水产动物微颗粒饲料加工工艺研究进展

水产动物幼体微颗粒饲料是近些年来国内外研究开发的热点,文中综述了国际上较为流行的几种微颗粒饲料造粒工艺,包括微黏合工艺、微包膜工艺、聚合反应工艺、相分离技术造粒工艺、物理机械法造粒以及混合法造粒工艺。微颗粒饲料制粒工艺是微颗粒饲料产业乃至水产育苗行业的关键技术,其进一步发展有赖于制粒工艺技术研究和水产动物幼苗营养及消化生理研究的综合进展。     

Dispersal of black sea bass (Centropristis striata) larvae on the southeast U.S. continental shelf: results of a coupled vertical larval behavior – 3D circulation model

In the marine environment, pelagic dispersal is important for determining the distribution and abundance of populations, as well as providing connections among populations. Estimates of larval dispersal from spawning grounds are important to determining temporal and spatial patterns in recruitment that may have significant influences on the dynamics of the population. We present a case study of the dispersal of Centropristis striata (black sea bass) larvae on the southeast U.S. continental shelf. We use a coupled larval behavior – 3D circulation model to compare the effects of the timing and location of spawning against that of larval vertical migration on larval dispersal. Using the results of field data on larval vertical distributions, we compare the dispersal of virtual 'larvae' which have ontogenetic changes in vertical behavior with that of particles fixed near the surface and near the bottom. Larvae were released at potential spawning sites four times throughout the spawning season (February through May) for 3 yr (2002–04) and tracked for the assumed larval duration (from 27 to 37 days including the egg stage). Results indicate that adult behavior, in the form of spawning time and location, may be more important than larval vertical behavior in determining larval dispersal on the inner- and mid- continental shelves of this region.     

莲草直胸跳甲成虫产卵选择性及叶位与幼虫发育适合度的关系

采用室内自由选择法和发育测定法研究莲草直胸跳甲(Agasicles hygrophila)成虫对喜旱莲子草(Alternanthera philoxeroides)叶位的产卵选择性及后代发育与不同叶位叶片的适合度.结果表明:(1)莲草直胸跳甲成虫嗜好在中部叶片的叶背产卵,以在第2对叶上的选择系数最高,选择率为35.18%,与第1对叶上的28.03%差异不显著,但显著高于对其他叶位的选择系数;(2)相对于在叶表进行取食,初孵幼虫显著趋向在叶背,且这样取食的1龄幼虫存活率高、发育历期显著缩短,这与雌虫选择在叶背产卵的习性相符,说明其选择有一定生物学意义,即有利于后代发育;(3)叶龄对莲草直胸跳甲各龄幼虫发育有显著影响,叶位越低,各龄幼虫的发育历期越长,但存活率上以取食第1叶位的为最高.     

Some developmental differences inEpinotia granitalis (Lepidoptera: Tortricidae) between two host tree species

To detect developmental differences inEpinotia granitalis in two host tree speciesCryptomeria japonica andChamaecyparis obtusa, the fourth or fifth instar larvae were collected daily from the two species located on the grounds of the National Forest Tree Breeding Center, from April 19 to May 9 in 1994 and April 18 to May 10 in 1995. Larvae ofE. granitalis collected fromC. obtusa had heavier body weight, developed to larger adults than those collected fromC. japonica, and mortality from the fourth or fifth instar larval stage to adults onC. obtusa was lower than that onC. japonica. All these facts suggest that larval performance onC. obtusa was higher than that onC. japonica.     

The Role of Mangroves in Retaining Penaeid Prawn Larvae in Klang Strait,Malaysia

The mangrove-fringed Klang Strait, Malaysia, retains approximately 65 billion penaeid prawn larvae annually prior to their settlement in coastal nursery grounds. This phenomenon appears to be due principally to tidal currents and lateral trapping in mangrove-fringed channels, the wind playing an insignificant role.     

甜菜夜蛾幼虫龄数和龄期的测定

甜菜夜蛾[Spodoptera exigua(Hübner)]属鳞翅目(Lepidoptera)夜蛾科(Noctuidae),是芦笋、番茄、棉花、萝卜、玉米等植物上的重要害虫。明确该虫幼虫的龄数和龄期,可为其预测预报和科学防治提供依据。对甜菜夜蛾幼虫各龄期的头壳宽度、体长和体重进行测量,并根据频次分布图、戴氏定律、Crosby生长法则和回归分析推断和验证甜菜夜蛾幼虫的虫龄数。结果显示,甜菜夜蛾1~5龄幼虫的头壳宽度范围分别为0.21~0.30、0.40~0.49、0.65~0.75、1.05~1.15、1.65~1.80 mm,频次分布呈现出5个明显的集中区域;1~5龄幼虫的体长范围分别为1.0~3.1、2.5~6.5、4.0~10.0、5.0~15.0、11.0~27.0 mm,各龄期体长出现重叠,频次分布集中区域不明显;1~5龄幼虫的体重范围分别为0.025~0.567、0.200~6.000、1.100~15.200、6.200~65.600、32.900~275.200 mg。结果表明,试验条件下甜菜夜蛾幼虫共5龄,幼虫头壳宽度可作为分龄指标,而幼虫体长和体重在各龄期出现较大程度的重叠,不宜作为分龄指标。     

Modeling the egg and larval transport pathways of the Antarctic toothfish (Dissostichus mawsoni) in the East Antarctic region: New insights into successful transport connections

The Antarctic toothfish (Dissostichus mawsoni) is an important fishery species widely distributed in the Southern Ocean, especially in areas covered by sea ice. Understanding fish distributions and life cycles, including the transport and survival of eggs and larvae, is essential for the assessment and sustainable management of the fishery. However, owing to difficulties with in situ winter observations, information on the early life stages of D. mawsoni is lacking. Here, we investigated the transport pathways of fish eggs and larvae through a particle tracking study, using satellite-derived ocean surface velocities in the East Antarctic region, which includes important D. mawsoni habitats and exploratory fisheries. Our results indicate that particles released from continental slopes are more likely to be successfully transported to suitable settlement grounds than those released from the BANZARE Bank (the southern region of the Kerguelen Plateau), which is situated further north and has been hypothesized to be a potential spawning ground for D. mawsoni. This study demonstrates successful source–settlement connections in relation to ocean recirculation and suggests important settlement regions for D. mawsoni larvae in the East Antarctic region.     

咸海卡拉白鱼胚胎和仔鱼早期发育

取3+龄咸海卡拉白鱼(Chalcalburnus chalcoides aralensis)进行全人工繁殖,对受精卵各阶段发育形态进行观察.该鱼受精卵呈圆球状,为沉性卵,微粘性,卵粒白色透明,直径(1.32±0.04) mm.胚胎发育可分为受精卵、卵裂期、囊胚期、原肠期、神经胚期、胚孔封闭期、肌节出现期、视泡形成期、尾芽期、肌肉效应期、胚动期、心脏搏动、出膜前期和孵化期.水温22～24 ℃时,受精卵经56 h 45 min孵化出仔鱼.胚胎发育所需积温1 232～1 344 h·℃.孵化第1天仔鱼沉卧水底,体色为白色,全长(4.51±0.08) mm;第4天仔鱼平游,开始摄食蛋黄和单细胞藻类;第6天鱼体卵黄囊消失,食轮虫或丰年虫幼体;第10天仔鱼全长(7.60～9.80) mm时下塘,仔鱼摄食浮游生物;第15天仔鱼全长(9.10～11.3) mm摄食人工饲料.     

海南“石斑鱼苗网”渔具属性辨析

对在2004年7~8月间南海区小型海洋渔具渔法调查中发现的“石斑鱼苗网”的渔具结构、属性、性能和管理进行了分析讨论,研究认为“石斑鱼苗网”属于敷网类,网团型,延绳式。对石斑鱼苗有良好的诱捕效果,从保护资源的角度出发,应对其实施规范管理。     

长吻鮠胚胎和胚后发育与温度的关系

鱼类的胚胎发育(embryonic development)与水温具有十分密切的关系。国内外一些学者先后探讨了鲤鱼(Cyprinus caripo)、湖红点鲑(Salvelimus namaycush)等多种鱼类发育的有效温度、最适温度和临界温度,以及鱼类胚胎对水温的敏感性、依从性等内容。