Influence of the length of time after hormonal stimulation on selected parameters of milt of ide Leuciscus idus L.

Milt of the Leuciscus idus L. was collected from five experimental groups, and selected parameters of its quality were analysed for 36 h (group II), 60 h (group III), 84 h (group IV) and 108 h (group V), respectively, after hormonal stimulation with Ovopel (1 granule kg^?1 of body weight). The control (group I) fish were not subjected to hormonal stimulation. The highest milt volume was obtained from the fish in group IV (0.70 ± 0.55 mL), where the largest volume of milt expressed per kilogram was also obtained (3.03 ± 1.94 mL kg^?1). Significant differences were also found in milt volumes obtained between group I and groups III (P<0.01) and IV (P<0.05). The highest percentage of motile spermatozoa was found in the milt of group IV (59%); significant differences were found between group I and groups II (P<0.01) and III (P<0.001). The value of osmotic pressure of seminal plasma was the highest in group IV (203.19 ± 37.63 mOsm kg^?1), and the lowest in group I (118.31 ± 41.13 mOsm kg^?1). Parameters determining milt quality and quantity indicate that the period of 60–84 h after hormonal stimulation with Ovopel is optimal for obtaining milt from ide.     

Acute ammonia toxicity during early ontogeny of ide Leuciscus idus (Cyprinidae)

Acute ammonia toxicity was investigated in four developmental stages of the juvenile ide, Leuciscus idus: 1, 10, 20 and 30 days after the first feeding. Mean (±SD) total length of the larvae was 8.5 ± 0.3, 15.7 ± 0.7, 23.0 ± 2.0 and 29.7 ± 2.0 mm, and standard weight was 1.6 ± 0.3, 9.2 ± 5.5, 94.9 ± 31.0 and 196.0 ± 31.7 mg, respectively. The larvae used for toxicity tests were reared in the experimental, closed recirculating system. Groups of fishes (n from 7 to 10; in respect of fish size) were exposed to the ammonium chloride solutions in 1-L glass units. Water temperature was 25 ± 0.1 °C for both the rearing and the toxicity tests. pH was not adjusted and ranged between 8.4 and 8.7. The ammonium chloride solutions were renewed every 12 h. At the same time, dead larvae were counted and removed, and the pH and temperature measurements were taken. Each acute toxicity test duration was 96 h, and lethal concentration LC₁, LC₅₀ and LC₉₉ values were calculated for 24, 48, 72 and 96 h. The susceptibility of the ide larvae to ammonia decreased linearly with age up to 20th day and surprisingly increased during the next 10 days. The LC₅₀ (48 h) values ranged from 0.27 mg L^?1 of unionized ammonia nitrogen for 1 day after the first feeding (AFF) larvae to 1.42 mg L^?1 at day 20 after first feeding. The LC₅₀ (48 h) for 30 days AFF was as high as 0.67 mg L^?1. The critical level of the unionized ammonia nitrogen for ide larvae was suggested as 0.21 mg L^?1.     

Life‐history characteristics of ide Leuciscus idus in the Eastern Baltic Sea

Otolith Sr:Ca and Ba:Ca profiles were used in parallel with age data to investigate the life‐history characteristics of ide, Leuciscus idus (L.) (n = 111), in the Väinameri Sea, West Estonia. Sr:Ca profiles were more variable and useful than Ba:Ca profiles. Flexible life‐history patterns were observed within and among the three study sites. Most of the individuals (72%) hatched in semi‐enclosed bays that are fresh water during spring spawning but are often flooded with brackish water during other seasons. The importance of lotic spawning varied among sites and was the highest (88%) in Matsalu Bay, moderate in Saunja Bay (33%) and lowest (0%) in Käina Bay. Young of the year emigrated from natal sites and entered the sea within the first summer; 95% did so during the first month post‐hatch. Juvenile ide undertook non‐spawning, freshwater migrations in the following spring; however, the reasons behind this phenomenon remain unknown. As the importance of lotic spawning has significantly decreased and multiple historically important ide spawning rivers lack anadromous runs altogether, it is suggested that actions should be taken to aid the recovery of those imperilled spawning stocks.     

Hepatocellular adaptation to extreme nutritional conditions in ide,Leuciscus idus melanotus L. (Cyprinidae). A morphofunctional analysis

The adaptive response of the omnivorous ide,Leuciscus idus melanotus, to drastic metabolic conditions was analyzed on different levels of organisation investigating a variety of parameters: Organism (condition factor, liver-somatic index), organ (liver structure), cellular and subcellular level (hepatocyte structure, glycogen and lipid storage, contents and distribution of nucleic acids, enzyme alterations).During starvation, ide were able to maintain liver integrity in a biphasic process: after an initial phase of disturbance, ide established a new structural and metabolic homeostasis. Recovery from starvation was possible only with a complete diet but not with a sucrose diet. Carbohydrate overload, as evoked by sucrose refeeding, did not result in liver or carcass fattening as known from mammals.To the best of our knowledge, the present study is the first to use enzyme histochemistry in fish nutrition research. In mammals, histochemistry is particularly helpful for understanding processes of hepatic metabolic adaptation. In fish, however, on the basis of our results, enzyme histochemical studies appear to be of limited value, as long as no further data are available on a zonal distribution of enzyme activities in teleost liver parenchyma. Instead, the histochemical detection of the distribution of hepatic storage products and RNA-positive material yielded important information on liver adaptive processes.Abbreviations H starvation - SU sucrose - AD artificial diet - AcP acid phosphatase - G6Pase glucose-6-phosphatase - G6PDH glucose-6-phosphate dehydrogenase - GLU -glucuronidase - ME malic enzyme - PHO glycogen phosphorylase - UE unspecific esterase - RER rough endoplasmic reticulum     

Success of nursing ide (Leuciscus idus, L.) fry related to the period of feeding with live food

The ide Leuciscus idus (Linnaeus 1758) belongs to autochthonous, less frequent and vulnerable fish species in the frame of ichthyofauna of the Czech Republic. It was the reason for testing the possibility of captive breeding and production of fry in a controlled environment. The goal of this paper was to find the optimal transfer time of ide larvae from live food (Artemia salina nauplii) to dry starter feed providing good survival and growth. At the end of the experiment, high values of cumulative survival (in percentages) and individual weight (in milligrammes) were found for ide fry in groups D (90.6%, 178.6 mg; 15 days A. salina + 10 days starter feed), A (89.9%, 169.9 mg; A. salina only) and C (88.6%, 160.4 mg; 10 days A. salina + 15 days starter feed). Significantly lower values of the given parameters were found in group B (57.1%, 92.6 mg; 5 days A. salina + 20 days starter feed), and the lowest ones were in group E (29.8%, 75.6 mg; starter feed only). Mean values of the level of ontogenesis at the end of the experiment in fry of A–E groups were analogous to length and weight growth. Groups D, C and A consisted of juveniles only (J1, J2), and groups B and E consisted of larvae and juveniles (L4, L5, L6, J1, J2). Condition and production parameters [Fulton’s coefficient of condition (FWC), total length (TL), weight (w), specific growth rate (SGR), food conversion ratio (FCR), cumulative survival] and relationships between basic lengths TL, fork length (FL) and standard length (SL) were evaluated.     

瓣结鱼的胚胎及幼鱼发育

首次记述了瓣结鱼的早期发育过程，对其胚胎及幼鱼发育各期特征先后进行了3次较为仔细的观察，并记述了胚胎发育的积温、积累度时值以及从孵化到105d的幼鱼的生长数据。成熟卵直径1.7～1.9mm，受精卵吸水膨胀后，外膜径达2.5～2.7mm，具粘性。在水温20.5～23.0℃条件下，受精卵历时71h7min孵化，初孵仔鱼平均全长6.6mm，经65～72d，幼鱼发育基本完成，对瓣结鱼胚胎发育的下限温度及早期发育作了探讨。     

银鲈胚胎和仔鱼的发育

本文对银鲈（Ｂｉｄｙａｎｕｓ ｂｉｄｙａｎｕｓ）胚胎和仔鱼的发育进行了观察,详细描述了发育各期的形态特征和所需时间。受精卵充分吸水后呈圆形,为浮性卵,在２３－２５℃时,孵化时间约为３２ｈ,仔鱼出膜后第３天卵黄囊消失,第５天开始摄食,到第７天基本发育完善。     

双齿围沙蚕胚胎及幼体发育的研究

2003-2004年，观察了双齿围沙蚕(Perinereis aibuhitensis)胚胎及幼体发育。结果表明，成熟卵为绿色，卵径175-228μm，多油球；胚胎发育经历卵裂期、囊胚期、原肠期、担轮幼虫期；后担轮幼虫期胚体脱卵膜孵化；幼体从3刚节疣足幼虫开始，在3刚节疣足幼虫后期开始摄食；4刚节疣足幼虫后期纤毛轮消失，进入匍匐阶段；10刚节疣足幼虫形态与生态都与成体相似；从受精卵发育到4刚节疣足幼虫的时间在不同水温情况下变化较大，水温在25-26℃为118h、而水温在27．5～32℃为82h。     

花胚胎和仔鱼发育的初步研究

本文报道了采用胸鳍基部一次注射LRHA-A2和DOM催产花鲭亲鱼,采用平铺、悬挂、底层漂浮棕榈皮鱼巢三种接卵方式及流水条件下遮光、不遮光,静水条件下遮光、不遮光四种不同孵化方式的试验结果.在水温18.2～19.8℃条件下,花刍骨胚胎发育需140 h破膜.观察了胚后组织、器官、系统生理发育过程.该鱼在破膜后52h进入混合营养期.不可逆点(PNR)为仔鱼破膜后第8d.     

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.     

花[鱼骨]胚胎和仔鱼发育的初步研究

本文报道了采用胸鳍基部一次注射LRHA-A2和DOM催产花亲鱼,采用平铺、悬挂、底层漂浮棕榈皮鱼巢三种接卵方式及流水条件下遮光、不遮光,静水条件下遮光、不遮光四种不同孵化方式的试验结果。在水温18.2-19.8℃条件下,花胚胎发育需140 h破膜。观察了胚后组织、器官、系统生理发育过程,该鱼在破膜后52h进入混合营养期。不可逆点（PNR）为仔鱼破膜后第8d。     

伊犁裂腹鱼胚胎及早期仔鱼发育的观察

2010年5月通过人工催产,人工授精方法获得伊犁裂腹鱼(Schizothorax pseudaksaiensis Herzenstein)受精卵,在人工培育的条件下对其胚胎和仔鱼发育进行观察.结果显示:伊犁裂腹鱼成熟卵为淡黄色,卵径为1.70～1.80 mm.受精40 min后,受精卵卵周隙接近最大化,此时卵径为2.9...     

3 种多环芳烃对条纹锯鮨胚胎发育及早期仔鱼的毒性效应

为探讨不同多环芳烃(PAHs)对海水鱼类早期生长发育的毒性效应及作用机制,分别比较研究了多环芳烃中的3环菲(Phe)、4环芘(Py)、5环苯并芘(Bap)单一暴露和与α-萘黄酮(ANF)联合暴露对条纹锯鮨(Centropristis striata)胚胎发育及早期仔鱼的毒性效应。对其胚胎中的细胞色素酶(EROD)活性、发育畸形(以心脏畸形为准)、孵化率和早期仔鱼死亡率等指标进行测定分析,结果显示:(1)Bap、Py的浓度与EROD活性之间的剂量效应关系比Phe明显,3种PAHs对条纹锯鮨胚胎中EROD活性的诱导能力由高到低依次为Bap、Py、Phe,其活性的最大值均出现在各物质的最高浓度组,其活性分别为对照组的857.52%、514.21%、280.50%;在ANF影响下,EROD的活性诱导被抑制,最高浓度组的活性分别为对照组的189.27%、278.55%、195.40%。(2)综合考虑孵化率、畸形指数和早期仔鱼死亡率等指标,3种PAHs对胚胎发育及早期仔鱼的毒性由高到低依次为Bap、Py、Phe,3种物质的浓度与受精卵的孵化率呈明显负相关,与畸形指数和仔鱼死亡率呈明显正相关;在ANF影响下,Bap和Py处理组的毒性效应得到明显抑制,Phe与ANF联合暴露处理组的毒性效应与单一暴露处理相比无相关性(P0.05)。研究表明,3种PAHs对条纹锯鮨的作用机制存在一定差异,Phe为非特异性麻醉毒性机制,Bap和Py可能通过AHR途径和CYP1 A活性诱导两种机制共同作用。     

pH对龟足胚胎和幼虫发育的影响

为探讨水体pH对龟足(Capitulum mitella)胚胎孵化和幼虫生长发育的影响,采用单因子实验的方法,在水温25-28℃条件下,研究了不同pH(5.0,5.5、6.0、6.5、7.0、7.5、8.0、8.5、9.0、9.5)对龟足胚胎的孵化时间、孵化率和幼虫存活率、变态率的影响.结果表明:pH为5.0时,胚胎不...     

斑点叉尾胚胎及卵黄囊期仔鱼发育的观察

试验对斑点叉尾的胚胎及卵黄囊期仔鱼形态发育的过程进行观察、描述,研究了其发育特征。结果表明：斑点叉尾受精卵在水温24±1℃时,出膜时间（胚胎期）约为147h 30min。水温25±1℃时,斑点叉尾鮰卵黄囊期约为134h。     

The effects of constant and oscillating temperature on embryonic development and early larval morphology in longfin yellowtail (Seriola rivoliana Valenciennes)

Constant and oscillating egg incubation temperatures on embryonic development and early larval morphology were studied in longfin yellowtail (Seriola rivoliana Valenciennes). We investigated the effects of constant temperatures from 16 to 32°C on embryo development and larval morphology at hatch, and whether oscillating temperature during embryogenesis could lead to larval morphological variations. After hatching, larval morphology and development during yolk sac (YS) utilization were examined in larvae at constant temperatures and larvae at 25°C that had oscillating temperature during egg incubation. Hatching rates were > 75%, only decreasing to ~ 50% at 30°C. At constant temperatures, the largest larvae occurred at 22 and 24°C. The oscillating temperature did not affect the timing of embryo development but resulted in larger and smaller larvae with a smaller and bigger YS, respectively, with a similar hatching time. Therefore, a growth response occurred in embryos during a window of development before hatching, depending on the adaptive response to temperature (spawn‐specific). After hatching, most of the YS was absorbed within 24 hr in all treatments, and the growth of the larval head was a priority with an optimal development at 26°C. There was compensatory growth in smaller larvae resulting in similar sizes after YS utilization, but larvae showed variations in body structure that could be important in further aquaculture research.     

盐度对七带石斑鱼胚胎发育和卵黄囊仔鱼生长的影响

观察比较了8个盐度梯度[10、15、20、25、30(自然海水)、35、40和45]下七带石斑鱼Epinephelus septem fasciatus受精卵的孵化周期、孵化率和畸形率及卵黄囊仔鱼的畸形率,并在上述条件下对七带石斑鱼进行了耐饥饿试验,测定其生存活力指数(SAI).结果显示,受精卵孵化的最适盐度范围为30～35,盐度高于35,孵化率随着盐度的升高而降低,仔鱼畸形率随之升高;盐度低于25,孵化率随盐度的降低而降低,仔鱼畸形率随之升高.仔鱼的最适生存盐度为30～35,此盐度下的仔鱼存活系数为24.7±0.36和23.27土3.01.     

红头丽体鱼红魔丽体鱼杂交子一代胚胎发育及仔鱼形态学观察

对红头丽体鱼[Cichlasoma synspilum（♀）]红魔丽体鱼[C.citrinellum（♂）]杂交子一代（F1）（俗称血鹦鹉）的胚胎及仔鱼形态发育进行观察,描述了各发育时期的发育时序和形态特征。平均受精率为（91.333.06）%,平均孵化率为（91.672.08）%;血鹦鹉的受精卵呈椭圆球形,黏性,有浅黄、白灰和红褐3种颜色,无油球,平均卵长径为（1.890.04）mm;发育过程可分为6个阶段：受精卵阶段、卵裂阶段、原肠期、神经胚期、器官形成期和孵出期,并进一步分为28个发育分期;在水温（300.5）℃下历时约52 h 36 min完成孵化。初孵仔鱼全长（3.710.05）mm,卵黄长径为（1.740.09）mm,短径为（1.250.07）mm,于第3天开始摄食轮虫,孵出后第5天卵黄囊完全消失。第13 天全长（11.861.02）mm,各鳍条基本形成,进入稚鱼期。     

纹稿虾虎鱼胚胎、早期仔鱼发育与盐度的关系

本文对纹缟虾虎鱼受精卵和早期仔鱼发育与盐度的关系进行了初步研究。结果表明:受精卵在盐度0～40时均表现出沉性;受精卵孵化的适盐范围为5～40,最适盐度为20～35;仔鱼在盐度低于30时,主要分布于底层,活力较差,盐度高于30时,主要分布中上层,活力较好;仔鱼在盐度5～45和无投饵状态下,SAI值为2.93～15.66,其中在盐度30～35时,SAI值最大(14.43～15.66)。从不同盐度下仔鱼的分布状态及仔鱼的生存指数综台分析,纹缟虾虎鱼仔鱼培育的最适盐度范围为30～35。