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1.
利用实验生态学方法研究不同个体大小的海蜇浮游幼体[平均伞径(2.5±0.1),(4.1±0.2),(11.7±0.5),(21.1±0.6)mm]对不同密度(10,30,50,80ind/L)的褐牙鲆卵[卵径(0.92±0.01)mm]和初孵仔鱼[全长(3.01±0.08)mm]的捕食率,解析海蜇浮游幼体对初孵仔鱼的捕食率随捕食时间(0.5,1,2,3,4,5h)的变化特征。结果表明,各个体组海蜇浮游幼体对卵的捕食率均显著低于对仔鱼的捕食率;它们对卵的捕食率与卵密度和海蜇个体大小的关系不显著,但对仔鱼的捕食率随海蜇个体大小及仔鱼密度的增大而显著升高;伞径21.1mm的个体对仔鱼的捕食率在开始捕食后1h时达到最大值[17.3ind/(predator.h)],此后随捕食时间的延长而逐渐下降。在自然水域中,如果二者发生时空上的匹配关系,海蜇浮游幼体对仔鱼的捕食可能影响褐牙鲆的早期存活及其资源补充量的变动。 相似文献
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The development of embryos and larvae of Babyloniaformosae habei living along the southeast coast of China is observed under laboratory conditions. The egg masses are laid by females on hard substrate at night and each capsule contains 100-500 eggs. Each egg is 250-280 mm in diameter. The fast two cleavages of the embryo are meridional and equal, and a polar lobe is produced. Larval kidney, which only consists of a single cell, appears during the gastrula stage on each side of the embryo. The right tentacle develops prior to the left one. At 25-27 ℃, an intracapsulate veliger stage is reached about 4.5 d after deposition. The larvae hatch on the fifth day as swimming veligers with a shell length of 360 -500 mm. The newly hatched larva can ingest suspended algal cells from the water column and remains in the pelagic stage for 8-10 d. The newly settled juveniles are 900-1 200 mm in shell length. 相似文献
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犬齿牙鲆胚胎及仔、稚、幼鱼形态发育观察 总被引：1，自引：0，他引：1
犬齿牙鲆(Paralichthys dentatus)卵为端黄卵,受精卵浮性,卵径950~1100μm,油球径200~225μm.在水温20.5~22.0℃,盐度33条件下培育,受精后1 h 20 min 进入卵裂期,6 h 10 min 进入囊胚期,11 h 20 min 进入原肠胚期,19 h 10 min 发育到胚孔封闭期,胚体形成,26 h 50 min 尾芽出现,33 h 35 min心跳开始,48 h 10 min 开始孵化出仔鱼.初孵仔鱼平均全长2.59 mm±0.02 mm,在培育水温为17.0~21.0℃,盐度24~34条件下,胚后发育时序为:1日龄~9日龄为仔鱼前期,10日龄平均全长5.52 mm±0.05 mm,卵黄囊和油球完全吸收进入仔鱼后期;40日龄平均全长20.82 mm±0.67 mm,各鳍鳍条发育形成进入稚鱼期;65日龄平均全长41.13 mm±0.88 mm,全身鳞被完整进入幼鱼早期 相似文献
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The feeding ofSagitta nagae, the most predominant chaetognath species in Suruga Bay, was studied. Specimens were collected with ORI-100 net (1.0 mm in mesh aperture) and MTD net (0.35 mm in mesh aperture) and were fixed with neutralized formalin. The main food organisms ofSagitta nagae were the copepods,Candacia bipinnata, Calanus pacificus andPareuchaeta russelli. The food-containing ratio (P/T, %) was higher at night and lower in the daytime. Here, P is the number ofSagitta containing food organisms in the gut and T is the total number ofSagitta examined. P/T was almost constant vertically in the upper 100 m layer. P/T was generally influenced neither by food density nor by the copepod numbers perSagitta in this study.Sagitta nagae took food throughout life. Food ingested bySagitta per day was calculated as 37.6% ofSagitta in dry weight. 相似文献
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G. D. James 《新西兰海洋与淡水研究杂志》2013,47(2):301-310
The development and distinctive features of the eggs and larvae of Caranx georgianus Cuvier, 1833 are described. Diameters of the egg and oil globule range between 0.76 mm and 0.86 mm, and 0.20 mm and 0.25 mm respectively. At 21 °c, the eggs hatched approximately 28 h after fertilisation. 相似文献
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利用实验生态学方法,研究温度(15、19和23℃)、光照(明和暗)、仔鱼大小[全长(3.01±0.08)mm初孵仔鱼和(3.79±0.13)mm孵化后5天仔鱼]对稚海蜇[伞径(21.1±0.4)mm]捕食褐牙鲆仔鱼的影响。结果表明,稚海蜇对初孵仔鱼的捕食率随着水温升高而显著升高。光照条件在各仔鱼密度(10,30,50和80ind/L)下均不显著影响稚海蜇对初孵仔鱼的捕食率,说明光条件并不显著改善稚海蜇捕食仔鱼的能力。在高仔鱼密度(50和80ind/L)下,稚海蜇对孵化后5天仔鱼的捕食率显著低于对初孵仔鱼的捕食率;但在低密度(10和30ind/L)下,稚海蜇对两个不同发育阶段仔鱼的捕食率之间无显著差异。在低仔鱼密度下,稚海蜇对仔鱼的捕食率较低,这会降低仔鱼个体大小对稚海蜇捕食率作用的显著性。这既表明仔鱼逃避被稚海蜇捕食的能力随其发育生长而提高,也反映了稚海蜇对不同个体大小仔鱼捕食作用受仔鱼密度制约。 相似文献
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The oxygen consumption reflects the aerobic energy production of an animal. For fish eggs and larvae the normal oxygen consumption represents the optimal conditions for growth and development. Under the stress of environmental pollution gross deviation in oxygen uptake rate of the developing fish embryo may reflect metabolic disturbances and impede the development. Since the eggs and larvae of cod (Gadus morhua L.) are likely to be exposed to oil pollution from offshore installations in the North Sea we decided to investigate the effects of the water-soluble fraction (WSF) of North Sea crude oil on the oxygen consumption of cod eggs and larvae. The results showed that oxygen consumption of the larvae at the time of final yolk absorption (5–7 days post hatching at 5°C) is strongly suppressed by oil exposure at concentrations down to 50 ppb. No effect on the oxygen uptake, however, was found during the egg stage. 相似文献
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J. G. Ruck 《新西兰海洋与淡水研究杂志》2013,47(3):313-326
In the Wellington area (central New Zealand) Forsterygion varium (Forster, in Bloch & Schneider 1801) spawns from early June to late November, Gilloblennius decemdigitatus (Clarke, 1879) from early June to early October, and G. tripennis (Forster, in Bloch & Schneider 1801) from July to October. They deposit their eggs on firm substrates below the low tide level. Egg clusters are attended by an adult fish until hatching, which in the laboratory at 11.5–13.5°C, occurs after 18 days for F. varium and 20 days for G. decemdigitatus. Development to hatching for G. tripennis takes about 21 days at 13–15°c. The egg development of all three species is illustrated. The yolk‐sac larvae (prolarvae) of F. varium, G. decemdigitatus, and G. tripennis at hatching average 5.85, 5.03, and 5.72 mm standard length respectively. Yolk‐sac larvae of F. varium have a single row of 9–17 small, stellate melanophores along the ventral midline of the tail. The yolk‐sac larvae of G. tripennis have up to nine melanophores along the ventral midline of the tail, a medium‐sized melanophore above the optic lobes, and a further two above the medulla. The yolk‐sac larvae of G. decemdigitatus have three large mid‐dorsal melanophores interspersed with five smaller, paler pigment cells, and three large mid‐ventral melanophores interspersed with three of the smaller cells. 相似文献
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The occurrence and distribution of eggs and larvae of anchovy, Engraulis japonicus, in Jeju Strait, Korea from May to November 2002 were investigated, and the relationships between the abundances of anchovy eggs and larvae and the oceanographic conditions, including meteorological data, were analyzed. During the sampling periods, the anchovy eggs occurred from May to October and about 95% of total egg abundance occurred in only two months from July to August, suggesting that the main spawning season of anchovies is confirmed in summer from July and August in Jeju Strait. The spawning area of anchovies gradually moved to the southern part of the survey area with time. The predominant anchovy larvae collected in this study were mostly smaller than 16.0 mm TL. Correlation analysis and multiple regression analysis showed that the anchovy egg abundance in the study area depended strongly on the wind conditions, especially less than 10 m/s, and increasing water temperature. Salinity variations also had significant effects on the abundance of anchovy larvae. 相似文献
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Temporal and spatial variations in the spawning activity ofSergia lucens were investigated in relation to some environmental conditions of Suruga Bay. The daily egg abundance varied considerably with the coefficient of variation from 81% to 269% in July. The spawning activity was most clearly affected by temperature, but the relationship to lunar period and content of chlorophylla were not obvious. Timing of the July spawning is predictable with increase of the surface temperature to 24°C and strong vertical movements of the 18°C isotherm depth; it is also related to modal length of the shrimp in June. It is suggested that intrusion of cold water at 20–50 m affects reproduction of the shrimps and vertical distribution of eggs and larvae. The shrimp population seemed to relate principally to two spawning grounds,i.e. the head part and the western part of the bay. The timing of spawning is not always synchronous throughout the bay. The spawning is sporadic and the distribution of eggs is patchy. This may reflect a recent decrease in the population of the shrimp due to increased fishing pressure.A part of the present paper is based on the thesis submitted by G. H. B. in partial fulfilment of the requirements for her degree of Master of Science at the Tokyo University of Fisheries in 1986. 相似文献
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渤海湾半滑舌鳎及焦氏舌鳎的鱼卵和仔稚鱼的形态 总被引：5，自引：0，他引：5
半滑舌鳎Cynoglossus semilaevis Günther和焦氏舌鳎C.joyneri Günther 均隶属于舌鳎科Cyonglossidae的舌鳎属Cynoglossus,系广泛分布在我国近海的底层鱼类。它们具有一定的经济价值。其中半滑舌鳎是该属中个体较大的种类,最大体长可达800毫米以上。素有名贵鱼类之称。惟产量不高。该类鱼多栖息在海湾水域,洄游距离短,活动范围小,是适合增养殖的对象之一。 关于这两种舌鳎的早期形态资料迄今尚未 相似文献
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Spawning, phases of embryonic development, intracapsular feeding mechanism and development mode of banded murex Hexaplex trunculus (Linnaeus, 1758) were examined using specimens from the Aegean Sea. In addition, the numbers and characteristics of non‐viable nurse eggs during different phases were examined in relation to the development phases of viable embryos. Females spawned between 59 and 162 egg capsules containing 306.76 ± 50.74 eggs. Trochophore larvae first appeared on the 15th day after spawning. Nurse egg consumption began on the 17th day after spawning when the embryos reached the early veliger stage. In the beginning, veligers consumed the nurse eggs by mechanically disintegrating them with velar cilia movement. From the 18th day after spawning, embryos began to consume whole nurse eggs, although mechanical disintegration continued until hatching. Viable embryos consumed the most developed nurse eggs first. The average number of nurse eggs consumed per embryo was 24.67 by the end of the intracapsular period. The average number of hatchlings was 11.95 ± 3.81 per capsule with 1321.48 ± 133.1 μm shell length. According to our observations H. trunculus shows dispersal polymorphism, with most of the hatchlings completing metamorphosis after a short planktonic non‐feeding period (up to 2 days), while others metamorphose prior to hatching. Planktonic hatchlings had both foot and well developed four‐lobed velum and minimum 1 3/4 whorls. Both hatchling types could be seen in the capsule mass from the same female. 相似文献
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Correction factors based on the catch ratios of egg and larval densities in the southern waters of Korea were estimated for
anchovyEngraulis japonica. This was undertaken in order to adjust ichthyoplankton data from different sampling methods, gear types and time. Samples
were collected during ichthyoplankton surveys in Korean waters from 1983 to 1994. The ratios for egg densities obtained in
vertical tows with a NORPAC net (ring Φ, 45 cm) compared to those obtained in oblique tows with a KOB net (ring Φ, 80 cm)
were 0.86 (CV = 0.65), 1.22 (CV = 0.36), and 0.93 (CV = 0.42) for early, middle, and later developmental stages, respectively.
The ratios for larval densities for vertical and oblique tows varied depending on size. For yolk-sac and small larvae (< 4
mm), the ratios were 3.08 (CV = 0.45) and 1.98 (CV = 1.34), while those of 4-6 mm, 6-8 mm, and 8-10 mm larvae were 0.44 (CV
= 1.31), 0.45 (CV = 1.70), and 0.56 (CV = 2.50), respectively. Ratios of day/night densities for larvae of 4-10 mm lengths
were lower (0.01-0.06) in offshore catches than values obtained in coastal areas (0.44-0.46) and similar values (0.16-0.04)
for vertical and oblique tows. Our results indicated that vertical towing is more efficient for sampling early life stages
(from eggs to larvae less than 4 mm long), while oblique towing is more efficient for larvae longer than 4 mm due to depth
preferences for each developmental stage (e.g., changes in egg buoyancy and vertical migration of larvae). 相似文献
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虎斑乌贼( Sepia pharaonis )胚胎发育及孵化历期观察 总被引：2，自引：0，他引：2
采捕虎斑乌贼野生卵群进行室内培育,采用显微成像系统,观察其胚胎发育过程,并详细描述各发育期的特征。结果显示:虎斑乌贼卵长径(30.7±2.4)mm,短径(13.4±1.3)mm,胚胎发育过程共分为卵裂、囊胚期、原肠期、器官芽原基出现、眼色由无色到黑色等30期,探讨了主要器官(眼、漏斗等)的发生变化过程。在胚体生长期间,胚体长度随时间逐渐增加,而卵黄大小则随之减小。从7—20d,胚体长度由2.5mm增至11.3mm,而卵黄直径由8.9mm减至4.5mm,胚体与卵黄长度比例由0.28增至2.51。在水温(23±0.5)℃,盐度28,pH7.41条件下,孵化高峰期为20—24d,孵化率为85.3%,初孵乌贼幼体平均体长(13.5±0.3)mm,平均胴体长(8.6±0.3)mm,平均体重(0.18±0.02)g。 相似文献
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在人工培育条件下,采用实验生态学方法,对绿鳍马面鲀(Thamnaconus modestus)仔、稚、幼鱼生长、发育与摄食特性的变化进行了研究。结果表明,绿鳍马面鲀仔、稚、幼鱼的各生长指标可拟合为具有1~2个生长转折点的2~3段直线,其中全长、体长、体质量、肛前长、头长、吻长和体高可拟合为3段直线,眼径可拟合为2段直线。头长在第一转折点后的生长速率显著高于其他指标,除头长和体高在第二个生长转折点后生长速率减慢外,其余各项生长指标生长速度均逐渐加快。3~4日龄“开口期”前后的仔鱼,摄食发生率和饱食率均较低,随后逐渐升高。摄食发生率在12日龄后达到100%,饱食率在25日龄后达到100%(消化道充塞度为3~4级)。绿鳍马面鲀仔、稚、幼鱼均为白天摄食类型,白天摄食量占全天摄食量的71.6%以上。随日龄增长,鱼苗饱食时间呈下降趋势,消化时间则呈上升趋势。了解绿鳍马面鲀早期的生长发育与摄食特性,可为人工育苗管理提供参考,以促进鱼苗生长,提高成活率。 相似文献
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