NL2029593B1

NL2029593B1 - Method for estimating body length and body weight by using shrimp eyeball diameter

Info

Publication number: NL2029593B1
Application number: NL2029593A
Authority: NL
Inventors: Chen Fudi; Zhou Li; Qiu Tianlong; Xu Jianping; Wu Bin; Sun Jianming; Du Yishuai
Original assignee: Inst Oceanology Cas
Priority date: 2021-11-02
Filing date: 2021-11-02
Publication date: 2023-06-01

Abstract

The present disclosure provides a method for estimating body length and body weight by using a shrimp eyeball diameter. Through acquiring an image of shrimp eyeballs, a 5 shrimp eyeball diameter is accurately acquired by software analysis, while body length and body weight of the shrimp can be accurately determined based on a ﬁtting model of the eyeball diameter with the body length and body weight. A correlation coefﬁcient between the shrimp eyeball diameter measured by the present disclosure and the body weight is comparable to that between the body length and the body weight; 10 furthermore, there is autoﬂuorescence in shrimp eyeballs under low-light conditions, which is convenient for computer image recognition and achieves automatic monitoring.

Description

METHOD FOR ESTIMATING BODY LENGTH AND BODY WEIGHT BY

USING SHRIMP EYEBALL DIAMETER

BACKGROUND ART

[01] The present disclosure pertains to a method for estimating biomorphological indicators in the field of marine biotechnology and a graphic recognition method in the field of information technology, and particularly relates to a method for estimating body length and body weight by using an eyeball diameter of ZLitopeneaus vannamei cultivated in circulating water.

[02] Litopeneaus vannamei, also known as Pacific white shrimp, is native to the

Pacific coastal waters of northern Peru to Sonora, Mexico, and is a warm-water commercial shrimp species. In the process of recirculating aquaculture, it is necessary to ensure sufficient feeding amount of bait, and to avoid deterioration of the water quality caused by excessive feeding of bait. Therefore, it is necessary to accurately calculate the biomass in the aquaculture system to carry out accurate feeding, save the feed cost, and reduce the water treatment load of the aquaculture system. In order to construct an automatic discrimination technology of shrimp biomass in the culture pond, the first thing to be solved is to find a computer recognition index to estimate the body weight of the shrimp, and further estimate the biomass in connection with the quantity of shrimps.

[03] In the related research on the morphological trait model of shrimp, many scholars at home and abroad applied multiple regression methods to analyze the relationships between morphological indexes of shrimp (such as body length, carapace length, carapace width, carapace depth, number of suprarostral spines, number of infrarostral spines, and tail length) and body weight!!! the results showed that there was a strong correlation between body length and body weight of Litopeneaus vannamei. However, estimation of the body weight based on body length requires measuring the length from the base of the eyestalk to the end of the uropod. In actual measurement, the body of the shrimp always exhibits a certain curvature, which results in a large error in measurement results and is not conducive to automatic computer recognition. Therefore, the development of a new method for estimating the body weight of the shrimp is of great significance for accurately estimating the aquaculture biomass and facilitating the automatic computer recognition.

[04] List of cited references:

[05] [1] Huang Z, Lin HZ, et al. Relationship between body length and weight of five Penaeus monodon families[J]. Guangdong Agricultural Sciences, 2011, 38(04): 116-119.

[06] [2] He T Multiple statistical and genetic parameter analysis of growth traits in

Litopeneaus vannamei[D]. Northwest Agriculture and Forestry University, 2010.

[07] [3] Gopalakrishnan A, Rajkumar M, Rahman M M, et al. Length-weight relationship and condition factor of wild, grow-out and ‘loose-shell affected’ giant tiger shrimp, Penaeus monodon (Fabricius, 1798) [J]. Journal of Applied Ichthyology, 2014, 30(1): 251-253.

[08] [4] Daud S K, Ang K J. Selection of broodstock of tiger prawn, Penaeus monodon Fabricius, on the basis of morphometric traits[J]. Pertanika Journal of

Tropical Agricultural Science, 1995, 18: 15-20.

[09] [5] Primavera J H, Parado-Estepa F D, Lebata J L. Morphometric relationship of length and weight of giant tiger prawn Penaeus mornodon according to life stage, sex and source[J]. Aquaculture, 1998, 164(1-4): 67-75.

[10] [6] Abohweyere P O, Williams A B. Length-weight relationship and condition factor of Macrobrachium macrobrachion in the Lagos-Lekki Lagoon system,

Nigeria[J]. Research Journal of Biological Sciences, 2008, 3(11): 1333-1336.

SUMMARY

[11] To solve the problems that the measurement error is large when measuring the body length of the shrimp and the body length is not easily acquired by machine vision recognition in a weak illumination environment, the present disclosure provides a method for estimating body length and body weight by using a shrimp eyeball diameter.

[12] The objective of the present disclosure is achieved by the following technical solution:

[13] Provided is a method for estimating body length and body weight by using a shrimp eyeball diameter, where body length and body weight of a shrimp can be accurately acquired by using a fitting relationship of a measured shrimp eyeball diameter and a known eyeball diameter with body length and body weight.

[14] The shrimp eyeball diameter is acquired by direct measurement or by computer image recognition.

[15] Shrimp eyeballs are subelliptic, and the shrimp eyeball diameter is a major axis length of an elliptic eyeball of the shrimp, that is, a farthest distance between two points of the edge of the shrimp eyeball 1s used as the shrimp eyeball diameter.

[16] The fitting relationship of the eyeball diameter (d) with the body length (L) and the body weight (W) is obtained based on measurements of at least 10 shrimps of the same species, L = fi(d), and W = f2(d), where f1 and f; are obtained by data fitting.

[17] the eyeball diameter d (in unit of mm), the body length L (in unit of mm), and the body weight W (in unit of g) are fitted,

[18] provided that a fitting relationship of the eyeball diameter with the body length and body weight of Litopenaeus vannamei is known: a relational expression between the shrimp eyeball diameter d and the body length L of the shrimp is: L = 15.978d — 2.31

[19] a relational expression between the eyeball diameter d and the body weight W is as follows: if

[20] d<2mm, W=0.0326d78:.

[21] 2mm<d<3.9 mm, W =0.0401d°19%:

[22] 3.9mm<d<58mm, W =0.0421d3%3!: and

[23] 5.8mm <d, W=0.1030d>%%°,

[24] The eyeball diameter d (in unit of mm), the body length L (in unit of mm), and the body weight W (in unit of g) are fitted,

[25] provided that a fitting relationship of the eyeball diameter with the body length and body weight of Fenneropenaeus chinensis is known: L = 4.9741d + 94.985; W = 5.4174d"%?7 where the range of application of the expressions is: 5.5 <d < 7.5.

[26] Provided that a fitting relationship of the eyeball diameter with the body length and body weight of Trachypenaeus curvirostris is known: L = 18.12d - 21.175; W = 0.0151d%%7 where the range of application of the expressions is: 4.0 <d < 6.5.

[27] Provided that a fitting relationship of the eyeball diameter with the body length and body weight of Oratosquilla oratoria is known: L = 21.703d - 15.703; W = 0.0549d°3° where the range of application of the expressions is: 5.0 <d < 7.0.

[28] The present disclosure has the following advantages and positive effects:

[29] 1. The shrimp eyeball diameter can be accurately measured, and the measurement error is small.

[30] 2. There is autofluorescence in shrimp eyeballs under low-light conditions, which is convenient for computer image recognition and achieves automatic monitoring.

[31] 3. A correlation coefficient between the shrimp eyeball diameter and the body weight is comparable to that between the body length and the body weight.

BRIEF DESCRIPTION OF THE DRAWINGS

[32] FIG. 1 schematically illustrates the selection of eyeballs of a shrimp;

[33] FIG. 2 illustrates a selection principle of the major axis of an eyeball of a shrimp;

[34] FIG. 3 illustrates a relationship between eyeball diameter and body length of

Litopeneaus vannamei,

[35] FIG. 4 illustrates a relationship between eyeball diameter and body weight of

Litopeneaus vannamei (d <2 mm);

[36] FIG. 5 illustrates a relationship between eyeball diameter and body weight of

Litopeneaus vannamei (2 mm <d <3.9 mm);

[37] FIG. 6 illustrates a relationship between eyeball diameter and body weight of

Litopeneaus vannamei (3.9 mm <d < 5.8 mm);

[38] FIG. 7 illustrates a relationship between eyeball diameter and body weight of

Litopeneaus vannamei (d> 5.8 mm),

[39] FIG. 8 illustrates a relationship between eyeball diameter and body length of #: chinensis,

[40] FIG. 9 illustrates a relationship between eyeball diameter and body weight of / chinensis;

[41] FIG. 10 illustrates a relationship between eyeball diameter and body length of 1. curvirostris;

[42] FIG. 11 illustrates a relationship between eyeball diameter and body weight of

I. curvirostris,

[43] FIG. 12 illustrates a relationship between eyeball diameter and body length of

O. oratoria;

[44] FIG. 13 illustrates a relationship between eyeball diameter and body weight of

O. oratoria.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[45] 1. Acquisition of a fitting relationship of eyeball diameter with body length and body weight of Litopeneaus vannamei

[46] At different growth stages of the shrimp, a total of 300 shrimp samples were 5 collected. The body length of the shrimp was measured using a vernier caliper, with a measurement accuracy of 0.02 mm. The measured body length of Litopeneaus vanmamei ranged from 19.12 mm to 161.3 mm. The body weight was measured using an analytical balance, with a measurement accuracy of 0.001 g. The measured body weight of Litopeneaus vannamei ranged from 0.084 g to 53.034 g.

[47] Images of eyeballs of shrimps were obtained by photographing, and the shrimp eyeball diameter was measured by computer software. As shown in FIG. 1, when photographing, the shrimp was placed under a dissecting microscope, so that the body of the shrimp was straightened to avoid bending; the dorsum of the shrimp was faced upward and photographed at a high angle; meanwhile, a measuring scale was placed during the photographing.

[48] The digmizer4.2 image analysis software was used to measure eyeball parameters of Litopeneaus vannamei. As shown in FIG. 2, the eyeball of the shrimp was subelliptic, and the major axis of the ellipse was selected as the eyeball diameter for measurement. The accuracy of the result was 0.01 mm. The measured eyeball diameter ranged from 1.33 mm to 12.1 mm. The eyeball diameter, body length, and body weight of Lifopeneaus vannamei are shown in Table 1.

[49] Table 1. The eyeball diameter, body length, and body weight of Lifopeneaus vannamei.

3.13 47.7 1.496

4.548 | 71.2 4.006

5.553 85 6.876 5.702 92 9.9163 5.802 | 92 9.9163

[50] Using the measured data for eyeball diameter d (14.21 mm <d < 70.93 mm) and body length L (19.12 mm < L < 161.3 mm), as shown in FIG. 3, a relational expression between the eyeball diameter d (in unit of mm) of the shrimp and the body length L (in unit of mm) of the shrimp was fitted by the linear regression method:

[51] L=15978d-2.31,R*=0.9793

[52] According to the growth characteristics of Litopeneaus vannamei, the piecewise fitting method was used when fitting, and the body length of Litopeneaus vannamei was used as a segmentation basis. As shown in FIGS. 4 to 7, the relational expression between the eyeball diameter d (in units mm) and the body weight W (in unit of g) is fitted when corresponding to the body length L of 0-30 mm, 30-60 mm, 60-90 mm, and > 90mm, respectively: if

[53] d<2mm, W=0.0326d*73% R2= 0.9288;

[54] 2mm <d<3.9mm, W=0.0401d3:%0 R2= 0.9629;

[55] 3.9mm<d<58mm, W=00421d*"" R2=0.9216; and

[56] 5.8mm <d, W=0.1030d%%2%¢ R2= 0.9457.

[57] Using the same method as above, 30 measurements were made on fresh 7 curvirostris, I. chinensis, and O. oratoria, respectively. As shown in Table 3, the measured eyeball diameter of 7: curvirostris ranged from 4.14 mm to 6.55 mm, the body length ranged from 55.31 mm to 96.41 mm, and the body weight ranged from 2.66 g to 9.95 g; the measured eyeball diameter of F. chinensis ranged from 5.5 mm to 7.52 mm, the body length ranged from 123.23 mm to 133 mm, and the body weight ranged from 24.32 g to 30.62 g; the measured eyeball diameter of O. oratoria ranged from 5.02 mm to 6.82 mm, the body length ranged from 88.9 mm to 129.72 mm, and the body weight ranged from 10.88 g to 34.33 g. As shown in FIGS. 8 to 13, the partial fitting relationships of the eyeball diameter d (in unit of mm) with the body length L (in unit of mm) and the body weight W (in unit of g) are as follows:

[58] F chinensis: L = 4.9741d + 94.985, R2 = 0.8424; W = 5.4174d"%%7 R2 = 0.8822, where the range of application of the expressions is: 5.5 <d <7.5.

[89] I curvirostris: L = 18.12d - 21.175, R2 = 0.9324; W = 0.0151d*%7 R2 = 0.881, where the range of application of the expressions is: 4.0 <d <6.5.

[60] O. oratoria: L = 21.703d - 15.703, R2= 0.8628; W = 0.0540d°3%!! R2= 0.877, where the range of application of the expressions is: 5.0 <d < 7.0.

[61] Table 2. The morphological data of E chinensis, T. curvirostris, and O. oratoria

Eyeball Body Body | Eyeball Body Body | Eycball Body Body ese

[62] 2. Sampling and measurement of eyeball diameter to obtain body length and body weight

[63] Fifty samples of Litopeneaus vannamei cultivated in circulating water were collected every five days, and samples were collected 6 times for a total of 300 shrimps. The dorsum of the shrimp was placed vertically upwards on the object stage of a dissecting microscope, a ruler was placed next to the shrimp as a reference, and an image was acquired.

[64] The dissecting microscope was equipped with a multifunctional control unit that integrated a 3.5-inch LCD display to store a shrimp image at a resolution of 2048 x 1536.

[65] The shrimp image was read in real time by a computer, and the pixels in the unit length of the ruler on the image were measured to obtain a length r of pixels included in the unit length on the ruler (pixel/mm).

[66] As shown in FIG. 2, the image near the eyeball of the shrimp was captured by image segmentation, the contour of the eyeball of the shrimp was obtained by the canny operator, the coordinates of all pixels on the contour were extracted, and the longest Euclidean distance between the coordinates was calculated to obtain a pixel length L. L xr was calculated to obtain a major axis length d (in unit of mm) of the eyeball of the shrimp.

[67] The body length and body weight of the shrimp were obtained by substituting d as the shrimp eyeball diameter into the eyeball-body length relationship and eyeball-weight relationship models of the shrimp.

[68] 3. Underwater image acquisition to obtain the body length and body weight

[69] An infrared camera was fixed vertically 30 cm away from the bottom of the culture pond to take underwater images, a coordinate system was set in a plane that could be photographed by the CCD lens, and the camera was focused on the plane of the coordinate system.

[70] The image was transmitted back to the host computer through wireless transmission, the image was stored in the hard disk, and the file address was saved in the database; the shooting time was used as the primary key, which is convenient for querying and saving the eyeball, body length, and body weight of the shrimp.

[71] The image was read in real time. Using a bright spot formed by the reflection of the eyeball of the shrimp as a feature point, the number of eyeballs (Q) was obtained by the edge detection algorithm of OpenCV, while the contour was extracted and the image near the eyeball of the shrimp was segmented. The number of shrimps in the coordinate system could be calculated by Q/2 and rounded up.

[72] The binarized contour of the eyeball of the shrimp was further extracted by image corrosion and image expansion; the coordinates of the pixels on each binarized image were obtained, and the Euclidean distance between any two points on the contour was calculated by the traversal method; the longest Euclidean distance was recorded and stored in the database.

[73] A total of 233 groups of eyeball data of Litopeneaus varmamei were collected from the database. The body length and body weight of the shrimp were calculated by using the eyeball-body length and eyeball-weight models of the shrimp, and the calculated body length and body weight were stored in the database. The corresponding data are shown in Table 3.

[74] Table 3 The eyeball diameter, body length, and body weight of Litopeneaus vannamei

Eyeball diameter (mm) Body length (mm) Measured body weight (g) | Calculated body weight oe ee

[75] Using this method to recognize the eyeball of the shrimp can avoid underwater image noise and achieve the purpose of accurately calculating the body weight.

In the recirculating aquaculture of Litopeneaus vannamei, the accurate total biomass of the aquaculture can be calculated by the host computer, and then the feeding amount can be regulated and the total aquaculture production can be estimated.

Claims

Claims L Method for estimating body length and body weight using a shrimp eyeball diameter, the method comprising: accurately acquiring body length and body weight of a shrimp using a fit relationship of a measured shrimp eyeball diameter and a known eyeball diameter with body length and body weight .

The method of claim 1, wherein the shrimp eyeball diameter is acquired by direct measurement or by computer image recognition.

The method according to claim 1 or 2, wherein shrimp eyeballs are subelliptical, and the shrimp eyeball diameter is a major axis length of an elliptical shrimp eyeball, i.e., a farthest distance between two points of the rim of the shrimp eyeball is used as the shrimp eyeball diameter .

The method according to claim 1, wherein the fit relationship of eyeball diameter (d) with body length (L) and body weight (W) is obtained from measurements of at least 10 shrimps of the same species, L = fi(d), and W = f2(d), where J and f> are obtained by data passes.

The method according to claim 1, 2, 3 or 4, wherein: the eyeball diameter d (in unit of mm), the body length L (in unit of mm) and the body weight W (in unit of g) are fitted; with the proviso that a fit relationship of the eyeball diameter with body length and body weight of Litopenaeus vannamei is known: a relational expression between the shrimp eyeball diameter d and the body weight L of the shrimp is L = 15.978d — 2.31 a relational expression between the eyeball diameter d and the body weight W is as follows: if d<2 mm, W = 0.0326d3739: 2mm <d<3.9 mm, W=0.0401d%1%; 39mm<d<5.8mm, W=0.0421d*"!: en

5.8mm <d, W = 0.1030d2°22.

The method according to claim 1, 2, 3 or 4, wherein: the eyeball diameter d (in unit of mm), the body height L (in unit of mm) and the body weight W (in unit of g) are fitted: with the condition that a fit relationship of eyeball diameter with body length and body weight of Fenneropenaeus chinensis is known: L = 4.9741d + 94.985; W =5.417d°%27 where the range of application of the expressions is 5.5 < d < 7.5.

The method according to claim 1, 2, 3 or 4, wherein: the eyeball diameter d (in unit of mm), the body length L (in unit of mm) and the body weight W (in unit of g) are fitted: with the condition that a fit relationship of eyeball diameter with body length and body weight of Rachypenaeus curvirostris is known: L = 18.12d - 21.175; W = 0.015d°5573 where the range of application of the expressions is 4.0 < d < 6.5.

The method according to claim 1, 2, 3 or 4, wherein: the eyeball diameter d (in unit of mm), the body length L (in unit of mm) and the body weight W (in unit of g) are fitted: with the condition that a fit relationship of eyeball diameter with body length and body weight of Oratosquilla oratoria is known: L = 21,703d - 15,703; W = 0.0549d%39!! where the range of application of the expressions is 5.0 < d < 7.0.