Studies On Acoustic Signals Of Abalone Feeding Activity Based On Passive Acoustics

Abalone is a precious dish on the table,and it is an important economic aquaculture product in coastal areas of China too.However,the abalone farming method still stays in the traditional extensive method,which the labor productivity,resource utilization rate and production efficiency are relatively low.With the help of passive acoustic technology,this paper intends to explore the acoustic characteristics and vocalization mechanism of abalone feeding activities,and attempt to use this technology as a breakthrough point to expand the acquisition approach of aquaculture data for abalone and other aquaculture organisms,so as to solve the problem of monitoring the activity status of aquaculture organisms.In this study,Haliotis discus hannai was studied as the object,Firstly,an experimental device was constructed and relevant experiments were designed.Combining with the physiological structure of abalone,the vocalization mechanism of abalone feeding activity was analyzed.Then the characteristics and rules of acoustic signals of abalone feeding activity were analyzed.Finally,in order to be applied in the actual farming process,a set of remote farming data acquisition system was designed,which applied the acoustics theory to the practice and helped to promote the technology of abalone farming.The main research conclusions of this paper are as follows:(1)The acoustic signals produced by abalone(60 mm± 2.7 mm in shell length)during feeding were verified in the laboratory,and the vocal mechanism was studied,that is,the acoustic signals produced by scraping and grinding the food with the tongue during feeding.(2)The acoustic signal characteristics and rules of abalone feeding activity were studied,when the abalone was fed on Asparagus schoberioides Kunth,the acoustic signals are mainly concentrated in the high frequency band(5.55～44.36 kHz),the peak frequency is 37.86±2.55 kHz,the maximum energy is-66.43±5.17 dB,the duration of each pulse sequence is 119.12 ± 70.51 ms,and each pulse sequence is composed of several sub-pulses.Nearly 70%of the pulse sequences were composed of 1 to 2 subpulses,and the duration of each sub-pulse was 42.62±19.72 ms.At the beginning of feeding activity,the feeding frequency was maintained at 0.61±0.04 times per minute.After 60 minutes,the frequency of feeding decreased significantly and remained at 0.48±0.08 times per minute.Preliminary analysis suggested that the feeding frequency of abalone was related to the degree of hunger.That is,in the process of feeding,the frequency of feeding decreases with the decrease of hunger.(3)This paper designs and implements a set of remote aquaculture data acquisition system to realize the acquisition and transmission of water quality and acoustic data.In this paper,the actual requirements of the system are analyzed at first,and the appropriate system architecture is designed based on the requirements.Then,the hardware and software parts of the system are designed and implemented.Finally,the test and optimization are carried out in the laboratory and the actual abalone farming production.This paper is the first to study the acoustical characteristics and rules of abalone feeding activities,which provides a case for the study of shellfish acoustics,and is beneficial to supplement and perfect the basic knowledge of shellfish research.At the same time,this paper designed and realized the data acquisition system of aquaculture,and applied passive acoustic technology to the system,expanded the method of data acquisition of abalone and other aquaculture organisms,and promoted the development of aquaculture industry to intelligent information.