草地螟幼虫和蛹的形态特征及雌雄鉴别方法

草地螟雌、雄成虫的形态特征及鉴别方法在室内研究及种群测报中已经广泛应用,但幼虫及蛹的形态特征及雌雄的鉴别方法目前尚没有报道。本文借助超景深三维显微系统,观察不同龄期草地螟幼虫的形态特征、5龄幼虫性别特征以及雌、雄蛹的区别,以期为草地螟幼虫和蛹的形态识别和性别鉴定提供科学分类依据。研究表明:1)初孵幼虫体色为淡黄色,随着龄期增大,体色逐渐加深,至末龄为灰黑色或黑色,3龄出现白斑和体侧纵带,5龄体背出现2条鲜黄色或黄白色背线;2)雄幼虫第5腹节背管两侧有一对精巢,呈白色半透明橘瓣状,3片精小囊隔膜将精巢分为4个小腔室,预蛹期2个精巢逐渐靠拢、融合并发生扭转,蛹期完全融合成为一个不可剥离的圆球体,直至生命结束;雌幼虫卵巢没有明显分化;3)雌蛹腹部8～10节分节不明显,第8腹节中央的生殖孔和第9腹节的产卵孔连接组成一纵裂缝,裂缝两侧平坦,裂缝下端与排泄孔上端距离较远,为(0.48±0.005)mm,腹部末端钝圆;雄蛹腹部8～10节分节明显,第8腹节无纵裂缝,第9腹节的生殖孔呈一纵裂缝与第10腹节相连,裂缝两侧各有一个半圆形瘤状突起,裂缝下端与排泄孔上端距离较近,为(0.24±0.005)mm,腹部末端较尖。     

村镇垃圾治理典型案例及问题分析

垃圾治理是农村人居环境整治的重要组成部分。当前各地农村围绕垃圾分类、收运及处理处置开展了众多实践尝试。为及时、深入地了解村镇垃圾的治理现状,本文基于2021年村镇垃圾治理实用技术与实践案例征集活动的结果,对比分析了应征案例的指标达成状况,系统梳理了村镇垃圾的分类收运、资源化利用及热处理三类典型案例的特点和存在的问题,旨在为我国村镇垃圾治理工作的高效推进提供参考。就分类收运而言,“五网协同”、“一户一码”、第三方运营等管理机制方面的创新对村镇垃圾治理的高效推进具有重要作用,同时也存在目标效果缺乏数据支撑、案例覆盖人口数量少及案例可推广性有待验证等问题。资源化处理方面,升级版的阳光房堆肥技术及模式运行成本较低,操作相对简便,可推广性强;虽然厨余（易腐）垃圾机械制肥推广应用较多,具有一定的适用性,但其运行成本高,且部分运行时间较短的工艺无法满足产物腐熟的要求。易腐垃圾昆虫生物转化技术的减量化和资源化水平较高,有较好的规模化推广应用前景。此外,大部分村镇生活垃圾热处理案例存在运行不稳定及污染物排放不达标等问题,因此应加强原料控制、热解（焚烧）过程优化等方面的科学研究和实践应用。     

对铜绿丽金龟幼虫有活性的苏云金芽孢杆菌菌株的分离及鉴定

为了发掘新的斑资源,从3种不同土壤类型的样品中分离得到了285株苏云金芽孢杆菌菌株。采用杀虫活性测定方法从中获得了13株对铜绿丽金龟幼虫具有高毒力的菌株。利用PCR—RFLP鉴定体系和SDS-PAGE蛋白分析法,研究了这13株苏云金芽孢杆菌的杀虫晶体蛋白基因类型和晶体蛋白表达情况。结果显示,有12株均含有编码毒杀铜绿丽金龟幼虫毒素蛋白的cry8Ca基因,而FTL53没有鉴定到已有的基因类型。这13株菌的伴孢晶体都含有分子量为130kDa的蛋白。本研究为不断发现新型的、具有高毒力的cry毒素基因奠定了基础。     

长江口沿岸碎波带三种暖水性鱼类仔鱼的出现

2006年6~10月,按月在长江口沿岸碎波带设置的13个采样点,用小型拖网进行仔稚鱼多样性调查时,采集到遮目鱼仔鱼1 ind、海鲢仔鱼40 ind、大海鲢仔鱼144 ind,这是在长江口水域首次发现遮目鱼仔鱼和海鲢的仔鱼。本文详细描述了该三种暖水性鱼类仔鱼的形态特征,探讨了其水平分布与环境因子的关系,提出了长江口附近水域存在产卵场的可能性,为该三种暖水性鱼类早期生活史中的地理分布以及生态习性提供科学依据。     

黑点青鳉的生长和摄食行为发育

针对黑点青鳉实验室养殖成活率低的问题,对其摄食行为发育进行研究,了解其早期阶段的摄食行为发育状况,为人工养殖提供理论依据。通过单摄像机结合镜面成像的方法,对黑点青鳉胚后发育阶段90 d摄食行为的观察与分析,研究了投喂卤虫无节幼体条件下黑点青鳉的生长特征和摄食行为发育。结果显示,幼体体长平均生长率为2.579%/d,体长与日龄间关系为y=3.132+0.383x-0.004x²+0.000 03x³,R²=0.98。通过各项摄食行为指标将其幼体生长发育分为3期6个阶段:仔鱼期(0～10 d)分为前仔鱼期(0～4 d)和后仔鱼期(5～10 d),稚鱼期(11～30 d)分为前稚鱼期(11～18 d)、中稚鱼期(19～24 d)和后稚鱼期(25～30 d),幼鱼期(31～65 d)。黑点青鳉幼体出膜4 d后开始投喂初孵卤虫,至10 d所有鱼苗均能捕食。黑点青鳉仔鱼期幼体死亡率较高,但摄食能力稳步提升,至该期末,摄食成功率提升至45%～55%,摄食效率达0.5～0.6个/min;稚鱼期幼体的各项摄食指标均有大幅度提升,对饵料的响...     

脱脂亮斑扁角水虻幼虫粉替代鱼粉对黄颡鱼幼鱼生长性能、营养素沉积率、血清生化指标和消化酶活性的影响

为研究脱脂亮斑扁角水虻幼虫粉(DBSFLM)替代鱼粉对黄颡鱼幼鱼生长性能、营养素沉积率、血清生化指标和消化酶活性的影响,本实验选用平均体质量为(1.67±0.01) g的黄颡鱼幼鱼480尾,随机分为4个处理组,分别投喂基础饲料(T0)和实验饲料[脱脂亮斑扁角水虻幼虫粉分别替代鱼粉20%(T20)、40%(T40)和60%(T60)],每个处理组3个重复,每个重复40尾鱼,养殖8周。结果显示,随着DBSFLM替代量的增加,黄颡鱼生长呈先增加后降低的趋势;T20组的终末均重、增重率和特定生长率最高,且显著高于T60组;实验组T20和T60的摄食量显著高于对照组和T40组;实验组的腹脂指数、灰分和钙沉积率呈下降趋势,其中T60组的腹脂指数、T40和T60组的灰分和钙沉积率达到显著水平;与对照组T0相比,实验组的肥满度、脏体比、肝体比、肠体比和胃体比、蛋白质、脂肪和磷沉积率及黄颡鱼体蛋白、体脂肪和灰分均没有显著差异;血清胆固醇和甘油三脂显著降低,高密度/低密度脂蛋白胆固醇显著升高,实验组T40的胃蛋白酶活性有增加趋势、肠道胰蛋白酶活性显著增加。研究表明,在本实验条件下,脱脂亮斑扁角水虻幼虫粉替...     

长江口崇明东滩夏秋季仔稚鱼的空间分布

2018年6月(夏)和9月(秋),对长江口崇明东滩水域的14个站位点的表层,运用大型浮游生物网(口径1.3 m,网目0.5 mm)水平船拖10 min采集仔稚鱼,实时采集水柱环境参数包括温度(SST)、盐度(SSS)、浊度(TUR)、深度(DEP)和叶绿素a(SSC),探讨该水域仔稚鱼的分布和多样性的变化特征.结果显示...     

The composition of the microbial community associated with Macrobrachium rosenbergii zoeae varies throughout larval development

The giant river prawn, Macrobrachium rosenbergii, is an economically important freshwater prawn. The cultivation of zoea larvae is crucial for the success of the M. rosenbergii industry. In this study, we surveyed the microbial community diversity and structure associated with M. rosenbergii zoeae at different stages of larval development. Samples of zoea larvae from different developmental stages were collected and subjected to high-throughput DNA sequencing. Firmicutes, Proteobacteria, Bacteroidetes and Actinobacteria were the dominant phyla in all six sample groups. At the genus level, the relative abundance of Bacillus decreased, and that of Enterobacter increased with the growth of the zoeae. This may have been related to the intestinal development of the zoea larvae. The microbial diversity of M. rosenbergii zoea larvae decreased significantly with development. The beta diversity analysis showed that the closer the developmental stage of M. rosenbergii, the more similar the structure of the associated bacterial communities.     

Estimation of Arachidonic Acid Requirement for Improvement of Pre‐maturation Growth and Egg and Larval Quality in the Female Blue Gourami (Trichopodus trichopterus; Pallas, 1770): A Model for the Anabantidae Family

This study investigates the dietary arachidonic acid (ARA) requirement from juvenile to maturation stage in an anabantid model fish, the blue gourami, Trichopodus trichopterus. Specifically we determined the optimum dietary ARA content to maximize juvenile growth and subsequent sexual maturation and to improve the quality of their eggs and offspring. Five experimental diets containing 0.02, 0.53, 1.05, 1.60, and 2.12% ARA (of dry weight) were fed to juveniles over 5 mo. The results showed that whole‐body fatty acid profile of broodstock significantly changed in fish fed diets of different ARA content (ANOVA, P < 0.003). The highest contents of 18:2n‐6 and Σn‐6 were obtained in fish fed 0.53% ARA, and a decreasing trend was observed with elevated dietary ARA levels. Monthly specific growth rate (SGR) measurements revealed significant differences in the juvenile stage, but the SGR of broodstock was unaffected by dietary ARA. Protein and ash content of whole‐body broodstock showed no differences among groups, while lipid content decreased as ARA levels increased. Maximum volume of the oocyte was obtained in the 1.05% ARA group, while the yolk sac size increased as dietary ARA increased. The optimum growth and survival of the larvae produced by broodstock were recorded in the 2.12 and 1.6% ARA groups, respectively. It was concluded that despite the presumed ability of freshwater fish to synthesize and meet their highly unsaturated fatty acid requirements, dietary ARA higher than 1.05% had significant stimulatory effects on growth of juveniles but no obvious influence on the growth of matured fish. Also, higher ARA levels (1.6–2.12%) were found to improve the quality of eggs and offspring.