Study On Ethogram Characteristics Of Sepiella Maindroni During Reproduction And Preference For Spawning Attachment Behavior

Sepiella maindroni was once one of the "four major seafoods" of Chinese East Sea.However,because of overfishing,destruction of spawning grounds and etc.,the fishing season has vanished.It is only used as a bycatch now.Sepiella maindroni has special characters like short life cycle,rapid generation renewal,and fast growth,which not only determine the reproductive period as an important stage of its life,but also the breeding behavior,the number of fertilized eggs and the survival rate of offspring.And these are the main sources of resource replenishment for Sepiella maindroni.The behavioral activities during the breeding period are the focus of study in the behavior of the Sepiella maindroni.How can we define these behaviors during the reproductive period and characteristics do they have? If various egg-attached substrates can affect spawning behavior? These are important aspects of the study of Sepiella maindroni behavior.In order to investigate these questions above,the author observed the behavioral activities of the Sepiella maindroni’s fry bred at the Xixuan Fisheries Science and Technology Island breeding base during the breeding period from June to July 2020 to2021 and analyzed the photographs and video data obtained.This study was taken with the fixed-point observation method,video survey method,target animal sampling method and transient scanning method.A behavioral spectrum of the Sepiella maindroni,which can qualitatively describes each behavioral characteristic is constructed through behavioral data of each type of parental sample during the breeding period.The "posture-action-environment" behavioral elements was used as the axis to distinguish and define the posture code,action code and environment code of the Sepiella maindroni.Based on this,the PAE coding system of the Sepiella maindroni was initially constructed with qualitatively describing the frequency of different behaviors.And finally,the author analyzes phenotypic plasticity of the Sepiella maindroni spawning behavior with statistical correlation.The main findings obtained were as follows.(1)Behavioral spectrum and characteristics of the Sepiella maindroni during the reproductive periodThere were 51 behaviors in 10 categories which were analyzed and defined during the reproductive period.The locomotor behavior includes 8 types: topwater,roaming,sideways swimming,surfacing,diving,hurrying in,hurrying out,and hitting walls.The feeding behavior is consisted of 7 types behaviors,which are foraging,predation,chewing,containing,snatching,carcass eating,and spitting.The resting behavior covers hovering,lying down,stacking,and slow swimming.The courtship behavior includes displaying,following,and touching.The domain behavior covers accompanying,alerting,threatening,confronting,fighting,and repelling.Displaying,following and touching belong to courtship behavior.companionship,alerting,threatening,confronting,fighting,repelling and leaving are classified as domain behavior.The mating behaviors contains trying to mate,holding pairs,pushing,moving sperm and shaking sperm.Screening,spawning and attaching are spawning behaviors and fighting,stealing,chasing and fleeing are conflict behaviors.The two types of flocking behaviors were parading and following.There are also four other behaviors named as ink-jetting,wrist bracing,wrist management and wall sticking.(2)PAE coding of the breeding behavior of Sepiella maindroniA preliminary PAE coding system was constructed for the reproductive behaviors of Sepiella maindroni.A total of 11 postures,25 movements and 13 environmental factors were distinguished and recorded.The components and structural levels of each behavior were also classified.(3)Phenotypic plasticity analysis of the spawning behavior of Sepiella maindroniThe spawning behavior of Sepiella maindroni is phenotypically influenced by different egg attachment bases.In this study,the frequency of spawning behavior and the amount of eggs attached were higher in the combined and retention type attachment substrates of the net-rope structure,while lower figures accounted in both aspects in trap and avoidance attachment substrates of the branching structure.And no spawning behavior occurred in the cave attachment substrates with smaller mesh size.