Comparison of laboratory-reared eggs, embryos and larvae of five labrid fishes

Eggs, embryos and larvae of five labrid fishes, Thalassoma cupido, Pteragogus flagellifer, Pseudolabrus japonicus, Halichoeres tenuispinnis, and H. poecilopterus, reared in the laboratory are described and compared. The eggs were buoyant and spherical, with a single, spherical oil globule. P. japonicus eggs were unique in lacking melanophores on the oil globule. Eggs of the remaining species closely resembled each other, except in diameter. Incubation periods were short, ranging from ca. 19 h in H. poecilopterus to ca. 31 h in P. japonicus. The newly-hatched embryos also resembled each other, having a short tail and large oval or pear-shaped yolksac, the anterior tip of which extended beyond the snout. The single oil globule was located at the anterior tip of the yolk. As the yolksac diminished with growth, its anterior tip moved posteriorly. The yolk and oil globule were completely absorbed 3 or 4 days after hatching. In all free embryos and larvae except for Pteragogus flagellifer, needle-like projections appeared on both the dorsal and anal finfold margins 12 h to 1 day after hatching. Although morphology of free embryos and larvae of all five species was very similar, differences in pigmentation, location of the anus, and the needle-like projections were apparent. Artificial keys to the newly-hatched embryos and larvae are given.     

Mercury in tigerfish (Hydrocynus vittatus, Castelnau), green happy (Sargochromis codringtonii, Boulenger) and kapenta (Limnothrissa miodon, Boulenger) from Lake Kariba, Zimbabwe

Concentrations of total mercury were determined in Hydrocynus vittatus (Castelnau), Sargochromis codringtonii (Boulenger), and Limnothrissa miodon (Boulenger) from two localities in Lake Kariba, Zimbabwe.
The mean concentrations of total mercury in H. vittatus from Basin 5 and Basin 2 were 0.08 mg kg⁻¹ and 0.094 mg kg⁻¹, respectively. In S. codringtonii, mean concentrations were 0.004 mg kg⁻¹ and 0.026 mg kg⁻¹ for Basins 5 and 2, respectively. No mercury was detected in L. miodon from Basin 2 while samples from Basin 5 had a mean concentration of 0.069 mg kg⁻¹ (wet weight). Total mercury concentrations were also determined on a dry weight basis.
Within each sampling area, total mercury concentrations were significantly different among species ( P  < 0.05). For H. vittatus and S. codringtonii, total mercury concentrations (in the same species) were not significantly different between the two localities ( P  < 0.05).
The factors causing the observed differences in total mercury between similar species from different localities and among different species in the same locality (sampling area) are discussed. From the observed low levels of mercury in all three species, it was concluded that the mercury constituted 'background levels'. These levels are below the maximum concentrations permissible in human fish foods.     

Further data on the reproduction and larval development of Knipowitschia caucasica (Gobiidae)

The courting spawning and parental care behaviours of Knipowitschia caucasica (Kawrajsky) in an aquarium are described and the earliest stages of ontogenetic development are illustrated.     

Age estimation,growth rate and size at sexual maturity of tigerfish Hydrocynus vittatus from the Okavango Delta,Botswana

The aims of this study were to determine relative age, growth rate and size at maturity of tigerfish in the Okavango Delta as a basis for the development of a fisheries management plan. A total of 206 tigerfish Hydrocynus vittatus, collected by angling in August 2005,2006 and 2007, was assessed for sexual maturity and relative ages were estimated from 135 of these, using scales and whole and sectioned otoliths. Sectioned otoliths were the most appropriate method for ageing H. vittatus of up to 20 years old. Males were present in all relative age classes, proving that they do not disappear from the population at a young age, as previously thought. Males matured at 451 mm TL and females at 522 mm TL, corresponding to an approximate relative age of four years for both sexes. Males lived for up to 20 years, females for up to 16 years.     

马尾松诱导抗性对马尾松毛虫幼虫生长发育的影响

利用不同受害方式和受害程度的马尾松 (PinusmassonianaLamb.)针饲养马尾松毛DendrolimuspunctarusWalker虫幼虫 ,研究受害松针对幼虫生长发育的影响。结果表明 :马尾松毛虫取食受害松针后 ,幼虫的取食量下降 ,排粪量减少 ,对食物的消耗和利用指数降低 ,幼虫发育速率缓慢 ,死亡率增加 ,从而影响马尾松毛虫的种群动态     

Histological assessment of selected tissues in tigerfish (Hydrocynus vittatus Castelnau, 1861) from the Sanyati Basin,Lake Kariba,Zimbabwe: a DDT-sprayed area

A pilot investigation was conducted in 2014 in the Sanyati Basin of Lake Kariba to ascertain whether long-term DDT spraying in the Kariba catchment had a negative effect on fish health. The aim was to assess the health of tigerfish, Hydrocynus vittatus, by means of histological analysis and to analyse water, sediment and tissue samples for bioaccumulated levels of chlorinated pesticides, including DDT. Eighteen tigerfish were collected by seine netting along the north-eastern shoreline of the Sanyati Basin in April 2014 and samples of their gill, liver, kidney, muscle and brain tissue were processed for histology and assessed using light microscopy. No detectable levels of DDT and/or its metabolites were found in the water or sediment samples and only a low concentration of p,p′-DDE in fish tissues. No major histological alterations were observed in the fish tissues. Consequently, there seems to be no risk of DDT exposure following the consumption of tigerfish from the Sanyati Basin of Lake Kariba. These results were unexpected, given the historical use of DDT within the current study area. It is recommended that these findings be compared with those from other regions of Lake Kariba.     

移虫日龄对蜂王生长发育的影响

移取1、2、3日龄工蜂幼虫进行人工育王,通过HPLC-MS的方法,分别测定4日龄蜂王幼虫体内保幼激素(JHⅢ)和9日龄蛹体内蜕皮激素(Ecd)的滴度,并通过形态学和解剖学的方法对不同移虫日龄培育的处女王的初生重、卵巢重、头重和卵巢管数进行比较分析,以研究不同移虫日龄对意大利蜂蜂王生长发育的影响。结果显示,不同移虫日龄所培育的蜂王幼虫4日龄JHⅢ和9日龄Ecd浓度均存在显著差异,且随着移虫日龄的增加,蜂王幼虫体内JHⅢ和Ecd含量均显著下降;不同移虫日龄所培育的处女王其初生重、卵巢重、头重及卵巢管数均存在显著差异,且随着移虫日龄的增加,蜂王的初生重、卵巢重和头重显著减轻,蜂王的卵巢管数显著减小;蜂王的初生重和卵巢管数成显著正相关关系,相关系数r=0.82。说明移虫日龄越小幼虫获得的生长条件越好,越有利于蜂王个体尤其是繁殖性状的发育,人工育王实践中应移取虫龄尽量小的幼虫。     

Morphological and behavioural development of halibut, Hippoglossus hippoglossus (L.) larvae

Live yolk-sac halibut, Hippoglossus hippoglossus (L.) larvae from rearing experiments at Austevoll Aquaculture Station, Norway, were examined from hatching to past first feeding for developmental morphology and behaviour. The findings include development of the respiratory and circulatory organs, eye pigmentation, mouth formation, organs of the digestive system and the process of yolk absorption, as well as swimming speed and activity levels.
A stomodeum is not present at hatching although drinking is possible through a pair of branchial pits which gradually develop into the operculum and gill basket. The mouth normally opens slowly, the gape being restricted by a transverse septum until bones are formed. The amount of time spent swimming varies from less than 15% of the observation period during the first 2 weeks after hatching to between 70 and 100% around the seventh week after hatching, when individual differences become more apparent. Larvae generally react with a burst of swimming when two come into contact. Speed and duration of swimming seems to be correlated with development of eye pigment, heart size and fin formation. The yolk-sac period is divided into four stages.     

饲养密度对黄粉虫幼虫生长发育的影响

黄粉虫原是一种仓库害虫 ,由于其幼虫、蛹、成虫都含有丰富的蛋白质和多种氨基酸 ,已被作为饲用资源昆虫来开发利用。作为一种群集性的昆虫 ,黄粉虫幼虫的生长受密度影响可分为 2个阶段 ,一是幼虫孵化后 1个月这段时间内 ,高密度处理的幼虫平均体重大于低密度处理的幼虫平均体重 ;二是孵化 1个月后直到化蛹 ,这段时间低密度的幼虫生长要比高密度的幼虫快得多。密度越大 ,历期越长。但密度对化蛹率没有影响。在幼虫生长过程中 ,各处理组中只有 3 2 0头虫密度处理组的幼虫在生长 1个月后显出拥挤效应。     

Influence of egg size on embryos and larvae of Fundulus heteroclitus (L.)

Egg size for Fundulus heteroclitus (L.) populations is concordant with the distribution of the two F . heteroclitus subspecies, i.e. F. h. heteroclitus eggs are considerably larger than F. h. macrolepidotus eggs. The influence of egg size on survival of embryos during incubation and survival and growth of newly-hatched larvae was estimated for four populations representing both subspecies along the Atlantic coast of the United States and in Delaware Bay. Survival of embryos was determined for incubation periods of 14, 21 and 28 days. Greatest differences in survival were detected following the longest incubation period where less than 50 per cent of the smaller F. h. macrolepidotus eggs survived while little or no mortality was detected among the larger F. h. heteroclitus eggs . Influence of egg size on larval survival was also greatest among those larvae hatched after 28 days where F. h. macrolepidotus larvae survived without food, for an average of 6 days, while F. h. heteroclitus larvae survived 11–12 days. F. h. heteroclitus larvae were significantly larger at hatching than F. h. macrolepidotus larvae. Larval growth rates were the same (0.4 mm day⁻¹) in both subspecies. As a result, size differences at hatching were still maintained after 42 days of growth. The differences in egg size along with other morphological and reproductive characteristics of F. heteroclitus populations probably represent genetically based adaptations to environmental conditions, of which the length of the spawning season is one of the major components stimulating the coevolution of these traits.     

四种昆虫饵料对穴蚁蛉幼虫生长发育及消化利用的影响

选择4种可规模化饲养的昆虫——米蛾Corcyra cephalonica、家蝇Musca domestica、斜纹夜蛾Spodoptera litura、甜菜夜蛾Spodoptera exigu幼虫来饲养穴蚁蛉Myrmeleon sagax(Walker)幼虫(俗称蚁狮),研究这4种饵料对蚁狮生长发育及消化利用的影响。结果显示,用家蝇幼虫饲养的蚁狮,其体重增长、相对生长率、化蛹率、蛹重均显著高于用斜纹夜蛾和甜菜夜蛾幼虫饲养的蚁狮,而幼虫历期则比斜纹夜蛾和甜菜夜蛾幼虫饲养的短;用米蛾幼虫饲养,虽然蚁狮体重增长、化蛹率和蛹重与用家蝇幼虫饲养的差异不显著,但其相对生长率却显著低于用家蝇幼虫饲养的蚁狮,幼虫历期也比用家蝇幼虫饲养的明显延长。同时食物消化利用的结果显示,用4种饵料饲养蚁狮,它们的近似消化率差异不显著,但食物利用率和食物转化率均以家蝇幼虫饲养的蚁狮最高。经分析比较,在4种饵料昆虫中,以用家蝇幼虫每4d喂蚁狮1次的饲养效果最佳。     

凹耳臭蛙胚胎发育及其分类学意义(英文)

通过人工受精的方法获得的凹耳臭蛙(Odorrana tormota)的早期胚胎及胚后幼体的发育过程,根据胚胎发育过程中的形态及生理特征变化规律进行分期。把凹耳臭蛙的发育过程分成两个阶段:1)早期胚胎发育阶段,即从蛙卵受精到鳃盖完成期,在18～23℃水温下,凹耳臭蛙早期胚胎发育阶段历时324h;2)蝌蚪发育阶段,即从鳃盖完成期结束到尾部被完全吸收,本阶段在20～24℃水温条件下历时1207h。凹耳臭蛙蝌蚪未发现腹吸盘特征,从形态特征上支持了分子系统分类学将之从湍蛙属划出的观点。实验中发现,多数胚胎在8细胞期为纬裂,16细胞期为经裂,同时有小部分胚胎(1.5%)在8细胞期为经裂,16细胞期为纬裂。该文进一步讨论了影响卵裂率、孵化率、发育速度,以及生态适应的因素。     

Growth and respiration of embryos and larvae of the rabbittish Siganus randalli (Pisces, Siganidae)

Growth and respiration of larval rabbitfish from Guam were examined. Larvae were reared from eggs in 2- to 10-ton tanks and were fed rotifers, Anemia , and artificial feed in succession as development proceeded through metamorphosis. Growth in length was rapid during the 12 h after hatching, then slowed until the larvae began to feed. The yolk sac was usually absorbed by 36 h after hatching. Rates of respiration of larvae and eggs were determined with a dissolved oxygen electrode at various times through development. Larval metabolism increased steadily during the embryonic stages culminating in a metabolic burst immediately after hatching. Respiration rates remained relatively stable from shortly after hatching until the onset of exogenous feeding, after which respiration rates increased with larval size. The respiration rates of post-yolk-sac larvae scaled isometrically with larval dry mass. Daily growth of feeding larvae was 27 to 28% of larval dry mass.     

Morphological studies on the early development of Taenia taeniaeformis larvae in susceptible mice

Bortoletti G. and Ferretti G. 1985. Morphological studies on the early development of Taenia taeniaeformis larvae in susceptible mice. International Journal for Parasitology15: 365–375. Taenia taeniaeformis larvae which develop into infective strobilocerci in C3H mice have been studied from the 5th to the 15th day of development (L5–L15), both at light and electron microscope level. The L5 were initially compact, without a central cavity but then become vacuolized. Until stages L7–L8 they were surrounded by a perilarval amorphous layer (PAL) made up of a finely granular material which prevented the host cells from making contact with the larval tegument. The larval volume increased considerably between stages L6 and L8, remained unchanged from L9 to L13, but continued to increase thereafter. The larval cellular layer, which appeared as a single, large ‘syncitial system’, grow until stages L14–L15 when the scolex anlagen began to form. The tegument was initially incompletely organized and was covered by microvilli. These were completely replaced by microtriches from stage L8 onward. Sometimes both microvilli and microtriches were together observed in stage L7. Microvilli fragments, sometimes beaded, could be observed at L5 within the damaged cytoplasm of host cell debris. Very often they were branched at different heights, especially in stages L5–L7. In L10–L15 all undamaged microtriches increased in density and formed bundles which invaded the host cells. In stages L5–L8 and in some L9, muscular bundles started to become organized inside the tegumental distal cytoplasm (TDC), and after become independent in the subtegumental cellular layer (SCL). Until L8–L9 the larvae were surrounded by host cells debris. From stages L8–L10 onwards the adjacent host cells were less damaged though the larval microtriches penetrated them deeply. In stages L5–L7 neutrophils together with macrophages and some damaged hepatocytes were detected, while eosinophils were present only from L8 onward. In the other stages neutrophils clearly diminished in numbers, whereas macrophages had increased. No mastcells and few plasma cells were observed.     

The development of the eye in Astyanax mexicanus (Characidae,Pisces), its blind cave derivative,Anoptichthys Jordani (Characidae,Pisces), and their crossbreds

The development of the eye of the characin Astyanax mexicanus, of its blind derivative Anoptichthys jordani, and crossbreds of both forms was studied at different ontogenetic stages by means of scanning- and transmission-electron microscopy. Astyanax exhibits a form of eye development resembling that in other characid species. A severe reduction of the eye could be observed in Anoptichthys starting with the second day of ontogeny. This degenerational process is characterized by the following features: 1) An overgrowth of epidermal tissue that gradually covers the surface of the eyeball; 2) the sinking of the eyeball below the surface of the integument; 3) the formation of epidermal channels from the body surface to the disappearing surface of the eyeball; 4) a severe degeneration of the retinal sensory cells; and 5) a small number of pigment granules in the pigment epithelial cells. The progeny of crosses between Astyanax and Anoptichthys show varying degrees of these degenerational signs. Taste buds and the lateral line organ display identical features in all crosses analyzed with the scanning electron microscope.     

二种活体饲料对东亚小花蝽生长发育和生殖的影响

本文比较了果蝇Drosophila melanogaster(Meigen)幼虫和西花蓟马Frankliniella occidentalis(Pergande)2种活体饲料对东亚小花蝽Orius sauteri(Poppius)生长发育和生殖的影响。结果显示:果蝇幼虫饲喂的东亚小花蝽幼虫发育历期12.36d,与西花蓟马饲喂的(12.19d)相近。果蝇幼虫饲喂的东亚小花蝽产卵量(89.58粒)与西花蓟马饲喂(95.72粒)相当。表明果蝇幼虫与传统活体饲料西花蓟马饲养东亚小花蝽的效果相当,可以很好的满足东亚小花蝽生长发育和生殖的要求。由于西花蓟马饲喂成本比较高,实际操作中有一定困难,果蝇幼虫是一种较为理想的活体饲料。     

麦麸饲料中细菌对家蝇幼虫生长发育的影响

从饲料用麦麸中分离出的12种细菌均能支持无菌家蝇Musca domestica L．幼虫在胰化酪蛋白大豆卵黄琼脂（TrypticaseSoy EggYolkAgar,TSEYA）培养基中完成整个生长发育过程。1）幼虫在接种香味类香味菌Myroidesodoratimimus的TSEYA培养基中生长时间最短,仅需97．61&#177;1．14h;2）幼虫在接种醋酸钙不动杆菌Acinetobacter calcoaceticus的TSEYA培养基中的化蛹率可达到86．81％;3）从接种嗜水汽单胞菌Aeromonas hydrophila的TSEYA培养基中得到的蝇蛹重量最高,达到20．15&#177;0．23mg／个;4）除铜绿假单胞菌Pseudomonasaeruginosa饲养的家蝇羽化率较低（60．87％）外,其余各种细菌饲养的羽化率在84．33％～97．47％之间。此外,枯草芽孢杆菌Bacillus subtilis、香味类香味菌、聚团肠杆菌Enterobacter agglomerans以及成团肠杆菌Pantoeaagglomerans可作为单一营养来源支持幼虫完成整个生长发育过程。对枯草芽孢杆菌、金黄色葡萄球菌Staphylococcusaurous、成团肠杆菌、大肠杆菌Escherichiacoli、奇异变形杆菌Proteusmirabilis以及香味类香味菌中各种营养成分进行分析,结果发现,6种细菌均能提供大量的维生素如（0．105～1．08g／kg）。在氨基酸方面,香味类香味菌和枯草芽孢杆菌中的10种昆虫必需氨基酸含量与总氨基酸含量之比（Essential amino acid／Totalaminoacid,EAA／TAA）最高,而金黄色葡萄球菌最低。这个比例与蛹重呈正相关（p=0．031）。在脂肪酸相对含量方面,金黄色葡萄球菌具有最高的饱和脂肪酸含量（76．38％）,香味类香味菌含有56．79％的不饱和脂肪酸,而枯草芽孢杆菌则具有最高的支链脂肪酸含量（42．16％）。     

不同食料植物对美国白蛾生长发育和繁殖的影响

2010年6月至7月,在室内研究了美国白蛾Hyphantria cunea(Drury)第1代幼虫对洋白蜡、欧美107号杨、法桐和白榆的取食量及不同的食料种类对美国白蛾生长发育和繁殖的影响。结果表明,美国白蛾对受试的各树种的取食量以洋白蜡为最多,完成一代平均每头可以取食2.21 g,其次为欧美107号杨1.95 g,再次为法桐和白榆,分别为1.85 g/头和1.68 g/头。3龄后幼虫对不同的寄主呈现出一定的偏好性,特别是5龄和6龄幼虫对不同的寄主的取食量表现出显著差异。不同的食料植物对美国白蛾幼虫和蛹的发育历期、存活率、蛹重、成虫寿命、产卵量等有显著影响。取食法桐对其生长发育和繁殖表现出明显的不利性,主要表现为幼虫期延长、蛹重减轻、单雌产卵量降低。     

Effects of temperature, salinity, and air exposure on development of the estuarine pulmonate gastropod Amphibola crenata

The primitive pulmonate snail Amphibola crenata embeds embryos within a smooth mud collar on exposed estuarine mudflats in New Zealand. Development through hatching of free-swimming veliger larvae was monitored at 15 salinity and temperature combinations covering the range of 2-30 ppt salinity and 15-25 °C. The effect of exposure to air on developmental rate was also assessed. There were approximately 18,000 embryos in each egg collar. The total number of veligers released from standard-sized egg collar fragments varied with both temperature and salinity: embryonic survival was generally higher at 15 and 20 °C than at 25 °C; moreover, survival was generally highest at intermediate salinities, and greatly reduced at 2 ppt salinity regardless of temperature. Even at 2 ppt salinity, however, about one-third of embryos were able to develop successfully to hatching. Embryonic tolerance to low salinity was apparently a property of the embryos themselves, or of the surrounding egg capsules; there was no indication that the egg collars protected embryos from exposure to environmental stress. Mean hatching times ranged between 7 and 22 days, with reduced developmental rates both at lower temperature and lower salinity. At each salinity tested, developmental rate to hatching was similar at 20 and 25 °C. At 15 °C, time to hatching was approximately double that recorded at the two higher exposure temperatures. Exposing the egg collars to air for 6-9 h each day at 20 °C (20 ppt salinity) accelerated hatching by about 24 h, suggesting that developmental rate in this species is limited by the rates at which oxygen or wastes can diffuse into and from intact collars, respectively. Similarly, veligers from egg capsules that were artificially separated from egg collars at 20 °C developed faster than those within intact egg collars. The remarkable ability of embryos of A. crenata to hatch over such a wide range of temperatures and salinities, and to tolerate a considerable degree of exposure to air, explains the successful colonization of this species far up into New Zealand estuaries.     

Growth, reproduction and recruitment patterns of the wide-eyed flounder, Bothus podas Delaroche (Pisces: Bothidae), from the Azores

The wide-eyed flounder, Bothus podas, occurs in many East Atlantic sub-tropical and temperate inshore areas and is the dominant flatfish in shallow-water areas around the Azores. The aim of this study was to examine the growth, reproductive biology and recruitment patterns of the wide-eyed flounder in the Azores. Adult fish samples were obtained by spear fishing and SCUBA hand netting at Faial Island. Juveniles were obtained from a complementary monthly beach-seining programme undertaken at Porto Pim Bay, Faial. Sex and development stage were determined by macroscopic examination of gonads, whereas age estimates were obtained by counting the number of opaque bands in the otoliths. In the Azores, B. podas reaches 6 years old, which is more than reported for the central Mediterranean, the only other population of this species that has been studied. The studied population has a sex ratio biased to males, which contrasts to a previous observational study, which noted a female-biased sex ratio. Spawning time, as determined from the gonadosomatic ratio and the macroscopic examination of gonads, was between July and September. This time period agrees with behavioural observations in the same area. Sexual maturity was estimated at a total length (TL₅₀) of 14.1 cm and at an age (A₅₀) of 1.7 years. Small juveniles occur on sandy inshore nursery areas for most of the year, but mainly between July and August each year. The presence of small fish throughout most of the year could suggest a protracted settlement period or slow growth on occasions on the shallow-water nursery grounds.