field lighting area is located below the detection box, and the dark field lighting area is located beside the detection box. The lighting environment can be switched between bright field and dark field lighting, so that both non-transparent plankton and transparent plankton can be observed, and it has strong universality. The bottom of the detection box and the side close to the induced light source are transparent walls, and the remaining walls are non-transparent walls. Optionally, the non-transparent wall can be black frosted glass to prevent the light emitted by the induced light source from affecting the behavior and movement direction of the plankton after being reflected by the wall of the detection box, resulting in inaccurate observation results.

[0008] In some embodiments, in order to form a good induced light source illumination angle, the optical axis of the beam coupler is located at the center of the water cross section in the detection box. Preferably, a collimator is also included, which is connected to the beam coupler and is used to limit the beam divergence range of the light induction unit to achieve a better lighting effect.

[0009] Furthermore, it also includes a fixed support unit, which includes a support structure, a connecting sheet metal and a fixed sheet metal, the detection box is detachably connected to the support structure, the connecting sheet metal connects the support structure and the imaging unit, and the fixed sheet metal connects the support structure and the light induction unit. The fixed support unit can limit the positional relationship between the various parts of the detection device, which is convenient for continuous research with the same or similar detection conditions.

[0010] A method for analyzing the phototaxis of plankton, used for analyzing the movement state of plankton, the method for analyzing the phototaxis of plankton comprising:

[0011] S1: Recording a plankton phototaxis video using the plankton phototaxis detection device described in any one of claims 1 to 6;

[0012] S2: converting the video into an image sequence;

[0013] S3: grayscale the images in the image sequence;

[0014] S4: Correcting the grayscale image;

[0015] S5: Select a tracking target to track according to the corrected image obtained in step S4;

[0016] S6: Obtaining the motion trajectory of the tracking target;

[0017] S7: Analyze the motion trajectory.

[0018] A method for analyzing the phototaxis of plankton, used for analyzing the quantity distribution of plankton, the method for analyzing the phototaxis of plankton comprising:

[0019] A1: Recording a plankton phototaxis video using the plankton phototaxis detection device described in any one of claims 1 to 6;

[0020] A2: converting the video into an image sequence;

[0021] A3: grayscale the images in the image sequence;

[0022] A4: Correct the grayscale image;

[0023] A5: extracting the background image of the video;

[0024] A6: gray-scaling and correcting the background image;

[0025] A7: Binarize the background image to obtain a region of interest of the detection box;

[0026] A8: cutting out the background image and the background image of the sequence image, and extracting an image after background correction based on the above images;

[0027] A9: performing Gaussian filtering-binarization operation on the background-corrected image;

[0028] A10: Perform spot detection and marking on the binarized image;

[0029] A11: Draw a plankton population distribution map based on the spot location information.

[0030] Furthermore, the “recording of a video of the phototropism of plankton” includes:

[0031] a: adding the water sample into the detection kit;

[0032] b: Turn on the lighting unit;

[0033] c: adjusting the distance between the blocking member and the inducing light source;

[0034] d: Add the test sample into the test box;

[0035] e: Open the blocking member and the induced light source, and the imaging unit starts recording.

[0036] Preferably, the “correcting the image obtained after graying” includes distortion correction and rotation correction. Distortion correction can correct the distortion caused by the difference in magnification of the lens system, and rotation correction can correct the angle error caused by the misalignment between the detection box and the camera, which is conducive to obtaining more accurate results in subsequent analysis.

[0037] In summary, the plankton phototaxis detection device of the present invention adopts an induced light source with switchable wavelengths, which can analyze the phototaxis characteristics of plankton for light of different wavelengths. Furthermore, 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, which can observe both non-transparent plankton and transparent plankton, and has strong universality. The method for analyzing the phototaxis of plankton using the plankton phototaxis detection device of the present invention is based on video data, and the movement state of plankton can be analyzed, including movement trajectory, movement angle, movement rate and its quantity distribution. Moreover, this detection device directly observes the plankton body, accurately detects the position of plankton, quantifies the recorded plankton phototaxis video, and generates corresponding data for scientific research, which is conducive to obtaining more accurate analysis results. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 It is a schematic diagram of the overall structure of the device for detecting the phototaxis of plankton of the present invention;

[0040] Figure 2 for Figure 1 A cross-sectional view of a device for detecting the phototaxis of plankton shown;

[0041] Figure 3 This is a schematic diagram of the supporting structure of the device for detecting the phototaxis of plankton in Example 2;

[0042] Figure 4 This is a schematic diagram of the structure of the connecting sheet metal of the plankton phototaxis detection device of Example 2;

[0043] Figure 5 This is a schematic structural diagram of a fixing member of a device for detecting the phototaxis of plankton in Example 2;

[0044] Figure 6 This is a schematic diagram of the structure of the fixed sheet metal of the plankton phototaxis detection device of Example 2;

[0045] Figure 7 for Figure 1 A top view of a device for detecting the phototaxis of plankton shown;

[0046] Figure 8 This is a schematic structural diagram of an adapter of a device for detecting the phototaxis of plankton in Example 2;

[0047] Fig. 9 for Figure 8 A cross-sectional view of the adapter shown;

[0048] Fig.10 This is a schematic diagram of the structure of the illuminator of the device for detecting the phototaxis of plankton in Example 2;

[0049] Fig.11 for Fig.10 A cross-sectional view of the luminaire shown;

[0050] Fig.12 This is the grayscale result of the video sequence of phototaxis of multi-chambered bryozoan larvae;

[0051] Fig.13 for Fig.12 The result image after distortion correction;

[0052] Fig.14 for Fig.13 The result image after rotation correction;

[0053] Fig.15 A schematic diagram of selecting a tracking target in Example 3;

[0054] Fig.16 This is the tracking result diagram of Example 3;

[0055] Fig.17aThe movement angle curve of the multi-chambered bryozoan larvae obtained by analysis in Example 3;

[0056] Fig.17b The movement rate curve of the multi-chambered bryozoan larvae obtained by analysis in Example 3;

[0057] Fig.18 This is the result diagram of background extraction in Example 4;

[0058] Fig.19 for Fig.18 The result image after image correction;

[0059] Fig. 20 This is the result image after the background image is binarized;

[0060] Fig.21 Schematic diagram of automatic selection of ROI;

[0061] Fig. 22 A schematic diagram of background correction based on the background image and ROI;

[0062] Fig.23 This is a schematic diagram of the distribution of plankton population at the beginning;

[0063] Fig.24 This is a schematic diagram of the plankton population distribution at the end;

[0064] Fig.25 This is a bar graph of the plankton population distribution at the beginning;

[0065] Fig.26 This is a bar graph showing the distribution of plankton population at the end of the period.

[0066] Reference numerals:

[0067] 101-infrared camera; 102-copper column; 201-induced light source; 202-optical 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-second through hole; 401-detection box; 402-blocking member; 501-support structure; 5011-first plate; 5012-second plate; 5013-side plate; 502-connecting sheet metal; 5021-mounting plate; 503-fixing member; 504-fixing sheet metal. DETAILED DESCRIPTION

[0068] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0069] The present invention provides a device for detecting the phototaxis of plankton, including a sample detection unit, a light induction unit, a lighting unit and an imaging unit. The light induction unit is used to emit light to detect the phototaxis of plankton. The lighting unit uses a light source that will not affect the plankton to illuminate the sample detection unit. The imaging unit is set to obtain the movement of the plankton. The research using the device for detecting the phototaxis of plankton of the present invention can analyze the movement state of the plankton based on the image obtained by the imaging unit, including the movement trajectory, movement angle, movement rate and its quantity distribution. The obtained plankton phototaxis image is quantified to generate corresponding data for scientific research, which is conducive to obtaining more accurate analysis results.

[0070] Example 1

[0071] See also Figure 1 and Figure 2 , which is a structural schematic 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 lighting 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 5011 and a second plate 5012 arranged in parallel, and the side plate 5013 connects the first plate 5011 and the second plate 5012. The sample detection unit includes a detection box 401, and the detection box 401 is detachably connected to the first plate 5011 and the second plate 5012 of the support structure 501. Preferably, the sample detection unit also includes a detachable blocking member 402, such as a baffle, a filter, etc. 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, and can divide the internal space of the detection box 401 into two parts, so as to limit the initial position of the detection sample in the detection box 401. When the light intensity is constant and it is necessary to measure the phototropism of plankton at a specific distance from the induced light source 201, the distance between the blocking member 402 and the induced light source 201 can be adjusted by moving the blocking member 402 horizontally.

[0072] The distance between the detection box 401 and the induced light source 201 can be adjusted to affect the divergence range of the induced light source 201 in the detection box 401. The present invention requires that the induced light source 201 fully diverges in the detection box 401 and fills the entire detection box 401. The connecting sheet metal 502 is installed on the side plate 5013. 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.

[0073] The light induction unit includes an induction light source 201, an optical fiber 202, and a beam coupler 203. The induction light source 201 is connected to the beam coupler 203 through the optical fiber 202. The beam coupler 203 is mounted on a fixing member 503. The fixing member 503 is mounted on a first plate 5011 of a support structure 501 through a fixing sheet metal 504. Specifically, the optical axis of the induction light source 201 is located on the central axis of the detection box 401 in the vertical direction. The fixing sheet metal 504 can be adjusted up and down to determine a suitable light output height. When using the plankton phototropism detection device of the present invention, the optical axis of the induction light source 201 is adjusted to be located at the center of the water body cross section in the detection box 401. Preferably, the induction light source 201 is set to a light source with switchable wavelengths, for example, a multi-wavelength laser, a supercontinuum white light laser, a broadband light source plus a filter, a multi-wavelength LED array, etc., which can detect the response of plankton to light of different wavelengths by emitting light of different wavelengths. Preferably, the light induction unit further includes a collimator 204, which is connected to the beam coupler 203. The collimator 204 can limit the light beam divergence range of the light induction unit to achieve a 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.

[0074] Example 2

[0075] See the instruction manual Figure 3 , which is a schematic diagram of the specific structure of the support structure 501 used in this embodiment. The side plate 5013 includes a first part and a second part which are perpendicular to each other, the first part is vertically arranged, and the two ends of the second part are respectively connected to the first plate 5011 and the second plate 5012. A plurality of through holes in the shape of rounded rectangles are arranged on the first plate 5011, the second plate 5012 and the first part, 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 the above structure is adjusted, the nut is first unscrewed, and then moved in the through hole. After moving to the target position, the nut is tightened to fix it.

[0076] See the instruction manual Figure 4 , 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 hole on the mounting plate 5021 and is fixed to the mounting plate 5021 by connecting the plurality of copper pillars 102. The viewing angle of the camera used in this embodiment is 76.6°, the size of the detection box 401 is 100mm x 20mm x 20mm, 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. See Figure 5 and Figure 6 , which is a schematic diagram of the structure of the fixing member 503 and the fixing sheet metal 504. The beam coupler 203 is connected to the disc-shaped fixing member 503 through threads, and the disc-shaped fixing member 503 is connected to the fixing sheet metal 504 through bolts.

[0077] See also Figure 7-Figure 11 In this embodiment, the lighting unit includes three illuminators respectively arranged in the bright field lighting area and the dark field lighting area. Specifically, the first illuminator 301 is arranged below the detection box 401, the second illuminator 306 and the third illuminator 307 are symmetrically distributed on both sides of the detection box 401 and below the bottom of the detection box 401. The first illuminator 301, the second illuminator 306 and the third illuminator 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 501 through the third adapter 304 and the fourth adapter 305. 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 circular through holes of different diameters, an elastic protrusion 308 is provided on the connecting portion on one side of the illuminator, the elastic protrusion 308 cooperates with the second through hole 310 to form a position fixation for the illuminator, and the second illuminator 306 and the third illuminator 307 can rotate around the central axis of the second through hole 310 to adjust the lighting 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 water level in the detection box 401. For example, in this embodiment, the water added to the detection box 401 accounts for 1 / 3 of the volume of the detection box 401, and the first illuminator 301 is 20 mm away from the bottom of the detection box. When the second illuminator 306 and the third illuminator 307 are used for illumination, it is required that the bottom of the detection box 401 is within the divergence angle of the light source, while 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.

[0078] Further, the bottom of the rectangular detection box 401 and the side close to the induced light source 201 are transparent walls, and the other walls are non-transparent walls. In this embodiment, the non-transparent wall is black frosted glass to prevent the light emitted by the induced light source 201 from affecting the behavior and movement direction of the plankton after being reflected by the wall of the detection box 401, resulting in inaccurate observation results. When conducting research, different illuminators are turned on according to the needs of observation to form different lighting environments. For example: when it is necessary to observe or record black plankton, the first illuminator 301 at the bottom of the detection box 401 is turned on to form a bright field lighting environment to highlight non-transparent plankton; when it is necessary to observe or record transparent plankton, the second illuminator 306 and the third illuminator 307 are turned on for dark field lighting to highlight transparent plankton.

[0079] Example 3

[0080] This embodiment is a method for obtaining the movement trajectory, movement angle, and movement speed of plankton using the plankton phototaxis detection device of the present invention.

[0081] In the process of using the device for detecting the phototropism of plankton of the present invention, the determination of whether to use bright field illumination or dark field illumination can be made by the following method:

[0082] The image of the plankton in the detection box 401 is taken under bright field lighting environment to obtain the sample contrast

[0083] Compare the obtained sample contrast with the sample contrast standard that needs to be achieved to determine whether the sample contrast standard is achieved;

[0084] If the result is yes, then brightfield illumination is used, if the result is no, then darkfield illumination is used.

[0085] Optionally, the judgment may also be made by taking an image in a dark field lighting environment and calculating the sample contrast.

[0086] After determining the lighting environment to be used, perform the phototaxis test of plankton:

[0087] S1: Recording a video of the phototaxis of plankton in a dark room. Taking the larvae of multilocular bryozoans as an example, the recording process is as follows:

[0088] S101, adding a water sample into the detection box 401;

[0089] S102, turning on the first illuminator 301 in the lighting unit;

[0090] S103, adjusting the distance between the blocking member 402 and the inducing light source 201 according to the distance between the multi-chambered bryozoan larvae and the inducing light source 201 to be observed;

[0091] S104, adding multi-chambered bryozoan larvae to a side of the detection box 401 away from the induction light source 201;

[0092] S105, start the induction light source 201, remove the blocking member 402, and the infrared camera 101 starts recording;

[0093] S106. After waiting for a period of time, the infrared camera 101 ends recording and obtains a video of the multi-chambered bryozoan larvae moving toward light.

[0094] S2: Convert the recorded video into an image sequence.

[0095] S3: grayscale the images in the sequence to obtain grayscale images, such as Fig.12 Grayscale processing of the image can convert the three-channel color image into a single-channel grayscale image, simplifying subsequent image processing operations.

[0096] S4: Perform image correction, perform lens distortion correction on the grayscale image, and obtain Fig.13 Lens distortion correction can correct the distortion caused by the difference in magnification of the lens system. The corrected image is rotated to obtain Fig.14 The rotation correction can correct the angle error caused by the misalignment between the detection box 401 and the camera.

[0097] S5: After obtaining the corrected image, the trajectory of the bryozoan larvae is tracked. First, the tracking target is selected, such as Fig.15 After selecting the tracking target, start tracking. Optionally, you can select one or more targets to track according to research needs.

[0098] S6: After the tracking is completed, the movement trajectory of the multi-chambered bryozoan larvae is obtained, such as Fig.16 shown.

[0099] S7: The movement trajectory of the bryozoan larvae was analyzed to obtain a curve diagram showing the change of its movement angle and speed over time, such as Fig.17a and Fig.17b shown.

[0100] The strength of phototaxis of multilocular bryozoan larvae was analyzed based on their movement angle and speed information.

[0101] Example 4

[0102] The present embodiment is a method for obtaining the quantitative distribution of plankton using the plankton phototaxis detection device of the present invention, wherein, when recording the plankton phototaxis video in step 1, the present embodiment does not use a blocking member to adjust the distance between the multi-chambered bryozoan larvae and the light source. Optionally, when obtaining the quantitative distribution of plankton, step 1 can be the same as that in embodiment 3; the method for processing the sequence images in steps 2-4 is the same as that in embodiment 3.

[0103] A1: Video recording of the phototaxis of plankton in a dark room, taking the larvae of multilocular bryozoans as an example:

[0104] A101, adding the water sample and the multi-chambered bryozoan larvae into the detection box 401, and allowing the multi-chambered bryozoan larvae to stand to allow the multi-chambered bryozoan larvae to be distributed throughout the detection box 401;

[0105] A102, turn on the first illuminator 301, start the induction light source 201, and start recording with the infrared camera;

[0106] A103. After waiting for a while, the infrared camera 101 ends recording and obtains a video of the multi-chambered bryozoan larvae moving toward light.

[0107] A2: Convert the recorded video into an image sequence.

[0108] A3: Grayscale the images in the sequence to obtain grayscale images, such as Fig.12 shown.

[0109] A4: Perform image correction and perform lens distortion correction on the grayscale image to obtain Fig.13 .

[0110] A5: Use the MOG2 (Gaussian mixture) algorithm to extract the background image of the recorded video and obtain Fig.18 .

[0111] A6: Grayscale, distortion correction and rotation correction are performed on the background image to obtain Fig.19 .

[0112] A7: Binarize the background image, analyze the binarized image, and obtain the ROI (region of interest) of the detection box 401, such as Fig. 20 , 21 As shown. Among them, Fig. 20 is the structure diagram after the background image is binarized. Fig. 20 Perform maximum contour detection to find the coordinates of the upper left corner of the contour, and then obtain the region of interest based on the pixel length of the region of interest = the number of pixels corresponding to the length of the container, and the pixel width of the region of interest = the number of pixels corresponding to the width of the container. The region of interest obtained in this embodiment is shown in Figure 21.

[0113] A8: Crop the ROI (region of interest) of the background image and the sequence image, and obtain the background-corrected image based on this. Specifically, in this embodiment, the two are subtracted to obtain the background-corrected image after the background is subtracted, such as Fig. 22 Optionally, the background-corrected image can be obtained by dividing the two.

[0114] A9: Perform Gaussian filtering and binarization operations on the background corrected image.

[0115] A10: Fig.23 , Fig.24 As shown, the binarized image is subjected to spot detection, and the detected spots are the larvae of multi-chambered bryozoans. The detected spots are marked in the intercepted original image sequence. Fig.23 This is a schematic diagram of the distribution of plankton at the beginning. Fig.24 The figure is a schematic diagram of the distribution of plankton population at the end. In this embodiment, the recording time of the plankton phototropism video is 30 seconds. Fig.23 This is a diagram showing the distribution of plankton population when recording for 1 second. Fig.24 Schematic diagram of the distribution of plankton population when the recording lasts for 30 seconds. Fig.23 , Fig.24 They all include three parts: upper, middle and lower parts, which are the original image, the image after background subtraction and binarization, and the image of spots drawn by spot detection on the binarized image. It can intuitively see the binarization effect and whether the spot detection algorithm is accurate.

[0116] A11: Draw a bar graph of the number distribution of multi-chambered bryozoan larvae based on the spot position information after spot detection, such as Fig.25 , Fig.26 As shown. Among them, Fig.25 express Fig.23 The distribution of the number of multilocular bryozoan larvae, Fig.26 express Fig.24 The number distribution of multi-chambered bryozoan larvae.

[0117] The phototaxis index was obtained by analyzing the number distribution information of planktonic multilocular bryozoan larvae at the beginning and end.

[0118] The above-mentioned number distribution bar graph is drawn as follows: the ROI area is divided into ten areas in the horizontal direction, the percentage of larvae in each area to the total number of larvae is calculated, and finally the percentage of larvae in the ten areas is drawn as a number distribution bar graph.

[0119] In some embodiments, multiple plankton phototaxis detection devices are set up at the same time, and the same lighting unit lighting position, distance between the induced light source and the detection box, imaging distance of the imaging unit, etc. are set. The same amount of water and equal number of plankton are put into them respectively, and induced light sources of different wavelengths are used to record plankton phototaxis videos. This can more quickly and accurately obtain the phototaxis characteristic information of plankton to light sources of different wavelengths.

[0120] In summary, the plankton phototaxis detection device provided by the present invention uses an induced light source with switchable wavelengths, which can be used to detect the phototaxis characteristics of plankton for light of different wavelengths. Furthermore, the lighting unit can switch between light and dark field lighting, which can observe both non-transparent plankton and transparent plankton, and has strong universality. In addition, the detector directly observes the plankton body, and the position detection of plankton is accurate and error-free. The analysis of the phototaxis characteristics of plankton using the plankton phototaxis detection device of the present invention is based on video data, and the movement state of plankton can be analyzed, including movement trajectory, movement angle, movement rate and its quantity distribution. The recorded plankton phototaxis video is quantified to generate corresponding data for scientific research, which is conducive to obtaining more accurate analysis results.

[0121] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. In addition to the above embodiments, there may also be different variations. The technical features of the above embodiments may be combined with each other. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for detecting the phototaxis of plankton, comprising a detection box and a light induction unit arranged on one side of the detection box, characterized in that: The light induction unit comprises an induction light source, an optical fiber and a beam coupler, the wavelength of the induction light source is switchable, the optical fiber connects the beam coupler and the induction light source, and the beam coupler is used to emit light; and further comprises: An illumination unit, distributed around the detection box and used for illuminating the detection box; An imaging unit, disposed above the detection box, for acquiring an image inside the detection box; The bottom surface of the detection box and the side close to the induced light source are light-transmitting wall surfaces; The lighting unit comprises a plurality of illuminators arranged below the detection box, and the plurality of illuminators are respectively arranged in a bright field lighting area and a 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 unit includes three illuminators respectively arranged in a bright field lighting area and a dark field lighting area, wherein the first illuminator is arranged below the detection box, and the second illuminator and the third illuminator are symmetrically distributed on both sides of the detection box and below the bottom of the detection box; the first illuminator, the second illuminator and the third illuminator are infrared illuminators; The second illuminator and the third illuminator are configured to have adjustable lighting angles; When the second illuminator and the third illuminator are illuminating, the bottom of the detection box is within the divergence angle of the light source, and the lens of the imaging unit is outside the divergence angle of the light source; The bottom of the detection box and one side close to the induced light source are transparent walls, and the remaining walls are black frosted glass; When it is necessary to observe or record non-transparent plankton, the first illuminator at the bottom of the detection box is turned on to form a bright field lighting environment to highlight the non-transparent plankton; when it is necessary to observe or record transparent plankton, the second illuminator and the third illuminator are turned on to perform dark field lighting to highlight the transparent plankton; The device further comprises a blocking member, which is detachably placed in the detection box and movable in the detection box.

2. The device for detecting the phototaxis of plankton according to claim 1, characterized in that: It also includes 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.

3. The device for detecting the phototaxis of plankton according to any one of claims 1 to 2, characterized in that: It also includes a fixed support unit, which includes a support structure, a connecting sheet metal and a fixed sheet metal, the detection box is detachably connected to the support structure, the connecting sheet metal connects the support structure and the imaging unit, and the fixed sheet metal connects the support structure and the light induction unit.

4. The device for detecting the phototaxis of plankton according to claim 3, characterized in that: It also includes a collimator, which is connected to the beam coupler and is used to limit the beam divergence range of the light inducing unit.

5. A method for analyzing the phototaxis of plankton, used for analyzing the movement state of plankton, characterized in that: The method for analyzing the phototaxis of plankton comprises: S1: Recording a plankton phototaxis video using the plankton phototaxis detection device described in any one of claims 1 to 4; S2: converting the video into an image sequence; S3: grayscale the images in the image sequence; S4: Correcting the grayscale image; S5: Select a tracking target to track according to the corrected image obtained in step S4; S6: Obtaining the motion trajectory of the tracking target; S7: Analyze the motion trajectory.

6. A method for analyzing the phototaxis of plankton, used for analyzing the quantitative distribution of plankton, characterized in that: The method for analyzing the phototaxis of plankton comprises: A1: Recording a plankton phototaxis video using the plankton phototaxis detection device described in any one of claims 1 to 4; A2: converting the video into an image sequence; A3: grayscale the images in the image sequence; A4: Correct the grayscale image; A5: extracting the background image of the video; A6: gray-scaling and correcting the background image; A7: Binarize the background image to obtain a region of interest of the detection box; A8: cutting out the background image and the background image of the sequence image, and extracting an image after background correction based on the above images; A9: performing Gaussian filtering-binarization operation on the background-corrected image; A10: Perform spot detection and marking on the binarized image; A11: Draw a plankton population distribution map based on the spot location information.

7. The method for analyzing the phototaxis of plankton according to any one of claims 5 or 6, characterized in that: The "recording of plankton phototropism video" includes: a: adding the water sample into the detection kit; b: Turn on the lighting unit; c: adjusting the distance between the blocking member and the inducing light source; d: Add the test sample into the test box; e: Open the blocking member and the induced light source, and the imaging unit starts recording.

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