Collective behaviors efficiently impart benefits to a diversity of species ranging from bacteria to humans.Fly larvae tend to cluster and form coordinated digging groups under crowded conditions,yet understanding the rules governing this behavior is in its infancy.We primarily took advantage of the Drosophila model to investigate cooperative foraging behavior.Here,we report that Drosophila-related species and the black soldier fly have evolved a conserved strategy of cluster digging in food foraging.Subsequently,we investigated relative factors,including larval stage,population density,and food stiffness and quality,that affect the cluster digging behavior.Remarkably,oxygen supply through the posterior breathing spiracles is necessary for the organization of digging clusters.More importantly,we theoretically devise a mathematical model to accurately calculate how the cluster digging behavior expands food resources by diving depth,cross-section area,and food volume.We found that cluster digging behavior approximately increases 2.2 fold depth,1.7-fold cross-section area,and 1.9 fold volume than control groups,respectively.Amplification of food sources significantly facilitates survival,larval development,and reproductive success of Drosophila challenged with competition for limited food resources,thereby conferring trophic benefits to fitness in insects.Overall,our findings highlight that the cluster digging behavior is a pivotal behavior for their adaptation to food scarcity,advancing a better understanding of how this cooperative behavior confers fitness benefits in the animal kingdom.
Yujie WuQiang WangWeikang YangSheng ZhangChuan-Xi MaoNana HeShaojie ZhouChuanming ZhouWei Liu
To improve the survival rate of larvae during material separation after biotransformation of existing residual film mixtures of Protaetia brevitarsis larvae,this paper adopts the method of combining physical test and EDEM simulation test,and selects Hertz Mindlin with JKR contact model to calibrate the discrete element simulation contact parameters of the Protaetia brevitarsis larvae and the frass mixture.First,the cylinder lifting method was used to determine the actual repose angle of the mixture of larvae and frass.The collision recovery coefficients between larvae-frass and steel,static friction coefficient,kinetic friction coefficient and the collision recovery coefficient between larvae were measured through physical tests such as the inclined plane method.The Plackett-Burman test was then used to screen out the factors that have a significant impact on the repose angle:Poisson’s ratio of frass,frass-frass rolling friction coefficient,frass JKR surface energy,frass-larvae JKR surface energy.The optimal value intervals of four significant factors were determined based on the steepest climb test,Based on the Box-Behnken response surface analysis test,the second-order regression model between the repose angle and four significant factors was determined,and variance and interaction effects were analyzed.And with the actual repose angle as the goal,the significant factors were optimized and the optimal parameter combination of the four significant factors was determined.The simulation test of material repose angle and screening was carried out with the optimal parameter combination,and compared with the physical test.It was found that the maximum relative errors of the two tests were 1.48%and 3.79%respectively,indicating that the calibrated parameter values are true and reliable,It can provide a reference for the discrete element simulation of the transportation and separation of the Protaetia brevitarsis larvae-frass mixture.
Yuanze LiJianhua XieJia ZhangYong YueQinghe MengYakun DuDeying Ma
The significant increase in the demand for biomass waste treatment after garbage classification has led to housefly larvae treatment becoming an attractive treatment option.It can provide a source of protein while treating biomass waste,which means that nutrients can be returned to the natural food chain.However,the performance of this technology in terms of its environmental impacts is still unclear,particularly with regards to global warming potential(GWP).This study used a life cycle assessment(LCA)approach to assess a housefly larvae treatment plant with a treatment capacity of 50 tons of biomass waste per day.The LCA results showed that the 95% confidence intervals for the GWP in summer and winter were determined to be 24.46-32.81 kg CO_(2) equivalent(CO_(2)-eq)/ton biomass waste and5.37-10.08 kg CO_(2)-eq/ton biomass waste,respectively.The greater GWP value in summer is due to the longer ventilation time and higher ventilation intensity in summer,which consumes more power.The main GWP contributions are from(1)electricity needs(accounting for 78.6% of emissions in summer and 70.2%in winter)and(2)product substitution by mature housefly larvae and compost(both summer and winter accounting for 96.8% of carbon reduction).
Tao LuFan LüNanlin LiaoHonghui ChaiHua ZhangPinjing He
Insects,particularly black soldier fly larvae(BSFM),Hermetia illucens,have been regarded as promising protein and lipid sources in animal feed,including fish.Digestibility is the key factor that affects nutrient utilization,feeding physiology and efficiency.In the present work,the effect of BSFM on the digestibility of red hybrid tilapia(RHT)compared to fish meal(FM)was ultimately unveiled.A 56-day growth trial was performed with 60 RHT(~30 g)randomly distributed into six tanks and fed two experimental diets containing FM as a reference diet and BSFM as a test diet.In addition,faeces were collected to determine their chromium concentration and proximate composition.The apparent digestibility coefficient(ADC)of dry matter,crude protein and energy in the BSFM diet were observed to be significantly higher than those in the FM diet.Besides,the growth performance of fish fed with the BSFM diet exhibited significantly higher(P<0.05)weight gain,specific growth rate,protein efficiency ratio and lower feed conversion ratio than those in the FM group.This study shows that the BSFM feed was well digested by tilapia and improved its growth performance.
针对斑马鱼幼鱼体积小,外观相似度高,运动模式不稳定等特征导致的目标丢失、目标身份匹配错误、轨迹混乱等问题,本文提出了一种基于卷积神经网络的多目标跟踪算法。算法分为目标检测和目标跟踪两部分。检测部分通过经典的检测算法YOLO(You Look Only Once)v5实现,跟踪部分,主要通过DeepSORT实现对斑马鱼幼鱼位置的跟踪与轨迹连接。针对幼鱼容易被漏检、错检等特点,在YOLOv5m的基础上改进了网络的检测层结构,提升对小目标的检测能力。同时融合双通道注意力机制(Convolutional Block Attention Module,CBAM)对网络对背景噪声的抗噪能力。结果表明,在小样本训练的情况下,本文提出的YOLOv5m-ss对斑马鱼幼鱼群体的检测精度@mAP(mean Average Precision)可达99.9%,相较原网络提升了9.4%。结合DeepSORT后的跟踪精度MOTA可达98.0%,在算法运行速度和精确率上都有一定优势。
为掌握分布于额尔齐斯河流域黑鲫(Carassius carassius)的胚胎及仔鱼发育规律,填补人工繁育空白,丰富其繁殖生物学数据,本研究在额尔齐斯河水域收集黑鲫亲本,通过人工催产受精的方式获得受精卵,对其早期发育特征进行观察。结果显示:黑鲫胚胎在(19.89±0.64)℃温度条件下,历经110 h 35 min孵化出膜,共需要积温2274.54 h·℃;黑鲫胚胎从受精卵开始,受精后50 min胚盘隆起,6 h 40 min发育至囊胚,17 h 20 min发育至原肠胚,26 h 20 min发育至神经,37 h 20 min出现肌节,70 h 35 min出现心跳,110 h 35 min孵化出膜,胚胎发育过程经历了受精卵、卵裂、囊胚、原肠胚、神经胚、器官形成和孵化共7个阶段(26个时期);孵出1 d的鱼苗全长(4.45±0.12)mm,卵黄囊饱满,静卧于水底,2d后鱼苗全长(5.13±0.18)mm,色素沉淀增加,出现短暂游动,3d后鱼苗全长(5.69±0.17)mm,对外界刺激敏感,卵黄囊吸收完毕,臀鳍和尾鳍清晰可见。本研究首次报道了额尔齐斯河黑鲫在人工催产条件下的早期发育的时序及特征,将为进一步实现苗种规模化繁育提供基础资料和重要参考。
